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McNamee, P.; Adams, P.W.R.; McManus, M.C.; Dooley, B.; Darvell, L.I.; Williams, A.; Jones, J.M. (2016)
Publisher: Elsevier BV
Journal: Energy Conversion and Management
Languages: English
Types: Article
Subjects: Energy Engineering and Power Technology, Renewable Energy, Sustainability and the Environment, Nuclear Energy and Engineering, Fuel Technology
Bioenergy is increasingly being used to meet EU objectives for renewable energy generation and reducing greenhouse gas (GHG) emissions. Problems with using biomass however include high moisture contents, lower calorific value and poor grindability when compared to fossil fuels. Torrefaction is a pre-treatment process that aims to address these issues. In this paper four torrefaction treatments of pine were performed and a mass–energy balance calculated. Using experimental data, a pellet production supply chain incorporating torrefaction was modelled and compared to an existing wood pellet system to determine life-cycle GHG emissions. Two utility fuels, wood chips and natural gas, were considered to provide process heat in addition to volatile gases released during torrefaction (torgas). Experimental results show that torrefaction reduces the moisture content and increases the calorific value of the fuels. Increasing torrefaction temperature and residence time results in lower mass and energy yields. GHG emissions reduce with increasing torrefaction severity. Emissions from drying & torrefaction and shipping are the highest GHG contributors to the supply chain. All 4 torrefaction conditions assessed outperformed traditional wood pellet supply chain emissions but more land is required which increases with temperature and residence time. Sensitivity analysis results show that emissions increase significantly where natural gas is used for utility fuel and no torgas is utilised.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • [1] European Commission. Directive 2009/28/EC of the European Parliament and of the council of 23 April 2009 on the promotion of the use of energy from renewable sources and amending and subsequently repealing directives 2001/ 77/EC and 2003/30/EC; 2009.
    • [2] European Commission. A policy framework for climate and energy in the period from 2020 to 2030. CM (2014) 15 final. Brussels; 2014.
    • [3] Lockwood M. The political sustainability of climate policy: the case of the UK Climate Change Act. Glob Environ Change 2013;23(5):1339-48.
    • [4] DECC. UK bioenergy strategy; 2012.
    • [5] DECC. 2014 UK greenhouse gas emissions, provisional figures. London; 2015.
    • [6] Lamers P et al. Developments in international solid biofuel trade - an analysis of volumes, policies, and market factors. Renew Sustain Energy Rev 2012;16 (5):3176-99.
    • [7] Ofgem. Renewables obligation: sustainability criteria guidance. Office for Gas and Electricity Markets; 2014.
    • [8] Ofgem. Biomass sustainability report 2013-14 dataset annual profiling information. London: Office of Gas and Electricity Markets; 2015.
    • [9] Uslu A, Faaij APC, Bergman PCA. Pre-treatment technologies, and their effect on international bioenergy supply chain logistics. Techno-economic evaluation of torrefaction, fast pyrolysis and pelletisation. Energy 2008;33(8):1206-23.
    • [10] Adams PWR, Shirley J, Whittaker C, Shield I, Darvell LI, Jones JM, McManus MC. Integrated assessment of the potential for torrefied wood pellets in the UK electricity market. In: World bioenergy 2014 conference, Jönköping, Sweden; 2014.
    • [11] National Non-Food Crops Centre (NNFCC). Techno-economic assessment of biomass densification technologies. Project 08-015. York; 2008.
    • [12] Ofgem. Annual sustainability report 2011-2012. London: Ofgem; 2012.
    • [13] Jarvinen T, Agar D. Experimentally determined storage and handling properties of fuel pellets made from torrefied whole-tree pine chips, logging residues and beech stem wood. Fuel 2014;129:330-9.
    • [14] Bergman P, et al. Torrefaction for biomass co-firing in existing coal-fired power stations: BIOCOAL. ECN report. Renewable energy in the Netherlands. ECN-C05-013; 2005.
    • [15] Tumuluru JS et al. A review of biomass densification systems to develop uniform feedstock commodities for bioenergy application. Biofuels Bioprod Biorefin-Biofpr 2011;5(6):683-707.
    • [16] van der Stelt MJC et al. Biomass upgrading by torrefaction for the production of biofuels: a review. Biomass Bioenergy 2011;35(9):3748-62.
