Mass-energy balance analysis for estimation of light energy conversion in an integrated system of biological H2 production

Abstract

The present study investigated an integrated system of biological H2 production, which includes the accumulation of biomass of autotrophic microalgae, dark fermentation of biomass, and photofermentation of the dark fermentation effluent. Particular emphasis was placed on the estimation of the conversion efficiency of light into hydrogen energy at each stage of this system. For this purpose, the mass and energy balance regularities were applied. The efficiency of the energy transformation from light into the microalgal biomass did not exceed 5%. The efficiency of the energy transformation from biomass to biological H2 during the dark fermentation stage stood at about 0.3%. The photofermentation stage using the model fermentation effluent could improve this estimation to 11%, resulting in an overall efficiency of 0.55%. Evidently, this scheme is counterproductive for light energy bioconversion due to numerous intermediate steps even if the best published data would be taken into account. © 2015 BRTeam. All rights reserved.The conversion of light energy into H2 was examined in an integrated three-stage scheme. Mass-energy balance regularities were applied to estimate energy conversion efficiencies at different stages.This three-stage scheme was found counterproductive for light energy bioconversion to H2.Please cite this article as: Gavrisheva A.I., Belokopytov B.F., Semina V.I., Shastik E.S., Laurinavichene T.V., Tsygankov A.A. Mass-energy balance analysis for estimation of light energy conversion in an integrated system of biological H2 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

“…The present dominating energy supply paradigm of food processing plants is mainly based on fossil fuel in the direct form or indirect electrical power. However, increasing level of carbon dioxide concentration in the atmosphere due to the widespread fossil fuels consumption and growing concern about their future shortage have spurred research into an efficient utilization of available fossil energy resources and development of alternative renewable sources [2,3]. In addition to the abovementioned issues, energy saving is considered with more interest by food manufacturers due to a significant impact of energy on the unit cost of food products [4].…”