Energy consumption and greenhouse gas (GHG) emissions of China's road transport sector have been increasing rapidly in recent years. Previous studies on the future trends trend to focus on the national picture and cannot offer regional insights. We build a novel bottom-up model to estimate the future energy demand and GHG emissions of China's road transport at a provincial level, considering local economic development, population and policies. Detailed technical characteristics of the future vehicle fleets are analyzed in several up-to date scenarios. The results indicate that China's vehicle stock will keep increasing to 543 million by 2050. The total direct petroleum demand and associated GHG emissions will peak at 508 million tonnes of oil equivalent (Mtoe) and 1500 million tonnes CO2 equivalent (Mt CO2,e) around 2030 in the Reference scenario. Natural gas vehicle diffusion has a large impact on petroleum demand reduction in the short term, with decreases of 41–46 Mtoe in 2050. Compared to the Reference case, battery electric and fuel cell vehicles will reduce petroleum demand by 94–157 and 28–54 Mtoe in 2050, respectively. When combined with decarbonization of future power supply, battery electric vehicles can play a significant role in reducing Well-to-Wheels GHG emissions in 2050 with 295–449 Mt CO2,e more reductions. The spatial distributions of future vehicle stock, energy demand and GHG emissions vary among provinces and show a generally downward trend from east to west. Policy recommendations are made in terms of the development of alternative fuels and vehicle technologies considering provincial differences, expansion of natural gas vehicle market and acceleration of electric vehicle market penetration.

Mobile air conditioning (MAC) is potentially a huge source of greenhouse gas (GHG) emissions in China from a life cycle (LC) perspective as the vehicle population increases in the future. The MAC-GHG-LCA model is developed to calculate LC GHG emissions from MAC systems, covering life-span refrigerant leakage (direct emissions) and emissions caused by energy use in MAC system production and operation (indirect emissions). Using R152a and R1234yf as alternative refrigerants instead of R134a in MAC systems can decrease LC GHG emissions by 22–32% and 17–29%, respectively. Their GHG reduction benefits mainly result from their lower global warming potential (GWP) values though the indirect emissions are only slight lower or even higher than R134a. Using R744 can offer reduction in 2050 though it will cause an increase of 20% in 2020. Total LC GHG emissions from MAC systems of the whole light duty vehicle (LDV) fleet in China will be 159 million tonnes of CO2-equivalent in 2050 in the scenario where R134a will be the only refrigerant adopted, about 3 times that in 2015. It is found that alternative low-GWP refrigerants can help reduce LC GHG emissions from MAC systems effectively. The shift from conventional cooling and heating technology to advanced heat pump technology in electric vehicles (EVs) can reduce electricity use in MAC system operation and reduce LC GHG emissions from the MAC systems in EVs.

Evaluations of food, energy and water (FEW) linkages are rapidly emerging in contemporary nexus studies. This paper demonstrates, from a food consumption perspective, the potential of life cycle thinking in understanding the complex and often “hidden” linkages between FEW systems. Our study evaluates the upstream virtual water and embodied energy in food consumption in the Tamar catchment, South West England, distinguishing between domestic production and imports origin. The study also evaluates key inputs, including virtual nutrients and animal feed, when tracking supply chain of food products. Based on current dietary patterns and food products selection, the catchment consumes annually 834 TJ, 17 hm3 and 244 hm3 of energy, blue water and green water, respectively. Tamar is not self-sufficient in terms of food and requires imports of food products, as well as imports of virtual nutrients and animal feed for local production. Consequently, 51% of the embodied energy and 88% blue and 45% green virtual water in food consumed within the catchment are imported. Most of the embodied energy (58%) and green virtual water (90%) are because of animal feed production, where nearly half of embodied energy (48%) and green virtual water (42%) come from imports. 92% of blue virtual water is used for irrigation and primarily happens elsewhere due to imports. Irrigation is the process that demands the largest amount of energy for the crop-based products, with 38% of their total energy demand, followed by fertilisers production (24%). Our study illustrates water and energy hotspots in the food life cycle and highlights potential FEW risks and trade-offs through trade. This is useful considering potential unexpected changes in trade under recent global socio-political trends. Currently available databases and software make LCA a key tool for integrated FEW nexus assessments.

The use of dynamical information, which is temporally and spatially explicit, to quantify environmental impacts is gaining importance in recent years. Life Cycle Assessment has been applied to identify environmental impacts of, for example, wheat production. However, conventional Life Cycle Assessment is typically limited by its static nature and cannot explicitly consider temporal and spatial variability in its matrix-based mathematical structure. To address this limitation, a novel dynamical Life Cycle Assessment framework that applies spatio-temporal mathematical models in Life Cycle Inventory is introduced. This framework employs the existing Enhanced Structural Path Analysis (ESPA) method paired with a spatial dispersion model to determine the localised emissions over time within the Life Cycle Inventory. The spatially explicit calculations consider emissions to the surrounding area of an origin. A case study was undertaken to demonstrate the developed framework using the production of wheat at the Helford area in Cornwall, UK. Results show the spatio-temporal dispersion for four example emissions atmosphere, soil, flowing and groundwater. These outcomes show that it is possible to implement both spatial and temporal information in matrix-based LCI. We believe this framework could potentially transform the way LCA is currently performed, i.e. in a static and spatially-generic way and will offer significantly improved understanding of life cycle environmental impacts and better inform management of processes such as agricultural production that have high spatial and temporal heterogeneity.

The use of agricultural residues to produce biomass briquette fuel (BBF) can reduce waste of resources and consumption of fossil fuels. We report the first detailed environmental impact assessment of cornstalk-based BBF in China using a cradle-to-grave life cycle assessment (LCA). The LCA study was conducted based on a typical large-scale cornstalk BBF demonstration project in China with an integrated and automated production system. The key life cycle stages such as cornstalk growth, cornstalk transportation, BBF production, transportation and utilisation were investigated. Our results suggest that cornstalk BBF in China is much more environmentally friendly than coal and is favourable when compared with other types of solid fuels produced from different biomass feedstock. For example, the climate change and fossil depletion impacts of cornstalk BBF in China (11 g CO2eq./MJ and 2 g oil eq./MJ, respectively) are an order of magnitude lower than those of coal (146 g CO2eq./MJ and 26 g oil eq./MJ, respectively). The results of this study can assist policy makers in evaluating the potential benefits of the large scale use of BBF made from agricultural residues.

© 2017 Elsevier Ltd. Decentralized rainwater harvesting (RWH) from roof runoff can complement the centralized supply of mains (drinking) water for a range of contexts, to assist in alleviating issues of water security. However, treatment to potable standard of harvested rainwater is not widespread. Consequently a comparative life cycle analysis (LCA) of decentralized and centralized potable water supply has not previously been undertaken. In this paper we describe a novel point-of-use (POU) treatment device, which was used to treat harvested rainwater to potable standard. We then provide a performance assessment for this system and an LCA with a comparison to centralized supply. Results of the performance assessment indicate a water saving efficiency (E T ) of between 0.6 and 100%, depending on rainfall (0.6 from April when rainfall was significantly below average). This highlights that the POU device was able to deal with the scale of roof runoff supply originating from a RWH system at a commercial building scale. The LCA results suggest that potable water produced from this decentralized RWH POU system currently performs more poorly than centralized water from an environmental perspective. Its impacts in most categories would be significantly reduced if the electricity consumed by the system were supplied from a renewable source such as solar PV or wind turbines instead of the UK grid. Priority should be given to optimizing the energy efficiency and exploring opportunities for combined use with renewable energy technologies in order to improve the environmental performance of POU treatment devices.

For much of their existence, the environmental benefits of artificial satellites, particularly through provision of remotely sensed data, seem likely to have greatly exceeded their environmental costs. With dramatic current and projected growth in the number of Earth-observation and other satellites in low Earth orbit, this trade-off now needs to be considered more carefully. Here we highlight the range of environmental impacts of satellite technology, taking a life-cycle approach to evaluate impacts from manufacture, through launch, to burn-up during de-orbiting. These include the use of renewable and nonrenewable resources (including those associated with the transmission, long-term storage, and distribution of data), atmospheric consequences of rocket launches and satellite de-orbiting, and impacts of a changing nighttime sky on humans and other organisms. Initial estimations of the scale of some impacts are sufficient to underscore the need for more detailed investigations and to identify potential means by which impacts can be reduced and mitigated.

