Life cycle assessment of an integrated forest biorefinery: hot water extraction process case study

Abstract

AbstractThe environmental footprint of bioproducts depends on the performance and implementation strategy of the biorefinery processes through which they are produced. Life cycle assessment (LCA) studies are categorized into two general types: attributional and consequential. The consequential life cycle assessment (CLCA) method illustrates the change of flows to and from environment, resulting from different potential decisions. Depending on the analysis goal, CLCA is known to be the proper approach to address the environmental analysis of integrated biorefineries with multiple bioproducts.In this study, an LCA of hot water extraction‐based biorefinery strategy was performed, including five production pathways. Defined process options consisted of an extraction of hemicellulose to produce (i) biogas, (ii) hemicellulose for animal feed, (iii) hemicellulose for C5‐sugars, (iv) C5‐sugars, and (v) furfural. Except for the “biogas”, acetate salt was the by‐product of all the process options. Consequential LCA results proved that the bark consumption, chemicals, and bioproducts transportation have significant environmental impacts. ‘Hemicellulose for C5‐sugars’ and ‘C5‐sugars’ outperformed other alternative options with a greenhouse gas reduction of 80% and 68%, respectively. Also, normalized results of these two options presented remarkable improvement of more than three times in human health impacts in comparison to existing process at the case study mill. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd