Influence of Reaction Time, Temperature, and Heavy Metal Zinc on Characteristics of Cellulose- and Wood-Derived Hydrochars from Hydrothermal Carbonization

• DOI: 10.1007/s12155-022-10482-6
• Publication Date: 2022-07-25T02:02:26Z
• Authors: Xin Zhao; Jin Huang; Zhaonan Li; Yao Chen; Michael Müller
• Keywords: 13. Climate action; 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology; 7. Clean energy; info:eu-repo/classification/ddc/620; 620

Abstract Hydrothermal carbonization (HTC) is a promising technique to convert biomass into valuable solid fuels. In this work, cellulose and wood-derived hydrochars were synthesized under hydrothermal carbonization conditions with different temperatures (200–250 ℃), reaction times (6 h or 12 h) and to determine their influence on hydrochars. Heavy metal element zinc is chosen to introduce into samples to simulate the heavy metal accumulate in biomass. The physical, chemical, and combustion properties of the hydrochars revealed that the majority of cellulose and wood conversion occurs at first 6 h, and faster conversion occurs at higher temperatures. The content of fixed carbon in the cellulose-derived hydrochar is higher than in wood-derived hydrochar. Moreover, cellulose is easier to be carbonized during HTC reaction than wood. O/C and H/C ratios of all hydrochars were similar to those of lignite and decreased with increasing reaction temperature. The composition of solids recovered after 12 h is similar at all temperatures, consisting primarily of sp2 carbons (furanic and aromatic groups) and alkyl groups. When a large amount of metal is introduced, part of the metal is combined with the energetic group, while the rest condense on the surface of the sample as zinc ions.