Recently, thermal conductivity, even and stable suspension of particles, and agglomeration of particles have been studied comprehensively. These properties are especially important parameters for nanofluids in small-size heat transfer devices like mini-channels, which are prone to block due to the small size of the channels. In the present study, a method was proposed to increase heat transfer using composite nano-phase change emulsions (NPCEs) slurries, utilizing the latent heat of PCM during melting. In this experimental study, a series of composite nano-phase change emulsions (NPCEs) with high thermal conductivity, high thermal storage, and low supercooling were developed and prepared from hexadecane, octadecane, hexadecanol, octadecanol, and nano-Al2O3. Heat transfer experiments were conducted in a mini-channels using the prepared NPCEs as working fluids. The effects of the nanoparticle concentration, NPCE type, and flow rate on multiple parameters, including the heat transfer coefficient, flow resistance, and heat transfer performance of composite NPCEs were investigated. As a result, the heat transfer experiments demonstrated that the proposed NPCEs as heat transfer fluids could enhance the heat transfer performance in mini-channels in comparison with deionized water. Compared with deionized water, the convective heat transfer coefficient was increased by a maximum of 1.28 %, 4.07 %, and 4.19 % with an octadecane concentration of 5 wt%, 10 wt%, and 20 wt%, respectively. The nano-emulsion with a combination of 5 wt% hexadecane, 5 wt% octadecane, and 1 wt% nano-Al2O3 achieved a maximum increase of 7.01 % in the heat transfer enhancement factor. In addition, the nano-emulsion with a combination of 5 wt% hexadecane, 5 wt% octadecane, and 1 wt% nano-Al2O3, in addition to 1.25 wt% hybrid nucleating agents allowed a maximum increase of 26.49 % in the heat transfer enhancement factor. The obtained results and performed analyses demonstrate that metal particle-composite alcohol hybrid nanofluid has high stability, high thermal conductivity, low subcooling, high durability, and a convenient preparation method, and is an appropriate choice as a working fluid, especially in small-scale heat transfer devices.

Phase change materials (PCMs) have remarkable energy storage capacity and promising applications in the field of thermal control of electronic products. The problem of thermal property improvement and heat transfer of PCMs in metal-foam heatsinks is an important task for thermal management of electronic components. Mixed paraffin samples were prepared by mixing appropriate proportions of paraffin (mass) at various temperatures. Differential scanning calorimetry analysis revealed that the maximum enthalpy of 206.3 J/g is obtained by mixing 20% of 17°C liquid paraffin and 80% of 29°C solid paraffin. Heating and cooling cycling tests revealed that mixed paraffin exhibits excellent thermal stability and that the regulation method marginally affects thermal stability. Moreover, composites were prepared by embedding PCM into a copper foam by melt impregnation. The thermal conductivity of the composites increased to 4.35 W/(mK), corresponding to 20 times its original value. In addition, density functional theory and experimental results were in good agreement, indicating that the regulation method is practical and effective.

The food system is a major source of both environmental and health challenges. Yet, the extent to which policy-induced changes in the patterns of food demand address these challenges remains poorly understood. Using a randomised-controlled survey of 5,912 respondents from the United Kingdom (UK), we evaluate the potential impact of carbon and/or health taxes, information and combined tax and information strategies on food purchase patterns and their resulting impact on greenhouse gas emissions and dietary health. Our results show that while information on the carbon and/or health characteristics of food is not irrelevant, it is the imposition of taxes which exerts the most substantial effects on food purchasing decisions. Furthermore, while carbon or health taxes are best at separately targeting emissions and health challenges respectively, a combined carbon and health tax policy maximises benefits both in terms of environmental and health outcomes. We show that such a combined policy could contribute to around one third of the residual emission reductions required to achieve the UK’s 2050 net zero commitments, while discouraging the purchase of unhealthy snacks, sugary drinks and alcohol and increasing the purchase of fruit and vegetables.

ZnO, nano ZnO and nano Al2O3 were mixed with microencapsulated phase change material slurry (MPCS) for improving the heat transfer performance of slurries in this paper. The thermal and rheological properties of MPCS were measured using DSC, thermal conductivity meter and rheometer. The results show that the thermal conductivity of 5 wt% MPCS with 1 wt% ZnO, nano ZnO and nano Al2O3 was 17.9 %, 19.4 % and 23.5 % higher than that of 5 wt% MPCS, respectively. The forced convection heat transfer experiment of slurries was carried out in a loop system with various heat flux and flow conditions. The influences of heat flux, flow rate and metal oxide particles on the flow and heat transfer behaviour of slurries were investigated. The results show that the heat transfer was significantly enhanced for all slurries with metal oxide particles under three flow conditions. Compared with water, the local heat transfer coefficient (hx) of MPCSs with 1 wt% ZnO, nano ZnO and nano Al2O3 increased by 6.5 %, 9.1 % and 12.4 % under laminar flow, 6.6 %, 15.5 % and 14.9 % under transition flow, and 15.7 %, 19.0 % and 21.6 % in turbulent condition, respectively.

Aluminum production is a major energy consumer and important source of greenhouse gas (GHG) emissions globally. Estimation of the energy consumption and GHG emissions caused by aluminum production in China has attracted widespread attention because China produces more than half of the global aluminum. This paper conducted life cycle (LC) energy consumption and GHG emissions analysis of primary and recycled aluminum in China for the year 2020, considering the provincial differences on both the scale of self-generated electricity consumed in primary aluminum production and the generation source of grid electricity. Potentials for energy saving and GHG emissions reductions were also investigated. The results indicate that there are 157,207 MJ of primary fossil energy (PE) consumption and 15,947 kg CO2-eq of GHG emissions per ton of primary aluminum ingot production in China, with the LC GHG emissions as high as 1.5–3.5 times that of developed economies. The LC PE consumption and GHG emissions of recycled aluminum are very low, only 7.5% and 5.3% that of primary aluminum, respectively. Provincial-level results indicate that the LC PE and GHG emissions intensities of primary aluminum in the main production areas are generally higher while those of recycled aluminum are lower in the main production areas. LC PE consumption and GHG emissions can be significantly reduced by decreasing electricity consumption, self-generated electricity management, low-carbon grid electricity development, and industrial relocation. Based on this study, policy suggestions for China’s aluminum industry are proposed. Recycled aluminum industry development, restriction of self-generated electricity, low-carbon electricity utilization, and industrial relocation should be promoted as they are highly helpful for reducing the LC PE consumption and GHG emissions of the aluminum industry. In addition, it is recommended that the central government considers the differences among provinces when designing and implementing policies.

A double waste stream problem arises from the increasing use of electrical and electronic equipment and their energy consumption: potentially toxic wastes from the equipment itself and potential acid mine drainage from the waste of the coal mines that provide the fuel to cover the energy demand. CEReS (Co-processing of Coal Mine & Electronic Wastes: Novel Resources for a Sustainable Future) is a novel method to co-process the coal mine and low-grade PCBs waste to reduce their environmental impacts while producing metals and other valuable products. The aim of this study is to investigate whether CEReS method is more environmentally friendly than the conventional practices of landfilling and incineration. Based on a Polish coal mine case study, our study found that the CEReS method could potentially eliminate the environmental impacts related to toxicity but increase the climate change impacts by ten times. A sensitivity analysis has shown that using a lower carbon electricity mix could reduce the climate change and fossil depletion impacts. It is also recommended to reduce water and energy requirements in some stages of the method.

China has the highest level of plastic production and consumption in the world. The plastic waste ban has resulted in a lack of raw materials for plastic reprocessing, while household appliance-related plastic (HAP), as a high-value and high-quality plastic waste source, receives great attention to fill such a gap. As HAP is scattered and has been rapidly increasing, a better understanding of the spatial-temporal patterns of HAP waste is critical. For the first time, this study quantifies the stocks and flows of plastics contained in five categories of household appliances (refrigerator, washing machine, air conditioner, TV, and computer) in China over 1978-2016 and maps their province-specific distribution through a dynamic stock-driven material flow analysis model. We find that (i) the HAP stocks are growing rapidly to reach around 25.4 million tonnes (MT) in 2016 and the HAP waste generated in 2016 is over 2 MT while the dismantling capacity is failing to catch up; (ii) the HAP waste in southeastern provinces is notably more than in northwestern provinces by approximately 11 times; (iii) washing machines (37%) and refrigerators (24%) are the major types of household appliances that contribute most to HAP waste generation; (iv) PP (38%) and PS (34%) are the major plastic types in HAP waste. These findings can provide quantitative references for the government to arrange waste management facilities, improve recycling capacities of dismantling companies, and promote coordinated efforts from multiple stakeholders to achieve efficient waste management of HAP.

