Biodiesel from Bark and Black Liquor-A Techno-Economic, Social, and Environmental Assessment

A techno-economic assessment and environmental and social sustainability assessments of novel Fischer-Tropsch (FT) biodiesel production from the wet and dry gasification of biomass-based residue streams (bark and black liquor from pulp production) for transport applications are presented. A typical French kraft pulp mill serves as the reference case and large-scale biofuel-production-process integration is explored. Relatively low greenhouse gas emission levels can be obtained for the FT biodiesel (total span: 16-83 g CO2eq/MJ in the assessed EU countries). Actual process configuration and low-carbon electricity are critical for overall performance. The site-specific social assessment indicates an overall positive social effect for local community, value chain actors, and society. Important social aspects include (i) job creation potential, (ii) economic development through job creation and new business opportunities, and (iii) health and safety for workers. For social risks, the country of implementation is important. Heat and electricity use are the key contributors to social impacts. The estimated production cost for biobased crude oil is about 13 euro/GJ, and it is 14 euro/GJ (0.47 euro/L or 50 euro/MWh) for the FT biodiesel. However, there are uncertainties, i.e., due to the low technology readiness level of the gasification technologies, especially wet gasification. However, the studied concept may provide substantial GHG reduction compared to fossil diesel at a relatively low cost.