Fermentation Of Organic Wastes Research Articles

Exploring Conditions That Enhance Durability and Performance of a Tubular Solid Oxide Fuel Cell Fed with Simulated Biogas

Tubular solid-oxide fuel cells (t-SOFCs) fed directly with biogas, an equiproportioned mixture of CH4 and CO2 produced by fermentation of organic waste, are subject to nonuniform thermal stresses due to internal dry reforming in the anode entrance region coupled with structure exfoliation due to coking, resulting eventually in cell rupture. The integral t-SOFC is of practical interest, although many laboratory studies are conducted in differential button cells. Guided by mechanistic understanding and a robust thermodynamic model, the operating temperature and biogas feed composition were explored experimentally in order to enhance durability and performance of the t-SOFC. Thus, a temperature of 900 °C, a feed CH4/CO2 ratio of 45/55, and a fuel utilization ≥25% were found to be optimal. The cell durability, performance, efficiency, and outlet gas composition at open-circuit voltage (OCV) as well as at different loads were found to be in accord with a thermodynamic analysis and mechanistic understanding based on a set of four independent overall reactions (ORs). It is shown that the OCV is independent of the chosen electrodic OR. In addition to single-tube experiments, a 5-tube SOFC pilot-unit was preliminarily tested as a step toward scale-up of this promising renewable energy technology.

Advanced Direct Internal Reforming Concepts for Solid Oxide Fuel Cells Running with Biogas

For the effective utilization of biogas, a CH4-CO2 mixture obtained from the anaerobic fermentation of organic wastes, as an alternative fuel for power generation, high temperature solid oxide fuel cell (SOFC) is one of the most attractive technologies due to its considerably high efficiency of over 50 %. Capability of direct internal reforming (DIR) operation of SOFC can make fuel-processing unit more simple and compact, and can further increase efficiency because heat released during power generation can be recycled for the fuel reforming in the stack. When biogas is supplied directly to SOFC, H2, main reactant for the electrochemical oxidation to generate electricity, is produced within the porous anode material through the simultaneous methane steam and dry reforming reactions, hereafter called methane multiple-reforming (MMR) process (Fig. 1) [1]. However, excess stresses thermally induced by the strong endothermic nature of the MMR process might cause electrolyte fracture. Therefore, the MMR process has to be properly controlled. In this study, advanced concepts to enhance cell performance and reduce thermal stresses accompanied by DIR were studied. Fig. 2-a shows an in-cell reformer concept, a sheet of Ni-loaded paper-structured catalyst (PSC) [2,3] is placed on the anode to partially reduce CH4conversion within the anode volume. Fig. 2-b shows a concept with thin gas-barrier mask made from dense YSZ on the anode surface, which can control reforming rate along fuel flow direction. Current-voltage (I-V) curves for the concepts of Figs. 2-a and b were measured at 800 oC using a 20 x 50 mm2 anode-supported cell (ASC) with the direct feed of simulated biogas mixture (CH4/CO2= 1), and then, a 3-dimensional CFD model of ASC coupling mass- and heat transfer, MMR and electrochemical processes was adjusted so that it can reproduce measured electrochemical behavior. For precisely predicting the consumption and production rates of gaseous species involved in the MMR process, the MMR was modeled using a method based on artificial neural network (ANN) (Inputs: CH4, CO2/CH4, H2O/CH4, Temperature; Outputs: Consumption and production rates of CH4 and H2, respectively). Using the experimentally-verified CFD model, distributions of gaseous species in fuel channel, temperature, thermally-induced stresses in electrolyte and cell deformations were estimated. This study revealed that electrolyte crack can occur at the middle region of the cell length while the minimum electrolyte temperature appears close to the fuel inlet. Performance enhancement with the in-cell reformer concept was confirmed, as shown in Fig. 3. Meanwhile, the concept using gas-barrier mask was found to be effective to reduce temperature gradient within the cell (see Fig. 4), as a result, increasing mechanical stability of DIR-SOFC. References 1 Meng Ni, Int. J. of Hydrogen Energy 38 (36) (2013) 16373–16386. 2 Y. Shiratori, T. Ogura, H. Nakajima, M. Sakamoto, Y. Takahashi, Y. Wakita, T. Kitaoka, K. Sasaki, Int. J. Hydrogen Energy 38 (2013) 10542–10551. 3 Y. Shiratori, M. Sakamoto, J. Power Sources 332 (2016) 170-179. Figure 1

Enrichment of d-lactic acid from organic wastes catalyzed by zero-valent iron: an approach for sustainable lactate isomerization

Approach for the enrichment of highly optically active d-lactic acid from organic waste fermentation by catalyzing using zero-valent iron.

