Amount Of Biogas Research Articles

Optimum loading ratio for co-digested wastewater sludge and brewery spent yeast

Anaerobic digestion (AD) is one of the most widely used technologies in the world for converting solid organic waste into energy and other value-added products. In the treatment of municipal wastewater, the disposal of sewage sludge is a problem of growing importance, as it contributes significantly to the operating costs of a wastewater treatment plant. It has also been recognised as a pollutant, albeit one with energy potential. In the brewing industry, a significant proportion of the raw materials used also end up as secondary raw materials or waste. Due to increased energy prices, brewer’s yeast has attracted great interest as an energy substrate, despite its difficult degradability under anaerobic conditions. AD offers the possibility to produce biogas and digestate from sewage sludge, resulting in a reduction in sludge volume and disposal costs. However, mono-digestion of sewage sludge often yields only a small amount of biomethane. To improve the quality and quantity of biogas, co-digestion is often used, leading to an increase in the economics of AD. However, the feedstock and co-digestion ratio need to be understood and carefully selected because they can affect the optimal methane production. Therefore, this study investigates the proportion of co-substrate that can optimise biogas yield. The co-fermented samples with different loading ratios of 1:1, 1:2 and 2:1 were characterised in terms of C/N ratio, total solids (TS), volatile solids (VS), moisture content and pH. They were measured by the standard method. In addition, the methanogenic potential was determined based on the biomethane potential (BMP) using the AMPTS 11 test. From the study, it was found that the optimum co-fermentation ratio was 1:2 of WWS: BSY with the highest biomethane production of 338.2 NmL CH4/g VS. Consequently, it was found that co-digestion of WWS with BSY can improve biomethane production and that brewer’s waste yeast could mitigate some of the limitations associated with mono-digestion of sewage sludge.

Operational Excellence in a Biogas Plant through Integration of Lean Six Sigma Methodology

Process optimization with Lean Six Sigma (LSS) has become more popular every day for years in almost every kind of industry. This integration has brought an even wider variety of possible application areas for industries and research institutes. Recently, the use of LSS for process optimization in biological fields has become more and more common. In this study, LSS methodology is used for process optimization in an industrial scale biogas plant in Hamburg, Germany. The methodology used includes all the DMAIC cycle and related tools. Hypothesis tests were used to calculate the p-value of each experiment for the LSS interpretation. Due to the experimental factors, one-way ANOVA and 1-sample Z-test were used to determine the p-values. By conducting hypothesis testing after the analysis phase of this study, it was found that particle size, freshness of the substrate, and the amount of sand content in the substrate had a significant effect on the desired amount of biogas produced with a p-value of less than 0.01. These root causes led to approaches that focused on high quality feedstock and sufficient pretreatment methods. This paper represents a pioneering example of integrating Lean Six Sigma into biogas plant operation.

The effect of Inoculum to Substrate and Carbon to Nitrogen Ratios on the Biogas Quantity and Quality from Anaerobic Digestion of Salvinia molesta: Experimental and Kinetic Studies

The purpose of this study was to investigate the effect of inoculum to substrate (I/S) and carbon to nitrogen (C/N) ratios on the biogas quantity and quality from anaerobic digestion of Salvinia molesta (SM). The I/S was adjusted to become 1.5, 2, 2.5 and the C/N was to become 21.5, 25, 30. Anaerobic digestion (AD) was operated during 30 days under the room pressure and temperature. The results showed that increase in I/S from 1.5 to 2.5 increased the biogas yield from 19.01 to 33.84 mL/g VS. Besides that, it increased the methane content from 52.54 to 69.01%. Furthermore, increase in C/N to 21.5 to 30 decreased the biogas yield from 33.84 to 30.85 mL/g VS and then decreased the methane content from 69.01 to 6.99%. Hence, the best condition was in the substrate with I/S of 2.5 and C/N of 21.5. The measured data was successfully predicted through the modified Gompertz and the first order kinetic models with R2 of 0.9905 and 0.9476 respectively.

