1,056 research outputs found

    Carbon Brainprint Case Study: optimising defouling schedules for oil- refinerypreheat trains

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    In an oil refinery, crude oil is heated to 360-370°C before entering a distillation columnoperating at atmospheric pressure where the gas fraction and several liquid fractions withdifferent boiling points (e.g. gasoline, kerosene, diesel, gas oil, heavy gas oil) are separated off.The crude oil is heated in two stages. The preheat train - a series of heat exchangers - heats itfrom ambient temperature to about 270°C when it enters the furnace, known as the coil inlettemperature. The furnace then heats the oil to the temperature required for distillation.The purpose of the preheat train is to recover heat from the liquid products extracted in thedistillation column. Without this, 2-3% of the crude oil throughput would be used for heating thefurnace; with the preheat train up to 70% of the required heat is recovered. It also serves tocool the refined products: further cooling normally uses air or water. Over time, fouling reduces the performance of the heat exchangers, increasing the amount ofenergy that has to be supplied. It is possible to bypass units to allow them to be cleaned, withan associated cost and temporary loss of performance. The cleaning schedule thus has animpact on the overall efficiency, cost of operation and emissions. The group at the Department of Chemical Engineering and Biotechnology at Cambridgedeveloped a scheduling algorithm for this non-linear optimisation problem. It yields a good,though not-necessarily optimal, schedule and can handle additional constraints, such as thepresence of desalters with specific temperature requirements within the preheat train. This isnow being developed into a commercial software product. Data from two refineries - one operated by Repsol YPF in Argentina and the Esso FawleyRefinery in the UK - were used to model the systems and test the algorithm. For the Repsol YPF refinery, when compared with current practice and including a constrainton the desalter inlet temperature, the most conservative estimate of the emissions reductionwas 773 t CO2/year. This assumed a furnace efficiency of 90%. The emissions reductionincreased to 927 t CO2/year at 75% efficiency and 1730 t CO2/year at 40%. These were basedon a stoichiometric estimate of the emissions from the furnace. Using a standard emissionfactor increased them by 7.4%. For Esso Fawley, the estimated emission reduction compared to no maintenance was1435 t CO2/year at 90% furnace efficiency. This increased to 1725 t CO2/year at 75% and3225 t CO2/year at 40% efficien

    On the estimation of temporal mileage rates

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    Analysis of the 2007/8 Defra Farm Business Survey Energy Module

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    Key points This study has delivered an invaluable baseline estimate of energy use and greenhouse gas (GHG) emissions on commercial farms in England. Energy use and GHG emissions associated with particular commodities were quantified and results broadly agreed with those derived by Life Cycle Assessment, but with much scatter in the environmental performance of farms.Direct energy use on farms was generally less that indirect (embedded) energy use, except for horticulture, which is dominated by heating fuel use. In contrast, most GHG emissions are incurred on farms, rather than as embedded emissions.Scatter in both environmental and economic performance underlies the somewhat disappointing finding of no clear positive link between farm financial performance and energy use or GHG emissions. However, the mere existence of these ranges shows that there is scope for improvement in both financial and environmental performance and that there is no apparent barrier for both to be achievable in harmony. The recording of such farm-level energy data is essential for the future, as it should enable improvements to be made in efficiency of energy use. The improved UK agricultural GHG inventory will depend on high quality energy data on agricultural activities. This study will be invaluable in identifying the level of detail needed. Future data requirements include: contractor work rates and fuel use per unit area and per unit time, fertiliser and pesticide use by brand name, enhanced output data, especially animal live weights, and horticultural produce recorded by weight rather than by value

    Emissions vs exposure: Increasing injustice from road traffic-related air pollution in the United Kingdom

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    © 2019 The Authors This paper presents unique spatial analyses identifying substantial discrepancies in traffic-related emissions generation and exposure by socioeconomic and demographic groups. It demonstrates a compelling environmental and social injustice narrative with strong policy implications for the UK and beyond. In the first instance, this research presents a decadal update for England and Wales to Mitchell and Dorling's 2003 analysis of environmental justice in the UK. Using 2011 UK Government pollution and emissions data with 2011 UK Census socioeconomic and demographic data based on small area census geographies, this paper demonstrates a stronger relationship between age, poverty, road NOx emissions and exposure to NO2 concentrations. Areas with the highest proportions of under-fives and young adults, and poorer households, have the highest concentrations of traffic-related pollution. In addition, exclusive access to UK annual vehicle safety inspection records (‘MOT’ tests) allowed annual private vehicle NOx emissions to be spatially attributed to registered keepers. Areal analysis against Census-based socioeconomic characteristics identified that households in the poorest areas emit the least NOx and PM, whilst the least poor areas emitted the highest, per km, vehicle emissions per household through having higher vehicle ownership, owning more diesel vehicles and driving further. In conclusion, the analysis indicates that, despite more than a decade of air quality policy, environmental injustice of air pollution exposure has worsened. New evidence regarding the responsibility for generation of road traffic emissions provides a clear focus for policy development and targeted implementation

