Briquetting of wheat, barley, canola and oat straw

Abstract

Abstract. In order to determine the briquetting characteristics of biomass in a commercial setting, a briquetter from Briquette Systems ((Model BP-100, Chico, CA) was used to study the compaction behavior of biomass chops from wheat, barley, canola and oat straw. The four types of biomass straw were chopped using hammer mill with screen size of 19.05, 25.40 and 31.75 mm. The chopped straw samples were conditioned to three moisture content levels (9%, 12% and 15% (w.b.)). The temperature of the single briquetting outlet was about 50 ±5°C, which was caused by the compression and frictional process. The mass of chops used for each kind of briquette sample was at least 4 kg in order to obtain steady-state operation and reliable process data from the briquetter. The compacted material was pushed ahead along the sleeve and it spent about 6-10 min before being extruded. The specific energy, throughput rate, as well as the density, and durability of manufactured briquettes were measured during or after briquetting. The applied compression pressure at different parameter combination ranged from 7 to 14 MPa. Results showed that higher pressure was caused at higher biomass moisture content. Larger particle size resulted in higher energy consumption and lower throughput rate during briquetting. The increase in moisture content decreased the total energy consumption and increased the throughput rate. The densities of briquettes were consistently of higher value when biomass samples were compressed at a lower moisture level. The moisture content and particle size can indirectly influence the briquette density by affecting the pressure and residence time in commercial briquette production.