Biomass multi-stage comminution for entrained-flow gasification process

Entrained-flow gasification is a clean and efficient biomass conversion technology, in which comminution is a critical but energy-consuming process. Multi-stage comminution is proposed to achieve economic operation of biomass gasification. The energy consumption of three representative biomasses (i. e. corn stover, sycamore branch and moso bamboo) was evaluated by employing a target screen size of 1 mm. The results showed that the two-stage milling process reduced the energy of corn stover and sycamore branch by about 27.98 % and 16.84 %, respectively, compared to the single-stage milling process. For moso bamboo, the energy was reduced by only 8.59 %, which is mainly due to the energy consumed for separating and breaking its tough fibers is much higher than that for over-milling. The analysis of energy consumption and particle size can be used to select the operating factors of the hammer mill to produce a suitable size of biomass particles for gasification.