BIOTRANSFORMATION OF WASTEWATER PRODUCTION OF BAKERY YEAST WITH BIOGAS GENERATION

Baking yeast enterprises are a source of environmental pollution by concentrated wastewater. They are usually diluted with water and discharged into sewerage. It is rational to use methane fermentation, which will ensure the removal of pollutants and make the process cost-effective through the use of biogas and digestion. Therefore, it is relevant to study the question of the influence of fermentation parameters on the cleaning efficiency. The aim of the work is to study the methane fermentation of yeast production effluents in a continuous mode. Objectives: analysis of solving the problem of wastewater treatment of yeast plants, study of the influence of process parameters (dilution rate, addition of cobalt salts) on the efficiency of treatment; gas generation; vitamin production. Initial COD of effluents 4500 mg O2/dm3, pH 6. Cultivation regime – continuous, dilution rate 4,1·10–3, 6,2·10–3, 8,2·10–3, 12,4·10–3 hours–1. Cleaning efficiency 78,9 %. High values ​​of dilution rate cause overload of activated sludge, which leads to reduced cleaning efficiency. The presence of cobalt also has a depressant effect. A significant amount of biogas (up to 5,2 dm3/dm3) is produced with a high content of methane (up to 85 %), which is an alternative fuel. As the dilution rate increases, the biogas and methane content decrease. With increasing dilution rate from 4,1·10–3 to 12,4·10–3 hours–1, biogas decreased from 1,11 to 0,94 dm3/g CODloading, and from 1,43 to 1,39 dm3/g CODfermentation. Similarly to the effect on the depth of purification, the inhibitory effect of cobalt on methanogeneration is observed. Digestion is a valuable fertilizer with a significant content of cobalamin vitamins (up to 95 μсg/g). The addition of cobalt salts stimulates the synthesis of vitamins, providing an increase of 26,7 to 51,6 %, improving the ratio between active and inactive forms.

Biogas Production and Biofertilizer Estimation from Anaerobic Co-Digestion of Blends of Wastewater and Microalgae

The study aimed to investigate the enhancement of biogas production through anaerobic digestion from blends of wastewater and microalgae. The microalgae functioned as a co-substrate. A series of laboratory-scale batch anaerobic co-digestion of the wastewater and microalgae were carried out under mesophilic conditions for 21 days. Biogas production rates from wastewater (WW) alone and different blends of WW and microalgae (MA) were analysed. In addition, the nutrient values and reduction in the volume of the WW after digestion were determined. The results show that the quantity and quality of biogas produced with different mix ratios of WW to MA (WW only, 3 : 1, and 3 : 2) were 24 mL CH4/g COD, 37 mL CH4/g COD, and 44 mL CH4/g COD, respectively. At the optimum mix ratio, the optimum methane produced was 44 mL CH4/g COD, which is much lower than volumes of gas STP conditions, which is 350 mL CH4/g COD. The values of TS, VS, and COD were also reduced by 43.11%, 40.09%, and 71.99% at the optimum mix ratio, respectively. The optimum mix ratio of 1732.77, 77.14, and 174.26 kg/year of urea, diammonium phosphate, and potash fertilizer, respectively, was obtained. The results indicate that biogas production can be improved through co-digestion of WW and MA as a co-substrate relatively, but to improve the production rate another substrate should be investigated. However, the result can be used as a supplementary investigation for practical application in energy production.

Department of Biosystems Engineering, Faculty of Agriculture, Tokat Gaziosmanpaşa University, 60250 Tokat

With the increase in the world population and the continuous development of technology, energy demands continue to increase. In general, the global energy needs are met by fossil sourced fuels. Depleting nature of fossil energy sources, their negative impacts on environment, increasing energy demands have led the efficient use of energy sources and the shift to local and renewable energy resources. Biogas is a renewable energy resource. Since organic wastes are used in biogas production, biogas offers a significant way of elimination of wastes and a source of energy. Animal wastes are the primary source of biogas. In this study, it is aimed to determine the biogas potential of Tokat province from animal wastes. Depending on this purpose, the amount of waste and biogas that can be obtained from animal waste and the energy potential that can be produced have been revealed by using the current data of the Provincial Directorate of Agriculture and Forestry. Energy equivalents of the biogas that can be obtained were also calculated. According to 2021 data, there are 303.952 cattle, 511.457 sheep and 247.333 poultry in Tokat province. Annually, 245.988 tons solid animal waste are obtained in Tokat province. In this study, conducted with the 2021 data of Tokat province, the amount of biogas that can be produced from animal wastes was calculated as 49 million m3/year. Districts with the greatest biogas potential are Merkez, Turhal and Zile respectively in 2021. The energy equivalent of biogas produced has been calculated as 292.000 MWh/year