Growth performances and changes of macronutrient ion concentrations in the culture medium when Euglena gracilis was cultured with nitrified digestate

ABSTRACTWe investigated the possibility of using Euglena gracilis to convert digestate from methane fermentation of organic wastes into a medium for soilless crop culture. The growth of E. gracilis cultured with aqueous solutions containing filtrate of raw digestate at 1–30% (v/v) and nitrified digestate at 10–100% (v/v) was examined. Concentrations of plant macronutrient ions in nitrified digestate before and after culturing E. gracilis were also examined. Specific growth rates in aqueous solutions containing filtrate of raw digestate at 1–10% and nitrified digestate at 10–100% showed no significant differences, respectively (0.781 ± 0.031 d−1 and 0.925 ± 0.033 d−1, mean ± standard error). The rates in the filtrate of nitrified digestate were significantly higher than those in the filtrate of raw digestate. Moreover, there were no significant differences between the concentrations of plant macronutrient ions other than in the filtrate of nitrified digestate before and after culturing E. gracilis. The concentration of decreased significantly by 10.5% of the initial concentration. As a result, the constituent ratio of plant macronutrient ions other than magnesium in the solution after culturing E. gracilis was similar to that in a standard nutrient solution for soilless culture.

Electricity Production from Organic Wastes Fermentation by Microbial Fuel Cell Process

This research studied the electricity production from organic wastes fermentation by microbial fuel cell by using a single chamber microbial fuel cell (SCMFC). Two sizes (1 L and 10 L) of simple SCMFC were fabricated by using a cylindrical plastic tank which anode compartment and cathode compartment separated by plastic plate with hole and covered with cotton fabric. The anode electrode contacted with organic matter and microorganisms where anaerobic reaction occurred to generate electron and proton. The electrons transferred through an external circuit while the protons diffused through the solution to the cathode electrode for reducing oxygen to water. From the study of the effect of different electrode types (carbon graphite rod, zinc metal, and copper metal) to the electricity generation using the SCMFC size 1 L in fermentation with synthetic sweetness solution (22%Brix) and the effective microorganism (EM) for 36 hrs, it found that the fuel cell which used copper metal as electrode produced electricity increasing over the times and has more efficient than the other electrode types. The study of electricity generation from organic waste fermentation by using the SCMFC size 10 L and using copper metal as electrode, the results showed that the fermentation of pineapple waste produced the current density, potential density, and power density higher than the fermentation of bananas and the fermentation of food garbage with EM. An optimal period of time for the production of electricity from this microbial fuel cell is the first five days of fermentation that the cells has voltage »500 mV, the current density 25.52 mA m-2, potential density 104.69 V m-2 and power density 12.59 mW m-2, and then decline over time five days (120 hrs). Moreover the bio-liquid fertilizer and the residues from the fermentation can be further used in agricultural because of the nutrient content (N, P, K), organic carbon and organic material contents available.

Comparison of alternative membranes to replace high cost Nafion ones in microbial fuel cells

The aim of this work was to compare the performance of microbial fuel cell (MFC) fitted with alternative, low cost membranes (AMs). Lab scale single chamber MFCs were loaded with sulphate-reducing inocula as biocatalyst and leachate from dark fermentation of organic wastes as substrate. The MFCs were fitted with either hybrid membrane made of agar and Nafion MH, agar membrane M6 (6% agar), agar membrane M2 (2% agar) or the control Nafion 117 membrane (NF-117).We found that the internal resistances (Rint) were generally low for all the cells. The lowest Rint corresponded to alternative membranes M6 and MH with a value ca. 90 Ω. So, results of Rint tend to favour the AMs. The costs of these membranes were only 2.5–6% of the cost of the NF-117 one. However, the powers delivered by MFC fitted with AMs were 4–40% (weighed average 28%) of the power of the cell fitted with the conventional NF-117. In spite of the reduced power, the AMs still exhibited a higher Power/Cost ratio (0.9–4.4. mW/US$) than that of the NF membrane (0.23 mW/US$.)We should highlight that the AMs do not require the conditioning treatment with hazardous chemicals typical of NF-117. Therefore, there is another competitive edge of AMs in the form of avoided costs of chemicals and hazardous waste disposal.

