In light of the massive energy supply shortage due to the Syrian war since 2011, renewable energy adoption has a high potential to cover the actual energy demand. Hence, this study aims to shed light on the factors that affect investment in biogas technology. With the scarcity of research on alternative energies in Syria, this paper focused on the characteristics of the Syrian environment toward biogas technology adoption. The results show that Syrian society accepts and desires to adopt new technologies, representing an optimal strategy to stimulate biogas technology use and the need to spread awareness about its benefits. The SWOT model was applied to identify strengths, weaknesses, opportunities, and threats facing biogas technology adoption. The analytical hierarchy process model was applied to set priorities and make better decisions related to the knowledge of biogas, acceptance of biogas technology, desire for and common approach for its use, the resulting organic fertilizer, and administrative and financial aspects. The work concludes that the southern region was at the forefront in the areas studied in terms of weights of biogas technology investment criteria, subsequently, the central and later the coastal regions. By presenting a systematic and comprehensive approach, this study represents a roadmap to assist decision-makers in inking decisions related to adopting and deploying biogas technology on a larger scale and contributes to developing a criterion for selecting biogas sites in Syria.

• Klíčová slova
• Analytic hierarchy process, Biogas adoption, Biogas technology, Developing countries, SWOT analysis,
• Publikační typ
• časopisecké články MeSH

The sustainable production and use of small-scale biogas energy are required to ensure clean household energy access in developing countries, including the Sub-Saharan Africa (SSA) region. This is influenced by market risks, which can be identified as political, economic, social, technical, legal, and environmental (PESTLE). This study examines peer-reviewed and grey literature for the period from 2000 to 2020 to identify the PESTLE constraints and assess their impact on the sustainable development of the technology in the SSA region. The production of biogas with small-scale plants is commonly done by rural and peri-urban households. Results show that economic constraints are the most dominant and reducing at a slow pace. This is followed by political constraints, which have received much attention in the last two decades. Despite the policy improvements, broader national bioenergy policies and interventions are still to make significant gains, especially in the Central African region. In order of significance, the Southern, East, and West Africa regions have made greater progress in reducing the constraints. To achieve the sustainable development of the technology, there is a need to further address the PESTLE constraints at national and regional levels. This study partly deduces that the unsustainable production, use, and inadequate regulation of the small-scale biogas sector are delaying its transition in the SSA region.

• Klíčová slova
• Anaerobic digestion, Bioenergy policy, Developing countries, Energy access, PESTLE constraints, Sustainable development,
• MeSH
• biopaliva * MeSH
• charakteristiky rodiny MeSH
• lidé MeSH
• technologie MeSH
• trvale udržitelný rozvoj * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• systematický přehled MeSH
• Geografické názvy
• subsaharská Afrika MeSH
• Názvy látek
• biopaliva * MeSH

Biogas production at a small-scale level through anaerobic digestion has been promoted in Vietnam as an appropriate technology for cooking and animal waste management within rural households. Despite the large number of small-scale biogas plants being built, there is an increase in the reported cases of their dis-adoption. This study attempts to present the state of the art of biogas plants' abandonment issue and reveal the fate of biogas plants. The primary data were collected in Thua Thien Hue province in central Vietnam among owners of small-scale biogas plants selected with the purposive sampling technique. Methods included semi-structured interviews with respondents who abandoned their biogas technology (at least 6 months before the primary data collection) (n = 37) and with respondents who continually use it (n = 62). SPSS 25 IBM was used for the binary logit model with 6 independent variables. Using a logistic regression analysis of various cross-sectional data, key forces were uncovered to determine the factors that can influence the abandonment of biogas technology. Results showed that households with more members working on the farm and those more satisfied with the biogas plant maintenance are less likely to abandon it. Respondents provided the information that their biogas plants mainly were not used for any other purpose after dis-adoption (excepting biogas plants used for further storage of human excreta because they were connected to toilets).

• Klíčová slova
• African swine fever, Appropriate technology, Biogas plant maintenance, Fixed-dome digester, Household anaerobic digester, Manure management, Technology abandonment,
• MeSH
• anaerobióza MeSH
• biopaliva MeSH
• bioreaktory MeSH
• hnůj * MeSH
• lidé MeSH
• nakládání s odpady * MeSH
• průřezové studie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Vietnam MeSH
• Názvy látek
• biopaliva MeSH
• hnůj * MeSH

Anaerobic digestion (AD) is a widely used technology that allows for the reprocessing and reduction of waste biomass. A study was conducted to see if the AD technology might be used to process radioactively polluted agricultural biomass. For this purpose, laboratory tests were carried out with a 20-liter model biogas plant (BGP) with the radionuclide 134Cs and operational tests with the South Bohemian commercial biogas plant monitoring the radionuclide 137Cs. The activities of 134Cs in inputs, contaminated grass or maize silage and in emerging fractions were investigated in the model fermenter. The activity of 134Cs in the dry matter during the fermentation process increased by 46% on average, which corresponds to a reduction of dry matter by 43% due to the production of biogas. 137Cs activities were measured in commercial BGP maize, grass, and whole plant silage, wheat, digestate, biogas, and aerosol samples. The commercial BGP fermentation process was more efficient, with an 80% reduction in dry mass weight. Dry biomass (1.37 Bq/kg) had a 137Cs massic activity that was 4.4 times lower than the activity of dry digestate mass (6.01 Bq/kg). The activity of the 137Cs in biogas aerosol was 1.1 × 10-7 Bq/m3 or less, and the decontamination factor was 6.9 × 106 or greater. Most Cs remain in the digestate. No other ways of radioactivity leakage have been identified.