Comparison of Bacterial and Archaeal Microbiome in Two Bioreactors Fed with Cattle Sewage and Corn Biomass

The bacterial and archaeal communities of two full-scale biogas producing plants (P1 and P2), associated with a 999 kW cogeneration unit, both located in North Italy, were analyzed at start up and fully operating phases, by means of various molecular approaches: (i) Automated Ribosomal Intergenic Spacer Analysis; (ii) cloning and sequencing of PCR amplicons of archaeal genes 16Srrna and mcrA; (iii) 16S rDNA high throughput next generation sequencing. P1 and P2 use the same technology and both were fed with cattle manure and corn silage. During the study of P1 also the post digester (fed with pig manure) was analyzed. The aim of this research was to characterize the bacterial and archaeal communities in two very similar plants to profile the core microbiota. The results of this analysis highlighted that the two plants (producing comparable quantities of volatile fatty acids, biogas, and energy) differed in anerobic microbiota (Bacteria and Archaea). Notably the methanogenic community of P1 was dominated by the strict acetoclastic Methanosaeta (Methanothrix) (up to 23.05%) and the unculturable Candidatus Methanofastidiosum (up to 32.70%), while P2 was dominated by the acetoclastic, but more substrate-versatile, Methanosarcina archaeal genus (49.19%). The data demonstrated that the performances of plants with identical design, in similar operating conditions, yielding comparable amount of biogas (average of 7237 m3 day−1 and 7916 m3 day−1 respectively for P1 and P2), VFA (1643 mg L−1 and 1634 mg L−1) and energy recovery (23.90–24 MWh day−1), depend on the stabilization of effective and functionally optimized methanogenic communities, but these communities are taxonomically different in the two biodigesters.

Biogas and Biomethane Production and Usage: Technology Development, Advantages and Challenges in Europe

In line with the low-carbon strategy, the EU is expected to be climate-neutral by 2050, which would require a significant increase in renewable energy production. Produced biogas is directly used to produce electricity and heat, or it can be upgraded to reach the “renewable natural gas”, i.e., biomethane. This paper reviews the applied production technology and current state of biogas and biomethane production in Europe. Germany, UK, Italy and France are the leaders in biogas production in Europe. Biogas from AD processes is most represented in total biogas production (84%). Germany is deserving for the majority (52%) of AD biogas in the EU, while landfill gas production is well represented in the UK (43%). Biogas from sewage sludge is poorly presented by less than 5% in total biogas quantities produced in the EU. Biomethane facilities will reach a production of 32 TWh in 2020 in Europe. There are currently 18 countries producing biomethane (Germany and France with highest share). Most of the European plants use agricultural substrate (28%), while the second position refers to energy crop feedstock (25%). Sewage sludge facilities participate with 14% in the EU, mostly applied in Sweden. Membrane separation is the most used upgrading technology, applied at around 35% of biomethane plants. High energy prices today, and even higher in the future, give space for the wider acceptance of biomethane use.

Using multi-objective optimisation with ADM1 and measured data to improve the performance of an existing anaerobic digestion system

