Techno-economic assessment of various hydrogen production methods - A review.

Hydrogen is a clean fuel that could provide energy incentives and reduce environmental impacts, if production platform is carefully selected and optimized. In specific, techno-economic and sensitivity analysis of the existing hydrogen production platforms and processes is need for an hour to boost the future hydrogen economical aspects. This will have greater impact on future hydrogen production project designs and developing new approaches to reduce the overall production costs to make it as cheaper fuel. The sensitivity analysis of various hydrogen production process such as pyrolysis, gasification, steam reforming of natural gas, dark fermentation, photobiolysis, water electrolysis and renewable liquid reforming were reviewed to evaluate their merits and demerits along with cost-effectiveness. On economic view point, steam reforming of natural gas is efficient, low cost and best methods for hydrogen production. A future research is required to reduce energy input and trapping carbon dioxide emission using membrane models.

Impact of mild alkali dosage on immobilized Exiguobacterium spp. mediated cost and energy efficient sludge disintegration.

Approaches to (extracellular polymeric substance) EPS removal were studied with major aim to enhance the biodegradability and sludge solubilization. In this study, a novel approach of entrapment of bacterial strain was carried out to achieve long term activity of protease secreting bacteria Exiguobacterium sp. A mild treatment of potassium hydroxide (KOH) was applied to remove EPS which was followed by entrapment under the biological pretreatment. The efficiency of Exiguobacterium was predicted through dissolvable organic and suspended solids (SS) reduction. The maximum dissolvable organic matter released was 2300mg/L with the solubilization of 23% which was obtained for sludge without EPS (SWOE). For dissolvable organic release, SWOE showed higher final methane production of 232mL/g COD at the production rate of 16.2mL/g COD.d. The SWOE pretreatment was found to be cost effective and less energy intensive beneficial in terms of energy and cost (43.9KWh and -8.2USD) when compared to sludge with EPS (SWE) pretreatment (-177.6KWh and -91.23USD).