Hydrothermal Processing

A techno-economic review of thermochemical cellulosic biofuel pathways

“…Solvent liquefaction is the processing of biomass in a pressurized solvent at elevated temperatures to directly produce liquid products (Elliott, 2011). Under relatively mild conditions the products are sugars and partially deconstructed lignin.…”

Treatment technologies for urban solid biowaste to create value products: a review with focus on low- and middle-income settings

“…Direct biomass liquefaction applied to coal has been an active research topic since the first Arab oil embargo in the 1970s (Elliott 2011). Low oil prices influences the research characterized by rather shortterm projects, a lack of cooperation and exchange of knowledge, and problems finding capital for commercial size plants (Toor et al 2011).…”

“…The high temperature is needed to initiate pyrolytic mechanisms in the bio-polymers, and the pressure has to be high enough to maintain a liquid water processing phase (Elliott 2011). HTL exploits the properties of superheated fluids to reduce mass transfer resistances, whereas the high pressure enables higher penetration of the solvent into the biomass structure to facilitate fragmentation of biomass molecules (Ramirez et al 2015).…”

“…Introduction Hydrothermal liquefaction (HTL), also known as direct liquefaction, implies processing of biomass in a hot, highly pressurized water environment for sufficient time to break down the solid biopolymeric structure into mainly liquid components called bio-oil or bio-crude (Elliott 2011;Elliott et al 2015;Peterson et al 2008). Water is an important reactant and catalyst, and thus wet biomass can be directly converted without an energy consuming drying step (Arturi et al 2016;Toor et al 2011;Xue et al 2016).…”

“…This causes a number of disadvantages, such as a relatively high water content, corrosive properties, and thermal instability etc. The oil product can be upgraded through catalytic hydro-processing, primarily to remove oxygen (Elliott 2011;Toor et al 2011) but this will increase production costs. A review of the available upgrading technologies and how they can be used to convert HTL bio-crude into a transportation fuel that meets current fuel property standards can be found in Ramirez et al (2015).…”