This paper presents a method to model and optimise the substrate feeding rate of an anaerobic digestion (AD) system. The method is demonstrated for a case study plant in Bangalore, India, using onsite kitchen waste to provide biogas for cooking. The AD system is modelled using Anaerobic Digestion Model No. 1 (ADM1) and a genetic algorithm (GA) is applied to control the substrate feeding rate in order to simultaneously minimise the volume of flared biogas, unmet gas demand and energy cost. Our results show that ADM1 can predict biogas yield from a continuously operated digester well with mean percentage errors between daily predicted and measured data values of only 5.7% for March 2017 and 17.8% for July 2017. When biogas flaring and unmet gas demand were minimised, the amount of biogas flared reduced from 886.62 m3 to 88.87 m3 in March and from 73.79 m3 to 68.49 m3 in July. When the energy cost was also considered within the objective function, the biogas flared reduced from 886.62 m3 to 281.27 m3 for March, but increased from 73.79 m3 to 180.11 m3 for July. The amount of flaring increased in July as the energy cost function increased biogas yield without considering surplus gas production beyond demand and storage capacity. As AD systems are often operated to maximise biogas production, these results highlight the need for multi-objective optimisation, particularly for off-grid AD systems.

Improving Biogas Yield Production at Room Temperature by Chemical Pretreatment

The present study focuses on the experimental research of the effect of alkaline chemical pretreatment by KOH on biogas production from anaerobic digestion of lagoon station’s sludge (dry basis) under mesophilic conditions (35± 2 °C). Different concentrations of KOH, i.e. 1, 2.5, 5 and 7.5% (w/w), were tested for 24 hours at room temperature. The results obtained after two months of digestion, based on the total volume of biogas measured, clearly indicate that the chemical alkaline pretreatment has a positive effect on the anaerobic digestion, since the amount of biogas produced increased by 35.3 % when the concentration of KOH was 5%. Indeed, according to the selected operating conditions, this concentration is considered optimal. Therefore, above this concentration, a blockage and inhibition of the methanogenic activity of the anaerobic digestion process were observed. These results also indicate that the alkaline chemical pretreatment can improve the CH4 content of the biogas obtained.

Biogas Pollution and Mineral Deposits Formed on the Elements of Landfill Gas Engines.

Municipal landfills generate a significant amount of high-energy biogas, which can be used as a renewable gaseous fuel. However, it is necessary to improve the quality of this biogas due to the presence of various chemical compounds. The most common pollutants in landfill biogas include volatile compounds of silicon, sulphur, phosphorus and chlorine. The aforementioned elements, as well as other metals, were found both in the deposits and in the engine oil. The paper presents detailed characteristics of the solid residues formed in selected parts of gas engines powered by landfill biogas. Its elemental composition and morphology were investigated in order to determine the structure and influence of these deposits. In order to better understand the observed features, selected analyses were also conducted for biogas, engine oil and the condensate generated during biogas dewatering. It was found that the content of individual elements in samples collected from the same part of the gas engine but sourced from various landfills vary. The occurrence of elements in deposits, e.g., Mg, Zn, P and Cr, depends on the location of sampling sites and the type of engine. It was also observed that the deposits formed in parts that come into contact with both biogas and engine oil contain Ca or Zn, which can be related to biogas pollutants as well as different oil additives. The presence of Al, Fe, Cu, Cr, Sn or Pb in selected motor oil samples can be explained by the penetration of metallic abrasives, which confirms the abrasive properties of the formed deposits. The analysis of the characteristic deposits may contribute to the selection of an appropriate landfill biogas purification technology, thus reducing the operating costs of energy cogeneration systems. Finally, we highlight challenges for biogas purification processes and anticipate the direction of future work.

Experimental Study of Increase of Biogas Production from Lagoon Station's Sludge by Alkaline Pretreatment

The present research focuses on the experimental study of the effect of alkaline pretreatment with NaOH on biogas production. Different concentrations of NaOH, i.e. 1, 2.5 and 5% (w/w), were tested on the lagoon station's sludge (dry basis) at room temperature for 24 h. The results obtained after 60 days of digestion, through the cumulative volume of biogas recorded, clearly indicate a positive effect of the chemical alkaline pretreatment on the anaerobic digestion since the amount of biogas produced increased by 42.6% when the NaOH concentration was close to 2.5%. This concentration is considered optimal under the chosen conditions. Indeed, inhibition of the methanogenic activity and a blockage of the digestion process are observed beyond this concentration. These results suggest that the alkaline pretreatment can improve the energy efficiency of the obtained biogas (CH4 content) and reduce the residence time.

