煅烧沸石咪唑骨架吸附烟气CO2促进节旋藻生长固碳

利用藻类生物捕集CO₂是一种很有前景的减排烟气CO₂的方法,但是烟气CO₂在藻液中停留时间短,向溶解无机碳的转化困难,限制了藻细胞的生长固碳。通过煅烧不同时间的锌沸石咪唑骨架来制备CO₂吸附剂,利用不饱和金属活性位点吸附CO₂并促进CO₂向HCOO₃^-的转化,为藻细胞的生长固碳提供充足的溶解无机碳。结果表明:煅烧6h得到的吸附剂拥有最大的比表面积和孔容积有利于CO₂吸附和转化,可提高藻液中HCOO₃^-浓度55.7%,使得钝顶节旋藻的光能利用效率在99.99%煤化工烟气CO₂条件下增加了2.43倍,培养时间从7天缩短至5天,生物质产量提高了74.7%,CO₂固定速率提高了93.7%,为微藻减排烟气CO₂提供了新思路。

Improved Carbon Fixation of Arthrospira Platensis by Calcinated ZIF-8 as CO2Adsorbents

The use of photosynthetic microorganisms to capture CO₂is a promising method for reducing CO₂emissions.However,the short residence time of CO₂in culture medium and the difficulty of conversion into dissolved inorganic carbon limit the growth and carbon fixation of algae cells.In this study,the CO₂adsorbent was prepared by calcining the zeolitic imidazolate framework(ZIF-8)for various time.Flue gas CO₂from coal-chemical industry could be adsorbed on the unsaturated metal sites and converted into HCOO₃^-,providing sufficient carbon source for the growth of cells.The CO₂adsorbent obtained by calcining for 6 h performed best due to the largest specific surface area and pore volume,which were conducive to the adsorption and conversion of CO₂.The HCOO₃^-concentration in culture medium increased by 55.7%,resulting in a 2.43-fold increase in the light energy utilization efficiency of Arthrospira platensis under 99.99%CO₂conditions.The cultivation time was shortened from 7 days to 5 days,and finally the biomass yield and the CO₂fixation rate were enhanced by 74.7%and 93.7%,respectively.