    • [17] Koppejan J, Sokhansank S, Jess J, Wright C, Boardman R. Status overview of torrefaction technologies. Enschede: International Energy Agency (IEA); 2012.
    • [18] Adams PWR, Shirley JEJ, McManus MC. Comparative cradle-to-gate life cycle assessment of wood pellet production with torrefaction. Appl Energy 2015;138:367-80.
    • [19] Stelte W, Sanadi AR, Shanf L, Holm JK, Ahrenfeldt J, Henrikson UB. Recent developments in biomass pelletization - a review. BioResources 2012;7(3).
    • [20] Bridgeman TG et al. An investigation of the grindability of two torrefied energy crops. Fuel 2010;89(12):3911-8.
    • [21] C.E.N Standard, BS EN 15148:2009. Solid biofuels - determination of the content of volatile matter; 2009.
    • [22] C.E.N Standard, BS EN 14775:2009. Solid biofuels - determination of ash content; 2009.
    • [23] C.E.N Standard, BS EN 14774-3:2009. Solid biofuels - determination of the moisture content; 2009.
    • [24] C.E.N Standard, BS EN 15104: 2011. Solid biofuels - determination of total content of carbon, hydrogen and nitrogen - instrumental methods; 2011.
    • [25] C.E.N Standard, BS EN 14918: 2009. Solid biofuels - determination of calorific value; 2009.
    • [26] Van Loo S, Koppejan J. The handbook of biomass combustion & cofiring. London: Earthscan; 2008.
    • [27] Advanced Fuel Research. User's guide to the FG-biomass pyrolysis model - version 10.0.15 for Windows; 2013.
    • [28] Basu P. Biomass gasification, pyrolysis and torrefaction: practical design and theory. Elsevier; 2013.
    • [29] International Standards Organisation (ISO). Environmental management - life cycle assessment - principles and framework. 2nd ed., EN ISO 14040. Geneva; 2006.
    • [30] International Standards Organisation (ISO). Environmental management - life cycle assessment - requirements and guidelines. 2nd ed., EN ISO 14044. Geneva; 2006.
    • [31] European Commission. Sustainability requirements for the use of solid and gaseous biomass sources in electricity, heating and cooling. Brussels; 2010.
    • [32] Enviva. Enviva Pellets Amory, Enviva LP, Bethesda, USA; 2015. Available from: .
    • [33] Forest Research. Understanding the carbon and greenhouse gas balance of forests in Britain. Edinburgh; 2012.
    • [34] Adams PWR, Bows A, Gilbert P, Howard D, Lee R, McNamara N, et al. Understanding greenhouse gas balances of bioenergy systems. Supergen Bioenergy Hub; 2013.
    • [35] Forestry Commission. C-sort model. Edinburgh: Forestry Commission; 2012.
    • [36] Hamelinck CN, Suurs RAA, Faaij APC. International bioenergy transport costs and energy balance. Biomass Bioenergy 2005;29(2):114-34.
    • [37] European Commission. Well-to-wheels analysis of future automotive and powertrains in the European Context Luxembourg.
    • [38] Centre BE. Typical calorific value of fuels; 2015. Available from: .
    • [39] Biograce II. Harmonised greenhouse gas calculations for electricity, heating and cooling for biomass; 2015. Available from: .
    • [40] Stelte W et al. Pelletizing properties of torrefied wheat straw. Biomass Bioenergy 2013;49:214-21.
    • [41] DEFRA. Government GHG conversion factors for company reporting. London: Department for Environment, Food & Rural Affairs (DEFRA); 2015. Available from: .
    • [42] IEA-ETSAP and IRENA. Biomass Co-Firing: Technology Brief; 2013.
    • [43] Forestry Commission. Understanding the carbon and greenhouse gas balance of forests in Britain. Edinburgh; 2012.
    • [44] Edwards R, Larive JF, Beziat JC. Well-to-wheels analysis of future automotive fuels and powertrains in the European Context. Luxembourg; 2011.
    • [45] Biomass Energy Centre. Typical calorific value of fuels. Taken from .
    • [46] Ofgem. The UK solid and gaseous biomass carbon calculator; 2012. Available from: .