Enhancing biogas production by anaerobic digestion of animal manure

ABSTRACT The objective of this work is to investigate enhancing biogas production by anaerobic digestion of three different animal droppings namely; cow, camel, and chicken. The investigation showed that biogas production can be enhanced by mixing equal mass of the above three animal manures and diluting by tap water at 37°C. The amount of biogas produced was increased by 12, 28 and 5 folds compared to that produced from digesting only cow, camel, or chicken manure, respectively. The digestion process was carried under batch mode condition in plastic bottles of 1.5 L volume. The bottles were immersed in a water bath to control its temperature at the desired values. The amount of biogas produced was determined via a syringe tightly connected to the bottle exit. The effect of dry solid mass fraction, pH, and temperature on the amount of biogas produced by digesting certain types of manure alone was studied. The results showed that the amount of biogas produced versus dry solid mass fraction goes through a maximum. The maximum value of the biogas produced occurred at solid mass fraction of 0.11, 0.1, and 0.16 for cow, camel, and chicken manure, respectively. Digestion of cow, camel, and chicken manure at 37°C increased the production by 2.2, 2.1, and 1.3 folds, respectively, compared to that obtained at 25°C.

Investigation of anaerobic degradability and biogas production of the starch and industrial sewage mixtures

Today, with the increase in industrialization, the disposal of organic sludge formed after industrial activities has started to pose a serious problem. For this reason, biogas production from such organic wastes under anaerobic conditions is very valuable in terms of both sustainable environmental policy and renewable energy recovery. In this study, the effects of mono-digestion and co-digestion of starch sludge (SS), industrial sewage sludge (IS), and wastewater (CIWW) from the cardboard manufacturing industry on the biogas production potential and the changes in parameters such as dissolved COD, carbohydrates and pH were presented. In addition, a pH-controlled study was carried out with the sample with the lowest final pH level (100% SS) after anaerobic fermentation. The mixtures were prepared to contain 100%SS, 100%IS, 100%CIWW, 75%SS-25IS, 66%SS-33IS, 50%SS-50%IS, 33%SS-66IS, and 25%SS-75%IS on a dry weight basis. The amount of biogas produced by 100%SS (257 mL) was almost 5 times greater than 100%IS (56 mL). The utilization of the CIWW together with SS and IS increased the biogas production potential approximately 10 times and 2 times, respectively. The highest biogas production was achieved with the anaerobic co-digestion (ACoD) of 25%SS and 75%IS as 332 mL. Under these conditions, biogas production increased by 29% and 493%, respectively, compared to mono-digestion of the substrates. As the SS ratio in the mixture increased, the pH value decreased due to VFA accumulation in the medium. In addition, there was a decrease of approximately 11% in biogas production. The soluble COD concentration of all mixtures increased after anaerobic fermentation except 100%IS. On the contrary, carbohydrate removal was observed in all reactors except 50%SS-50%IS mixture.

Experimental assessment of the influences of liquid-solid-gas fuel blends on DI-CI engine behaviors

This study aims to deeply investigate the effects of the boron nanoparticles reinforced diesel fuel along with various biogas (BG) flow rates (0.5, 1, and 2 L/min) on the engine performance and emission characteristics of a diesel engine. The tests were carried out using a single-cylinder, four-stroke, direct injection, compression-ignition engine at a constant engine speed of 1500 rpm and under the varying engine loads from 2.5 to 10 Nm with gaps of 2.5 Nm. In the results, it is seen that EGT started to decrease in both the addition of boron nanoparticles and the addition of biogas compared to that of conventional diesel fuel (DF). EGT reduced by 8.6% for DF+Boron test fuel, 14.4% for DF+Boron+ 0.5 BG, 21% for DF+Boron+ 1 BG, and 23.4% for DF+Boron+ 2 BG. Compared to diesel fuel, CO, NOx, and HC emissions decreased with the addition of nanoparticles at all loads. However, as the amount of biogas increased, CO and HC emissions increased, but NOx emissions decreased. CO emission dropped by 22.2% for DF+Boron test fuel, however, increased to be 5.6%, 16.7%, and 36.1% for DF+Boron+ 0.5 BG, DF+Boron+ 1 BG, and DF+Boron+ 2 BG respectively. NOx emission reduced by 4.9%, 8.6%, 10.7%, and 14.8% for DF+Boron, DF+Boron+ 0.5 BG, DF+Boron+ 1 BG, and DF+Boron+ 2 BG respectively. In comparison to that of conventional DF, the brake specific fuel consumption (BSFC) value decreased by 8.42% for DF+Boron test fuel due to high energy content of nanoparticles, but it increased by 10.94% for DF+Boron+ 0.5 BG, 28.01% for DF+Boron+ 1 BG, and 60.2% for DF+Boron+ 2 BG. In addition, brake thermal efficiency BTE value increased by 8.04% for boron-added test fuel, but it declined by 9.41% for DF+Boron+ 0.5 BG, 19.38% for DF+Boron+ 1 BG, and 32.2% for DF+Boron+ 2 BG as compared to that of DF. In the conclusion, it is noticed that the engine characteristics have worsened by the introduction of biogas into the cylinder, but these worsened characteristics can be improved with the presence of boron nitride nanoparticles.

