Optimal production of hydrogen through integration of solar energy, carbon capture and utilisation

Abstract

Global warming is recognized as one of the most severe environmental problems. According to the Paris Agreement, efforts are directed towards limiting the global temperature increase to within 2oC by 2100 to mitigate the impacts of global warming. Since CO2 stands out as one of the primary contributors to this phenomenon, the study on reducing CO2 emissions in industry has gain great attention in recent years. Hydrogen, as a clean fuel and important raw material in refinery, its demand had been rising annually. Considering the status, solar-aided hydrogen production process using molten salt has been proposed. This system using solar can run the requirement operating hours, however, the total annualized cost of this process is still higher than conventional method (using fossil fuel). In this work, we first develop the solar-aided hydrogen production process using molten salt. Then an optimisation framework using machine learning techniques is developed to optimise the operating conditions in this process. Four configurations of the process are optimised. Although the optimisation results decreased compared with the base case correspondingly, the best configuration TAC is still higher than the conventional steam methane reforming method. Moreover, the CO2 capture model is using a simplified separation model, which reduces the accuracy of the CO2 capture efficiency and cost evaluation. Consequently, rigorous model for CO2 capture using Methyl diethanolamine (MDEA) and piperazine are investigated and integrated into the hydrogen production process. To enhance the economic competitiveness of the process, CO2 utilisation for chemicals production ethylene glycol and polypropylene carbonate are evaluated. Through CO2 utilisation, the entire process becomes profitable covering the expensive cost for solar field and CO2 capture process.

Date of Award	16 Apr 2024
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Nan Zhang (Co Supervisor) & Jie Li (Main Supervisor)