In order to investigate the control mechanism of composite phase change materials (PCM), a series of composite nano-phase change emulsion (NPCE) were prepared in this paper with high thermal conductivity, high heat storage and low supercooling using hexadecane, octadecane, hexadecanol, octadecanol and various metal nano-particles. Through the control mechanism, it is expected to adjust the phase transition range of NPCE to a desirable range. The NPCEs were characterized by particle size analyser, cryogenic transmission electron microscope (Cryo TEM), differential scanning calorimeter (DSC), thermal conductivity meter and rheometer. The results showed that the NPCEs was successfully prepared with uniform dispersion, great stability, low viscosity and narrow particle size distribution. DSC results showed that the latent heat of NPCE with 20 wt. % hexadecane was 55.86 kJ/kg. The supercooling degree of prepared NPCEs using 1.25 wt. % of hybrid nucleating agents was reduced by 81%. Metal oxides effectively improved the thermal conductivity of NPCEs. The thermal conductivity of the NPCEs with 1wt. % nano Al2O3 was 0.70 W/(m ⋅ K), which was increased by 21%. The viscosity of the NPCEs increased with the increase of metal oxide concentrations and decreased with the increase of temperature. Importantly the NPCEs presented a shear thinning effect and can be considered as Newtonian fluid after shear rate of 2 s−1, which had great potential in the thermal energy storage system.

Shifting towards more meat-intensive diets may have indirect health consequences through environmental degradation. Here we examine how trends in dietary patterns in China over 1980–2010 have worsened fine particulate matter (PM2.5) pollution, thereby inducing indirect health impacts. We show that changes in dietary composition alone, mainly by driving the rising demands for meat and animal feed, have enhanced ammonia (NH3) emissions from Chinese agriculture by 63% and increased annual PM2.5 by up to ~10 µg m–3 (~20% of total PM2.5 increase) over the period. Such effects are more than double that driven by increased food production solely due to population growth. Shifting the current diet towards a less meat-intensive recommended diet can decrease NH3 emission by ~17% and PM2.5 by 2–6 µg m–3, and avoid ~75,000 Chinese annual premature deaths related to PM2.5.

The new energy industry (NEI) is key to achieving a clean and low-carbon economy. Improving its technical efficiency, a factor reflecting the ability of an enterprise or industry to produce maximum economic outputs from a given set of inputs and production technologies, is vital for the healthy development of the NEI. Nevertheless, due to the fragmentation of industry data, it is still difficult to accurately measure the technical efficiency of China’s NEI and understand the driving factors behind it. Based on the panel data derived from 17,457 observations on new energy enterprises in 29 Chinese provinces during 1998 and 2013 (latest data available), this paper uses data envelopment analysis (DEA) and geographically and temporally weighted regression (GTWR) for the first time to investigate the spatiotemporal characteristics and driving factors of the technical efficiency of China’s NEI. The results show that the technical efficiency of China’s NEI was relatively low and increased modestly from 0.44 in 1998 to 0.52 in 2013. Exploring the reasons from the perspective of spatiotemporal heterogeneity, we find that enterprise scale and technological progress are the major driving factors for increasing NEI’s technical efficiency. However, the role of economic development in improving efficiency has gradually disappeared. Moreover, the negative effect of state-owned enterprises on efficiency becomes increasingly obvious. The effect of new energy resources is negligible. Our main contribution is the technical efficiency of China’s NEI which is measured at the provincial level and its main driving factors are explored by considering spatiotemporal heterogeneity. Accordingly, we put forward some specific recommendations to improve the technical efficiency of China’s NEI.

Composites composed of paraffin wax and copper foam with porosity of 95 % and pore density of 15 ppi, 30 ppi, and 50 ppi were prepared by the melt impregnation method. Two building models of the same size were made using gypsum board. The roof of the experimental model was covered with 50ppi copper foam /paraffin composite phase change board, and the roof of the reference model was covered with foam insulation board. The heat transfer experiment was conducted with a constant heat flux. EnergyPlus software was also employed to simulate the energy saving effects of the building models. The size and material of the model established during the simulation are consistent with the experimental model. Experimental results showed that the phase change composite board delayed the highest indoor temperature for 1.5 h, and it also reduced the indoor maximum temperature by 1.2° and the indoor energy consumption by 21 %. The simulation results showed that the phase change composites board delayed the appearance of the highest indoor temperature by 1.3 h and reduced the highest indoor temperature by 1.1°C, and the maximum indoor energy consumption decreased by 19 %. The copper foam/paraffin composite material can effectively improve the thermal comfort and reduce the energy consumption of the building model.

In this paper, a composite structure double layer phase change walls with expanded graphite (EG) was investigated. By adding the EG, the time needed for the phase change process and the wall to work was both accelerated. The effect of composite phase change walls on the indoor thermal comfort and building energy consumption were investigated experimentally. The results show that the double layer phase change wall with the EG can suppress the temperature fluctuation. In addition, it simulated the cooling and heating loads with or without phase change walls based on the climatic conditions in Shanghai. The results show that the heating load in winter is reduced by more than 15%. The simulated values are consistent with the experimental values, and the temperature deviation at the same measuring point within the same period is small. The maximum temperature change between the experimental and simulated values is less than 1 °C. The double layer phase change wall with the EG can reduce the temperature fluctuation and improve the indoor thermal comfort.

The transition towards a sustainable energy mix is required to achieve Sustainable Development Goal 7 for affordable and clean energy. Remote islands not connected to grid which depend on diesel generators may appear ideal because they can benefit from a variety of renewable energy sources. However, renewable energy deployment requires a lifetime perspective to not inherit waste and other problems to future generations. The aim of this paper is to present a life cycle sustainability framework developed and applied for the case of the island of Ushant off North West France. Seven renewable energy generation scenarios were examined and assessed using technoeconomic, social and environmental indicators utilising life cycle costing and life cycle assessment modelling. The results show that only three out of the seven examined renewable energy scenarios manage to cover the 6807 MWh per annum demand. These scenarios can improve all the indicators against the business-as-usual diesel generation scenario except the ones related to toxicity and reduce greenhouse gas emissions by more than 92%. The easy-to-use framework allows the users to adjust their scenarios and receive useful insight about the nature of the trade-offs between the various indicators. It can also be adapted and updated to include more technologies and support the investigation of more sustainable energy scenarios of other remote island cases in the future.

The transition to a low-carbon economy will be material-intensive. Production of these materials (from mining to manufacturing) incurs environmental costs that vary widely, depending on the geology, mineralogy, extraction routes, type of product, purity of product, background system or manufacturing infrastructure. Understanding the impacts of the raw materials underpinning the low-carbon economy is essential for eliminating any dissonance between the benefits of renewable technologies and the impacts associated with the production of the raw materials. In this Review, we propose an integrated life cycle assessment and geometallurgical approach to optimize the technical performance and reduce the environmental impact of raw material extraction. Life cycle assessments are an effective way of understanding the system-wide impacts associated with material production, from ore in the ground to a refined chemical product ready to be used in advanced technologies such as batteries. In the geometallurgy approach, geologists select exploration targets with resource characteristics that lend themselves to lower environmental impacts, often considering factors throughout the exploration and development process. Combining these two approaches allows for more accurate and dynamic optimization of technology materials resource efficiency, based on in situ ore properties and process simulations. By applying these approaches at the development phase of projects, a future low-carbon economy can be achieved that is built from ingredients with a lower environmental impact.

The aim of this study was to conduct the first comprehensive life cycle assessment and economic analysis on ethanol produced from agave. Compositional and field data from a field experiment in Queensland, Australia was used. Our study shows that ethanol yields from agave (7414 L/ha/year) are comparable to Brazilian sugarcane (9900/L/ha/year) and higher than US corn ethanol (3800/L/ha/year). Furthermore, agave outperforms current first generation biofuel crops in water-related impacts, including Freshwater Eutrophication (96% lower than corn and 88% lower than sugarcane), Marine Ecotoxicity (59% lower than corn and 53% lower than sugarcane) and Water Consumption (46% lower than corn and 69% lower than sugarcane). The life cycle fossil energy use (Fossil Resource Scarcity) for agave is 58% lower than corn and 6% higher than sugarcane. The Global Warming impact for agave is also 62% and 30% lower than that of corn and sugarcane, respectively. Although its Land Use impact, measured by land occupied per unit ethanol output, is 98% higher than corn and 2% higher than sugarcane, agave can be grown on arid land that is not suitable for food crops. The economic analysis suggests that first generation ethanol production from agave is not commercially viable without government support. Overall, the results show that agave is promising for biofuel production in the water-energy-food-environment context.

