Hydrothermal liquefaction of high ash containing sewage sludge at sub and supercritical conditions

Co-liquefaction of sewage sludge with wheat straw in supercritical water – potential for integrating hydrothermal liquefaction with wastewater treatment plants

“…Looking at co-liquefaction runs the same trend is observed: a progressive decrease in the biocrude yields is obtained for increasing ratios of straw in the feed. The results are in line with previous studies, where digested SS conversion produced ∼40% biocrude without a catalyst and ∼43% with a catalyst, 27 while the liquefaction of straw led to ∼24% biocrude without a catalyst and 23.5% with a catalyst. 11 Lower biocrude yields from straw compared to SS are related to the different compositions of the two feedstocks and the lower/higher tendency of biomass constituents to convert into biocrude.…”

Hydrochar derived from municipal sludge through hydrothermal processing: A critical review on its formation, characterization, and valorization

“…An acidic environment was found to promote the production of fatty substances, while the formation of N-containing organic compounds and ketone organics was enhanced at alkaline conditions (Liu et al, 2020). The addition of K 2 CO 3 could increase biocrude yield and energy recovery from SS under both subcritical (350 °C for 15 min) and supercritical (400 °C for 15 min) conditions (Shah et al, 2020). However, several studies of HTL and HTG have stated that adding Na 2 CO 3 or K 2 CO 3 had no significant effects on the quality or yield of biocrude (Suzuki et al, 1988;Suzuki and Nakamura, 1989;Wang et al, 2013).…”

“…a HTP = hydrothermal processing; HTC = hydrothermal carbonization; HTL = hydrothermal liquefaction; HTG = hydrothermal gasification; references (Aida et al, 2016;Aragón-Briceño et al, 2017;Berge et al, 2011;Couto et al, 2018;Danso-Boateng et al, 2015;Escala et al, 2013;Fakkaew et al, 2018;Fei et al, 2019aFei et al, , 2019bFeng et al, 2018;He et al, 2019He et al, , 2013Huang et al, 2013Huang et al, , 2014Huang and Tang, 2016;Inoue et al, 1997;Khoshbouy et al, 2019;Lee et al, 2019;Leng et al, 2018Leng et al, , 2015bLi et al, 2010Li et al, , 2012M. Liu et al, 2017;Liu et al, 2018;Liu et al, 2019;Ma et al, 2019aMa et al, , 2019bMishra and Mohanty, 2020;Molton et al, 1986;Nazari et al, 2017;Ovsyannikova et al, 2020;Paneque et al, 2017;Parmar and Ross, 2019;Peng et al, 2016;Qian et al, 2020;Ren et al, 2017;Saetea and Tippayawong, 2013a;Shah et al, 2020;Shao et al, 2015;Shi et al, 2019;Smith et al, 2016;…”

Phosphorus recovery from municipal sludge-derived ash and hydrochar through wet-chemical technology: A review towards sustainable waste management

“…They have significant advantages, such as deodorization, high efficiency, substantial waste volume reduction (~90%), organic pollutants destruction, and pathogen deactivation [19,20]. More importantly, incineration and HTL generated solid residues (i.e., ash and hydrochar, respectively) are concentrated with P (9-13% and 4-13%, respectively) comparable to lowgrade phosphate rock [14,[21][22][23]. A comprehensive assessment considering technological, environmental, and economic aspects has shown that sludge ash could be a more promising source than wastewater and municipal sludge for P recovery (60-90% of total wastewater input) [16].…”