Integrating photoenzymatic decarboxylation and anaerobic digestion to convert food waste into hydrocarbon: Performance and process intensification

The integration of photoenzymatic decarboxylation and anaerobic digestion (AD) to convert food waste into hydrocarbon was conducted for the first time. The performance of fatty acid photodecarboxylase from Chlorella variabilis NC64A ( Cv FAP) was optimized in a biphasic system with petroleum ether as the oil phase; conversion of palmitic acid reached 42.2 % in 1 h, which was 26.4 times that in the single-phase catalysis. This biphasic system was further employed to convert the lipase hydrolysate of waste oil from food waste into hydrocarbon, where the production rate of C17 hydrocarbon was 1.7 mM/h. Meanwhile, the non-oil components from food waste were used in AD to generate C1 hydrocarbon methane. Adding magnetite increased the specific methane yield up to 154.0 % compared to the control group on day 22. The average hydrocarbon generation rate and energy production rate in photoenzymatic decarboxylation were 24.3 and 269 times those in AD, respectively.