The Effects of Using Pretreated Cotton Gin Trash on the Production of Biogas from Anaerobic Co-Digestion with Cow Manure and Sludge

Anaerobic co-digestion (AcoD) has been practiced for decades to convert waste into value-added energy products, especially biogas. This study aimed to assess the potential of biogenic methane (CH4) production from the co-digestion of pretreated cotton gin trash (CGT), cow manure, and sludge. CGT contains high cellulosic content, making it a reliable feedstock for biogenic methane production. To further improve the biogas quantity and quality, the CGT was subjected to physical pretreatments, i.e., hot water (HW), ultra-sonication (US), and a combination of both (HW+US). After 91 days of AcoD, 79–110 L of biogas was produced by the treatments. Among the treatments, HW+US-pretreated CGT presented maximum biogas production capacity, at 110 L. Besides, this treatment showed the high-quality biogenic CH4 content, 52.4% of the total biogas volume, with an improved conversion rate of 0.37 L/g of volatile suspended solids consumed. In addition, this study discussed the structural changes in feedstock due to pretreatments and correlated them with the corresponding biogenic methane production. The study reports the potential of pretreated CGT conversion to CH4. It will impact the circular economy by contributing to on-farm energy requirements and reducing the financial expenditures incurred in this regard.

Hodnotenie vybraných genotypov Miscanthus na produkciu bioplynu ako možného riešenia regionálnej bioenergie

Plantations of fast-growing crops represent local agroecosystems providing provisioning services in the form of phytomass that can be utilized for energy and/or non-energy purposes. Permanent grasses such as Miscanthus are identified as potentially suitable sources of raw materials for the output of second-generation biofuels. The experiments focused on the production ability of the perennial energy grass Miscanthus were performed in the region of SW Slovakia. It was confirmed that the studied genotypes (Miscanthus sinensis Tatai and Miscanthus × giganteus) exceeded the cost-efficient level of biomass production. The above-ground biomass of the studied genotypes was ensiled and afterwards fed to the experimental fermenters to evaluate the biogas production. The experiments with individual silage mixtures lasted 600 hours. The total amount of biogas produced from M. × giganteus and M. sinensis Tatai silage mixture was 273 dm3 and 328 dm3, respectively. The average share of methane in the biogas of both studied samples of silage mixtures was 51%. On the basis of the 10-year average yields of the studied Miscanthus genotypes achieved in our conditions, it is possible to produce 8 181 m3/ha (M. × giganteus) and 11 248 m3/ha (M. sinensis Tatai) of biogas from the silage mixtures. The achieved production represents sufficient and stable amount of biogas and its use can be economically efficient and sustainable in the long run in SW Slovakia.