    • [47] Defra, Environmental Agency, AEA and North Energy. Biomass Environmental Assessment Tool (BEAT2), AEA & North Energy; 2008. Available from: .
    • [48] Bergman PCA, et al. Torrefaction for biomass co-firing in existing coal-power stations. ECN biomass; 2005. p. 1-71.
    • [49] Ibrahim RHH et al. Physicochemical characterisation of torrefied biomass. J Anal Appl Pyrolysis 2013;103:21-30.
    • [50] Bridgeman TG et al. Torrefaction of reed canary grass, wheat straw and willow to enhance solid fuel qualities and combustion properties. Fuel 2008;87 (6):844-56.
    • [51] Medic D et al. Effects of torrefaction process parameters on biomass feedstock upgrading. Fuel 2012;91(1):147-54.
    • [52] Demirbas A. Relationships between lignin contents and fixed carbon contents of biomass samples. Energy Convers Manage 2003;44(9):1481-6.
    • [53] Prins MJ, Ptasinski KJ, Janssen F. Torrefaction of wood - Part 2. Analysis of products. J Anal Appl Pyrolysis 2006;77(1):35-40.
    • [54] Ofgem. Renewables obligation: sustainability criteria. London: Ofgem; 2014.
    • [55] McKechnie J et al. Forest bioenergy or forest carbon? Assessing trade-offs in greenhouse gas mitigation with wood-based fuels. Environ Sci Technol 2011;45(2):789-95.
    • [56] Ter-Mikaelian MT et al. Carbon debt repayment or carbon sequestration parity? Lessons from a forest bioenergy case study in Ontario, Canada. Glob Change Biol Bioenergy 2015;7(4):704-16.
    • [57] Nave LE et al. Harvest impacts on soil carbon storage in temperate forests. For Ecol Manage 2010;259(5):857-66.
    • [58] Röder M, Whittaker C, Thornley P. How certain are greenhouse gas reductions from bioenergy? Life cycle assessment and uncertainty analysis of wood pellet-to-electricity supply chains from forest residues. Biomass Bioenergy 2015;79:50-63.
    • [59] Haberl H et al. Correcting a fundamental error in greenhouse gas accounting related to bioenergy. Energy Policy 2012;45:18-23.
    • [60] Cherubini F et al. Energy- and greenhouse gas-based LCA of biofuel and bioenergy systems: key issues, ranges and recommendations. Resour, Conserv Recycl 2009;53(8):434-47.
    • [61] Stelte W et al. Pelletizing properties of torrefied spruce. Biomass Bioenergy 2011;35(11):4690-8.
    • [62] Li H et al. Pelletization of torrefied sawdust and properties of torrefied pellets. Appl Energy 2012;93:680-5.
    • [63] Larsson SH et al. Effects of moisture content, torrefaction temperature, and die temperature in pilot scale pelletizing of torrefied Norway spruce. Appl Energy 2013;102:827-32.
    • [64] Bergman PCA. Combined torrefaction and pelletisation: the TOP process. Petten: ECN; 2005.
    • [65] Batidzirai B et al. Biomass torrefaction technology: techno-economic status and future prospects. Energy 2013;62:196-214.
    • [66] European Commission. Directive 2001/80/EC of the European Parliament and of the council of 23 October 2001 on the limitation of emissions of certain pollutants into the air from large combustion plants. The European Parliament and the council of the European Union, Editor; 2001.
    • [67] Djomo SN et al. Impact of feedstock, land use change, and soil organic carbon on energy and greenhouse gas performance of biomass cogeneration technologies. Appl Energy 2015;154:122-30.
    • [68] Stephenson AL, MacKay DJC. Life cycle impacts of biomass electricity in 2020: scenarios for assessing the greenhous gas impacts and energy input requirements of using North American woody biomass for electricity generation in the UK. London: Department of Energy & Climate Change; 2004.
    • [69] Harris ZM, Spake R, Taylor G. Land use change to bioenergy: a meta-analysis of soil carbon and GHG emissions. Biomass Bioenergy 2015.
    • [70] Wihersaari M. Evaluation of greenhouse gas emission risks from storage of wood residue. Biomass Bioenergy 2005;28(5):444-53.
    • [71] He X et al. Dry matter losses in combination with gaseous emissions during the storage of forest residues. Fuel 2012;95(1):662-4.
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