The influence of carbon content in the mixture of substrates on methane production

Abstract

A lot of different chemical reactions take place in the biochemical process of biogas formation but the most important of them include the reaction of bonding carbon dioxide with hydrogen and the decomposition of acetic acid. Other factors, such as temperature, pH, etc., only limit the amount of methane or, in extreme cases, they even stop the process of methane formation. The paper presents an analysis of the influence of the amount of available carbon in the substrate and inoculum on biogas production, as well as of the validity of the relation between methane production and carbon/hydrogen ratio which is often mentioned in the literature. The analyses were made on the basis of the results of several dozen laboratory experiments on methane production for five groups of substrates: cultivated plants, animal faeces, plant waste, animal waste and municipal waste. This provided the basis for the formulation of the conclusion that there is no significant relation between the carbon/hydrogen ratio and methane production, and an alternative biogas calculator was suggested to estimate methane production with the known content of carbon in the substrate and inoculum. This calculator was also adapted to the conditions of agricultural biogas plants, and then it was tested in those conditions. It should also be mentioned that the innovative aspect of the study presented herein is the model developed for the estimation of methane production on the basis of carbon content only, providing estimates with a smaller error than in the case of the calculators!

Evaluation of physicochemical, microbiological, and energetic characteristics of four agricultural wastes for use in the production of green energy in Moroccan farms

“…The amount of carbon available of the substrate determines the maximum amount of methane and carbon dioxide that can be formed by anaerobic digestion [58]. We also know that carbon is essential for bacterial growth [59].…”

Higher Abundance of Sediment Methanogens and Methanotrophs Do Not Predict the Atmospheric Methane and Carbon Dioxide Flows in Eutrophic Tropical Freshwater Reservoirs

“…P-PO 4 3– influences methanogenesis and upstream metabolic pathways, including acidogenesis and acetogenesis ( Wang et al, 2015 ). DTC availability is a likely determinant of maximum CO 2 and CH 4 production ( Mulka et al, 2016 ), while BOD also implies organic carbon availability ( Vigiak et al, 2019 ). Higher DIC concentration in aquatic environments originate from organic carbon remineralization to CO 2 and methanogenesis ( Ogrinc et al, 2002 ), corroborated by the positive correlation observed.…”

Microbiome dysbiosis regulates the level of energy production under anaerobic condition

“…Our analysis revealed that OC and TN content was higher at the time of loading of slurry in the AD compared to that of highest biogas production stage (at Day 35). The amount of carbon available of the substrate determines the maximum amount of CH 4 and CO 2 that can be formed by anaerobic digestion [7]. Conversely, C/N ratio remained lowest in this peak stage of CH 4 production.…”

“…However, attention must be paid towards undesired emissions of methane (CH 4 ) and nitrous oxide (N 2 O) from manure storage [6]. Moreover, anaerobic digestion of livestock manure improves organic fertilizer quality compared with undigested manure [7], and the load of the pathogenic microorganisms and related antimicrobial resistance is also decreased through the biological process of anaerobic degradation [8]. The rising energy prices and increasing concern of emission of greenhouse gases are the major concern for the people and agro-industries worldwide to consider the wider application of AD technology.…”