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An Overview of Fermentative Hydrogen Production Technologies
Published in Sonil Nanda, Prakash K. Sarangi, Biohydrogen, 2022
Prakash K. Sarangi, Sonil Nanda, Ajay K. Dalai, Janusz A. Kozinski
Hydrogen generation through the microbial conversion process has gained much interest due to the utilization of renewable feedstocks and environmentally friendly processes. Fermentative methods for hydrogen generation through dark fermentation and photo-fermentation along with optimization of various parameters are necessitated for maximum hydrogen recovery. The major pathways for biological hydrogen generation are photolysis of water, oxidation of organic acids by photo-fermentation and dark fermentation. Dark fermentation is one of the widely used processes of hydrogen production as it provides low input of energy from the feedstock. However, process parameters such as temperature, hydraulic retention time, the partial pressure of hydrogen, pH, reaction time, bioreactor type, substrate concentration, microorganism type, pretreatment process have key roles in regulating the hydrogen generation with maximum recovery through fermentative processes.
A Brief Overview of Fermentative Biohythane Production
Published in Sonil Nanda, Prakash K. Sarangi, Biomethane, 2022
Prakash K. Sarangi, Sonil Nanda
Dark fermentation is the most potential process for hydrogen generation (Kumar et al., 2017; Łukajtis et al., 2018) by various microorganisms from waste biomass. A mixture of gases along with H2 and CO2 are produced (Kotsopoulos et al., 2006; Temudo et al., 2007; Datar et al., 2004; Najafpour et al., 2004). Various microorganisms such as Enterobacter spp., Bacillus spp., and Clostridium spp., have the potential to produce hydrogen from cellulosic substances (Levin et al., 2004). Bacteria can convert glucose to pyruvic acid, which is later converted to CO2 and H2 (Figure 7.1) through this method. The first phase has a pH value of 5–6 with a hydraulic retention time of 1–3 days, which are appropriate for acetogens towards the degradation of wastes to H2.
Bioconversion of Waste Biomass to Biohydrogen
Published in Prakash Kumar Sarangi, Sonil Nanda, Bioprocessing of Biofuels, 2020
Prakash Kumar Sarangi, Sonil Nanda
Dark fermentation is considered as a promising method for hydrogen production from waste biomass and specific microorganisms (Kumar et al. 2017; Łukajtis et al. 2018; Sarangi and Nanda 2020). During this method, a mixed gas containing H2 and CO2 is produced along with other gases like CH4, CO and H2S, which depends on the type of feedstock, microorganisms and process conditions (Datar et al. 2004; Najafpour et al. 2004; Kotsopoulos et al. 2006; Temudo et al. 2007). In dark fermentation, the bacterium converts organic substances like raw biomass, sugars and wastewater to hydrogen. Due to the complete absence of light, this process is regarded as dark fermentation. Moreover, dark fermentation is advantageous over photo-fermentation in requiring smaller bioreactors, less energy and low cost because of the absence of light energy to facilitate microbial growth. Some notable microorganisms like anaerobic bacteria such as Bacillus spp., Enterobacter spp. and Clostridium spp. are utilized for the conversion of cellulosic substrates to biohydrogen (Levin et al. 2004). During the dark fermentation, the bacterium converts glucose to pyruvic acid, thereby producing ATP through the glycolytic pathways. Furthermore, with the utilization of pyruvate ferredoxin oxidoreductase and hydrogenase, CO2 and H2 are produced from pyruvic acid (Figure 6.2). During dark fermentation, biohydrogen production generally depends on the degradation of pyruvate to acetyl-CoA and further to acetate, butyrate and ethanol.
