• Energy Research

Perform pretreatment is crucial particularly in the case of the use of hard-degradable biomass, the biochemical susceptibility to degradation, for example, alcoholic fermentation is limited. Biomass disintegration processes lead to the destruction of compact structures and release of the organic substance to the phase dissolved in a resultant increase in the concentration of dissolved easily degradable organic substances. Effective pretreatment should meet several criteria, including ensuring the separation of lignin from cellulose, to increase the share of amorphous cellulose, provide a higher porosity substrates, eliminate waste sugars limit formation of inhibitors, minimize energy costs. The aim of this paper is to show the possibilities of using electromagnetic microwave radiation for pre-treatment plant biomass before the fermentation process of alcohol and comparison of the effectiveness of the described method with other commonly used techniques of pre-treatment. The substrate subjected to microwave treatment has a fast rate of hydrolysis and a high content of glucose in the hydrolyzate, which increases the efficiency of the production of bioethanol.

Abstract Methane fermentation is a versatile and established technology that should be optimized at all stages, starting from biomass storage and ending at digestate management. A commonly used method of biomass storage is ensiling, and the methane production of the biomass is determined by the products of the ensiling fermentation. Therefore, this study determined the effect of fermentation stimulants, fermentation inhibitors and osmotic condition improvers on the methane production of Sida hermaphrodita silages. Methane production was highest (334.6 ± 8.1 L/kg VSadded) with silage prepared with molasses, which increased its content of carbohydrates and lowered its ammonium nitrogen content. Production of methane was also high with untreated plant (304.0 ± 10.1 L/kg VSadded). Methane production correlated with Methanosarcinaceae abundance in the sludge. Principal component analysis revealed that first principal component was strongly correlated with indicators related with ensiling performance. Ensiling had no effect on the hemicellulose content and lowered the pH of silage independent of the additive used.

One of the most effective technologies involving the use of lignocellulosic biomass is the production of biofuels, including methane-rich biogas. In order to increase the amount of gas produced, it is necessary to optimize the fermentation process, for example, by substrate pretreatment. The present study aimed to analyze the coupled effects of microwave radiation and the following acids: phosphoric(V) acid (H3PO4), hydrochloric acid (HCl), and sulfuric(VI) acid (H2SO4), on the destruction of a lignocellulosic complex of maize silage biomass and its susceptibility to anaerobic degradation in the methane fermentation process. The study compared the effects of plant biomass (maize silage) disintegration using microwave and conventional heating; the criterion differentiating experimental variants was the dose of acid used, i.e., 10% H3PO4, 10% HCl, and 10% H2SO4 in doses of 0.02, 0.05, 0.10, 0.20, and 0.40 g/gTS. Microwave heating caused a higher biogas production in the case of all acids tested (HCl, H2SO4, H3PO4). The highest biogas volume, exceeding 1800 L/kgVS, was produced in the variant with HCl used at a dose of 0.4 g/gTS.

This paper presents data on methane fermentation of algal biomass containing Chlorella sp. and Scenedesmus sp. The biomass was obtained from closed-culture photobioreactors. Before the process, the algae were subjected to low temperature and pressure pretreatment for 0.0, 0.5, 1.0 and 2.0 h. The prepared biomass was subjected to mesophilic methane fermentation. The amount and composition of the biogas formed in the process were determined. The amount of biogas produced was larger when the biomass was subjected to thermal preprocessing. The proportion of methane in the gas also increased. Extending the heating time beyond 1.0 h did not significantly improve the biogassing effects.

