Life cycle cost and economic assessment of biochar-based bioenergy production and biochar land application in Northwestern Ontario, Canada

摘要

Background:Replacement of fossil fuel based energy with biochar-based bioenergy production can help reduce greenhouse gas emissions while mitigating the adverse impacts of climate change and global warming.However,the production of biochar-based bioenergy depends on a sustainable supply of biomass.Although,Northwestern Ontario has a rich and sustainable supply of woody biomass,a comprehensive life cycle cost and economic assessment of biochar-based bioenergy production technology has not been done so far in the region.Methods:In this paper,we conducted a thorough life cycle cost assessment(LCCA) of biochar-based bioenergy production and its land application under four different scenarios:1) biochar production with low feedstock availability;2) biochar production with high feedstock availability;3) biochar production with low feedstock availability and its land application;and 4) biochar production with high feedstock availability and its land application-using SimaPro~,EIOLCA~ software and spreadsheet modeling.Based on the LCCA results,we further conducted an economic assessment for the break-even and viability of this technology over the project period.Results:It was found that the economic viability of biochar-based bioenergy production system within the life cycle analysis system boundary based on study assumptions is directly dependent on costs of pyrolysis,feedstock processing(drying,grinding and pelletization) and collection on site and the value of total carbon offset provided by the system.Sensitivity analysis of transportation distance and different values of C offset showed that the system is profitable in case of high biomass availability within 200 km and when the cost of carbon sequestration exceeds CAD $60 per tonne of equivalent carbon(CO_2e).Conclusions:Biochar-based bioenergy system is economically viable when life cycle costs and environmental assumptions are accounted for.This study provides a medium scale slow-pyrolysis plant scenario and we recommend similar experiments with large-scale plants in order to implement the technology at industrial scale.