Article

An integrated appraisal of energy recovery options in the United Kingdom using solid recovered fuel derived from municipal solid waste. Waste Manage (Oxford)

Sustainable Systems Department, School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK.
Waste Management (Impact Factor: 3.22). 06/2009; 29(8):2289-97. DOI: 10.1016/j.wasman.2009.03.031
Source: PubMed

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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Available from: Phil Longhurst, Nov 19, 2014
    • "Garg et al. (2009) and Cimpan and Wenzel (2013) have added evidence of the fact that SRF co-combustion in cement kilns yields favourable results compared to other energy recovery pathways. In particular Garg et al. (2009) used energy and mass flow measurements , a semi-quantitative risk analysis, an environmental assessment and a financial assessment to demonstrate that SRF cocombustion with coal in cement kilns is the optimal among four different co-combustion scenarios. The low technological risks and the good experience of cement kiln operators in handling waste derived fuels were also mentioned as favourable conditions. "
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    ABSTRACT: The paper describes the performances of the energy recovery pathway from the residual waste based on the production of a Solid Recovered Fuel (SRF) to be exploited via co-combustion in a cement kiln. The SRF is produced in a single stream Mechanical-Biological Treatment plant, where bio-drying of the waste is followed by mechanical refining in order to fulfil the quality requirements by the cement kilns. Peculiar of this MBT is the fact that sorting residues are disposed in a nearby landfill, managed according to a bioreactor approach, where landfill gas is collected for electric energy recovery. A detailed mass and energy balance of the system is presented based on one year operational data, followed by its Life Cycle Assessment. Results show that the system is energetically and environmentally effective, with most of the impacts being more than compensated by the savings of materials and energy. Major role in determining such outcome is the displacement of petcoke in the cement kiln, both in terms of its fossil CO2 emissions and of its life cycle impacts, including the trans-oceanic transport. To check the robustness of the results, two sensitivity analyses are performed on the landfill gas collection efficiency and on the avoided electric energy mix.
    No preview · Article · Oct 2015 · Waste Management
    • "Finally, mono-combustion plants may be an interesting option for SRF presenting a lower quality (Velis et al., 2010). It has to be stressed that the choice of the final SRF user is greatly affected by local waste management strategies and market policies, as well as by public acceptance, especially in the case of waste-to-energy plants (Garg et al., 2009;Psomopoulos, 2014). In Italy, end of waste (EoW) criteria to qualify SRF as a fuel were introduced by the Italian Ministerial Decree 22 (2013). "
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    ABSTRACT: This work assessed the quality in terms of solid recovered fuel (SRF) definitions of the dry light flow (until now indicated as refuse derived fuel, RDF), heavy rejects and stabilisation rejects, produced by two mechanical biological treatment plants of Rome (Italy). SRF classification and specifications were evaluated first on the basis of RDF historical characterisation methods and data and then applying the sampling and analytical methods laid down by the recently issued SRF standards. The results showed that the dry light flow presented a worst SRF class in terms of net calorific value applying the new methods compared to that obtained from RDF historical data (4 instead of 3). This lead to incompliance with end of waste criteria established by Italian legislation for SRF use as co-fuel in cement kilns and power plants. Furthermore, the metal contents of the dry light flow obtained applying SRF current methods proved to be considerably higher (although still meeting SRF specifications) compared to those resulting from historical data retrieved with RDF standard methods. These differences were not related to a decrease in the quality of the dry light flow produced in the mechanical-biological treatment plants but rather to the different sampling procedures set by the former RDF and current SRF standards. In particular, the shredding of the sample before quartering established by the latter methods ensures that also the finest waste fractions, characterised by higher moisture and metal contents, are included in the sample to be analysed, therefore affecting the composition and net calorific value of the waste. As for the reject flows, on the basis of their SRF classification and specification parameters, it was found that combined with the dry light flow they may present similar if not the same class codes as the latter alone, thus indicating that these material flows could be also treated in combustion plants instead of landfilled. In conclusion, the introduction of SRF definitions, classification and specification procedures, while not necessarily leading to an upgrade of the waste as co-fuel in cement kilns and power plants, may anyhow provide new possibilities for energy recovery from waste by increasing the types of mechanically treated waste flows that may be thermally treated. Copyright © 2015. Published by Elsevier Ltd.
    No preview · Article · Aug 2015 · Waste Management
    • "Essentially SRF is a heterogeneous product processed into homogenous mixture where an understanding of the composition and energy potential would present a number of benefits such as customer confidence, operator control and process monitoring. SRF being a low emission fuel produced by mechanical biological treatment (MBT) from MSW has high biomass fraction and also available at much lower cost or zero cost, has a significant potential as an alternate to conventional fossil fuel (Cozens, 2004; Garg et al., 2009; Velis et al., 2012). In Europe the demand for SRF and its standardization is increasing, with a European standard method in place (European Committee for Standardisation, 2006a). "
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    ABSTRACT: An experimental study was completed using a previously developed and innovative image analysis approach, which has been applied here to shredded waste materials representative of waste-derived fuels. Waste components were collected from source-segregated recycling containers and shredded to <150mm. These materials were then used to produce 3× samples of different composition. The samples were spread to represent materials on a conveyor belt, and multiple images of each sample were captured using 10×10cm and 20×20cm quadrats. The images were processed using ERDAS Imagine software to determine the area covered by each waste component. This coverage was converted into a mass using density data determined as part of this study, yielding a determined composition which was then compared with the known composition of the samples. The image analysis results indicated a strong correlation with the actual values (mean r=0.89). The area coverage of the sample (10×10cm or 20×20cm) contributes to the accuracy as the dot-grid approach used with the particle size within the samples may result in components not being sufficiently monitored. This manuscript presents initial results of the application of an adapted innovative image-based method, and critically assesses how the technique could be improved and developed in the future. Copyright © 2015 Elsevier Ltd. All rights reserved.
    No preview · Article · Mar 2015 · Waste Management
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