Sustainability assessment of photobiological hydrogen production using anaerobic bacteria (Rhodospirillum rubrum) via exergy concept: Effect of substrate concentrations

Abstract

The detailed exergy analysis of photobiological hydrogen production from syngas through water-gas shift (WGS) reaction via anaerobic bacteria Rhodospirillum rubrum was presented. Several exergetic parameters for the fermentation process were computed based on both the conventional exergy and eco-exergy concepts. The microorganisms were supported using acetate as carbon source at various concentrations (0.5-3 g/L) in a CO-enriched media in a batch culture and produced hydrogen by utilizing the harmful carbon monoxide. The results manifested that the cumulative rational exergetic efficiency based on the conventional exergy was lower than that obtained using the eco-exergy concept. However, the cumulative exergy destruction based on the conventional exergy concept was higher than of the eco-exergy theory. Therefore, it seems that the eco-exergy concept was much more suitable as decision-making tool to assess the sustainability of renewable energy projects containing living microorganisms. The highest cumulative process exergetic efficiency values were achieved at the acetate concentration of 1 g/L via the exergy and eco-exergy concepts, at 0.5156% and 0.5139%, respectively. This revealed the suitability of this dosage for large-scale biohydrogen production. Principally, the findings of this study can provide a theoretical framework for decision making on sustainability and renewability of the biological hydrogen production.

Selection and preparation of CO2 sorbent for sorption‐enhanced steam reforming process of raw coke oven gas

“…Steam reforming of hydrocarbons was a kind of feasible approaches for hydrogen production, because the more hydrogen via it can be produced, not just from the reforming materials, but also from steam. Currently, the steam reforming of CH 4 , bio-oil, tar, and so on for hydrogen production has been investigated widely [10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Therefore, steam reforming of RCOG should be an attractive technique for hydrogen or H 2 -rich syngas production and tar component removal, with surplus steam supply or substantial energy waste to produce steam in the iron and steel enterprises, although RCOG itself contains only 10-15 vol % steam with the very low S/C ratio (the mole ratio of steam and carbon in RCOG) [2].…”

Comprehensive exergy analysis of a commercial tomato paste plant with a double-effect evaporator

“…This could be attributed to the unique conceptual features of this approach in providing a deep insight into the structure of physical, thermodynamic, and ecological costs. Unlike exergy analysis, conventional energy analysis, based on the first law of thermodynamics, has been demonstrated to be an inefficient and unreliable tool for assessing energy systems because of its shortcoming in measuring the quantity of the thermodynamic irreversibilities [7,8]. It is interesting to note that exergy analysis can help to develop strategies and guidelines for more effective use of fossil fuel resources and to mitigate the impact of their high consumption rates on the environment.…”

Carbon monoxide fermentation to bioplastic: the effect of substrate adaptation on Rhodospirillum rubrum

“…Even though the CO conversion mechanism is not yet fully understood, genetic and biochemistry studies have demonstrated that the CO conversion of R. rubrum is mediated by a membrane protein complex, which orchestrates the biological water-gas shift (WGS) reaction (CO + H 2 O ➔ CO 2 + H 2 ) [13] (Fig. 1).…”