Typology of Crop Residues and Energy Recovery in Heavily Agricultural Areas: Case of the Departments of Soubré, Daloa, Issia and Sassandra (Côte d’Ivoire)

The valorization of crop residues could constitute an energy source (biogas) allowing to reduce the energy needs of populations in agricultural regions, improve their living conditions and slow down deforestation as well as greenhouse gas emissions. This work aims to determine the typology of agricultural waste in the departments of Soubré, Sassandra, Daloa and Issia, to determine the number of residues generated in these departments, and to assess the biogas potential of these departments said residues. Field observations were made to identify the different types of waste, then, based on agricultural statistical data from the Ministry of Agriculture and biogas productivity indexes, the quantities of agricultural residues and biogas were estimated. Agricultural residues consist of pods (50%), stalks (19%), cobs (3%), Straws (8%), stalks (2%), shells (9%), fibers (7%), husks (1%), and bunches (1%). In addition, these localities have 465266.3 t of pods, 173583.2 t of stalks, 84280.0 t of shells, 75,857 t of straws, 12,000 t of husks, 10,987 t of bunches and 6793.0 t of fibers. The departments of Soubré, Sassandra, Daloa and Issia contain a total potential energy of 235.87 × 106 m3 of biogas. However, this is unevenly distributed among the localities. The volume of biogas recorded is higher in the department of Soubré (74.91 × 106 m3) which is followed respectively by the departments of Daloa (62.27 × 106 m3), Issia (52.77 × 106 m3 and Sassandra (45.93 × 106 m3). The departments of Soubré, Sassandra, Daloa and Issia have a very large potential for the production of agricultural residues that may be of interest to economic operators for recovery in biogas production units.

Biogas Production with Beef Cattle Manure and Wastewater from Hydraulic Fracturing

HighlightsHydraulic fracking wastewater is evaluated as a possible alternative to freshwater in combination with beef cattle manure for bio-methane generation by anaerobic digestion (AD).Optimum conditions for AD with fracking wastewater remain unknown, but differ from AD with freshwater.Contrary to AD with freshwater, biogas production with fracking wastewater increased with lower MC.Abstract. Wastewater from hydraulic fracturing (HF) and manure from beef cattle production are two of the largest waste streams in the Texas Panhandle. The objective of this study was to evaluate the potential of generating biogas, a renewable natural gas, from the combination of HF wastewater and beef manure through anaerobic digestion (AD) at varying moisture contents. In a laboratory study, substrate combinations of manure mixed with produced and flowback water (PFW), well water (WW), and a 50/50 mixture of PFW and WW were evaluated at four moisture contents (MC; 65%, 70%, 80%, and 90%). Beef manure was harvested from the West Texas A&M University research feedlot. The PFW was collected from a HF operation in the Texas Panhandle. The combinations of manure and WW at 90% MC yielded the greatest amount of biogas and methane (CH4). The greatest amount of biogas and CH4 with the combination of manure and PFW was produced at 65% MC. This combination produced 57% less biogas than the optimum CH4-producing WW treatment. Diluting PFW with WW produced amounts of CH4 comparable to WW at 80% MC. While there is potential to generate biogas and methane with PFW and manure, more research is needed to isolate the CH4-inhibiting constituents in PFW. Keywords: Anaerobic digestion, Manure, Methane, Produced and flowback water.

Effective treatment of oily sludge for biogas and methane gas production at mesophilic using anaerobic batch reactor (AnBR)

The oily sludge is one of the toxic organic sludge generated from petroleum oil refineries plants and categorized as priority pollutants. Anaerobic batch treatment using bacteria species is a key strategy for treating toxic pollutants. The present study aims to produce biogas and methane gas at mesophilic conditions by using potential bacteria existing in oily sludge. The oily sludge was found rich in microorganisms adapted to extreme toxic organic waste and capable of adjusting to severe environmental conditions. The potential microorganism was isolated by enrichment technique to analyze the potential of the isolated strains to assimilate under lab scale. Anaerobic batch treatment at mesophilic temperature of ±35 °C, pH (6–8), 60 rpm mixing for 21 days with sample feed of 1L, 1.5L and 2L of oily sludge to produce biogas and methane gas by water displacement method. The results from anaerobic batch treatment shows that total biogas yield obtained, including methane yield of 25369 mL and 3900 mL, respectively at optimum feed volume of 2L. Overall, the study's findings revealed that oily sludge has the potential bacteria to produce the amount of biogas and methane gas. The large amount of oily sludge can be recycled, which will reduce environmental contamination. The investigations from the current study will help with the feasibility of oily sludge treatment in the future.