微藻光合作用固定燃煤发电厂烟气CO2及其生物质能源化资源化利用已成为低碳循环的核心技术，是实现我国“双碳”目标有效途径之一。然而烟气中CO2浓度高（相对自然界藻类生长的空气氛围），且存在易溶酸性气体，如SO2等，对微藻光合生长及碳转化过程是极大挑战，造成我国微藻捕集烟气CO2的工程应用非常有限。为促进微藻固定烟气CO2发展，针对烟气高浓度CO2和含SO2等酸性气体的特点，从耐受烟气氛围的高效藻种构建、微藻对高浓度碳的代谢及转化过程调控再到烟气中高浓度CO2在光生物反应器中的传输及转化过程进行全面综述。小球藻是最有望实现微藻生物固定烟气CO2的藻种。通过筛选和驯化等方式，小球藻可适应烟气的高碳浓度和一定浓度下酸性气体的胁迫，并保持较高固碳速率。烟气在光生物反应器内溶解传输及引起多相流动是影响微藻固碳性能的关键，强化反应器内的CO2传输并抑制SO2酸性气体溶解是有效提高微藻光合固碳的有效手段，同时优化反应器结构，改善光照、混合和曝气条件等可有效提高微藻生物量的积累与烟气CO2的固定速率。微藻生物质的利用能有效增加微藻减排烟气CO2的经济性，总结了微藻生物质能源化、资源化、高值化可利用途径和研究进展，包含微藻酯交换合成生物柴油、微藻热解合成生物油和生物气以及微藻发酵合成生物合成气的工艺流程和相关研究进展。为提高微藻生物质资源利用的经济效益，指出微藻作为高值产品合成原料的利用方向，以及藻渣作为碳基材料的资源化利用方式。提出以发展高价值利用为前提，协同微藻基生物燃料和生物炭等产品的高值化、能源化、资源化梯级利用方向，以此提高微藻生物固定烟气CO2系统的经济性和可行性，同时推动微藻生物质新能源的研究，为我国烟气CO2的生物减排及资源化利用提供指导，促进绿碳经济发展。

Microalgae photosynthesis for fixing CO2 in the flue gas of coal-fired power plants and its use for biomass energy has become an important core technology in the low carbon cycle, and it is one of the effective ways to achieve the "double carbon" goal in China. However, the high CO2 concentration in flue gas (relative to the natural air atmosphere for algae growth) and the presence of easily soluble acidic gases such as SO2 pose a great challenge to the photosynthetic growth of microalgae and the carbon conversion process, resulting in the limited engineering application of microalgae for flue gas CO2 capture. In order to promote the development of microalgae for flue gas CO2 fixation, this paper presented a comprehensive review from the construction of efficient algal species tolerant to flue gas atmosphere, the regulation of metabolism and conversion processes of microalgae for high carbon concentration to the transport and conversion processes of high CO2 concentration from flue gas in photobioreactors. The results show that Chlorella is the most potential algae species to be used for the biological fixation of flue gas CO2. Through screening and domestication, Chlorella can adapt to the high carbon concentration of flue gas and the stress of acidic gases at certain concentrations, while maintaining a high rate of carbon fixation. In addition, the dissolved transport and multiphase flow of flue gas in the photobioreactor are the key factors affecting the carbon fixation performance of microalgae. Enhancing CO2 transport and inhibiting the dissolution of SO2 acidic gas in the reactor are also effective means to improve the photosynthetic carbon sequestration of microalgae. The use of microalgae biomass is an effective means of carbon sequestration. The use of microalgae biomass can effectively increase the economics of microalgae to reduce flue gas CO2 emissions. This paper presented a summary of the research progress on the use of microalgae biomass as an energy resource, including the process flow and related research progress of microalgae transesterification for biodiesel, microalgae pyrolysis for bio-oil and biogas, and microalgae fermentation for biosynthesis gas. In order to improve the economic efficiency of microalgae biomass resources utilization, the direction of utilization of microalgae as a raw material for the synthesis of high-value products, as well as the way of resource utilization of algal sludge as a carbon-based material were pointed out. The direction of high-value energy-based resourceful tertiary utilization of microalgae-based biofuels and biochar and other products in collaboration, which with the premise of developing high-value utilization was proposed as a way to improve the economics feasibility of microalgae bio-fixed flue gas CO2 systems. While it can promote the research of new energy sources of microalgae biomass. This paper provids some guidance for the biological emission reduction and resourceful utilization of flue gas CO2 in China, aimed at promoting the development of green carbon economy.

0 引言

1 适合烟气氛围微藻藻种的构建

   1.1 高效固碳藻种选育

   1.2 藻种碳代谢及产物合成途径改良

2 微藻光生物反应器内气液多相能质传递及生化转化

   2.1 烟气CO2气体在反应器内的流动及转化

   2.2 烟气中酸性气体SO2胁迫下的微藻生物固碳

   2.3 光生物反应器内微藻固定烟气CO2过程调控

3 固碳后微藻生物质的资源化利用

   3.1 微藻生物质的能源化利用

   3.2 微藻高附加值产品利用

4 微藻光合固定烟气CO2及资源化利用前景与挑战

5 结语及展望