采用天然石灰石作脱硫剂,在固定床上进行高温煤气脱硫,研究脱硫剂粒径、用量、温度和入口H2S浓度对脱硫性能的影响及脱硫反应对逆水煤气变换反应的影响,并得到CaO的转化率曲线。结果表明:粒径对脱硫效果的影响很大,其中以0.38~0.9mm的石灰石脱硫效果最佳;脱硫剂用量增加,气固之间的接触机会增加,脱硫反应进行得更完全;温度对脱硫过程的影响比较复杂,最佳的脱硫温度为脱硫剂完全煅烧的温度;在一定的空速下,随着入口H2S浓度的减小,反应速率减慢;脱硫剂明显加快逆水煤气变换的反应速率,起到催化剂的作用,但是产生的CaS堵塞了脱硫剂的微孔,催化活性减弱,使逆水煤气变换反应速率减慢。
Natural limestone was adopted as high temperature desulfurization sorbent, tests for hot gas desulphurization were carried out in a fixed bed reactor. The influence of desulfurization conditions such as grain size, desulfurization sorbent dosage, temperature, and H2S concentration in the inlet were investigated. Meanwhile the influence of desulfurization reaction on the reverse water shift reaction was studied. The conversion curve of calcium in limestone was obtained. It is showed that the grain size has great influence on desulfurization reaction, the size of 0.38- 0.9 mm has the best desulfurization effect. With the increase of desulfurization sorbent dosage, gas-solid contact chance increases and the desulfurization reacts more fully. The temperature has complicated influence on desulfurization, the best one is on which the desulfurization sorbent was completely calcined. The reaction rate slows down and completely breakthrough time extends with the decrease of H2S concentration in the inlet gas; Desulfurization sorbent acts as a catalyst for the reverse water shift reaction, enhancing its reaction rate. But CaS blocks micropores, reduces reaction activity and the reverse water-shift reaction rate slows down.