Abstract:

The characteristics of CO₂ separation in biogas by hydrate method in impinging flow reactor were investigated experimentally. Two different systems, pure water and sodium dodecyl sulfate (SDS), were selected to investigate the effects of pressure, temperature and impact intensity during hydrate formation process. The experimental results showed that the increase of pressure in pure water system or SDS system was conducive to the rapid formation of hydrate, but not conducive to the CO₂ capture. By changing the impact intensity of the impinging stream reactor, it was found that the CO₂ separation factor (S.F.) reached the maximum in both systems when the impact intensity was 0.128, the maximum value of S.F were 138.9 and 64.5, respectively.The experimental results showed that the additive SDS could promote the formation of hydrate, and the optimal concentration was 600 mg/L when the gas consumption,CO₂ recovery S.Fr.(CO₂) and CH₄ recoveryS.Fr.(CH₄) reached the maximum. However, the promotion effect of SDS on CH₄ hydrate formation process was greater than that of CO₂ hydrate, which was not conducive to the CO₂ separation from biogas, but the separation factor of CO₂ would be reduced.

Key words: hydrate, biogas, separation, CO₂ capture, separation factor

摘要：

实验考察了撞击流式反应釜内水合物法分离沼气中CO₂的特性。选取纯水和十二烷基硫酸钠（SDS）两个不同的体系，考察了水合物生成过程中压力、温度、撞击强度的影响。实验结果表明在纯水体系和SDS体系下压力的升高均有利于水合物的快速生成，但并不利于沼气中的二氧化碳捕集；实验通过改变撞击流式反应器的撞击强度发现，当撞击强度为0.128时，CO₂分离因子(S.F.)在纯水和SDS两种体系下均达到最大，纯水体系下S.F.的最大值为138.9，SDS体系下S.F.的最大值为64.5；实验结果表明添加剂SDS可以促进水合物的生成，最适宜的浓度为600 mg/L，此时耗气量、CO₂水合率S.Fr.(CO₂)和CH₄水合率S.Fr.(CH₄)达到最大，但SDS对CH₄水合物生成过程的促进作用大于CO₂水合物，反而不利于CO₂的分离，降低CO₂的分离因子。

关键词: 水合物, 沼气, 分离, 二氧化碳捕集, 分离因子