This study analyzed the effects of thermohydrolysis on the anaerobic conversion efficiency of lignocellulosic biomass, comparing conventional and microwave heating methods. The research aimed to identify the optimal temperature and duration for biomass pre-treatment to maximize biogas output. Four temperatures (100 °C, 130 °C, 150 °C, and 180 °C) and six durations (10, 15, 20, 25, 30, and 40 min) were tested. The results showed that microwave heating increased biogas production compared to conventional heating at the same temperatures and durations. At 150 °C, microwave heating for 20 min produced 1184 ± 18 NmL/gVS of biogas, which was 16% more than the 1024 ± 25 NmL/gVS achieved through conventional heating. Statistically significant differences in biogas output between microwave and conventional heating were observed at 130 °C, 150 °C, and 180 °C, with the greatest difference recorded between 130 °C and 150 °C: 13% for conventional heating and 18% for microwave heating. Notably, increasing the temperature from 150 °C to 180 °C did not result in a statistically significant rise in biogas production. The energy balance analysis revealed that microwave heating, despite its lower efficiency compared to conventional heating, resulted in higher net energy gains. The most favorable energy balance for microwave heating was observed at 150 °C, with a net gain of 170.8 Wh/kg, while conventional heating at the same temperature achieved a gain of 126.2 Wh/kg. Microwave heating became cost-effective starting from 130 °C, yielding an energy surplus of 18.2 Wh/kg. The maximum energy output from microwave conditioning was 426 Wh/kg at 150 °C, which was 158 Wh/kg higher than conventional heating. These findings suggest that microwave thermohydrolysis, particularly at 150 °C for 20 min, enhances both biogas production and energy efficiency compared to conventional methods. The results highlight the potential of microwave pre-treatment as an effective strategy to boost methane fermentation yields, especially at temperatures above 130 °C.

The objective of the present study was to determine the effectiveness of biogas production during methane fermentation of wastewaters originating from the dairy, tanning and sugar industries, by means ofrespirometric measurements conducted at a temperature of 35 degrees C. Experiments were carried out with the use of model tanks of volume 0.5 dm3. A high production yield of biogas, with methane content exceeding 60%, was achieved in the case of the anaerobic treatment of wastewaters from the dairy and sugar industries. A significantly lower effect was observed in the case of tanning wastewaters. The effectiveness of the fermentation process decreased with increasing loading of the tanks with a feedstock of organic compounds. By loading a model tank with this feedstock, the effectiveness of treatment ranged from 62.8% to 71.4% residual chemical oxygen demand for dairy wastewaters and from 57.9% to 64.1% for sugar industry wastewaters. The efficiency of organic compound removal from tanning wastewaters was below 50%, regardless of the method applied.

Abstract The use of algae as a potential substrate in biogas production processes has been discussed sporadically, therefore this manuscript provides an overview of reference data published so far on that matter. The goal of this review is to present possibilities of applying algae biomass for biogas production purposes and to determine the effectiveness of the fermentation process of algae belonging to various taxonomic groups, originating from various biocenoses and characterized by different morphology and properties. Finally, this work reports on methods and technological solutions for algae biomass production as well as impediments and opportunities stemming from algae biomass use in biogas production technologies.

Hydrogen is an environmentally friendly biofuel which, if widely used, could reduce atmospheric carbon dioxide emissions. The main barrier to the widespread use of hydrogen for power generation is the lack of technologically feasible and—more importantly—cost-effective methods of production and storage. So far, hydrogen has been produced using thermochemical methods (such as gasification, pyrolysis or water electrolysis) and biological methods (most of which involve anaerobic digestion and photofermentation), with conventional fuels, waste or dedicated crop biomass used as a feedstock. Microalgae possess very high photosynthetic efficiency, can rapidly build biomass, and possess other beneficial properties, which is why they are considered to be one of the strongest contenders among biohydrogen production technologies. This review gives an account of present knowledge on microalgal hydrogen production and compares it with the other available biofuel production technologies.

These studies were designed to determine the optimum parameters of respirometric susceptibility test substrates for anaerobic digestion plant for example silage Sida. Biochemical dynamics of organic material determined by measuring blood OxiTop. The experiment was conducted in three series of research, different load measuring cells, the initial charge of organic compounds, a series of I – 5 gd.o.m/l, Series II – 10 gd.o.m/l, Series III – 20 gd.o.m/l. Fermentation was carried out in mesophilic conditions for 20 days in an anaerobic reaction chambers inoculated with activated sludge. Achieved a maximum of 3500 ml of biogas in series III, the least biogas created in Series I, which introduced the smallest load of organic compounds. Based on the results of the biogas production rate was determined in a series I was on y = 365 ml/gd.o.m, in the second series was y = 319 ml/gd.o.m. and the series III y = 278 ml/gd.o.m. Measuring the quality of the resulting biogas pointed to the relationship between the content of methane in the biogas with an initial charge of organic matter introduced into the reaction chamber, the methane content of the biogas ranged from 37% in the third series of up to 48% in the series and the experiment.