AbstractAccurate estimation of the spatiotemporal variations of solar radiation is crucial for assessing and utilizing solar energy, one of the fastest‐growing and most important clean and renewable resources. Based on observations from 2,379 meteorological stations along with scare solar radiation observations, the random forest (RF) model is employed to construct a high‐density network of daily global solar radiation (DGSR) and its spatiotemporal variations in China. The RF‐estimated DGSR is in good agreement with site observations across China, with an overall correlation coefficient (R) of 0.95, root‐mean‐square error of 2.34 MJ/m2, and mean bias of −0.04 MJ/m2. The geographical distributions of R values, root‐mean‐square error, and mean bias values indicate that the RF model has high predictive performance in estimating DGSR under different climatic and geographic conditions across China. The RF model further reveals that daily sunshine duration, daily maximum land surface temperature, and day of year play dominant roles in determining DGSR across China. In addition, compared with other models, the RF model exhibits a more accurate estimation performance for DGSR. Using the RF model framework at the national scale allows the establishment of a high‐resolution DGSR network, which can not only be used to effectively evaluate the long‐term change in solar radiation but also serve as a potential resource to rationally and continually utilize solar energy.

The rapid expansion of offshore wind farms (OWFs) in response to increasingly ambitious renewable energy and climate targets in the UK has led to growing concerns about conflicts and synergies with existing fishing activities. The complex relationship between energy and food in the marine environment needs to be explicitly evaluated from an energy-food nexus perspective. On one hand, developing OWFs has potential to reduce GHG emissions and increase energy security through diversifying energy supply and providing domestically produced electricity. On the other hand, the expansion of OWFs could have fish supply implications through impacts on seafood production.
There are indirect linkages between OWFs and fishing activities through limited economic production factors, influenced heavily by market forces, and direct linkages through physical and environmental interactions, driven mostly by policies and management practices and affected by ecosystem dynamics. These complex linkages could lead to both negative and positive impacts of OWFs on seafood production and consequently availability and affordability of food supply from the marine environment. Through indirect economic linkages OWFs can affect the demand, supply and prices of the production factors such as labour and capital needed by the seafood production sectors. In terms of direct physical and environmental linkages, the exclusion of fishing activities from OWF areas could result in a decrease in fish landings while reduced fishing activities and artificial reef effect provided by OWF structures could have positive impacts on preservation of fish stocks.
To quantitatively evaluate this marine energy-food nexus from a macroeconomic perspective, a static computable general equilibrium (CGE) model is developed, using Scotland as a case study. A particular focus is on the disaggregation of (i) the electricity and seafood sectors to explicitly reflect their economic interconnectedness in order to better model the impacts on availability of food and energy security; (ii) the household groups with different income levels to concentrate on the affordability of energy and food and the distributional effects on welfare. To better emphasise the physical and environmental linkages, two additional modules are created in the model. The innovative marine resource allocation module simulates the spatial conflicts between OWFs and fishing activities while integrating the natural capital and ecosystem services approach further extends the modelling framework to analyse feedbacks between economy and environment. There are therefore three versions of the CGE model, each with a different focus and structure.
The first one uses the basic structure of the CGE model to assess the near-term, indirect impact of decreasing cost of OWFs through economic linkages. The results suggest that high cost under subsidy and low cost of OWFs would have positive impacts on energy security and limited negative impacts on seafood production sectors. In particular, the falling cost of electricity from OWFs would have a small positive impact on the economy overall and benefit lower income households, contributing to the reduction in fuel poverty.
The second application includes marine resource as an additional production factor and creates a novel marine resource allocation module within the model to better capture the physical interactions between expanding OWFs and fishing activities. The model shows that massive expansion of OWFs results in increasing energy security but significant negative impacts on seafood supply as marine resource is taken away from fisheries by expanding OWFs.
The third application integrates natural capital, represented by fish stock, into the CGE model to evaluate the environmental impacts of OWFs considering ecosystem dynamics and feedbacks. Expanding OWFs would reduce fishing output and thus preserve fish stock. However, the artificial reef effect of OWFs would increase the fish stock, eventually benefiting fishing output. The combination of these two opposing impacts suggests that the artificial reef effect is sufficient to mitigate the negative impacts of expansion of OWFs as long as fishermen could get access to the fish stocks close to OWFs.
Overall, the model results demonstrate that expanding OWFs would enhance energy security but also bring negative impacts on fish supply. Therefore, there is a need for integrated management of food and energy in the marine environment. To minimise conflicts and maximise synergies from the nexus perspective, co-locating OWFs and fishing activities through marine spatial planning could be a possible solution. The modelling framework is also applicable to other marine renewable energies to assess their potential impacts on energy security and seafood supply, and on the wider economy.

The anticipated benefits of integrative economic frameworks, that link economic production with ecosystem impacts, have been well documented. However, due to the difficulties of separating the economic contribution of marine activities from those of terrestrial activities, the current size and structure of the marine economy is unknown. In addition, the capacity of natural capital assets to supply specific marine benefits is not comprehensively defined under current applications of the natural capital approach. Consequently, marine benefits have not been systematically linked with production in the economy, and the effect of causal relationships between the economy and marine natural capital assets have not been estimated.

In response to these shortcomings, this thesis develops an integrative framework to combine macroeconomic systems with marine and coastal ecosystems under the natural capital approach in the UK. The framework combines marine natural capital assets and the environmental benefits they supply, with economic production. Firstly, the UK marine economy is systematically defined, using input-output tables for 2014. The contribution of all activities in the market economy that occur within, and depend upon, marine and coastal environments in the UK are analysed. Secondly, the way that benefits from natural capital are supplied is defined using a composite index. Characteristics of natural capital, and other forms of capital (i.e. financial, human, social, manufactured), that affect the supply of specific environmental benefits are analysed, and indicators for each characteristic are selected. Indicators are ranked and weighted, and benefit supply is represented as a composite index. Finally, the causal relationships between the economy and natural capital assets are identified and measured.

Case studies from the UK marine and coastal environment are used to apply the framework using data from 2013 to 2018. The strengths of the integrative framework, and its shortcomings, are discussed in the context of the natural capital approach and its application to the marine environment.

The aim of this study is to investigate whether eliminating plastics entirely under existing waste infrastructure and management practices could have an adverse effect on climate change, using a case study on the hypothetical substitution of Polyethylene Terephthalate (PET) with glass as the material for bottling liquids in the domestic sector in Cornwall, England. A life cycle environmental impacts-based model was created using high resolution local data on household waste and current management practices in combination with Life Cycle Assessment (LCA) datasets. The model allows users to define key system parameters such as masses of materials, transport options and end-of-life processes and produces results for 11 environmental impact categories including the Global Warming Potential (GWP). The results from the application of this model on the case study of Cornwall have shown that the substitution of PET with glass as the material for bottling under the current waste infrastructure and management practices could lead to significant increases in GWP and hinder efforts to tackle climate change. A sensitivity analysis of the glass/PET mass ratio suggests that in order to achieve equal GWP the glass bottles need to become approximately 38% of the weight they are now. Increasing the recycled content and decreasing losses during the recycling processes could also help lower the GWP by 18.9% and 14.5%, respectively. This model can be expanded further to include more types of plastics and other regions to evaluate designs of new regional circular economy with less plastics waste and pollution. Our study suggests that it is necessary and crucial to consider the specific waste infrastructure and management practices in place and use science-based models that incorporate life cycle thinking to evaluate any solutions to plastics pollution in order to avoid problem shifting.

The marine and coastal environment is an important economic asset in the UK, and there is a need for greater information about marine economic activities for the purposes of marine management and policy. However, due to the difficulties of quantifying some marine sectors and separating them from terrestrial activities, the current size and structure of the marine economy is unknown. This paper defines a systematic approach to quantifying the UK marine economy, aiming to capture all activities in the market economy that occur within and depend upon UK marine and coastal environments, and estimates its contribution to the UK economy as a whole. The approach draws on previous research in this area and links sectors used in marine planning with the methodologies used in national accounts. The results suggest that the marine economy contributes double the amount of previous estimates to the UK economy. Changes in the structure of the marine economy, partly due to the expansion of offshore wind energy, may affect its economic contribution. The results also show that marine and coastal leisure and recreation sectors, which were previously thought to have a small economic contribution, are the second largest sector in the UK marine economy and account for the largest number of jobs. By disaggregating the economic sectors, the approach used here can underpin a marine natural capital approach, enabling economic activities to be linked with aspects of marine natural capital.

