Optimal scheduling strategy for integrated green hydrogen-ammonia-methanol multi-energy synergy toward renewable energy accommodation

Against the backdrop of high-proportion renewable energy grid integration, this paper proposes an economic dispatch strategy for a multi-energy complementary integrated energy system featuring a hydrogen-ammonia-methanol integrated unit to address the issue of renewable energy curtailment in Northeast China. To promote renewable energy accommodation, the system uses an electrolytic cell to convert surplus electricity into hydrogen. Using a P2G system, hydrogen reacts with CO2 to produce CH4 and CH3OH. Under specific conditions, it can also react with N2 to produce liquid ammonia. The heat generated by all three reaction processes can be recovered via a waste heat boiler. Simulation results show that, compared to Scenario 2, Scenario 1 reduces daily wind and solar curtailment by 21.92% and lowers costs by 0.16%. Compared to Scenario 3, Scenario 1 reduces daily curtailment by 26.81% and lowers costs by 0.79%, and compared to Scenario 4, Scenario 1 reduces daily curtailment by 15.07% and lowers costs by 1.57%. By introducing an integrated hydrogen-ammonia-methanol production unit, the system has established a complete conversion chain from green electricity to green chemical products. This not only enables the long-term, large-scale storage of renewable energy but also provides a viable pathway for the green substitution of industrial raw materials.