Hydrothermal liquefaction of wet biomass in batch reactors: Critical assessment of the role of operating parameters as a function of the nature of the feedstock

Sustainable Resource Recovery from Dairy Waste: A Case Study of Hydrothermal Co-liquefaction of Acid Whey and Anaerobic Digestate Mixture

“…Hydrothermal liquefaction (HTL) is an attractive thermochemical waste reforming process that can be incorporated into CBE systems due to its capability of handling the high moisture content of different types of agricultural and food wastes. , This includes anaerobic digestate produced by anaerobic digestion (AD), allowing HTL to be coupled with the commercially available AD process . HTL benefits from the change of water properties at near-supercritical conditions (280–360 °C and 10–20 MPa), where the ionic product of water increases from 10–14 at 25 °C to 10–12 and 10–11 at 280–360 °C and the dielectric constant of water decreases from 80 at 25 °C to 15 at 360 °C . With these properties, HTL can convert the organic matrix in high-moisture dairy wastes into carbon-rich biocrude oil with low heteroatom content and improved energy recovery and selectively extracts the inorganic nutrients into the aqueous-phase coproduct (HTL-AP) or precipitate them into the solid byproduct called hydro-char. , The near-supercritical water temperature of HTL can also kill pathogens in the dairy waste, yielding a sterilized effluent …”

“…20 HTL benefits from the change of water properties at near-supercritical conditions (280−360 °C and 10−20 MPa), where the ionic product of water increases from 10−14 at 25 °C to 10−12 and 10−11 at 280−360 °C and the dielectric constant of water decreases from 80 at 25 °C to 15 at 360 °C. 18 With these properties, HTL can convert the organic matrix in high-moisture dairy wastes into carbon-rich biocrude oil with low heteroatom content and improved energy recovery and selectively extracts the inorganic nutrients into the aqueous-phase coproduct (HTL-AP) or precipitate them into the solid byproduct called hydro-char. 21,22 The near-supercritical water temperature of HTL can also kill pathogens in the dairy waste, yielding a sterilized effluent.…”

“…Hydrothermal liquefaction (HTL) is an attractive thermochemical waste reforming process that can be incorporated into CBE systems due to its capability of handling the high moisture content of different types of agricultural and food wastes. , This includes anaerobic digestate produced by anaerobic digestion (AD), allowing HTL to be coupled with the commercially available AD process . HTL benefits from the change of water properties at near-supercritical conditions (280–360 °C and 10–20 MPa), where the ionic product of water increases from 10–14 at 25 °C to 10–12 and 10–11 at 280–360 °C and the dielectric constant of water decreases from 80 at 25 °C to 15 at 360 °C .…”

Characterization of Biocrude Produced by Hydrothermal Liquefaction of Municipal Sewage Sludge in a 500 mL Batch Reactor

“…On a laboratory scale, the HTL process is mainly investigated in batch reactors, and several studies have shown that a high heating rate positively affects the yield in biocrude, independently from the nature of the raw material treated. − However, most of the literature is based on HTL experiments performed in very small-scale batch reactors (generally a few mL), not allowing to properly assess the effect of thermal transients, which instead occur on larger scale systems, on product yields and quality. − In addition, small reaction volumes allow effective extraction of the biocrude phase with the use of a low amount of an appropriate extraction solvent, preferably characterized by negligible water solubility and a low boiling point (such as dichloromethane (DCM), ethyl acetate, tetrahydrofuran, or petroleum ether). ,− For scale-up purposes, the quantity of extraction solvent should be minimized for both economic and environmental reasons. In this direction, centrifugation was recently applied to the entire slurry derived from the HTL process carried out in a 140 mL lab-scale batch reactor by Mujahid and co-workers .…”

Hydrothermal liquefaction of sewage sludge: use of HCOOH and KOH to improve the slurry pumpability in a continuously operated plant

“…In recent years, in which the ecological and energetic transitions represent the main challenges that drive the technological development of the industries, the hydrothermal liquefaction (HTL) of biomass is considered a potential advantageous technology for the production of biocrude (BC) as green energy carrier [ 1 , 2 ]. HTL takes place within a temperature range of 300–400 °C and a pressure range of 10–40 MPa [ [3] , [4] , [5] , [6] ]. It is usually conducted using wet feedstocks because the water of the matrix constitutes a solvent and a co-reagent beside being a catalyst of hydrolytic reactions.…”