In this study, we conducted life cycle assessments (LCAs) for fuels based on different types of agricultural residues and determined the characteristics common to all LCAs. Each fuel type required specific conversion technology during the feedstock stage, particularly during the production and collection processes. We divided the field-to-fuel life cycle into five high-level and relatively independent sub-stages: production of agricultural residues, collection of agricultural residues, conversion of agricultural residues to biofuels, biofuel distribution, and biofuel utilization. We then illustrated the common characteristics during the feedstock stage for the first two field-to-fuel life cycle sub-stages: production and collection of agricultural residues. Agricultural residues-to-grain weight and price ratios and multifactorial LCA allocations were summarized for the production stage. In addition, the energy use availability coefficient, collection radius, and emissions were determined for each fuel type during the collection stage. System boundaries and benefits of direct emissions reduction during the feedstock stage were also discussed. Our results provide guidance for future LCA studies on agricultural residue-based biofuels.

China’s electric power industry contributes a significant amount of carbon emissions as well as air pollutants such as SO2, NOx, and fine particles. In order to detect co-benefits of carbon reduction and air pollution control, this study analyzed the emission reduction, emission reduction factors, and synergistic effect factors of technical and structural emission reduction measures in the electric power industry in the Jiangsu, Zhejiang, and Yunnan provinces and Shanghai City. The main findings are: (1) the structural emission reduction measures in all four regions had positive co-control effects. Therefore, promoting renewables can achieve remarkable co-benefits; (2) the result demonstrated that the direct removal ability of pollutants by technical emission reduction measures was better than the structural emission reduction measures in all four case studies. However, there were no or few carbon reduction co-benefits associated with their utilization; (3) in all cases, CO2 had the highest emission factor value, which means that there is still room for synergistic carbon reduction; (4) air pollutants and CO2 emission intensity from the Yunnan power plants were much higher than that of the other three regions. In order to achieve the overall co-benefits, co-control measures should be promoted and strengthened in western areas such as Yunnan.

Natural gas has been promoted rapidly recent years to substitute traditional vehicle fuels. However, methane leakages in the natural gas supply chains make it difficult to ascertain whether it can reduce greenhouse gas emissions when used as a transport fuel. This paper characterizes the natural gas supply chains and their segments involved, estimates the venting and fugitive leakages from natural gas supply chains, decides the distribution among segments and further integrates it with life cycle analysis on natural gas fueled vehicles. Domestic natural gas supply chain turns out to be the dominant methane emitter, accounting for 67% of total methane leakages from natural gas supply chains. Transportation segments contribute 42–86% of the total methane leakages in each supply chain, which is the greatest contribution among all the segments. Life cycle analysis on private passenger vehicles, transit buses and heavy-duty trucks show that compressed natural gas and liquefied natural gas bring approximately 11–17% and 9–15% greenhouse gas emission reduction compared to traditional fossil fuels, even considering methane leaks in the natural gas supply chains. Methane leakages from natural gas supply chains account for approximately 2% of the total life cycle greenhouse gas emissions of natural gas vehicles. The results ascertain the low-carbon attribute of natural gas, and greater efforts should be exerted to promote natural gas vehicles to help reduce greenhouse gas emissions from on-road transportation.

3rd International Critical Metals Meeting, Edinburgh, 30 April - 2 May 2019

Rare earth elements (REE) are considered to be critical raw materials due to the combination of their high importance in a range of low-carbon technologies and the concentration of supply, which. is dominated in China. The REE industry has a legacy of environmental damage and the mining, processing, and separating out of the REE requires a significant quantity of energy and chemicals.
Life cycle assessment (LCA) is a method to quantify the environmental impacts of a product or process and can be applied to the raw materials production sector. This thesis presents how LCA can be applied for REE projects in development. The results can help identify environmental hotspots for a project, and analyse alternatives to help reduce the environmental impacts of REE production.
Mineral processing simulation are commonly used in REE project development and data generated from these studies can be used to carry out a LCA. This approach was presented with the Songwe Hill REE project in Malawi. The mineral processing simulation output data which includes energy and chemical flows is used as the life cycle inventory data (LCI) and calculated with characterization factors to generate life cycle impact assessment (LCIA) results such as global warming potential. This data can inform future engineering studies or process simulations.
REE projects, like all mining projects, can last decades and extract different ore compositions throughout this life-time. A method is presented to generate tempo- rally explicit LCA results. The Bear Lodge REE project, which is in the prefeasibility stage of development and located in the United States, is used as a case study. LCIA results highlight that grade and mineralogy can influence the LCIA results. The relationships between environmental impacts and grade and mineralogy are explored.
Thirdly, a method is presented to include LCA data in the mine scheduling pro- cess. LCIA data can form an environmental block model alongside the economic block model for a deposit. These spatially explicit data can then be used as a constraint within long-term mine scheduling simulations. The results indicate that significant reductions in global warming impact can be achieved at a small economic cost.
Finally advances to the current resource depletion impact categories are achieved, advancing the previous methods which neglect socio-economic, regulatory and geopolitical aspects, nor do they include functionalities such as material recycling or reuse that control the supply of raw materials. I examine the economic scarcity potential (ESP) method and make advances based on recent developments in material criticality. ESP criticality scores for 15 REE with the addition of Au, Cu, platinum-group metals (PGM), Fe and Li are measured and a case study is presented to for the inclusion of REE ESP scores for the materials that form a NdFeB permanent magnet.
This thesis has a focus on utilising LCA in a proactive manner and incorporating it into the planning stages of REE projects to encourage responsible production of REE.

The emergence of the water–energy–food (WEF) nexus has resulted in changes to the way we perceive our natural resources. Stressors such as climate change and population growth have highlighted the fragility of our WEF systems, necessitating integrated solutions across multiple scales. While a number of frameworks and analytical tools have been developed since 2011, a comprehensive WEF nexus tool remains elusive, hindered in part by our limited data and understanding of the interdependencies and connections across the WEF systems. To achieve this, the community of academics, practitioners and policy-makers invested in WEF nexus research are addressing several critical areas that currently remain as barriers. First, the plurality of scales (e.g. spatial, temporal, institutional, jurisdictional) necessitates a more comprehensive effort to assess interdependencies between water, energy and food, from household to institutional and national levels. Second, and closely related to scale, a lack of available data often hinders our ability to quantify physical stocks and flows of resources. Overcoming these barriers necessitates engaging multiple stakeholders, and using experiences and local insights to better understand nexus dynamics in particular locations or scenarios, and we exemplify this with the inclusion of a UK-based case study on exploring the nexus in a particular geographical area. We elucidate many challenges that have arisen across nexus research, including the impact of multiple scales in operation, and concomitantly, what impact these scales have on data accessibility. We assess some of the critical frameworks and tools that are applied by nexus researchers and articulate some of the steps required to develop from nexus thinking to an operationalisable concept, with a consistent focus on scale and data availability.

Energy consumption and greenhouse gas (GHG) emissions of China's road transport sector have been increasing rapidly in recent years. Previous studies on the future trends trend to focus on the national picture and cannot offer regional insights. We build a novel bottom-up model to estimate the future energy demand and GHG emissions of China's road transport at a provincial level, considering local economic development, population and policies. Detailed technical characteristics of the future vehicle fleets are analyzed in several up-to date scenarios. The results indicate that China's vehicle stock will keep increasing to 543 million by 2050. The total direct petroleum demand and associated GHG emissions will peak at 508 million tonnes of oil equivalent (Mtoe) and 1500 million tonnes CO2 equivalent (Mt CO2,e) around 2030 in the Reference scenario. Natural gas vehicle diffusion has a large impact on petroleum demand reduction in the short term, with decreases of 41–46 Mtoe in 2050. Compared to the Reference case, battery electric and fuel cell vehicles will reduce petroleum demand by 94–157 and 28–54 Mtoe in 2050, respectively. When combined with decarbonization of future power supply, battery electric vehicles can play a significant role in reducing Well-to-Wheels GHG emissions in 2050 with 295–449 Mt CO2,e more reductions. The spatial distributions of future vehicle stock, energy demand and GHG emissions vary among provinces and show a generally downward trend from east to west. Policy recommendations are made in terms of the development of alternative fuels and vehicle technologies considering provincial differences, expansion of natural gas vehicle market and acceleration of electric vehicle market penetration.

