An integrated appraisal of energy recovery options in the United Kingdom using solid recovered fuel derived from municipal solid waste.
ABSTRACT This paper reports an integrated appraisal of options for utilising solid recovered fuels (SRF) (derived from municipal solid waste, MSW) in energy intensive industries within the United Kingdom (UK). Four potential co-combustion scenarios have been identified following discussions with industry stakeholders. These scenarios have been evaluated using (a) an existing energy and mass flow framework model, (b) a semi-quantitative risk analysis, (c) an environmental assessment and (d) a financial assessment. A summary of results from these evaluations for the four different scenarios is presented. For the given ranges of assumptions; SRF co-combustion with coal in cement kilns was found to be the optimal scenario followed by co-combustion of SRF in coal-fired power plants. The biogenic fraction in SRF (ca. 70%) reduces greenhouse gas (GHG) emissions significantly ( approximately 2500 g CO(2) eqvt./kg DS SRF in co-fired cement kilns and approximately 1500 g CO(2) eqvt./kg DS SRF in co-fired power plants). Potential reductions in electricity or heat production occurred through using a lower calorific value (CV) fuel. This could be compensated for by savings in fuel costs (from SRF having a gate fee) and grants aimed at reducing GHG emission to encourage the use of fuels with high biomass fractions. Total revenues generated from coal-fired power plants appear to be the highest ( 95 pounds/t SRF) from the four scenarios. However overall, cement kilns appear to be the best option due to the low technological risks, environmental emissions and fuel cost. Additionally, cement kiln operators have good experience of handling waste derived fuels. The scenarios involving co-combustion of SRF with MSW and biomass were less favourable due to higher environmental risks and technical issues.
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ABSTRACT: An integrated appraisal of five technology scenarios for the co-combustion of biosolids in the UK energy and waste management policy context is presented. Co-combustion scenarios with coal, municipal solid waste, wood, and for cement manufacture were subject to thermodynamic and materials flow modeling and evaluated by 19 stakeholder representatives. All scenarios provided a net energy gain (0.58-5.0 kWh/kg dry solids), having accounted for the energy required for transportation and sludge drying. Co-combustion within the power generation and industrial (e.g., cement) sectors is most readily implemented but provides poor water utility control, and it suffers from poor public perception. Co-combustion with wastes or biomass appears more sustainable but requires greater investment and presents significant risks to water utilities. Incongruities within current energy and waste management policy are discussed and conclusions for improved understanding are drawn.Environmental Science and Technology 03/2006; 40(3):649-58. · 5.26 Impact Factor
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ABSTRACT: The project conceived in 1929 by Gardner Murphy and the writer aimed first to present a wide array of problems having to do with five major "attitude areas"--international relations, race relations, economic conflict, political conflict, and religion. The kind of questionnaire material falls into four classes: yes-no, multiple choice, propositions to be responded to by degrees of approval, and a series of brief newspaper narratives to be approved or disapproved in various degrees. The monograph aims to describe a technique rather than to give results. The appendix, covering ten pages, shows the method of constructing an attitude scale. A bibliography is also given.Archives of Psychology. 01/1932; 22:1--55.
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ABSTRACT: Efforts to improve the energy efficiency of waste incineration and biomass combustion plants continue to attract an increasing level of importance as the drive to improve energy efficiency and the security of energy supply continues to gather pace. All renewable sources of energy are important to help minimise the impact of climate change of processes feeding the ever rising worldwide demand for energy. Waste incineration and biomass combustion plants can make important contributions in both the short-to-medium and the long term. In the efforts to utilise these sources as efficiently as possible, a number of materials and process control issues are critical and gaseous and deposit corrosion are frequently limiting factors.This paper describes an integrated approach to the understanding of materials behaviour in waste and biomass boilers. The approach involves monitoring the combustion conditions on the grate of boilers in order to determine flue gas conditions that will have an impact on energy recovery as well as plant performance from the materials perspective. Plant monitoring was also carried out using a cooled process probe whose main purpose was to collect solids from the flue gases of a range of power plants. The deposits were then available for use in laboratory and pilot plant corrosion tests. An innovative process sensor instrument is described. From the materials side, the results of a comprehensive study involving the collection of thermodynamic and kinetic data relevant to boiler materials corrosion, and the building of a model enabling the prediction of corrosion behaviour have been described and used for materials selection. This integrated approach is started to enable more efficient materials studies to be carried out and in the same frame, improvements in plant process control to be achieved.Materials at High Temperatures 12/2007; 24(4):323-332. · 0.34 Impact Factor