Sustainability of UK shale gas in comparison with other electricity options: Current situation and future scenarios.

Many countries are considering exploitation of shale gas but its overall sustainability is currently unclear. Previous studies focused mainly on environmental aspects of shale gas, largely in the US, with scant information on socio-economic aspects. To address this knowledge gap, this paper integrates for the first time environmental, economic and social aspects of shale gas to evaluate its overall sustainability. The focus is on the UK which is on the cusp of developing a shale gas industry. Shale gas is compared to other electricity options for the current situation and future scenarios up to the year 2030 to investigate whether it can contribute towards a more sustainable electricity mix in the UK. The results obtained through multi-criteria decision analysis suggest that, when equal importance is assumed for each of the three sustainability aspects shale gas ranks seventh out of nine electricity options, with wind and solar PV being the best and coal the worst options. However, it outranks biomass and hydropower. Changing the importance of the sustainability aspects widely, the ranking of shale gas ranges between fourth and eighth. For shale gas to become the most sustainable option of those assessed, large improvements would be needed, including a 329-fold reduction in environmental impacts and 16 times higher employment, along with simultaneous large changes (up to 10,000 times) in the importance assigned to each criterion. Similar changes would be needed if it were to be comparable to conventional or liquefied natural gas, biomass, nuclear or hydropower. The results also suggest that a future electricity mix (2030) would be more sustainable with a lower rather than a higher share of shale gas. These results serve to inform UK policy makers, industry and non-governmental organisations. They will also be of interest to other countries considering exploitation of shale gas

Life cycle costs and environmental impacts of production and consumption of ready and home-made meals

Consumption of ready-made meals is growing rapidly and yet little is known about their economic and environmental impacts. This paper focuses on the economic aspects to estimate the life cycle costs, value added and consumer costs of ready-made meals, in comparison with the equivalent meals prepared at home. Their life cycle environmental impacts are also considered. A typical roast dinner is considered, consisting of chicken, vegetables and tomato sauce. Different production and consumption choices are evaluated, including sourcing of ingredients, chilled or frozen supply chains and types of appliance used by the consumer to prepare the meal. The estimated life cycle costs of the ready-made meal range from £0.61–£0.92 per meal and for the home-made from £0.68–£1.12. The lowest life cycle costs are found for the chilled ready-made meal heated in a microwave, 11% below the costs of the best home-made option. The life cycle costs of the frozen meal are similar to the best home-made option. The chilled ready-made meal has the highest value added (£2.01) compared to the frozen (£1.22) and the home-made meal (£0.44). However, from the consumer perspective, the cheapest option is the home-made meal (£1.17) while the chilled ready-made option is most expensive (£2.61). If the meal options are compared on both the life cycle costs and environmental impacts, the home-made meal is the best option overall. These findings can be used to inform both producers and consumers on how their choices influence costs and environmental impacts of food.The authors are grateful to BECAS Chile and UK Engineering and Physical Sciences Research Council, EPSRC (grant no. EP/K011820) for funding this research

Environmental sustainability of cellulose-supported solid ionic liquids for CO2 capture

Solid ionic liquids (SoILs) with cellulose as a support have been demonstrated recently to be effective and low-cost sorbents for CO2 capture. However, at present it is not clear whether they remove more CO2 than is released in the rest of the life cycle, including their manufacture, regeneration and disposal. It is also unknown what other impacts they may have over the whole life cycle while attempting to mitigate climate change. Therefore, this study evaluates for the first time the life cycle environmental sustainability of cellulose-supported SoILs in comparison with unsupported SoILs and some other sorbents. Four SoILs are assessed for 11 life cycle impacts, including global warming potential (GWP), with and without the cellulose support: methyltrioctyl ammonium acetate ([N1888][Ac]), tetraethyl ammonium acetate ([N4444][Ac]), tetra-octylammonium bromide ([N8888]Br) and 1-butyl-4-methylimidazolium bromide ([Bmim]Br). They are compared with one of the ILs in the liquid state (trihexyltetradecylphosphonium 1,2,4-triazolide ([P66614][124Triz])) and with three conventional sorbents: monoethanolamine (MEA), zeolite powder and activated carbon. The results show that SoILs with cellulose loading in the range of 70%–80 wt% have better environmental performance per unit mass of CO2 captured than the unsupported SoILs. The net removal of CO2 eq. over the life cycle ranges from 20% for pure [Bmim]Br to 83% for [N1888][Ac] with 75% cellulose and for [N4444][Ac] with both 75% and 80% loadings. However, pure [N8888]Br generates three times more CO2 eq. over the life cycle than it removes. Among the SoILs, [N4444][Ac] with 80% cellulose has the lowest life cycle impacts for eight out of 11 categories. When compared to the conventional sorbents, it has significantly higher impacts, including GWP. However, it is more sustainable than [P66614][124Triz]. The results of this study can be used to target the hotspots and improve the environmental performance of cellulose-supported SoILs through sustainable design

