A framework for the exergy analysis of future transport pathways: Application for the United Kingdom transport system 2010-2050

Exergy analysis has been used to quantify the historical resource use efficiency and environmental impact of transport systems. However, few exergy studies have explored future transport pathways. This study aims to, (a) develop a conceptual framework for the exergy analysis of multiple future transport and electricity pathways, (b) apply this framework to quantify future resource consumption and service delivery patterns, (c) discuss the policy-relevant results that exergy studies of future transport systems can offer. Multiple transport and electricity pathways developed by the UK Government are used to explore changes in energy use, useful work delivery and greenhouse gas emissions. In passenger transport, ambitious electrification results in a 20% increase of useful work delivery, whilst reducing GHG emissions and energy consumption by 65%. For freight, international shipping and aviation, smaller exergy efficiency improvements make useful work delivery and greenhouse gas emissions highly dependent on transport demand. Passenger transport electrification brings a step-change in useful work delivery, which if accompanied by low-carbon electricity, significantly reduces greenhouse gas emissions. The efficiency of low-carbon electricity systems is significant for useful work delivery, but not dominant across the scenarios explored. High penetration of renewables and electrified transport is the most resource-efficient combination in this context.EB was supported by Newcastle University with funding from the UK Engineering and Physical Sciences Research Council (EPSRC). AG acknowledges funding through a Marie Curie International Incoming Fellowship (Project ABioPES, 302880) offered by the European Commission. AS commenced the research in this paper whilst at IN+ Center for Innovation, Technology and Policy Research, Instituto Superior Técnico - University of Lisbon with funding from FCT (PhD grant SFRH/BD/46794/2008), and finalized it while at the University of Cambridge (EPSRC grant EP/K011774/1).This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.energy.2015.07.02

Potential for energy savings by heat recovery in an integrated steel supply chain

Heat recovery plays an important role in energy saving in the supply chain of steel products. Almost all high temperature outputs in the steel industry have their thermal energy exchanged to preheat inputs to the process. Despite the widespread development of heat recovery technologies within process stages (process heat recovery), larger savings may be obtained by using a wider integrated network of heat exchange across various processes along the supply chain (integrated heat recovery). Previous pinch analyses have been applied to optimise integrated heat recovery systems in steel plants, although a comparison between standard process heat recovery and integrated heat recovery has not yet been explored. In this paper, the potential for additional energy savings achieved by using integrated heat recovery is estimated for a typical integrated steel plant, using pinch analysis. Overall, process heat recovery saves approximately 1.8 GJ per tonne of hot rolled steel (GJ/t hrs), integrated heat recovery with conventional heat exchange could save 2.5 GJ/t hrs, and an alternative heat exchange that also recovers energy from hot steel could save 3.0 GJ/t hrs. In developing these networks, general heat recovery strategies are identified that may be applied more widely to all primary steel production to enhance heat recovery. Limited additional savings may be obtained from the integration of the steel supply chain with other industries.Dr. McBrien’s work on this paper was funded by EPSRC grant EP/G007217/1, and Dr. Serrenho and Professor Allwood were funded by EPSRC grant EP/N02351X/1.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.applthermaleng.2016.04.09

Scrap, carbon and cost savings from the adoption of flexible nested blanking

Steel accounts for 6% of anthropogenic CO2 emissions, most of which arises during steelmaking rather than downstream manufacturing. While improving efficiency in steelmaking has received a great deal of attention, improving material yield downstream can have a substantial impact and has received comparatively less attention. In this paper, we explore the conditions required for manufacturers to switch to a more materially efficient process, reducing demand for steel and thus reducing emissions without reducing the supply of goods to consumers. Furthermore, we present an alternative processing route where parts can be cut in flexible arrangements to take advantage of optimal nesting across multiple part geometries. For the first time, we determine the potential savings that flexible nested blanking of parts could achieve by calculating the potential for grouping orders with tolerably-similar thickness, strengths, ductility and corrosion-resistance. We found that 1,080 kt of CO2 and 710 kt of steel worth € 430M could be saved each year if this scheme was adopted across all European flat steel mills serving the automotive sector

The economic growth enigma revisited : the EU-15 since the 1970s

Current macro-econometric models mostly incorporate just two factors of production, labour and capital (with a time-dependent multiplier representing technological change or total factor productivity). These models assume that energy is an intermediate product of some combination of human labour and capital. These models also assume that the supply of energy is driven by economic demand. We assume the contrary, i.e. that useful energy is a primary input, derived (mostly) from natural capital. This failure to capture the impact of primary resources (as useful energy) on economic growth leads to inappropriate formulation of economic growth theories. To understand that impact better we need explicit evidence of marginal products of capital, labour and useful energy or useful work. As applied to the explanation of the past half century of economic growth of the EU-15 countries, the new results demonstrate the use of non-parametric relationships between capital, labour and useful energy to explain economic growth. They also indicate that marginal products of capital, labour and useful energy are variable - the marginal product depends on the levels of capital stock, labour input and useful energy flows. The proposed semi-parametric production function suggests country-specific policy implications for the EU (and other countries)

