Feasibility of Biohydrogen Purification from Carbon Dioxide Mixture via Integrated Microalgae-Membrane Contactor Towards Zero Carbon Emission

Abstract

Biohydrogen (H2) mixed with carbon dioxide (CO2) produced from the fermentation of Palm Oil Mill Effluent (POME) could be a potential renewable energy source. However, an effective technique to treat both gases towards zero carbon emission has become a major concern. In this study, a new approach was introduced to treat H2/CO2 mixture from POME fermentation by an integrated microalgae-membrane contactor system. Polyvinylidine fluoride (PVDF) hollow fibre membrane used in the integrated membrane contactor system abled to give the highest purified H2% from mixed H2/CO2 in the microalgae liquid absorbent (Chlorella Vulgaris) (69.4%) followed by Bold Basal Medium (BBM) (59.1%) and distilled water (55.9%). This initial result showed that the microalgae possessed better ability to absorb CO2 into the liquid stream via the PVDF membrane contactor. Next, investigation on optimizing the system’s operational parameters using BBM as liquid absorbent showed the highest CO2 absorption flux and efficiency were obtained at initial solution pH of 10. Further investigation showed that the absorption efficiency was enhanced as the liquid flow rate increased up to 0.4 L/min and the gas flow rate was at 0.1 L/min. Upon utilizing 0.6 g/L microalgae, the purified H2% found to remarkably increase up to 83.2%. In conclusion, the use of the developed integrated microalgae-membrane contactor system to purify the bio-H2 from CO2 mixture is a promising alternative method for zero carbon emission especially in palm oil industry.