Preparation and Characteristics of Biomass Gel Foam with High Foaming and Film-Forming Properties for Preventing Coal Spontaneous Combustion

ABSTRACTTo overcome the problem of poor biocompatibility of inorganic gel foam, a biomass gel foam was prepared using carboxymethyl chitosan, tannic acid, and ammonium ferric citrate as raw materials. The results indicated that the gel foam exhibited optimal comprehensive performance when the mass concentrations of foaming agent, stabilizer, gelling agent, and crosslinking agent were 0.8, 0.2, 0.9, and 0.6 wt%, respectively. At this point, the foaming multiple was up to 8 and the half-life was 7.79 days. Compared to pure foam, the gel foam demonstrated excellent water retention and film-forming properties. After continuous heating at 80°C for 10 hours, its water retention rate remained as high as 49.34%. The foam film formed after 120 hours of room temperature drying reached a thickness of 1 cm without any liquid separation phenomenon. The gel foam exhibited a good inhibition effect on the spontaneous combustion and oxidation process of coal. The CO inhibition rate reached 67.43% at 100°C, and the cross-point temperature was effectively delayed by 18.2°C. Moreover, the gel foam exhibited excellent burn resistance properties.KEYWORDS: Biomassgel foamcoal spontaneous combustionfoaming multiplewater retention propertyfilm-forming property AcknowledgementsThis work was supported by the National Natural Science Foundation of China [52074011]; Key Research and Development Projects in Anhui Province [2022i01020016]; Outstanding Youth Scientific Research Project in Anhui Province [2022AH020055]; University Synergy Innovation Program of Anhui Province [GXXT-2022-018].Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementData will be made available on request.Credit author statementShibin Nie: Methodology, Funding acquisition, Project administration, Writing-Reviewing and Editing. Zhentao Cai: Conceptualization, Formal analysis, Data curation, Writing-Original draft preparation. Dong Hu: Project administration, Supervision. Chao Han: Investigation, Writing-Reviewing and Editing.Additional informationFundingThis work was supported by the National Natural Science Foundation of China [52074011]; Key Research and Development Projects in Anhui Province [2022i01020016]; University Synergy Innovation Program of Anhui Province [GXXT-2022-018]; outstanding Youth Scientific Research Project in Anhui Province [2022AH020055].