    Participatory planning for eco-trekking on a potential World Heritage site: The communities of the Kokoda Track

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    Participatory Rural Appraisal (PRA) is an approach to data collection in participatory research. In this approach, the researcher is required to acknowledge and appreciate that research participants have the necessary knowledge and skills to be partners in the research process. PRA techniques were used to collect data on the Kokoda Track, Papua New Guinea, illuminating the communities' perceptions of eco-trekking and how they could better benefit from it. This case study is an example of the implementation of community-based eco-tourism development and of understanding the multiplicity of forces that support or undermine it. © The Australian National University

    Developing an index of vulnerability to motor fuel price increases in England

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    As the outlook for oil prices remains uncertain, this paper develops a method to assess which areas of England would be most vulnerable to future motor fuel price increases. Building on previous research, we define and operationalise three dimensions of vulnerability: exposure (the cost burden of motor fuel), sensitivity (income) and adaptive capacity (accessibility with modes alternative to the car). We exploit unique data sets available in England, including the ‘MOT’ vehicle inspection data and DfT Accessibility Statistics. This allows us to map vulnerability to fuel price increases at a spatially disaggregated level (Lower-layer Super Output Areas), taking into account motor-fuel expenditure for all travel purposes, and the ability of households to shift to other modes of travel. This is an advancement on the ‘oil vulnerability’ indices developed in previous international research

    Progress with air quality management in the 60 years since the UK clean air act, 1956. Lessons, failures, challenges and opportunities

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    © 2016 WIT Press, www.witpress.com. This paper explores the challenges, opportunities and progress made with managing air quality since the United Kingdom parliament passed the Clean Air Act, 1956. It seeks to identify the factors contributing to successful management of air quality and the factors that have acted, or continue to do so, as barriers to progress. The public health catastrophe of the 1952 London Smog created the political momentum for the 1956 Act to be passed. The nature of the contemporary air pollution challenge is reviewed in terms of the public health burden, the economic cost and the governmental response. The contemporary response is considered inadequate for the scale and intensity of the problem

    'Alive after five' : constructing the neoliberal night in Newcastle upon Tyne.

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    The development of the ‘night-time economy’ in the UK through the 1990s has been associated with neoliberal urban governance. Academics have, however, begun to question the use and the scope of the concept ‘neoliberalism’. In this paper, I identify two common approaches to studying neoliberalism, one exploring neoliberalism as a series of policy networks, the other exploring neoliberalism as the governance of subjectivities. I argue that to understand the urban night, we need to explore both these senses of ‘neoliberalism’. As a case study, I take the ‘Alive After Five’ project, organised by the Business Improvement District in Newcastle-upon-Tyne, which sought to extend shopping hours in order to encourage more people to use the city at night. Drawing from Actor-Network-Theory, I explore the planning, the translation, and the practice of this new project. In doing so, I explore the on-going nature and influence of neoliberal policy on the urban night in the UK

    Policy disconnect: A critical review of UK air quality policy in relation to EU and LAQM responsibilities over the last 20 years

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    © 2018 Elsevier Ltd This paper critically reviews United Kingdom (UK) air quality policy in relation to European and Local Air Quality Management (LAQM) responsibilities over the last 20 years. The arguments articulated in this paper highlight the gulf between national and local air quality management in the UK, including differences in legislation, legal responsibilities, scales of operation, monitoring and modelling requirements, exceedence reporting and action planning. It is argued that local authorities cannot be held responsible for the UK's failure to achieve the European Union (EU) nitrogen dioxide (NO2) limit values due to fundamental differences between local government responsibilities under LAQM and the UK compliance assessment reporting to the EU. Furthermore, unambitious and counterproductive national policies and the failure of EU light-duty vehicle type approval tests and Euro standards to reduce real-world emissions of nitrogen oxides (NOx) are the main reasons for continued NO2 limit value exceedences. This failure of EU and national air quality policies has effectively undermined local authority action to improve local air quality, resulting in delays in achieving the standards, wasted resources at local and national levels, and, ultimately, unnecessary loss of life and increased morbidity in the UK population. This paper concludes that the current emphasis that the UK government is placing on implementation of Clean Air Zones (CAZs) to achieve the Ambient Air Quality Directive (2008/50/EC) (AAQD), and avoid substantial fines imposed by the European Court of Justice (CJEU), is flawed. Based on the arguments presented in this paper, a series of recommendations is proposed for the European Union, the UK government, devolved administrations and local authorities
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