全碳素生物转化沼气制备生物航煤制造路线研究进展

Biogas primarily composed of methane (CH₄) and carbon dioxide (CO₂) is recognized as a clean and renewable energy source with potential to replace fossil fuels. Currently, the most common way to utilize biogas is by using combined heat and power (CHP) units to generate electricity and heat. However, burning CH₄ in biogas releases an equivalent amount of CO₂, resulting in a lower carbon-atom economy. To enhance the carbon-utilization efficiency of biogas and reduce greenhouse gas emission, this review suggests a novel route of biological converting both CH₄ and CO₂ in biogas produced from anaerobic digestion of food wastes for sustainable aviation fuel (SAF) production with applications of synthetic biology techniques and biomanufacturing strategies. Photoautotroph microorganisms and aerobic methanotrophs are used to convert CO₂ and CH₄ in biogas, respectively. Primary pathways and key enzymes for lipid biosynthesis from CO₂ and CH₄ by photoautotrophic microbes and methanotrophic bacterial and strategies for carbon flux improvement are introduced and discussed. As the precursor of SAF, the lipids produced by aforementioned microbes need to undergo recovery, pre-treatment, and upgrading procedures. The effects of different technologies developed for lipid recovery (flocculation, dissolved air flotation (DAF), centrifugation, coagulation, filtration) and upgrading (Hydrogenated Esters and Fatty Acids (HEFA), Fischer-Tropsch (F-T), Alcohol-to-jet (ATJ), Hydroprocessed Fermented Sugars (HFS) on efficiency and operation cost are evaluated. Besides, physical properties of SAF derived from different raw materials are compared. The global warming potential of SAF production using different feedstock by HEFA are summarized and the reduction of greenhouse emission can be up to 80% comparing with petroleum-based ones. This review discusses the metabolic pathways, biosynthesis strategies, fermentation technology, recovery and upgrading processes for the production of biogas-derived SAF. It also provides an outlook on strategies to improve the economic efficiency of microbes-based SAF manufacturing and guideline for commercial applications of biotechnology in fuel production. (Figure presented).