Opportunities of energy supply of farm holdings on the basis of small-scale renewable energy sources

One of the major national economic problems of Russia is raising of agricultural production, which will provide strategic security and sustainable supply of the population with provisions. Creation of subsidiary small holdings, farm holdings, and peasant farm holdings will require addressing issues of energy supply. At considerable distance of small farms from centralized energy systems (by fuel, electricity and thermal energy) it is proposed to create a system of local energy networks on the basis of low-powered power plants using renewable energy sources (RES). There is economic unreasonableness of use of imported components of small power plants. Creation of new combined small power plants on renewable energy sources produced by domestic manufacturers is recommended. Schemes of arrangements of small power plants based on renewable energy sources are proposed, variants and characteristics of a basic source are provided—biogas plants developed by the authors. Calculations revealed that heat and power supply of self-contained farms distant from small power plants based on renewable energy sources is 2.5–2.6 times cheaper than from centralized networks. Production of biogas through anaerobic fermentation of organic waste of cattle complexes is considered as the basis. The analysis of biowaste output in various cattle farms is carried out, and the volume of biogas is determined to meet the requirements of these farms in electrical and thermal energy. The objective of the present article is to study the possibility of creating small combined power plants in Russia based on renewable sources of energy for independent consumers.

Changes in glucose fermentation pathways by an enriched bacterial culture in response to regulated dissolved H2 concentrations.

It is well established that metabolic pathways in the fermentation of organic waste are primarily controlled by dissolved H2 concentrations, but there is no reported study that compares observed and predicted shifts in fermentation pathways induced by manipulating the dissolved H2 concentration. A perfusion system is presented that was developed to control dissolved H2 concentrations in the continuous fermentation of glucose by a culture highly enriched towards Thermoanaerobacterium thermosaccharolyticum (86 ± 9% relative abundance) from an originally diverse consortia in the leachate of a laboratory digester fed with municipal solid waste. Media from a 2.5 L CSTR was drawn through sintered steel membrane filters to retain biomass, allowing vigorous sparging in a separate chamber without cellular disruption. Through a combination of sparging and variations in glucose feeding rate from 0.8 to 0.2 g/L/d, a range of steady state fermentations were performed with dissolved H2 concentrations as low as an equivalent equilibrated H2 partial pressure of 3 kPa. Trends in product formation rates were simulated using a H2 regulation partitioning model. The model correctly predicted the direction of products redistribution in response to H2 concentration changes and the acetate and butyrate formation rates when H2 concentrations were less than 6 kPa. However, the model over-estimated acetate, ethanol and butanol productions at the expense of butyrate production at higher H2 concentrations. The H2 yield at the lowest dissolved H2 concentration was 2.67 ± 0.08 mol H2 /mol glucose, over 300% higher than the yield achieved in a CSTR operated without sparging.

Development of a Photosynthetic Microbial Electrochemical Cell (PMEC) Reactor Coupled with Dark Fermentation of Organic Wastes: Medium Term Perspectives

In this article the concept, the materials and the exploitation potential of a photosynthetic microbial electrochemical cell for the production of hydrogen driven by solar power are investigated. In a photosynthetic microbial electrochemical cell, which is based on photosynthetic microorganisms confined to an anode and heterotrophic bacteria confined to a cathode, water is split by bacteria hosted in the anode bioactive film. The generated electrons are conveyed through external “bio-appendages” developed by the bacteria to transparent nano-pillars made of indium tin oxide (ITO), Fluorine-doped tin oxide (FTO) or other conducting materials, and then transferred to the cathode. On the other hand, the generated protons diffuse to the cathode via a polymer electrolyte membrane, where they are reduced by the electrons by heterotrophic bacteria growing attached to a similar pillared structure as that envisaged for the anode and supplemented with a specific low cost substrate (e.g., organic waste, anaerobic digestion outlet). The generated oxygen is released to the atmosphere or stored, while the produced pure hydrogen leaves the electrode through the porous layers. In addition, the integration of the photosynthetic microbial electrochemical cell system with dark fermentation as acidogenic step of anaerobic digester, which is able to produce additional H2, and the use of microbial fuel cell, feed with the residues of dark fermentation (mainly volatile fatty acids), to produce the necessary extra-bias for the photosynthetic microbial electrochemical cell is here analyzed to reveal the potential benefits to this novel integrated technology.

