Hydrothermal liquefaction of wood wastes in a concentrating solar plant: A techno-economic analysis

Abstract

This paper reports the simulation and techno-economic analysis of a hydrothermal liquefaction (HTL) solar plant for bio-oil production from forestry residues. The HTL solar plant is designed to process 1 ton of biomass daily. The heat required by the HTL process is provided by a parabolic trough solar collector field and a natural gas boiler to allow continuous operation. The annual simulation of the thermal performance of the plant is carried out using the TRNSYS software. The considered location is Temixco, México, and a Typical Meteorological year is used to characterize the site's climate. The bio-oil yield is calculated by a kinetic model that considers the biomass's composition and the slurry's temperature. An economic model is implemented that includes the costs involved and helps determine the bio-oils minimum selling price for the system's financial viability. The obtained yields of biogas, bio-oil, biochar, and organic aqueous phase are 13.3, 29.4, 13.6, and 42.9 wt%, respectively. The minimum fuel sale price (MFSP) for the annual production obtained is estimated between $1.27 and USD 1.55/kg. Eliminating transportation costs, the value of MFSP was assessed in a range of $0.89 to USD 1.09/kg. The results show that integrating concentrated solar thermal technology for processing lignocellulosic waste from the sawmill industry may be an attractive, viable, and sustainable option for producing biofuels, with potential application in countries with high availability of forest biomass, such as Mexico.