Life cycle environmental sustainability of valorisation routes for spent coffee grounds: From waste to resources

© 2020 The Authors. Spent coffee grounds (SCGs) have a potential to be used as a feedstock for higher value-added products, such as biodiesel. However, the environmental implications of the valorisation of SCGs are largely unknown. This study evaluates the life cycle environmental impacts of utilising SCGs for biodiesel production in comparison with the widely used disposal of SCGs as a waste stream: incineration, landfilling, anaerobic digestion, composting and direct application to land. The scope is from cradle to grave and the functional unit is defined as ‘treatment of 1 tonne of SCGs’. The results show that the most environmentally sustainable option is incineration of SCGs, with net-negative impacts (savings) in 14 out of 16 categories, followed by direct application of SCGs to land with 11 net-negative impacts. Biodiesel production is the least sustainable option with the highest impacts in 11 categories, followed by composting. The paper also demonstrates that following various waste hierarchy and resource valorisation guidelines instead of a life cycle approach could lead to a choice of environmentally inferior SCG utilisation options. Therefore, these guidelines should be revised to ensure that they are consistent and underpinned by life cycle thinking, thus aiding sustainable resource management in a circular economy context.UK Engineering and Physical Sciences Research Council (Gr. no. EP/K011820/1) and The University of Manchester through the N8 AgriFood Local Pump Priming Fun

Developing and implementing circular economy business models in service-oriented technology companies

The service sector has the potential to play an instrumental role in the shift towards circular economy due to its strategic position between manufacturers and end-users. However, there is a paucity of supporting methodologies and real-life applications to demonstrate how service-oriented companies can implement circular economy principles in daily business practice. This paper addresses this gap by analysing the potential of service-oriented companies in the information and communication technology (ICT) sector to build and implement circular economy business models. To this end, the Backcasting and Eco-design for the Circular Economy (BECE) framework is applied in an ICT firm. BECE, previously developed and demonstrated for product-oriented applications, has been developed further here for applications in the service sector. By shifting the focus from a product-oriented approach to a user-centred eco-design, the paper shows how ICT firms can identify, evaluate and prioritise sustainable business model innovations for circular economy. The two most promising business model innovations are explored strategically with the aim of designing circular economy models consistent with the company's priorities of customer satisfaction and profitability. The findings suggest that ICT companies may be able to support the deployment of a circular economy in the service-oriented technology sector. Importantly, micro and small organisations can play a fundamental role if provided with macro-level support to overcome company-level barriers. Finally, the BECE framework is shown to be a valuable resource to explore, analyse and guide the implementation of circular economy opportunities in service-oriented organisations. Further research to verify the application of the findings to other service-oriented organisations is recommended

Utilising carbon dioxide for transport fuels : the economic and environmental sustainability of different Fischer-Tropsch process designs

Producing fuels and chemicals from carbon dioxide (CO2) could reduce our dependence on fossil resources and help towards climate change mitigation. This study evaluates the sustainability of utilising CO2 for production of transportation fuels. The CO2 feedstock is sourced from anaerobic digestion of sewage sludge and the fuels are produced in the Fischer-Tropsch (FT) process. Using life cycle assessment, life cycle costing and profitability analysis, the study considers four different process designs and a range of plant capacities to explore the effect of the economies of scale. For large-scale plants (1,670 t/day), the FT fuels outperform fossil diesel in all environmental impacts across all the designs, with several impacts being net-negative. The only exceptions are ozone depletion, for which fossil diesel is the best option, and global warming potential (GWP), which is lower for fossil diesel for some process designs. Optimising the systems reduces the GWP of FT fuels in the best case by 70% below that of fossil diesel. Assuming a replacement of 9.75–12.4% of fossil diesel consumed in the UK by 2,032, as stipulated by policy, would avoid 2–8 Mt of CO2 eq./yr, equivalent to 2–8% of annual emissions from transportation. However, these fuels are not economically viable and matching diesel pump price would require subsidies of 35–79% per litre. Optimising production yields would allow decreasing the subsidies to 8%. Future research should be aimed at technology improvements to optimise these systems as well as evaluating different policy mechanisms needed to stimulate markets for CO2-derived fuels