Effects of pH control and concentration on microbial oil production from Chlorella vulgaris cultivated in the effluent of a low-cost organic waste fermentation system producing volatile fatty acids

The objective of this study was to investigate the feasibility of applying volatile fatty acids (VFAs) produced from low-cost organic waste to the major carbon sources of microalgae cultivation for highly efficient biofuel production. An integrated process that consists of a sewage sludge fermentation system producing VFAs (SSFV) and mixotrophic cultivation of Chlorella vulgaris (C. vulgaris) was operated to produce microbial lipids economically. The effluents from the SSFV diluted to different concentrations at the level of 100%, 50%, and 15% were prepared for the C. vulgaris cultivation and the highest biomass productivity (433±11.9mg/L/d) was achieved in the 100% culture controlling pH at 7.0. The harvested biomass included lipid contents ranging from 12.87% to 20.01% under the three different effluent concentrations with and without pH control. The composition of fatty acids from C. vulgaris grown on the effluents from the SSFV complied with the requirements of high-quality biodiesel. These results demonstrated that VFAs produced from the SSFV are favorable carbon sources for cultivating C. vulgaris.

Biohydrogen, biomethane and bioelectricity as crucial components of biorefinery of organic wastes: a review.

Biohydrogen is a sustainable form of energy as it can be produced from organic waste through fermentation processes involving dark fermentation and photofermentation. Very often biohydrogen is included as a part of biorefinery approaches, which reclaim organic wastes that are abundant sources of renewable and low cost substrate that can be efficiently fermented by microorganisms. The aim of this work was to critically assess selected bioenergy alternatives from organic solid waste, such as biohydrogen and bioelectricity, to evaluate their relative advantages and disadvantages in the context of biorefineries, and finally to indicate the trends for future research and development. Biorefining is the sustainable processing of biomass into a spectrum of marketable products, which means: energy, materials, chemicals, food and feed. Dark fermentation of organic wastes could be the beach-head of complete biorefineries that generate biohydrogen as a first step and could significantly influence the future of solid waste management. Series systems show a better efficiency than one-stage process regarding substrate conversion to hydrogen and bioenergy. The dark fermentation also produces fermented by-products (fatty acids and solvents), so there is an opportunity for further combining with other processes that yield more bioenergy. Photoheterotrophic fermentation is one of them: photosynthetic heterotrophs, such as non-sulfur purple bacteria, can thrive on the simple organic substances produced in dark fermentation and light, to give more H2. Effluents from photoheterotrophic fermentation and digestates can be processed in microbial fuel cells for bioelectricity production and methanogenic digestion for methane generation, thus integrating a diverse block of bioenergies. Several digestates from bioenergies could be used for bioproducts generation, such as cellulolytic enzymes and saccharification processes, leading to ethanol fermentation (another bioenergy), thus completing the inverse cascade. Finally, biohydrogen, biomethane and bioelectricity could contribute to significant improvements for solid organic waste management in agricultural regions, as well as in urban areas.

Lactic acid accumulation from sludge and food waste to improve the yield of propionic acid-enriched VFA

According to our previous study, propionic acid-enriched volatile fatty acids (VFA), the preferred carbon source of biological wastewater nutrient removal, can be produced via the lactic acid pathway during the two-stage fermentation of organic wastes using Propionibacterium acidipropionici. In the current study a new strategy, based on lactic acid accumulation from sludge and food waste, was introduced to significantly increase the yield of propionic acid-enriched VFA. First, the effect of different temperature on the two-stage fermentation was fully discussed. Both advantages and disadvantages of the fermentation in different temperatures were elaborated. Furthermore, the proposed metabolic pathway at 35°C and 50°C was introduced. It was observed that by initially controlling temperature at 50°C for 4h and subsequently at 35°C for 2d, the steady and maximal accumulation of lactic acid was obtained in the first stage, which resulted in the yield of propionic acid-enriched VFA in the second stage being increased to 15.3g COD/L and the percentage of propionic acid in VFA reaching 69.9%.

Comparative Study of the Bio-Disintegration Behavior of Polylactic Acid under Laboratory and Pilot-Scale Composting Conditions

In recent years, compostable plastics have gained a great attention as green materials due to the problems of more plastic waste generated each year over the world. One attractive of compostable plastics is that after use they can be biodegraded by natural microorganisms in the composting process within a specified period of time. Degree and rate of disintegration during composting is an important requirement that is used to determine the compostability of these plastics. This research work studied and compared the disintegration behaviors of PLA laboratory and pilot-scale composting conditions according to ISO 20200:2004 and ISO 16929:2002. Finally, the results from the disintegration testing could be used to evaluate the compostability, biological properties and impacted of a plastic material on the fermentation of organic waste in the composting plant.

