Hydrogen-rich syngas production from sewage sludge and hydrochars via catalytic gasification with SrO
Małgorzata Sieradzka, Klaudia Czerwińska, Maciej Śliz, Izabela Kalemba–Rec, Kamil Kornaus, Janusz A. Koziński, Małgorzata Wilk
Abstract
This study investigates the production of high-quality syngas from sewage sludge and its hydrochars through gasification and catalytic gasification processes. The following types of sludge were analyzed: digested (MS1) and non-digested (MS2) municipal sludge from Silesian wastewater treatment plants (WWTPs) and two industrial sludge hydrochars (HC_IS1, HC_IS2). Hydrochars (HC_MS1, HC_MS2, HC_IS1, HC_IS2) were derived via hydrothermal carbonization at 200 °C and 2 h. Gasification and catalytic gasification processes with SrO were conducted under a CO 2 atmosphere at 850 °C. Gas chromatography was employed to identify syngas components, including H 2 , CH 4 , CO 2 , and CO. The results demonstrated that the presence of a catalyst significantly increased hydrogen (H 2 ) yield, particularly during the heating stage. For instance, hydrogen increased from 4 % to 21.7 % for HC_MS1, although with HC_MS2 no hydrogen was found until the addition of a catalyst, SrO, which increased hydrogen to 7.6 %. The findings confirm the potential of gasification for syngas production from sewage sludge and hydrochars. • Hydrochar is potential feedstock for hydrogen production via gasification. • H 2 -rich syngas is produced from sewage sludge and hydrochars via gasification. • Catalytic gasification with SrO in CO 2 atmosphere at 850 °C boosted H 2 yield. • Presence of SrO significantly increased H 2 yield.