Microorganisms as New Sources of Energy

Abstract

The use of fossil energy sources has a negative impact on the economic and socio-political stability of specific regions and countries, causing environmental changes due to the emission of greenhouse gases. Moreover, the stocks of mineral energy are limited, causing the demand for new types and forms of energy. Biomass is a renewable energy source and represents an alternative to fossil energy sources. Microorganisms produce energy from the substrate and biomass, i.e., from substances in the microenvironment, to maintain their metabolism and life. However, specialized microorganisms also produce specific metabolites under almost abiotic circumstances that often do not have the immediate task of sustaining their own lives. This paper presents the action of biogenic and biogenic–thermogenic microorganisms, which produce methane, alcohols, lipids, triglycerides, and hydrogen, thus often creating renewable energy from waste biomass. Furthermore, some microorganisms acquire new or improved properties through genetic interventions for producing significant amounts of energy. In this way, they clean the environment and can consume greenhouse gases. Particularly suitable are blue-green algae or cyanobacteria but also some otherwise pathogenic microorganisms (E. coli, Klebsiella, and others), as well as many other specialized microorganisms that show an incredible ability to adapt. Microorganisms can change the current paradigm, energy–environment, and open up countless opportunities for producing new energy sources, especially hydrogen, which is an ideal energy source for all systems (biological, physical, technological). Developing such energy production technologies can significantly change the already achieved critical level of greenhouse gases that significantly affect the climate.

Techno-Economic Assessment of Biohydrogen Production from Dark Fermentation of Wastewater Sludge

“…to the modeled results, and a discrepancy between 15 to 20% has been observed in the biohydrogen production, [18], [19], [33], [67], and for organic acid production, a variation of about 10 to 17% has been observed. The reason behind this discrepancy might be the following:…”

“…Dark fermentation (DF), also known as dark fermentation (DF), stands out as a promising option within the realm of biohydrogen production methods, in which anaerobic microorganisms produce hydrogen utilizing carbohydrate-rich substrate in the absence of light [17]. The key advantage of this green technique includes simple operational requirements, stable hydrogen production, and minimal energy consumption [18]. More importantly, this method can utilize various non-economic biomass as feedstock such as the wastewater and organic fraction of municipal waste, providing enormous economic and environmental benefits over conventional techniques through clean energy supply and reduction in the cost of municipal wastewater and solid waste management [19].…”

“…The principal organic components within the sludge are carbohydrates, fats, and proteins, which are broken down by hydrogen-producing bacteria such as Clostridium through the DF process [18]. Based on the production stage of the municipal wastewater sludge, it can be classified as the primary sludge (PS) and waste-activated sludge (WAS), generated from the primary and secondary treatment units of the WWTPs [26].…”

Conversion of Post-Refining Waste MONG to Gaseous Fuel in a Rotary Gasifier

“…The motivation to search for alternative energy sources is a result of the depletion of fossil resources, growing energy prices, and negative environmental impact [1,2]. The global irreversible, long-term trend for increase in energy consumption [3,4] requires new energy sources [5,6] in order to guarantee energy security with simultaneous environmental sustainability [7,8]. The dynamic growth of solar energy, hydro, and wind which are strongly affected by weather/season conditions [9] is still insufficient to phase out fossil fuels [10,11].…”