The influence of total solids content and initial pH on batch biohydrogen production by solid substrate fermentation of agroindustrial wastes

Hydrogen is a valuable clean energy source, and its production by biological processes is attractive and environmentally sound and friendly. In México 5 million tons/yr of agroindustrial wastes are generated; these residues are rich in fermentable organic matter that can be used for hydrogen production. On the other hand, batch, intermittently vented, solid substrate fermentation of organic waste has attracted interest in the last 10 years. Thus the objective of our work was to determine the effect of initial total solids content and initial pH on H2 production in batch fermentation of a substrate that consisted of a mixture of sugarcane bagasse, pineapple peelings, and waste activated sludge. The experiment was a response surface based on 22 factorial with central and axial points with initial TS (15–35%) and initial pH (6.5–7.5) as factors. Fermentation was carried out at 35 °C, with intermittent venting of minireactors and periodic flushing with inert N2 gas. Up to 5 cycles of H2 production were observed; the best treatment in our work showed cumulative H2 productions (ca. 3 mmol H2/gds) with 18% and 6.65 initial TS and pH, respectively. There was a significant effect of TS on production of hydrogen, the latter decreased with initial TS increase from 18% onwards. Cumulative H2 productions achieved in this work were higher than those reported for organic fraction of municipal solid waste (OFMSW) and mixtures of OFMSW and fruit peels waste from fruit juice industry, using the same process. Specific energetic potential due to H2 in our work was attractive and fell in the high side of the range of reported results in the open literature. Batch dark fermentation of agrowastes as practiced in our work could be useful for future biorefineries that generate biohydrogen as a first step and could influence the management of this type of agricultural wastes in México and other countries and regions as well.

Fluid-dynamics characteristics of a vortex-ingesting stirred tank for biohydrogen production

In this work, a novel stirred tank for the production of biohydrogen by fermentation of organic wastes is presented. The bioreactor is designed for ensuring effective mixing of the liquid phase, full contact between the substrate and the biofilm and energy efficient hydrogen recovery. A vortex-ingesting dual impeller stirred vessel equipped with a central draft tube containing the support for the attached-growth process is proposed. The local hydrodynamics features of the system have been investigated experimentally by Particle Image Velocimetry (PIV) and Digital Image Processing methods for determining the velocity fields of the two phases, the bubble size distribution and the central vortex shape at different working conditions. Additionally, power consumption was measured by a strain gauge technique for quantifying energy requirements. The results confirm that the reactor hydrodynamics characteristics are adequate for the selected application and that it can ensure the external gas recirculation towards a gas separation unit for the hydrogen recovery and purification, without additional energy input with respect to that provided for stirring.

Characterization by length heterogeneity (LH)-PCR of a hydrogen-producing community obtained in dark fermentation using coastal lake sediment as an inoculum

Sustainable biohydrogen production can be achieved by dark fermentation of organic wastes, and studies were carried out using a range of substrates and inocula. The bacterial populations involved were mainly identified as facultative anaerobes (Enterobacteriaceae) and strictly anaerobes (Clostridiales), and their dynamics in relation to H2 and metabolite production depends on the physical and environmental conditions of the bioreactor. This study has evaluated the use of length heterogeneity (LH)-PCR fingerprinting to detect changes in the microbial community during continuous hydrogen production under dark fermentation. A mesophilic continuous dark fermentation was established using coastal lake sediment as an inoculum in a synthetic medium with glucose as a substrate. The LH-PCR profiling associated to the sequencing of 16S rRNA genes was used for the characterization of the bacterial community and identification of species during a continuous production of H2. The resulting dominant units of the communities present at both 24 h (batch) and 210 h (continuous culture) were affiliated to species of the genus Clostridium. Fluctuations based on their relative abundance over time were observed. At 24 h, a higher ratio was detected for the group Clostridium butyricum - Clostridium tertium followed by Clostridium bifermentans and Clostridium perfringens, while at 210 h, the group Clostridium aurantibutyricum - Clostridium acetobutylicum was the most abundant. The LH-PCR profiling has proven to be a sensitive and rapid method for the evaluation of the dynamics of a functional consortium formed by species of the genus Clostridium and has a potential for studies aimed at the optimization of biohydrogen production.

Mitigation of climate change: which technologies for Vietnam?