• Klíčová slova
• (137)Cs, Biogas technology, Biomass, Waste processing,
• MeSH
• anaerobióza MeSH
• biomasa MeSH
• biopaliva * MeSH
• bioreaktory MeSH
• kukuřice setá MeSH
• lipnicovité MeSH
• monitorování radiace * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biopaliva * MeSH
• Cesium-134 MeSH Prohlížeč
• Cesium-137 MeSH Prohlížeč

The presented set of data brings results of the experimental production of biogas and methane from silages of alternative substrates consisting of maize and three leguminous species with a potential to make the production of biogas more friendly to the environment because the cultivation of legumes is generally considered to be more environment friendly than the cultivation of maize: white sweet clover (Melilotus albus Medik.), fodder vetch (Vicia villosa Roth.) and white lupin (Lupinus albus L.). Obtained data allow to compare the composition of experimental substrates and their important parameters (VS, DM, NDF, ADF, CF, starch, cellulose, hemicellulose, CP, lipids and ADL) as well as the yield of biogas, methane and methane in biogas from silage produced as a monosubstrate from the biomass of maize shreddings on the one side with silages produced from the mixture of biomass from maize and diverse legumes on the other side. This set of data can contribute to awareness about possibilities for reducing environmental risks connected with the cultivation of maize in growers of energy crops and operators of biogas plants. The reason is that a considerable number of farmers do not use new technologies of growing biomass for the production of biogas as they cannot quantify the potential impact on biogas yield and hence on the profitability of biogas plant operation. The measured values demonstrate that silages made from the mixed culture were reaching at least the same production of biogas and its quality as the monocultural maize silage.

• Klíčová slova
• Anaerobic digestion, Biogas, Biomass, Cropping system, Legumes, Methane yield, Silage,
• Publikační typ
• časopisecké články MeSH

Mycotoxins can pose a threat to biogas production as they can contaminate the feedstock used in biogas production, such as agricultural crops and other organic materials. This research study evaluated the contents of deoxynivalenol (DON), zearalenone (ZEA), fumonisin (FUM), and aflatoxin (AFL) mycotoxins in maize silage prior to it being processed in a biogas plant and in digestate produced at the end of the anaerobic digestion (AD) process. In the experiment, three samples of silage were collected from one silage warehouse: Variant 1 = low contamination, Variant 2 = medium contamination, and Variant 3 = heavy contamination, which were subjected to investigation. A significantly reduced biogas production was recorded that was proportional to the increasing contamination with molds, which was primarily due to the AD of silage caused by technologically erroneous silage treatment. The AD was connected with changes in silage composition expressed by the values of VS content, sugar content, lactic acid content, acetic acid content, and the ratio of lactic acid content to acetic acid content. The production of biogas and methane decreased with the increasing contents of NDF, ADF, CF, and lignin. The only exception was Variant 2, in which the content of ADF, CF, and lignin was lower (by 8-11%) than that in Variant 1, and only the content of NDF was higher (by 9%) than that in Variant 1. A secondary factor that also correlated with changes in the composition of the substrate was the development of undesirable organisms, which further contributed to its degradation and to the production of mycotoxins. It was also demonstrated in this study that during the AD process, the tested mycotoxins were degraded, and their content was reduced by 27-100%. Only the variant with low mold contamination showed a DON concentration increase of 27.8%.

• Klíčová slova
• anaerobic biogas, anaerobic digestion, digestate, maize silage, methane, mycotoxins,
• Publikační typ
• časopisecké články MeSH

Cassava is a staple food in many countries, and this food source differs from other crops in that its processing generates a highly polluting and toxic residue (manipueira) that requires further treatment. The present study analyzed the economic feasibility of anaerobic digestion of manipueira for producing clean electricity through distributed generation (DG) while simultaneously eliminating toxic compounds. This eliminates the toxic residues. For this, an approach for the sizing of DG plants from manipueira biogas was presented, a non-trivial task which is not widespread in the literature. For two plants with different capacities, a deterministic economic analysis was carried out based on the criteria of Net Present Value, Internal Rate of Return, and Discounted Payback. Finally, the project risk was assessed through a sensitivity and stochastic analysis using Monte Carlo Simulation. The empirical verification was done on Brazilian data. When considering the NPV criterion, the results indicate a feasibility probability of 9.25% and 81.21% for scenarios 01 and 02, respectively. The results show that scale gains were important in reducing the impact of the investment and, at the same time, the larger scale of the project makes the cost of capital more relevant to the result. These findings show the need for subsidies for the investment, in addition to the promotion of specific credit lines that enable small-scale generation, or that can improve results in greater capacity.

