Storing Sunlight in Waste-Derived Syngas - SusTechTalks2026

This talk explores making synthetic fuel from municipal waste using renewable energy (solar). The key reaction, dating back to the 1860s, involves heating carbon in steam to produce hydrogen and carbon monoxide. 

This endothermic reaction requires heating, traditionally done by alternately burning coke and injecting steam. Using intermittent renewable electricity for heating is now feasible. A metric ton of carbon requires 4 MWh of heat to produce 13.1 MWh of syngas; a 3-to-1 energy gain. The gas can be stored, burned to make power, or converted into methanol, methane, jet fuel, or diesel. The water-gas shift reaction can be used to increase the hydrogen at the expense of CO. The resultant CO2 (about half) can be sorted out of the gas stream and sequestered. 

Following the water-gas shift, the Fischer-Tropsch (FT) process converts syngas into hydrocarbons, with water as a byproduct. An example design uses 9,000 tons of trash daily from the Sylmar, CA, landfill, supplemented with coal, brush, or tires to produce syngas. The project would need significant power and infrastructure, including large gasifiers and GW-scale PV. 

The project addresses landfill overuse and methane leakage, and provides a renewable energy solution for synthetic fuel production, though it requires substantial investment and the development of large gasifiers.