Vietnam is one of the countries suffering from the most serious adverse effects due to climate change and sea level rise. The main cause of climate change is the increased activities generating greenhouse gases. Organic waste is the main source of carbon dioxide emission, which has the largest concentration among different kinds of greenhouse gases in the earth’s atmosphere. The conversion of organic waste and biomass into energy contributes not only to supply cleaner energy but also to reduce emissions of greenhouse gases. Vietnam has a large potential of biomass and agricultural by-products. The technologies to turn biomass into different kinds of bio-energies were developed and applied all over the world. Biogas was called as "brown revolution" in the field of new energy. Biogas production technology now has been studied and applied widely in the world, particularly in developing countries with warm climate that is suitable for anaerobic fermentation of organic waste. The biogas digester can be built with any capacity, needs small investment and the input materials are widely available. The biogas energy is used for many purposes such as cooking, lighting, running engines, etc. It is a production technology quite consistent with the economy of developing countries and really brings to life more civilized and convenient to rural areas.

Improving Biogas Separation and Methane Storage with Multilayer Graphene Nanostructure via Layer Spacing Optimization and Lithium Doping: A Molecular Simulation Investigation

Methane is a desirable alternative to conventional fossil fuels, and also a main component of biogas from anaerobic fermentation of organic wastes. However, its relatively lower purity and poor storage by existing adsorbent materials negatively affect its wide application. Thus, efficient, cost-effective, and safe adsorbent materials for methane purification and storage are highly desired. In this study, multilayer graphene nanostructures (MGNs) with optimized structure are investigated as a potential adsorbent for this purpose. The effects of layer distance and Li doping on MGN performance in terms of methane storage and acid gas (H(2)S and CO(2)) separation from biogas are examined by molecular simulations. The mechanisms for the interactions between gas molecules and substrates are elucidated by analyzing the binding energy, geometric structures, and charge distribution from the first-principles calculations. The results show that nonhydrocarbons in biogas can be effectively separated using Li-doped MGNs with the optimal layer distance of 0.68 nm, and then the pure methane gas can be stored in MGNs with capacity satisfying the DOE target. This work offers a molecular-level insight into the interactions between gas molecules and MGNs and might provide useful information for development of new materials for methane purification and storage.

Enhanced H2 fermentation of organic waste by CO2 sparging

This study aimed to improve the productivity of dark fermentative hydrogen production from organic waste. An anaerobic sequencing batch reactor was used for hydrogen fermentation and it was fed with food waste (VS 4.4 ± 0.2% containing 27 g carbohydrate-COD/L) at various CO2 sparging rates (40–120 L/L/d), hydraulic retention times (HRTs; 18–42 h), and solid retention times (SRTs; 18–160 h). CO2 sparging increased the H2 productivity by 5–36% at all the examined conditions, confirming the benefit of the replacement of headspace gas by CO2. The maximum H2 production was obtained by CO2 sparging at 80 L/L/d, resulting in the H2 productivity of 3.18 L H2/L/d and the H2 yield of 97.3 mL H2/g VSadded. Increase of n-butyrate and isopropanol yields were concurrent with the enhanced H2 yield by CO2 sparging. Acidogenic efficiency, the sum of H2, organic acid, and alcohol, in the CO2-sparged reactor ranged from 47.9 to 56.0%, which was comparable to conventional acidogenesis. Thermodynamic analysis confirmed that both CO2 sparging and CO2 removal were beneficial for H2-producing reactions, but CO2 sparing has more profound effect than CO2 removal on inhibiting H2-consuming reactions.

Energetic Valorization of Biomethane Produced from Cow-Dung

The anaerobic digestion offers an advantageous alternative to landfilling, incineration and composting since it is considered as the most appropriate treatment solution. Indeed, the biogas naturally produced by the fermentation of organic waste into anaerobic digesters, contains between 40 and 60% of methane, which gives it fuel character and its valorisation allows energy conservation while protecting the environment by reducing the greenhouse gases emission. This process corresponds perfectly to the policy of sustainable development. The objective of this paper is to popularize the technique of organic waste biomethanisation or anaerobic digestion in order to produce renewable energy and cleaner environment through the exploitation of research results. In this work, we used as support the experimental results obtained in the laboratory. The mesophilic anaerobic digestion of cowdung, into an experimental digester of 800 liters capacity, has produced 26.478 m3 of biogas for 77 days with an average optimal composition of 61% in methane and energy equivalent to 592.8MJ (164.5 kWh). These results are hopeful for the use of cattle wastes mass available in Algeria, or even household wastes.