Synthesis of Large-Scale Bio-Hydrogen Network Using Waste Gas from Landfill and Anaerobic Digestion: A P-Graph Approach

Abstract

Due to the expanding concern on cleaner production and sustainable development aspects, a technology shift is needed for the hydrogen production, which is commonly derived from natural gas. This work aims to synthesise a large-scale bio-hydrogen network in which its feedstock, i.e., bio-methane, is originated from landfill gas and palm oil mill effluent (POME). Landfill gas goes through a biogas upgrader where high-purity bio-methane is produced, while POME is converted to bio-methane using anaerobic digestor (AD). The generated bio-methane is then distributed to the corresponding hydrogen sink (e.g., oil refinery) through pipelines, and subsequently converted into hydrogen via steam methane reforming (SMR) process. In this work, P-graph framework is used to determine a supply network with minimum cost, while ensuring the hydrogen demands are satisfied. Two case studies in the West and East Coasts of Peninsular Malaysia are used to illustrate the feasibility of the proposed model. In Case Study 1, four scenarios on the West Coast have been considered, showing total cost saving ranging between 25.9% and 49.5%. This showed that aside from the positive environmental impact, the incorporation of bio-hydrogen supply can also be economically feasible. Such benefits can also be seen in Case Study 2, where the uptake of biogas from landfill and POME sources on the East Coast can lead to a 31% reduction on total network cost. In addition, the effect of bio-hydrogen supply network on carbon footprint reduction was analysed in this work.