Mobile air conditioning (MAC) is potentially a huge source of greenhouse gas (GHG) emissions in China from a life cycle (LC) perspective as the vehicle population increases in the future. The MAC-GHG-LCA model is developed to calculate LC GHG emissions from MAC systems, covering life-span refrigerant leakage (direct emissions) and emissions caused by energy use in MAC system production and operation (indirect emissions). Using R152a and R1234yf as alternative refrigerants instead of R134a in MAC systems can decrease LC GHG emissions by 22–32% and 17–29%, respectively. Their GHG reduction benefits mainly result from their lower global warming potential (GWP) values though the indirect emissions are only slight lower or even higher than R134a. Using R744 can offer reduction in 2050 though it will cause an increase of 20% in 2020. Total LC GHG emissions from MAC systems of the whole light duty vehicle (LDV) fleet in China will be 159 million tonnes of CO2-equivalent in 2050 in the scenario where R134a will be the only refrigerant adopted, about 3 times that in 2015. It is found that alternative low-GWP refrigerants can help reduce LC GHG emissions from MAC systems effectively. The shift from conventional cooling and heating technology to advanced heat pump technology in electric vehicles (EVs) can reduce electricity use in MAC system operation and reduce LC GHG emissions from the MAC systems in EVs.

An expandable electric vehicle (EV) life-cycle analysis (LCA) model (EV-LCA) is developed to analyze the life cycle (LC) energy consumption (EC) and greenhouse gas (GHG) emissions of EVs considering variations in electricity grid mix and vehicle energy efficiency performance. Employing EV-LCA as a common model platform, a case study is conducted to assess the LC GHG emissions of an average passenger battery electric vehicle (BEV) and plug-in hybrid electric vehicle (PHEV) with a comparative internal combustion engine vehicle (ICEV) under real-world driving conditions in China, the U.S. Japan, Canada and EU, based on country-specific data. The model is shown to be applicable and flexible to assess the average EC and GHG emissions performance of EVs at both regional and national level under large-scale adoption. The case study indicates that currently BEVs show a positive performance in GHG emissions reduction (GER) (ranging from 30% to 80%) when compared to gasoline ICEVs globally. It is also found that the GER effect of EV is highly variable geographically due to significant differences in the electricity grid mix and GHG emissions intensity of grid electricity among countries. EVs can achieve higher GER with the development of low carbon electricity in future. The GER potential of PHEV is significantly influenced by the all-electric range (AER). Several policy suggestions are presented, including the consideration of regional characteristics in GER assessment of EVs and the need to accelerate low-carbon electricity development.

Globally, crop straw is a rich resource and further establishment of its use as an energy source is an important aspect in developing the circular economy. Projects in this vein can bring benefits such as improving energy access and living conditions as well as boosting the local economy and employment opportunities in rural communities. This paper presents a detailed case study on the production of bio-natural gas (BNG) from corn straw in China, using Life Cycle Analysis (LCA) to assess energy consumption and greenhouse gas (GHG) emissions, conducting economic analysis, and analyzing operation management models. The “Nongbaomu” business model (whereby professional personnel assist farmers in the management of straw collection, bundling, storage and transportation) and the “Mutual Offsetting in Kind” business model (whereby farmers can buy a quota of the project's BNG products at a lower price in return for selling straw to the project) can ensure the acquisition of straw by the BNG project at stable prices and high quality. Because the main product (BNG) replaces refined oil products used by automobiles and the byproduct (organic fertilizer) replaces traditional fertilizer (produced using coal), the project offers the potential for significant decreases (up to 80%) in life cycle GHG emissions and fossil fuel use. Benefited from the relatively high natural gas prices in the project location and applicable government subsidies, our studied case was found to be economically viable. The findings in this study are also likely to be relevant to other countries where governments should develop industrial policies that support the development of rural distributed energy, and introduce and implement appropriate subsidies to allow BNG to compete in the traditional natural gas market. Although, enterprises are responsible for selecting an effective business models and the most appropriate technological pathway, governments should also identify the ways in which they can support businesses to make these choices.

Evaluations of food, energy and water (FEW) linkages are rapidly emerging in contemporary nexus studies. This paper demonstrates, from a food consumption perspective, the potential of life cycle thinking in understanding the complex and often “hidden” linkages between FEW systems. Our study evaluates the upstream virtual water and embodied energy in food consumption in the Tamar catchment, South West England, distinguishing between domestic production and imports origin. The study also evaluates key inputs, including virtual nutrients and animal feed, when tracking supply chain of food products. Based on current dietary patterns and food products selection, the catchment consumes annually 834 TJ, 17 hm3 and 244 hm3 of energy, blue water and green water, respectively. Tamar is not self-sufficient in terms of food and requires imports of food products, as well as imports of virtual nutrients and animal feed for local production. Consequently, 51% of the embodied energy and 88% blue and 45% green virtual water in food consumed within the catchment are imported. Most of the embodied energy (58%) and green virtual water (90%) are because of animal feed production, where nearly half of embodied energy (48%) and green virtual water (42%) come from imports. 92% of blue virtual water is used for irrigation and primarily happens elsewhere due to imports. Irrigation is the process that demands the largest amount of energy for the crop-based products, with 38% of their total energy demand, followed by fertilisers production (24%). Our study illustrates water and energy hotspots in the food life cycle and highlights potential FEW risks and trade-offs through trade. This is useful considering potential unexpected changes in trade under recent global socio-political trends. Currently available databases and software make LCA a key tool for integrated FEW nexus assessments.

In this paper, the influence of the addition of n-butanol on fuel properties, combustion, and emission characteristics for a diesel engine was studied. Kinematic viscosity, lower heating value, closed-cup flash point, density, cetane number, and distillation were measured. The engine performance and emissions were also tested at nine loads of 1200 rpm. On this basis, numerical models of the diesel at 100% load for five fuels were established based on Computational Fluid Dynamics (CFD). Next, CFD was used to evaluate the interactive influences among fuel properties and emissions quantitatively. The results demonstrated that kinematic viscosity, lower heating value, closed-cup flash point, density, and cetane number presented downward trends of varying degree with the increase in n-butanol content. Also, 10 vol. %, 50 vol. %, 90 vol. %, and 95 vol. % distillation temperatures decreased, and the range of decline decreased gradually. Hydrocarbon (HC), carbon monoxide (CO), and particulate matter emissions decreased, while nitrogen oxides (NOx) emissions and fuel consumption increased. In the combustion process, the regions of concentration for the formation of HC and CO were the gap and near the wall, and the production of HC emissions lagged behind that of CO emissions.

The use of dynamical information, which is temporally and spatially explicit, to quantify environmental impacts is gaining importance in recent years. Life Cycle Assessment has been applied to identify environmental impacts of, for example, wheat production. However, conventional Life Cycle Assessment is typically limited by its static nature and cannot explicitly consider temporal and spatial variability in its matrix-based mathematical structure. To address this limitation, a novel dynamical Life Cycle Assessment framework that applies spatio-temporal mathematical models in Life Cycle Inventory is introduced. This framework employs the existing Enhanced Structural Path Analysis (ESPA) method paired with a spatial dispersion model to determine the localised emissions over time within the Life Cycle Inventory. The spatially explicit calculations consider emissions to the surrounding area of an origin. A case study was undertaken to demonstrate the developed framework using the production of wheat at the Helford area in Cornwall, UK. Results show the spatio-temporal dispersion for four example emissions atmosphere, soil, flowing and groundwater. These outcomes show that it is possible to implement both spatial and temporal information in matrix-based LCI. We believe this framework could potentially transform the way LCA is currently performed, i.e. in a static and spatially-generic way and will offer significantly improved understanding of life cycle environmental impacts and better inform management of processes such as agricultural production that have high spatial and temporal heterogeneity.

The use of agricultural residues to produce biomass briquette fuel (BBF) can reduce waste of resources and consumption of fossil fuels. We report the first detailed environmental impact assessment of cornstalk-based BBF in China using a cradle-to-grave life cycle assessment (LCA). The LCA study was conducted based on a typical large-scale cornstalk BBF demonstration project in China with an integrated and automated production system. The key life cycle stages such as cornstalk growth, cornstalk transportation, BBF production, transportation and utilisation were investigated. Our results suggest that cornstalk BBF in China is much more environmentally friendly than coal and is favourable when compared with other types of solid fuels produced from different biomass feedstock. For example, the climate change and fossil depletion impacts of cornstalk BBF in China (11 g CO2eq./MJ and 2 g oil eq./MJ, respectively) are an order of magnitude lower than those of coal (146 g CO2eq./MJ and 26 g oil eq./MJ, respectively). The results of this study can assist policy makers in evaluating the potential benefits of the large scale use of BBF made from agricultural residues.

