Comparative Life Cycle Assessment Of Pellet Production And Utilization With Different Technical Scenarios

Biomass pellet fuel is a clean and efficient alternative energy of fossil fuels,which has many advantages such as abatement of air pollutant emissions, effective control of haze, reasonable use of agriculture and forestry waste, to promote the adjustment of the energy industry, and to protect national energy security. Biomass pellet has broad industrialization prospect, as an optimal replacement for solid fossil fuel. China has abundant agriculture and forest residues resource to develop large-scale pellet commercialization. To evaluate various environmental impacts of different technical scenarios, life cycle methodology can provide insights into the environmental performances of different technologies and can support the choice of a better domestic pellet large-scale development. Using 1 tonne of biomass pellets as a functional unit, comparative life cycle assessment of pellet production and utilization with different technical scenarios are carried on.(1)The inventory data of raw materials supply logistics, densification stage, transportation to users, pellets combustion and ash disposal were collected and put into conversion and calculation. A method of CML-IA was used in this study to assess the potential environmental impacts generated in the life cycle system of pellet. Ten impact categories including abiotic depletion potential and global warming potential were analyzed. In the single environmental impact, major contributors were fresh water aquatic ecotox potential and photochemical oxidation potential, which account for about 58.3%~67.1% and 9.9%~17.1%, respectively.(2)By using global normalization references and weighting method based on ecotaxes, the LCA single score for the assessed 10 mid-point impact categories of six technical scenarios were evaluated. Different technical scenarios lead to different environmental impacts. By using global normalization references and weighting method based on ecotaxes, the LCA single score for the assessed 10 mid-point impact categories of six technical scenarios were evaluated(10.27~11.11). Different technical scenarios lead to different environmental impact. Scenario 4 has the lowest environmental impact.(3)Sensitivity analysis was carried out to examine the effect of variations in system inputs and outputs. Allocation methods, transport distance and combustion emissions were identified as the key driving forces for impact categories of pellet. Fresh water aquatic ecotox potential and eutrophication potential were reduced by 32.6% and 15.7%, with changing allocation methods.(4)The policy planning of biomass pellet industry development at home and abroad were comparatively analyzed. Technical and non-technical obstacles in the development of national biomass pellet were listed, such as investment and financing, supply chain, and marketing requirement, which can help to build market and infrastructure, determine the development priority and promote the development of straw pellet fuel sustainable vitality.