Development of hydrothermal liquefaction using microalgae for biocrude production

Abstract

Biofuels from biomass are the sustainable low-carbon transport fuels. Microalgae is a newlinepromising renewable biofuel source due to its higher photosynthetic efficiency, growth newlinerate, and oil yield. This study focuses on biofuel production through thermochemical newlineconversion method of hydrothermal liquefaction (HTL) of microalgae. HTL process newlineoccurs at elevated temperatures (200-400 and#870;C) and pressure (5-20 MPa). In which biomass newlineundergo dehydration and decarboxylation reactions to produce the liquid phase, biocrude, newlinesolid residue, and gaseous products. However, many engineering challenges exist for newlinelarge-scale operation of HTL. This work aims to understand the HTL of microalgae for newlinebiocrude production and then optimise the HTL process conditions. newlineIn the literature, process conditions and operating parameters have been studied to newlineimprove biocrude yield from HTL. However, a further step in this field is needed to newlineintensify HTL to enhance energy return and economic aspects. Thus, the present study newline newlineuses process intensification method to HTL, which includes Catalytic HTL, Co- newlineliquefaction, and continuous HTL. Further, the development of kinetic modelling of HTL newline newlineof microalgae for biocrude production and the techno-economic and environmental newlinefeasibility of transportation fuels from HTL at large-scale production are investigated. newlineFinally, the scope and suggestions for future work in this field are presented. newlineThe first study of this work involves catalytic HTL of spirulina platensis using red newline newlinemud as a heterogeneous catalyst. This work was carried out in a batch reactor. Non- newlinecatalytic HTL and catalytic HTL using both red mud and activated red mud at various newline newlineprocess conditions such as temperature (250 350 °C), reaction time (20 60 minutes), newlineslurry concentration (10 30 wt.%) and catalyst-to-biomass ratio (1:2 1:4) were newlineinvestigated.