Experimental and numerical investigation on pyrolysis and combustion behavior of biomass bast fibers: Hemp, flax and ramie fibers

Abstract

As an important renewable biomass material, bast fiber of crops has various application values. However, its flammable and decomposable characteristics bring challenges to its storage and practical applications. In this work, a steady-state tube furnace (SSTF) was built independently. And the pyrolysis and combustion behavior of three typical bast fibers: hemp, flax, and ramie were systematically studied. Among them, the total heat release of hemp and ramie was about 49.4 % higher than that of flax. And the average CO content of flax and ramie were 35.2 % and 39.5 % lower than hemp, respectively. Data-based fire hazard assessment illustrated that the hemp had the highest fire hazard. A Genetic Algorithm (GA)-based four-step reaction model was proposed and accurately predicted the pyrolysis process of bast fibers (F_dev≤0.016). Furthermore, the pyrolysis products of bast fibers were studied based on TG-FTIR and PY-GC-MS. On this basis, the possible production mechanism of pyrolysis products was proposed. This work will provide a reference for research on pyrolysis and combustion of biomass.