An indicative appraisal has been undertaken of a combined Anaerobic Digestion (AD) and Steam Methane Reforming (SMR) process to produce hydrogen (H2) from organic waste. The AD plant was based on the plant in Tilburg (The Netherlands), and was modelled from the kerbside organic waste collections through to methane production. The technical feasibility of H2 production of this combined process was assessed based on biogenic waste collected in Bath and North East Somerset (B&NES); a municipal area in the South West of England (UK). The B&NES collection trials yielded data that could be used to estimate the catchment area for an AD plant on a commercial scale. A thermodynamic evaluation of the combined process included energy and exergy analysis in order to determine the efficiency of each process, as well as to identify the areas that lead to inefficiencies. The main energy losses were associated with compressor inefficiencies. In contrast, the main exergy consumption was found to be due to the fermentation in the digestion tanks. The overall technical efficiency of the plant does not compare well with other processes when compost is considered as a waste product. However, the H2 is produced comes from entirely renewable sources and has the benefit of nearzero carbon emissions in contrast to fossil fuels. Finally, the case study included an indicative economic assessment of the collection to production chain. The use of high quality source sorted waste could yield of high levels of biogas and high quality compost could be produced. Should compost were employed as a useful by-product, then the adoption of the combined process would be economically attractive.
Keywords hydrogen production, biogenic municipal waste, steam reforming of methane, anaerobic digestion, technology assessment, thermodynamic analysis