scholarly journals EFFECT OF SOLIDS CONCENTRATION AND SUBSTRATE TO INOCULUM RATIO ON METHANE PRODUCTION FROM ORGANIC MUNICIPAL SOLID WASTE

Detritus ◽  
2021 ◽  
pp. 3-12
Author(s):  
Mario F. Castellón-Zelaya ◽  
Simón González-Martínez
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Methane Production ◽  
Reaction Times ◽  
Operational Parameters ◽  
Anaerobic Reactors ◽  
Solids Concentration ◽  
Biogas Plants ◽  
Substrate To Inoculum Ratio ◽  
The Times

Organic Fraction of Municipal Solid Waste (OFMSW) is usually stored under variable humidity conditions and long periods before processing them in anaerobic digestion plants. Lately, the fermented OFMSW is mixed with recirculated digestate from the same biogas plants, which is used as methanogenic inoculum. Although both the moisture content during the storage of OFMSW and the inoculum concentration in the feed mixture to the anaerobic reactors are determining factors for the process, to our knowledge, no studies have been done about the combined effect of these operational parameters on methane production. Therefore, this study focused on determining how humidity conditions during OFMSW storage and the substrate to inoculum ratio (S/I) in the methanisation stage can be adjusted to improve methane production. OFMSW was stored at 35°C and 10, 20, and 28%TS for 15 days. In the second stage, methanisation of previously fermented OFMSW was allowed at different S/I ratios of 0.5, 1.0, and 1.5. Ethanol and acetic acid accounted for 90% of all products of fermentation. The lowest solids concentration reached the highest fermentation degree. Compared to fresh OFMSW (without storing), methane from fermented OFMSW increased 32% and, the times to reach the maximum methane production decreased between 11 and 40%. For fermented OFMSW, S/I ratio of 1.0 is the best condition to produce methane. ANOVA shows that, independently of solid concentration during storage, the S/I ratio is the main parameter improving methane production and reducing reaction times.

scholarly journals Silage of the organic fraction of municipal solid waste to improve methane production

2021 ◽  
Author(s):  
Mario F. Castellón-Zelaya ◽  
Simón González-Martínez
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Methane Production ◽  
Organic Fraction ◽  
Acid Fermentation ◽  
Fermentation Processes ◽  
Silage Fermentation ◽  
Solids Concentration ◽  
Biogas Plants ◽  
Metabolites Production

Abstract The silage of the organic fraction of municipal solid waste (OFMSW) is a common practice in biogas plants. During silage, fermentation processes take place, affecting the later methanisation stage. There are no studies about how OFMSW silage affects methane production. This work aimed to determine the effects of silage (anaerobic acid fermentation) at different solids concentrations and temperatures on methane production. OFMSW was ensiled at 20, 35, and 55 °C with total solids (TS) concentrations of 10, 20, and 28% for 15 days. The ensiled OFMSW was then tested for methane production at the substrate to inoculum ratios (S/I) of 0.5, 1.0, and 1.5. Independently of the temperature, the production of the metabolites during silage increases with decreasing solids concentration. The highest metabolites production were lactic acid, ethanol, and acetic acid, representing together 95% of the total. Methane production from ensiled OFMSW at 10% solids concentration shows, under every tested condition, better methane production than from fresh OFMSW. Ensiled OFMSW produces more methane than fresh OFMSW, and methane production was highest at 35 °C.

Anaerobic co-digestion of organic fractions of municipal solid waste: Synergy study of methane production and microbial community

2021 ◽  
Vol 151 ◽  
pp. 106137
Author(s):  
Yiran Zhou ◽  
Kangyi Huang ◽  
Xiuyao Jiao ◽  
Nemanja Stanisavljevic ◽  
Lei Li ◽  
...  
Keyword(s):  
Microbial Community ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Methane Production ◽  
Organic Fractions

scholarly journals The generation of a mathematical model of the biogas production process from organic municipal solid waste

