Hydrothermal carbonization of agricultural residues: A case study of the farm residues -based biogas plants

Hydrothermal carbonization (HTC) of biomass isa promising method to produce carbonaceous materials. The work presented in this article addresses the application of hydrothermal carbonization (HTC) to produce a solid fuel named HTC-Biochar, whose characteristics are comparable to lignite coal. Biogas sludge (SD), maize silage (MS), and barley silage (BS) as a substrates were hydrothermally carbonized in a 1.5 L batch reactor at 200 ??C for 6 h. The effect of mixing ratios of different substrates on HTC was investigated. Chemical compositions and combustion characteristics of hydro-chars obtained from mono- and co-carbonization were evaluated. Result showed that HTC increased carbon contents and higher heating values (HHV) by 1.4???14.4% and 13???36%, respectively. The evolution of the H/C and O/C atomic ratios indicated that dehydration and decarboxylation occurred during hydrothermal carbonization for all samples. Furthermore, a significant synergistic enhancement was observed for HHV and carbon content. A mixing ratio of 1:1 for BS and SD showed the best performance for co-HTC. In summary, hydrothermal co-carbonization is a promising strategy to tailor high-performance hydro-char for energy applications. ?? 2018 The Authors. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-ncnd/4.0/).