稻壳在水蒸气中气化实验研究

摘要

The rice husk gasification experiments were performed in a fluidized bed gasifier with steam as gasifying agent. The effects of reaction temperature(500—700℃),steam flow rate(7—11kg/h), and feed rate(1.2—3.6kg/h)on gas yield and the compositions of the main components(H2,CO, CH4,CO2)were investigated,respectively. The results showed that the higher reaction temperature could lead to higher gas yield and higher content of H2 and CH4. With the increase of the reaction temperatures,the content of CO first decreased then increased. The effect of the increase of steam flow and feed rate on gas yield at 500℃ and 700℃ was not the same,which indicated that the leading reactions in the fluidized bed at different reaction temperature were different . At 700℃,the increase of the steam flow and feed rates did niot change the content of H2,CO,and CO2 significanly;and the volume fraction of CH4 remained about 12％. Within the scope of the experimental conditions,when the reaction temperature was 700℃,steam flow 7kg/h,and feed rate 1.2kg/h,the gas yield and the volume fraction of H2 reached the maximum values of 725L/h and 18.05％,respectively.%在流化床实验装置上以水蒸气为气化剂,对稻壳进行热解气化的实验研究,分别考察单因素反应温度(500～700℃)、蒸气流量(7～11kg/h)和进料速率(1.2～3.6kg/h)对产气率及其主要组分(H2、CO、CH4、CO2)的影响.实验结果表明:温度的升高可提高气化气产率及气体组分中CH4和H2的含量,同时降低了CO2的含量,随温度升高,CO的含量呈先增加再降低的趋势.蒸气流量和进料速率的增加对产气率影响分别在500℃和700℃呈现出了不同的规律,说明了在不同反应温度下床内起主导作用的反应不同.在700℃,随蒸气流量和进料速率增加,气化气中H2、CO和CO2的含量都有小幅度变化,CH4体积分数稳定在12％左右.在条件考察范围内,当反应温度为700℃、蒸气流量为7kg/h、进料速率为1.2kg/h时,产气率和H2体积分数分别有最大值,为725L/h和18.05％.