Life-Cycle Assessment of coal-biomass based electricity in Chile: Focus on using raw vs torrefied wood

In this article, the environmental impacts associated to cofiring coal with forest biomass for electricity production in Chile are analyzed for: (i) untreated pine pellets and (ii) torrefied-pretreated pine pellets. Results show that energy production from cofiring coal/untreated wood pellets or coal/torrefied pellets, featured significant reductions in environmental impacts, as compared with pure coal plants. Indeed, reductions in acidification (28-26%), abiotic depletion (15-7%), eutrophication potential (15-12%), global warming potential (16-6%), photochemical oxidation (28-23%), human toxicity (17-15%), terrestrial ecotoxicity (12-9%), and marine aquatic ecotoxicity (17-15%) were obtained when untreated or treated pellets were used as a substitute for coal. Moreover, the environmental profile of torrefied pine evidenced its low impact per energy unit, in most of the studied categories except for eutrophication and marine aquatic ecotoxicity, for which the harvesting, logistic chain and torrefaction processes were the most important contributors.