Analysis of biomass hydrothermal liquefaction and biocrude-oil upgrading for renewable jet fuel production: The impact of reaction conditions on production costs and GHG emissions performance

This paper shows a detailed analysis of a biomass HTL process by considering changes in three main reaction variables (i.e. catalysts (water, Na2CO3(aq.), and Fe(aq.)), temperature (280-340 degrees C), and catalysts/biomass mass ratio (0-0.33 kg catalysts/kg biomass)), and by assessing their influence on the techno-economic and GHG emissions performance. This analysis is based on Aspen Plus simulations, process economics and life-cycle GHG assessment on SimaPro (using Ecoinvent 2.2). Results showed that the lowest production cost for biocrude oil is achieved when HTL is performed at 340 degrees C with Fe as catalyst (450 (sic)/tbiocrude-oil or 13.6 (sic)/GJ(biocrude-oil)). At these conditions, the biocrude oil produced has an oxygen content of 16.6 wt%, and a LHV of 33.1 Mj/kg(biocrude-oil). When the hydrotreatment and hydrogen generation units are included, the total production costs was 1040 (sic)/tupgraded-oil or 0.8 (sic)/Lupgraded-oil. After fractionation, the estimated production cost was 1086 (sic)/t(biojet-fuel) or 25.1 (sic)/GJ(biojet-fuel). This value is twice the commercial price of fossil jet fuel. However, the allocated life cycle GHG emissions for renewable jet fuel were estimated at 13.1 kgCO(2-eq)/Gh(biojet-fuel), representing only 15% the GHG emission of fossil jet fuel and therefore, indicating a significant potential on GHG emission reduction. (C) 2017 The Authors. Published by Elsevier Ltd.