木屑高温水蒸气气化制备富氢燃气的特性研究

摘要

Steam gasification experiments of sawdust for production of hydrogen-rich gas were earned out in a high-temperature bench-scale fixed bed reactor without catalyst. The effects of material 3 g, temperature (750-1050℃) and steam flow rate (0-1. G/min) on the gas components, hydrogen yield, low heating value (QLHV) of gas and other evaluations for gasification were investigated. The results indicated that the temperature and steam flow rate had great effect on the fuel gas components. The yield of hydrogen was promoted by increasing the temperature and introduction of proper steam. However, heating value of product was decreased with the increasing amount of steam at high temperature. As the temperature was 1000℃ and steam flow rate was 1. 02 g/min, the hydrogen content reached the maximum, up to 51.03 % . Besides, the maximum hydrogen yield was 71.08 g/kg(dry basis), which was 41. 32% of the theoretical maximum yield of 172.02 g/kg(dry basis) for this feedstock. The optimal flow rate of steam was 1.02 g/min at 850℃. Over the range of the experimental conditions used, the LHV of the fuel gas was between 11 and 13 MJ/m3. The experimental results proved that high-temperature steam gasification is an effective methodology for hydrogen-rich gas production using biomass as feedstock.%在高温固定床反应器内,无催化剂作用下,进行了木屑高温水蒸气气化制取富氢燃气的特性研究.实验主要研究3g原料,反应温度(750～1050 ℃)及水蒸气流量(0～1.5g/min)对燃气组分、产氢率、燃气热值(QLHV)等气化过程评价指标的影响.实验结果表明:反应温度和水蒸气流量对燃气组分影响很大,较高的反应温度和加入适量的水蒸气有利于氢气的产生,但随着反应温度的升高和水蒸气流量的增加会使燃气热值降低.在1000℃时,水蒸气流量为1.02 g/min时,燃气中氢气体积分数可达51.03％,产氢率为71.08 g/kg(以干燥基计,下同),为理论最大产氢率(172.02 g/kg)的41.32％.考虑到实际操作过程,在反应温度为850℃时,水蒸气流量的最佳值为1.02 g/min.木屑高温水蒸气气化所得燃气热值在11～13 MJ/m3范围内变化.研究结果证明,高温水蒸气气化是生物质制取富氢燃气的一种有效方法.