The deformation of metal powder particles: Hardness and microstructure

© 2017 The Authors. Published by Elsevier Ltd. The modelling of powder densification requires knowledge about the material properties of the particles. Some models use the material properties of the material in bulk as inputs for modelling the densification of assemblies of powder particles. It is important to understand how these properties differ when the material is in powder form. Existing works tend to analyse bulk material or powder exclusively and rarely compare properties such as hardness between the two. This work compares the microstructures and hardness of metal powder with bulk material with the aim of guiding the assumptions made in the modelling of metal powder densification. It is expected that the rapid solidification typical in the atomisation of metals results in significant differences in behaviour when compared with material produced via casting and hot/cold working

The Need for Robust, Consistent Methods in Societal Exergy Accounting

© 2017 The AuthorsStudies of societal exergy use have the common aim of tracing the flow of exergy along society, and are used to gain insights into the efficiency of energy use and linkages to economic growth. However, their methodological approaches vary greatly, with significant impacts on results. Therefore, we make a review of past studies to identify, synthesize and discuss methodological differences, to contribute to a more consistent and robust approach to societal exergy accounting. Issues that should be taken into account when making methodological options are discussed and key insights are presented: (1) For mapping of primary inputs and useful exergy categories, the inclusion of all natural resources is more consistent but it has the cost of not being able to distinguish the various energy end-uses in the production of materials. (2) To estimate primary electricity, none of the methods currently used is able to capture simultaneously the efficiency of the renewable energy sector, the environmental impact and the efficiency of energy use in society. (3) To estimate final-to-useful exergy conversion efficiencies, standard thermodynamic definitions should be used because the use of proxies fails to distinguish between increases in exergy efficiency and increases in the efficiency of providing energy services

Industry 1.61803: the transition to an industry with reduced material demand fit for a low carbon future

Arising from a discussion meeting in September 2016, this editorial introduces a special issue on the transition to a future industrial system with greatly reduced demand for material production and attempts to synthesize the main findings. The motivation for such a transition is to reduce industrial greenhouse gas emissions, but unlike previous industrial transformations, there are no major stakeholders who will pursue the change for their own immediate benefit. The special issue, therefore, explores the means by which such a transition could be brought about. The editorial presents an overview of the opportunities identified in the papers of the volume, presents examples of actions that can be taken today to begin the process of change and concludes with an agenda for research that might support a rapid acceleration in the rate of change.The work of J.M.A. and A.C.S. on this paper was funded by EPSRC grant reference EP/N02351X/1 and that of A.C.H.S. by EPSRC grant reference EP/K039326/1

The influence of UK emissions reduction targets on the emissions of the global steel industry

The steel industry is the world's largest industrial source of CO$_{2}$ emissions. Recent UK economic policies have led to reduced domestic steel production giving an apparent reduction in national emissions. However, demand for goods made from steel has not reduced. Emissions have thus been transferred not reduced and implementation of UK climate policies may in future expand this ‘carbon leakage.’ This paper explores how future UK demand for goods made from steel might be supplied while satisfying national climate policies, and how this will influence global CO$_{2}$ emissions. Current flows and stocks of steel are estimated from existing databases. Evidence from other developed economies suggests that per capita stocks are tending towards a saturation level so future demand is forecast from population growth and the expected rate of replacement of a stable stock. The carbon intensities of five different steel-making routes are used to predict the allowed scale of future domestic steel production within the industrial emissions allowances set in four energy pathways defined by the UK Government. The remaining requirement for steel must be sourced offshore and the associated emissions are predicted, to give an estimate of the global emissions arising from final demand in the UK. The results show that current UK climate strategy may have a limited effect in reducing the CO$_{2}$ emissions of the global steel industry, unless the UK shifts towards producing more of its own steel products with domestic secondary steel-making. This option would also increase the security of UK supply and support an expansion of UK manufacturing.This work was supported by EPSRC, grant references EP/K011774/1 and EP/K039326/1.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.resconrec.2016.01.00

Technologies for the global energy transition

The availability of reliable, affordable and mature technologies is at the basis of an effective decarbonization strategy, that should be in turn supported by timely and accurate policies. Due to the large differences across sectors and countries, there is no silver bullet to support decarbonization, but a combination of multiple technologies will be required to reach the challenging goal of decarbonizing the energy sector. This chapter presents a focus on the current technological solutions that are available in four main sectors: power generation, industry, transport and buildings. The aim of this work is to highlight the main strengths and weaknesses of the current technologies, to help the reader in understanding which are the main opportunities and challenges related to the development and deployment of each of them, as well as their potential contribution to the decarbonization targets. The chapter also provides strategies and policy recommendations from a technology point of view on how to decarbonize the global energy systems by mid-century and of the necessity to take a systems approach

Scrap, carbon and cost savings from the adoption of flexible nested blanking

Steel accounts for 6% of anthropogenic CO2 emissions, most of which arises during steelmaking rather than downstream manufacturing. While improving efficiency in steelmaking has received a great deal of attention, improving material yield downstream can have a substantial impact and has received comparatively less attention. In this paper, we explore the conditions required for manufacturers to switch to a more materially efficient process, reducing demand for steel and thus reducing emissions without reducing the supply of goods to consumers. Furthermore, we present an alternative processing route where parts can be cut in flexible arrangements to take advantage of optimal nesting across multiple part geometries. For the first time, we determine the potential savings that flexible nested blanking of parts could achieve by calculating the potential for grouping orders with tolerably similar thickness, strengths, ductility and corrosion-resistance. We found that 1080 kt of CO2 and 710 kt of steel worth €430M could be saved each year if this scheme was adopted across all European flat steelmills serving the automotive sector