Torrefaction of Lawson Cypress Cone Biomass, Bituminous Coal and Their Blends for Industrial Usage

Abstract

Biochar from heat pretreatment of Lawson cypress cone (LCC) biomass, which in this case is a renewable energy source, will enhance its calorific energy value and hydrophobicity to replace coal, a nonrenewable energy source in thermal power plants and metallurgical processes. As such, some associated adverse effects of using coal (viz., bituminous coal, BC), including emissions, costs and availability are to some extent, checked. For that reason, the present study aimed at subjecting 20 m particle size BC, LCC and their equal, 3:1 and 1:3 blends (in form of Samples I-V) to torrefaction in a retort furnace between 0-225 min and 0-300 to produce char whose respective mass yields, energy density, fixed carbon content and weight loss would enable their selection for particular industrial application. In terms of optimal torrefaction temperature and residence time in the furnace, Sample I-V in that order, are the best. Due to 13.3 g low weight loss or 13.3% low mass yield of sample V (i.e. 100% LCC), it is suitable for co-firing bioenergy plant. The blends can go into thermal power plants, filtration and metallurgical processes due to their higher energy density and improved combustion characteristics, as obtained in this study. Therefore, LCC is an important biomass that needs to be characterize further for specific utilization to produce biochar of specific grade and industrial usage.