2020 ◽  
Vol 180 ◽  
pp. 02019 ◽  
Author(s):  
Marzhan Temirbekova ◽  
Madina Aliyarova ◽  
Iliya Iliev ◽  
Aliya Yelemanova ◽  
Saule Sagintayeva
Keyword(s):  
Mathematical Model ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Biogas Plant ◽  
Model Parameters ◽  
Biochemical Processes ◽  
Biogas Plants ◽  
The Mathematical Model

This paper justifies the efficiency of the biogas collection and utilization at the MSW (municipal solid waste) landfill in Almaty with the installation of several modern biogas plants. The optimal mode of processes occurring in a biogas plant is determined by computer generated simulations. Mathematical model parameters were identified to describe biochemical processes occurring in a biogas plant. Two approaches are used to resolve the mathematical model: the finite-difference method for solving the system of differential equations and simulation modeling by using the Any Logic package. A program is written in the algorithmic language C ++. Numerous calculations were carried out, the results of which are presented in curves and their qualitative picture is consistent with the ongoing processes. The created computer program allows to make a preliminary forecast of anaerobic fermentation occurring in the bioreactor depending on volume of the substrate, methane microorganisms and temperature conditions.

High-solids anaerobic digestion: comparison of three pilot scales

2008 ◽  
Vol 58 (9) ◽  
pp. 1757-1763 ◽  
Author(s):  
J. Guendouz ◽  
P. Buffière ◽  
J. Cacho ◽  
M. Carrère ◽  
J.-P. Delgenes
Keyword(s):  
Anaerobic Digestion ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Methane Production ◽  
Operating Conditions ◽  
High Solids ◽  
Dry Digestion ◽  
Mesophilic Conditions ◽  
Production Efficiencies

Two experiments were undertaken in three different experimental set-ups in order to compare them: an industrial 21-m3 pilot reactor, a new 40-ℓ laboratory pilot reactor and bmp type plasma bottles. Three consecutive batch dry digestion tests of municipal solid waste were performed under mesophilic conditions with the same feedstock in all vessels. Biogas and methane production at the end of the tests were similar (around 200 m3 CH4STP/tVS) for both pilot reactors and were different from the bottle tests. The dynamics of methane production and VFA accumulation concurred. However, the maximal levels of VFA transitory accumulation varied between reactors and between runs in a same reactor. Ammonia levels were similar in both reactors. These results show that the new reactor accurately imitates the conditions found in the larger one. Adaptation of microorganisms to the waste and operating conditions was also pointed out along the consecutive batches. Thermophilic semi-continuous tests were performed in both reactors with similar conditions. The methane production efficiencies were similar.

Anaerobic digestion of co-mingled municipal solid waste and sewage sludge

1998 ◽  
Vol 38 (2) ◽  
pp. 127-132 ◽  
Author(s):  
N. Hamzawi ◽  
K. J. Kennedy ◽  
D. D. McLean
Keyword(s):  
Sewage Sludge ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Biogas Production ◽  
Empirical Models ◽  
Organic Fraction ◽  
Primary Sludge ◽  
Digestion Process ◽  
Solids Concentration ◽  
Anaerobic Biodegradability

This study evaluated the technical feasibility of the anaerobic co-digestion process in the context of typical North American solid waste. Using biological activity tests, an optimal mixture was identified with 25% organic fraction of municipal solid waste (OFMSW) and 75% sewage sludge (65% raw primary sludge (RAW), 35% thickened WAS (TWAS)) based on biogas production. Also, based on the rate of biogas production, the most anaerobically biodegradable components of the OFMSW were paper and grass. The TWAS and the newspaper were found to be the least biodegradable components. Lab-scale testing indicated that alkaline pretreatment increased the biodegradability of the sewage sludge/OFMSW mixture the most, as compared to the untreated control. Thermochemically pretreated feedstocks inhibited anaerobic biodegradability as compared to the control, whereas the anaerobic biodegradability of thermally pretreated feed was not found to be significantly different from that of the control. Empirical models were developed based on alkaline dose, feed total solids concentration and particle size for biogas production and removal of TS and VS. All three experimental factors were found to be significant with respect to the response variables studied.

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