© 2017 Elsevier Ltd. Decentralized rainwater harvesting (RWH) from roof runoff can complement the centralized supply of mains (drinking) water for a range of contexts, to assist in alleviating issues of water security. However, treatment to potable standard of harvested rainwater is not widespread. Consequently a comparative life cycle analysis (LCA) of decentralized and centralized potable water supply has not previously been undertaken. In this paper we describe a novel point-of-use (POU) treatment device, which was used to treat harvested rainwater to potable standard. We then provide a performance assessment for this system and an LCA with a comparison to centralized supply. Results of the performance assessment indicate a water saving efficiency (E T ) of between 0.6 and 100%, depending on rainfall (0.6 from April when rainfall was significantly below average). This highlights that the POU device was able to deal with the scale of roof runoff supply originating from a RWH system at a commercial building scale. The LCA results suggest that potable water produced from this decentralized RWH POU system currently performs more poorly than centralized water from an environmental perspective. Its impacts in most categories would be significantly reduced if the electricity consumed by the system were supplied from a renewable source such as solar PV or wind turbines instead of the UK grid. Priority should be given to optimizing the energy efficiency and exploring opportunities for combined use with renewable energy technologies in order to improve the environmental performance of POU treatment devices.

China's photovoltaic power (PV) power industry currently faces a challenge in excessive production capacity. The aim of this study is to determine how the Chinese government should regulate this industry with positive externalities in order to achieve equilibrium and maximize social welfare in a market economy. This paper formulates an investment model in corporate government theory that includes government, bank systems, and private- and state-owned enterprises. Using the model developed, the relationships between the government's preferred investment strategy and its budget constraints, and the related tax rate or subsidy level are analyzed in the context of China's PV power sector. Main findings of this study are as follows: Firstly, both types of enterprises can achieve optimal social investment if the budget constraints are not excessively binding as the government will have sufficient financial resources to subsidize both types regardless of how funds are obtained. Secondly, state-owned enterprises will choose a higher investment level when government budget constraints are binding because the government lacks money. Thirdly, if the tax rate is so low that the government cannot raise adequate tax to ensure production, raising funds from profits is a better choice. Due to the fact that the positive externality and incremental cost of the PV power technology compared to the local grid's mainstream power technology vary spatially and temporally, which type of enterprises is favored depends on the local real-time situation. This paper also finds that assigning PV power production to a state-owned enterprise is always the favored strategy in areas where the solar resource is not abundant and the PV sector is in its early stage, which helps to accomplish strong positive externality as early as possible in a few years. In areas where solar resource is abundant, private enterprises are supported to develop PV power. Furthermore, as the incremental cost of PV over conventional power to grid decreases with China's grid electricity becoming cleaner and more expensive, subsidy to PV power sector should be decreased and a wider range of private enterprises should be encouraged to make investment in this industry.

In this study, biomass-based EL (ethyl levulinate) was evaluated as an additional fuel to biodiesel and diesel. Physical and chemical properties, including intersolubility, cold flow properties, spray evaporation, oxidation stability, anti-corrosive property, cleanliness, fire reliability and heating value of twelve different EL-biodiesel-diesel blends were analyzed. The results show that the fuel blends that were in line with China's national standard for biodiesel blend fuel (B5) have similar physical and chemical properties to pure diesel with improved cold flow properties. Optimized fuel blends based on grey relational analysis and analytic hierarchy process were selected to evaluate engine performance and emissions using an unmodified diesel engine test bench. The results show that engine power and torque with the fuel blends were in general similar to those with diesel (less than 3% differences). Both brake specific fuel and energy consumption were lower with the fuel blends than with diesel, suggesting higher fuel conversion efficiencies for the fuel blends. HC (Hydrocarbon) and CO (carbon monoxide) emissions and smoke opacity reduced significantly with the fuel blends compared with diesel while NOx (nitrogen oxides) and CO2 (carbon dioxide) emissions increased. Our study suggests that EL produced from lignocellulosic biomass could be used as a blending component with biodiesel and diesel for use in unmodified diesel engines and could potentially be a promising environment-friendly fuel.

Biomass can be relatively easily stored and transported compared with other types of renewable energy sources. Crop straw can be converted into densified solid biofuel via briquette fuel technology to expand its possible applications and enhance its utilisation efficiency. However, the potential economic, environmental and social impacts of crop straw briquette fuel need to be assessed before its large-scale use. This paper provides a comprehensive evaluation of these impacts for a fully-operating 2×104 t/a corn stalk briquette fuel plant in China. The results show that with a life time of 15 years, a purchase price of 150 RMB/t for corn stalk and the current sales price of 400 RMB/t for briquette fuel, the plant has a net present value of 9.6 million RMB or 1.5 million USD, an internal rate of return of 36% and a short investment payback period of 4.4 years. The life cycle greenhouse gas emissions are found to be 323 t CO2,e/year or 1kg CO2,e/GJ, much lower than that of coal. Additionally, the process reduces pollution by decreasing the amount of corn stalk that is discarded or burnt directly in the field. In terms of social impacts, the use of corn stalk briquetting fuel plant is expected to play an important role in increasing local residents' income, improving rural ecological environments, alleviating energy shortages, guaranteeing energy security, and promoting socialism new rural reconstruction. © 2013 Elsevier Ltd.

Bioethanol is the world's largest-produced alternative to petroleum-derived transportation fuels due to its compatibility within existing spark-ignition engines and its relatively mature production technology. Despite its success, questions remain over the greenhouse gas (GHG) implications of fuel ethanol use with many studies showing significant impacts of differences in land use, feedstock, and refinery operation. While most efforts to quantify life-cycle GHG impacts have focused on the production stage, a few recent studies have acknowledged the effect of ethanol on engine performance and incorporated these effects into the fuel life cycle. These studies have broadly asserted that vehicle efficiency increases with ethanol use to justify reducing the GHG impact of ethanol. These results seem to conflict with the general notion that ethanol decreases the fuel efficiency (or increases the fuel consumption) of vehicles due to the lower volumetric energy content of ethanol when compared to gasoline. Here we argue that due to the increased emphasis on alternative fuels with drastically differing energy densities, vehicle efficiency should be evaluated based on energy rather than volume. When done so, we show that efficiency of existing vehicles can be affected by ethanol content, but these impacts can serve to have both positive and negative effects and are highly uncertain (ranging from -15% to +24%). As a result, uncertainties in the net GHG effect of ethanol, particularly when used in a low-level blend with gasoline, are considerably larger than previously estimated (standard deviations increase by >10% and >200% when used in high and low blends, respectively). Technical options exist to improve vehicle efficiency through smarter use of ethanol though changes to the vehicle fleets and fuel infrastructure would be required. Future biofuel policies should promote synergies between the vehicle and fuel industries in order to maximize the society-wise benefits or minimize the risks of adverse impacts of ethanol. © 2013 American Chemical Society.

A life-cycle analysis (LCA) of greenhouse gas (GHG) emissions and energy use was performed to study bio-jet fuel (BJF) production from micro-algae grown in open ponds under Chinese conditions using the Tsinghua University LCA Model (TLCAM). Attention was paid to energy recovery through biogas production and cogeneration of heat and power (CHP) from the residual biomass after oil extraction, including fugitive methane (CH4) emissions during the production of biogas and nitrous oxide (N2O) emissions during the use of digestate (solid residue from anaerobic digestion) as agricultural fertilizer. Analyses were performed based on examination of process parameters, mass balance conditions, material requirement, energy consumptions and the realities of energy supply and transport in China (i.e. electricity generation and heat supply primarily based on coal, multiple transport modes). Our LCA result of the BJF pathway showed that, compared with the traditional petrochemical pathway, this new pathway will increase the overall fossil energy use and carbon emission by 39% and 70%, respectively, while decrease petroleum consumption by about 84%, based on the same units of energy service. Moreover, the energy conservation and emission reduction benefit of this new pathway may be accomplished by two sets of approaches: wider adoption of low-carbon process fuels and optimization of algae cultivation and harvest, and oil extraction processes. © 2013 by the authors.