Effect of continuous micro-aeration on hydrogen production by coal bio-fermentation
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Hongyu Guo, Saisai Li, Zhenwei Yang, Xianbo Su, Shufeng Zhao, Bo Song, Shangwei Shi
The technology of hydrogen production by dark fermentation mainly uses fermentation bacteria to degrade biomass in a dark environment to produce hydrogen. According to the metabolic characteristics of hydrogen production, there are two basic pathways for hydrogen production by fermentation bacteria: hydrogen production by pyruvate decarboxylation and hydrogen production by NADH+H+/NAD+ balance regulation (Lee, Show, and Su 2011; Yang and Wang 2017). Hydrogen production by pyruvate decarboxylation can be divided into two ways: hydrogen production by pyruvic acid decarboxylation-ferredoxin-hydrogenase pathway and hydrogen production by pyruvic acid decarboxylation-formic acid cleavage pathway (Fu et al. 2021). Hydrogen production from coal by anaerobic fermentation is mainly based on the secretion of extracellular enzymes by microbial flora in mine water, which hydrolyze carbohydrates, proteins and fats in coal into sugars, amino acids and glycerol, fatty acids, and then produces H2 through the acid-producing fermentation stage and hydrogen-producing acetic acid stage (Su et al. 2020), which can effectively reduce the environmental pollution caused by coal combustion and achieve carbon emission reduction at an early date, which has attracted the attention of researchers globally(Chen, Yin, and Wang 2020; Yan and Guo 2008)。
Dark co-fermentation of rice straw and pig manure for biohydrogen production: effects of different inoculum pretreatments and substrate mixing ratio
Published in Environmental Technology, 2021
Hong Chen, Jun Wu, Hong Wang, Yaoyu Zhou, Benyi Xiao, Lu Zhou, Guanlong Yu, Min Yang, Ying Xiong, Sha Wu
Hydrogen is a clean and renewable resource with a high energy yield (142 kJ/g). However, the current industrial hydrogen production, typical by the steam reforming of natural gas and electrolytic water, both of which are highly energy-consumed [1]. Biohydrogen is considered as an alternative to industrial hydrogen because it can be produced at ambient temperature and pressure though photo and dark fermentation [2]. Among of them, dark fermentation is the most promising technology for biohydrogen production, in which protons are reduced to biohydrogen by hydrogen-producing microorganisms and soluble organic matter and solids remain in the fermentation liquid, accompanying CO2 production without light consumption [3]. Meanwhile, organic wastes used for dark fermentation contribute considerable cost savings and greenhouse gas emission reduction [4], in which the end-product for combustion does not release nitrous oxide and sulphur dioxide. Until now, various organic wastes have been selected for the biohydrogen production, including simple organic substances such as xylose [5] and glucose [6], as well as complex organic substances such as sorghum syrup [7] and kitchen waste [8]. Dark fermentation has rapidly become a research hotspot for biohydrogen production due to its superior ability to generate clean energy while treating organic wastes.
Effect of metal ions on dark fermentative biohydrogen production using suspended and immobilized cells of mixed bacteria
Published in Chemical Engineering Communications, 2018
Patrick T. Sekoai, Michael O. Daramola
The current global economy is largely dependent on fossil fuels. This has resulted in an unprecedented increase in atmospheric carbon dioxide concentration and rapid depletion of fossil fuel reserves (Show et al., 2012). Moreover, emissions from combustion of fossil fuels are considered the main cause of environmental challenges, such as acid rain, air pollution, depletion of stratospheric ozone, and the greenhouse effect (Das and Veziroglu, 2001). These problems have reinvigorated researchers all around the world to search for sustainable and alternative energy source that could mitigate the environmental effects of hydrocarbon fuels (Das and Veziroglu, 2001). Hydrogen has been repeatedly flagged as a suitable replacement to fossil fuels due to its non-polluting and high energy characteristics (Sekoai and Daramola, 2015). Dark fermentation (also referred to as dark fermentative biohydrogen production) is the most viable method of producing hydrogen because it is less energy intensive and uses different substrates including waste materials. In addition, the process uses various microorganisms such as facultative and strict anaerobes that hydrolyze the substrate under anaerobic conditions to produce hydrogen together with soluble metabolites such as volatile fatty acids and alcohols (Xiao et al., 2013).