• Klíčová slova
• Manipueira, discounted cashflow, distributed generation, financial viability, investment,
• MeSH
• biopaliva * MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Brazílie MeSH
• Názvy látek
• biopaliva * MeSH

Biogas desulfurization based on anoxygenic photosynthetic processes represents an alternative to physicochemical technologies, decreasing the risk of O2 and N2 contamination. This work aimed at assessing the potential of Allochromatium vinosum and Chlorobium limicola for biogas desulfurization under different light intensities (10 and 25 klx) and H2S concentrations (1 %, 1.5 % and 2 %) in batch photobioreactors. In addition, the influence of rising biogas flow rates (2.9, 5.8 and 11.5 L d-1 in stage I, II and III, respectively) on the desulfurization performance in a 2.3 L photobioreactor utilizing C. limicola under continuous mode was assessed. The light intensity of 25 klx negatively influenced the growth of A. vinosum and C. limicola, resulting in decreased H2S removal capacity. An increase in H2S concentrations resulted in higher volumetric H2S removal rates in C. limicola (2.9-5.3 mg L-1 d-1) tests compared to A. vinosum (2.4-4.6 mg L-1 d-1) tests. The continuous photobioreactor completely removed H2S from biogas in stage I and II. The highest flow rate in stage III induced a deterioration in the desulfurization activity of C. limicola. Overall, the high H2S tolerance of A. vinosum and C. limicola supports their use in H2S desulfurization from biogas.

• Klíčová slova
• Desulfurization, H(2)S, Methane, Photosynthetic bacteria,
• MeSH
• biopaliva MeSH
• Chlorobi * MeSH
• fotobioreaktory MeSH
• sulfan * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biopaliva MeSH
• sulfan * MeSH

The production of renewable energy in agricultural biogas plants is being widely criticized because-among other things-most of the feedstock comes from purpose-grown crops like maize. These activities (generously subsidized in the Czech Republic) generate competitive pressure to other crops that are used for feeding or food production, worsening their affordability. Unique pretreatment technology that allows substitution of the purpose-grown crops by farming residues (such as husk or straw) was built 6 years ago on a commercial basis in Pěčín (Czech Republic) under modest funding and without publicity. The design of the concept; financial assessment and moral viewpoint were analyzed based on practical operating data. It showed that the apparatus improves economic, environmental and moral acceptance as well. However, according to the government's view, public funding for this type of processing was shortened, "because waste materials represent a lower cost". The impact of such governance was analyzed as well.

• Klíčová slova
• Environmental assessment, Financial analysis, Moral consideration, Process management, Renewable energy,
• MeSH
• biopaliva * MeSH
• elektrárny MeSH
• financování vládou MeSH
• lidé MeSH
• mravy MeSH
• náklady a analýza nákladů MeSH
• průmyslový odpad * MeSH
• technologie * ekonomika   etika   MeSH
• zachování přírodních zdrojů * MeSH
• zachování zdrojů energie * MeSH
• zásobování potravinami * ekonomika   etika   MeSH
• zemědělské plodiny MeSH
• zemědělství * ekonomika   etika   MeSH
• životní prostředí MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• biopaliva * MeSH
• průmyslový odpad * MeSH

Hydrogen sulfide is widely known as the most undesirable component of biogas that caused not only serious sensoric and toxic problems, but also corrosion of concrete and steel structures. Many agricultural and industrial waste used in biogas production, may contain a large amount of substances that serve as direct precursors to the formation of sulfide sulfur-sources of hydrogen sulfide in the biogas. Biological desulfurization methods are currently promoted to abiotic methods because they are less expensive and do not produce undesirable materials which must be disposed of. The final products of oxidation of sulfides are no longer hazardous. Biological removal of sulfide from a liquid or gaseous phase is based on the activity of sulfur-oxidizing bacteria. They need an oxidizing agent such as an acceptor of electrons released during the oxidation of sulfides-atmospheric oxygen or oxidized forms of nitrogen. Different genera of sulfur-oxidizing bacteria and their technological application are discussed.

• Klíčová slova
• Autotrophic denitrification, Biodesulfurization, Biogas, Hydrogen sulfide, Sulfur-oxidizing bacteria,
• MeSH
• Bacteria metabolismus   MeSH
• biotechnologie metody   MeSH
• mikrobiologie životního prostředí * MeSH
• oxidace-redukce MeSH
• síra metabolismus   MeSH
• sulfidy MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• síra MeSH
• sulfidy MeSH