Biofuels are increasingly promoted worldwide as a means for reducing greenhouse gas (GHG) emissions from transport. However, current regulatory frameworks and most academic life cycle analyses adopt a deterministic approach in determining the GHG intensities of biofuels and thus ignore the inherent risk associated with biofuel production. This study aims to develop a transparent stochastic method for evaluating UK biofuels that determines both the magnitude and uncertainty of GHG intensity on the basis of current industry practices. Using wheat ethanol as a case study, we show that the GHG intensity could span a range of 40-110 gCO2e MJ-1 when land use change (LUC) emissions and various sources of uncertainty are taken into account, as compared with a regulatory default value of 44 gCO2e MJ-1. This suggests that the current deterministic regulatory framework underestimates wheat ethanol GHG intensity and thus may not be effective in evaluating transport fuels. Uncertainties in determining the GHG intensity of UK wheat ethanol include limitations of available data at a localized scale, and significant scientific uncertainty of parameters such as soil N2O and LUC emissions. Biofuel polices should be robust enough to incorporate the currently irreducible uncertainties and flexible enough to be readily revised when better science is available. © 2013 IOP Publishing Ltd.

Henan is the main agricultural province in China and is the top producer of wheat, representing 25% of the national wheat output. Henan has been the top province in terms of total food crop production since 2000. So, agricultural residue resources, which could provide material for future social and economic development, are abundant in Henan. But the province is facing critical problems from burning agricultural residues. Both efficient use and environmental protection of the resources are beginning to receive more attention. This study assessed the agricultural residue resources available for utilization and examined recent development targets in Henan. Agricultural residues were estimated for the base year 2009. Approximately 59.12 million tonnes of agricultural residues were consumed in various ways, and the average percentage of agricultural residue utilization was 70.07%. Agricultural residue is mainly used as a fertilizer, an energy source, industrial material, forage, and as feedstock for edible fungi. Short-term targets were provided for the development of suitable uses for agricultural residues through several demonstration projects, which will help to increase the efficient use of agricultural residue in Henan, China.

China's road transport sector is expected to be a major factor affecting national and global oil availability and prices, and is a major contributor to China's greenhouse gas emission increase and urban air pollution. Reasons for bioethanol and biodiesel to be considered as promising alternatives to conventional transportation fuels in China include energy security and environmental concerns. The present article analyzes the current status and future potential of bioethanol and biodiesel development in China, as well as the energy demand and emissions for different feedstock options from a life cycle perspective. Copyright © Taylor & Francis Group, LLC.

The sustainability of large-scale biofuel production has recently been called into question in view of mounting concerns over the associated impact on land and water resources. As the most predominant biofuel today, ethanol produced from food crops such as corn in the US has been frequently criticised. Ethanol derived from cellulosic feedstocks is likely to overcome some of these drawbacks, but the production technology is yet to be commercialised. Sugarcane ethanol is the most efficient option in the short term, but its success in Brazil is difficult to replicate elsewhere. Agaves are attracting attention as potential ethanol feedstocks because of their many favourable characteristics such as high productivities and sugar content and their ability to grow in naturally water-limited environments. Here, we present the first life cycle energy and greenhouse gas (GHG) analysis for agave-derived ethanol. The results suggest that ethanol derived from agave is likely to be superior, or at least comparable, to that from corn, switchgrass and sugarcane in terms of energy and GHG balances, as well as in ethanol output and net GHG offset per unit land area. Our analysis highlights the promising opportunities for bioenergy production from agaves in arid or semi-arid regions with minimum pressure on food production and water resources. © 2011 the Royal Society of Chemistry.

Alternative transportation fuels are projected to grow substantially due to energy security concerns especially in the US and China. Moreover, some of these fuels can potentially reduce greenhouse gas (GHG) emissions from the transportation sector and hence, can help to mitigate climate change. We present a comprehensive review on Well-to-Wheel fossil fuel use and GHG emissions of biofuels and synthetic fuels in the US and China including emissions from land-use change. Our results are carefully benchmarked to the emissions caused by crude oil-derived fuels as well as synthetic fuels from fossil feedstocks in order to estimate the potential emission reduction or increase. The review strongly suggests that biofuels and synthetic fuels can contribute to GHG mitigation in the transport sector only if appropriate feedstocks are used and emissions from land-use change are minimised. © 2010 the Royal Society of Chemistry.

Rapidly growing energy demand and emissions from China's road transportation vehicles in the last two decades have raised concerns over oil security, urban air pollution and global warming. This rapid growth will be likely to continue in the next two to three decades as the vehicle ownership level in China is still very low. The current status of China's road transport sector in terms of vehicles, infrastructure, energy use and emissions is presented. Mitigation measures implemented and those that can reasonably be expected to be adopted in the near future are analysed. Recent studies exploring the future trends of road vehicle energy demand and emissions under various strategies are reviewed. Moreover, those studies which assessed various fuel/propulsion options in China from a life cycle perspective are examined to present an overview of the potential for reducing energy use and emissions. Recommendations for further developments are also made. It is concluded that comprehensive and appropriate strategies will be needed to minimise the adverse impacts of China's road vehicles on energy resources and the environment. Fortunately, China appears to be heading in this direction. © 2010 Elsevier Ltd. All rights reserved.

Rapidly-rising oil demand and associated greenhouse gas (GHG) emissions from road vehicles in China, passenger cars in particular, have attracted worldwide attention. As most studies to date were focused on the vehicle operation stage, the present study attempts to evaluate the energy demand and GHG emissions during the vehicle production process, which usually consists of two major stages-material production and vehicle assembly. Energy demand and GHG emissions in the material production stage are estimated using the following data: the mass of the vehicle, the distribution of material used by mass, and energy demand and GHG emissions associated with the production of each material. Energy demand in the vehicle assembly stage is estimated as a linear function of the vehicle mass, while the associated GHG emission is estimated according to the primary energy sources. It is concluded that the primary energy demand, petroleum demand and GHG emissions during the production of a medium-sized passenger car in China are 69,108 MJ, 14,545 MJ and 6575 kg carbon dioxide equivalent (CO2-eq). Primary energy demand, petroleum demand and GHG emissions in China's passenger car fleets in 2005 would be increased by 22%, 5% and 30%, respectively, if the vehicle production stage were included. © 2009 Elsevier Ltd. All rights reserved.

Life cycle analysis is considered to be a valuable tool for decision making towards sustainability. Life cycle energy and environmental impact analysis for conventional transportation fuels and alternatives such as biofuels has become an active domain of research in recent years. The present study attempts to identify the most reliable results to date and possible ranges of life cycle fossil fuel use, petroleum use and greenhouse gas emissions for various road transportation fuels in China through a comprehensive review of recently published life cycle studies and review articles. Fuels reviewed include conventional gasoline, conventional diesel, liquefied petroleum gas, compressed natural gas, wheat-derived ethanol, corn-derived ethanol, cassava-derived ethanol, sugarcane-derived ethanol, rapeseed-derived biodiesel and soybean-derived biodiesel. Recommendations for future work are also discussed. © 2009 Elsevier Ltd. All rights reserved.

Life cycle energy, environment and economic assessment for conventional diesel (CD) and soybean-based biodiesel (SB) in China was carried out in this paper. The results of the assessment have shown that compared with CD, SB has similar source-to-tank (StT) total energy consumption, 76% lower StT fossil energy consumption, 79% higher source-to-wheel (StW) nitrogen oxides (NOX) emissions, 31%, 44%, 36%, 29%, and 67% lower StW hydrocarbon (HC), carbon monoxide (CO), particulate matter (PM), sulfur oxides (SOX), and carbon dioxide (CO2) emissions, respectively. SB is thus considered to be much more renewable and cleaner than CD. However, the retail price of SB at gas stations would be about 86% higher than that of CD without government subsidy according to the cost assessment and China had to import large amount of soybean to meet the demand in recent years. Therefore, although SB is one of the most promising clean and alternative fuels, currently it is not a good choice for China. It is strategically important for China to diversify the feedstock for biodiesel and to consider other kinds of alternative fuels to substitute CD. © 2008 Elsevier Ltd. All rights reserved.

Rapidly rising energy consumption in China has attracted worldwide attention. This paper provides some insights into future energy supply and demand based on an analysis of the current situation and unique features of energy use in China. With a population of over 1.3 billion, China will need a massive amount of energy to maintain its high economic growth rate. Fast development, in the transportation sector, in particular, has resulted in continuing growth in oil imports, threatening China's energy security. Heavy reliance on coal has caused serious environment problems in China and possibly more widely, mainly by the emission of greenhouse gases such as carbon dioxide, a major contributor to global warming. The Chinese government has been taking measures to improve energy efficiency and energy conservation to control energy consumption as well as promoting the use of clean energy such as hydroelectricity and natural gas, to replace coal, to reduce energy related pollution. © 2007 Energy Institute.