Renewable CO2 absorbent for carbon capture and biogas upgrading by membrane contactor
Renewable CO2 absorbent for carbon capture and biogas upgrading by membrane contactor
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可再生二氧化碳吸收剂，用于通过膜接触器进行碳捕获和沼气升级
DOI：
10.1016/j.seppur.2017.11.043
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发表时间：
2018-04-03
影响因子：
8.6
通讯作者：
Zhao, Shuaifei
中科院分区：
文献类型：
--
作者：
He, Qingyao;Yu, Ge;Zhao, Shuaifei
本研究采用新型的可再生吸附剂从沼液（BS）的沼气升级通过膜接触器。通过添加碱液、真空再生或真空膜蒸馏等方法可以提高沼液吸收CO2的能力。这些方法用于生产四种类型的可再生CO2溶剂，包括真空再生BS、通过VMD从BS回收的氨水（RAA）、氧化钙处理BS和氢氧化钾处理BS。研究了这些可再生吸收剂用于膜接触器从沼气中捕集CO2的效果。随着原料气中CO2体积分数的增加，CO2脱除效率降低，但吸收速率增加。吸收温度对可再生吸收剂的CO2吸收率影响有限。在膜接触器中，RAA在四种可再生吸收剂中表现出最好的CO2吸收性能。与壳程上的RAA相比，在管程上流动的RAA导致高50%的CO2去除效率。在低气体流速下，可以不使用部分吸收剂和中空纤维。因此，在使用膜接触器进行沼气提质时，应仔细考虑膜组件参数的选择，包括组件的长度、中空纤维的数量、沼气流量和吸收性能。
This study employs novel renewable absorbents derived from biogas slurry (BS) for biogas upgrading via membrane contactors. CO2 absorption capacity of biogas slurry can be enhanced by adding alkali solutions, vacuum regeneration or vacuum membrane distillation (VMD). These methods are used to produce four types of renewable CO2 solvents, including vacuum regenerated BS, recovered aqueous ammonia (RAA) from BS by VMD, calcium oxide treated BS and potassium hydroxide treated BS. These renewable absorbents for CO2 capture from biogas by membrane contactors are investigated. CO2 removal efficiency reduces but absorption rates increase with the rise in CO2 volume fraction in the feed gas stream. Absorption temperature has a limited effect on CO2 absorption rates of the renewable absorbents. RAA shows the best CO2 absorption performance among the four types of renewable absorbents in the membrane contactor. RAA flowing on the tube side leads to a 50% higher CO2 removal efficiency compared with RAA on the shell side. At low gas flow rates, partial absorbents and hollow fibers may not be utilized. Thus, selection of membrane module parameters, including the length of module, the number of hollow fibers, biogas flow rates and absorption performance, should be carefully considered when using membrane contactors for biogas upgrading.