Methane Gas Production Research Articles

Derivation of Optimal Operation Factors of Anaerobic Digesters through Artificial Neural Network Technology

The anaerobic digestion of sewage sludge in South Korean wastewater treatment plants is affected by seasonal factors and other influences, resulting in lower digestion efficiency and gas production, which cannot reach optimal yields. The aim of this study was to improve the digestion efficiency and gas production of sludge anaerobic digestion in a wastewater treatment plant (WWTP) by using data mining techniques to adjust operational parameters. Through experimental data obtained from the WWTP in Daegu City, South Korea, an artificial neural network (ANN) technology was used to adjust the range of the organic loading rate (OLR) and hydraulic retention rate (HRT) to improve the efficiency and methane gas production from anaerobic sludge digestion. Data sources were normalized, and data analysis including Pearson correlation analysis, multiple regression analysis and an artificial neural network for optimal results. The results of the study showed a predicted 0.5% increase in digestion efficiency and a 1.3% increase in gas production at organic loads of 1.26–1.46 kg/m3 day and an HRT of 26–30 days. This shows that the ANN model that we established is feasible and can be used to improve the efficiency and gas production of sludge anaerobic digestion.

Transforming spent coffee grounds into a valuable resource for the enhancement of concrete strength

The decomposition of organic waste going to landfills produces methane gas, which is 21 times worse than CO2 in its global warming potential. Spent coffee grounds (SCG) are one type of organic waste that makes up a significant proportion of the organic waste going to landfills. Therefore, it becomes imperative to look for a recycling solution to transform this waste into a valuable resource. The concrete industry has the potential to contribute significantly to increasing the recycling rate of this waste material. However, due to its high organic content, it is unsuitable to be used directly in structural concrete. Therefore, this experimental project looks at pyrolysing this waste at different temperatures (350 and 500 °C) to identify its suitability in improving the physicochemical and mechanical properties of concrete. The raw and pyrolysed forms of SCG were used as a replacement of fine aggregates (FA; sand) at 5, 10, 15 and 20% volume replacement levels. X-ray fluorescence (XRF), Carbon, Hydrogen, Nitrogen, and Sulfur (CHNS) analysis, laser diffraction particle size analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and compressive strength tests were undertaken to investigate the properties of the raw material and their performance in the blended concrete composites. The results show that the leaching of organic compounds from the SCG hinders the hydration reaction of cement particles, thereby significantly hampering the compressive strength of SCG-blended concrete. However, pyrolysing the SCG at 350 °C led to a significant improvement in its material properties, which resulted in a 29.3% enhancement in the compressive strength of the composite concrete blended with coffee biochar.

PERENCANAAN INSTALASI PENGOLAHAN AIR LIMBAH PADA INDUSTRI TAHU (Studi Kasus Pabrik Tahu WD Lamper Lor Semarang Selatan)

In the production process, the tofu industry produces solid and liquid waste. The waste contains organic matter with high levels of BOD, COD, and TSS and does not meet quality standards. If the waste is directly discharged into the environment, it will reduce the carrying capacity of the environment. This research was conducted at the WD Lamper Lor Tofu Factory, with the aim of planning the design and RAB for the construction of the wastewater treatment plant at the Tofu Factory. This research uses quantitative analysis methods which are presented in the form of numbers which are then explained and interpreted in the form of descriptions. The quality of BOD, COD, TSS, and pH were 144 mg/L, respectively; 380 mg/L; 98 mg/L; and 4.34. Based on the quality standards, the wastewater does not meet the requirements, so it is necessary to plan a wastewater treatment plant. Researchers plan the processing stages, namely Reservoir, Equalization, Anaerobic Digester, Gas Storage, Presettlement Tub, Anaerobic Biofilter, and Final Sedimentation Tub. The estimated effluent from the processing of BOD, COD, and TSS is 2,916 mg/L, respectively; 7.695 mg/L; 2.116 mg/L. In addition to processing it into water that is fit for reuse, the design of this wastewater treatment plant produces methane gas that can be used for the tofu-making process or can be used on a household scale. The total budget plan for the planning of the Wastewater Treatment Plant at the WD Tofu Factory is 31,106,117.05.

Fermentation Characteristics, Digestibility, and Estimation of Ruminant Methane from Saponin: A Quantitative Study

The effect of using saponins on ruminants' performance differed from several published research data based on the level of saponins added to the feed. This research was conducted to analyze the effect of saponins on fermentation characteristics, digestibility, and estimation of methane in ruminants with a mixed model approach from published journal articles—a total of 127 studies from 32 journals national and international. The variable measured included the level of saponins (%), dry matter intake, Average Daily Gain (ADG), Dry Matter Digestibility (DMD), Organic Matter Digestibility (OMD), Crude protein (CP), Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), protozoa population, bacterial population, Volatile Fatty Acid (VFA), acetate/C2, propionate/C3, butyrate/C4, valerate/C5, acetate/propionate (C2/C3), NH3, pH, and methane gas production. The results showed that using saponins in ruminants increased ADG, CP, ADF, NDF degradation, Total VFA, and proportion of propionate. The addition of saponins level reduced the protozoa population, acetate proportion, and the ratio of acetate: to propionate (C2/C3). In contrast, feed intake and digestibility decreased with the administration of saponin. The bacterial population were similar among treatments, and methane production increased by increasing saponins. In conclusion, the administration of saponin level recommended is 0.3-3.1% of the total ration to improve performance and increase feed efficiency.

Estimation of Greenhouse Gas Emissions in Waste Management at Basirih Landfill Banjarmasin South Kalimantan Indonesia

Methane gas (CH4) is one of the main Greenhouse Gases (GHG), after carbon dioxide (CO2) which contributes greatly to global warming. The presence of methane gas in the atmosphere increases ± 0.6% per year. In the final processing stage of waste at the landfill in conditions without oxygen (anaerobic), the waste that is stockpiled will produce methane gas (CH4). Landfill Basirih is the only TPA serving the City of Banjarmasin, with the waste coming in every day continuing to increase and has the potential to generate emissions. The aim of this study is to estimate greenhouse gas emissions from biological waste management activities and from waste collection activities, as well as analyzing a comparison of the increase in GHG emissions based on an inventory of the last 10 years at the Basirih TPA. The method used in this research is the Intergovernmental Panel on Climate Change (IPCC) method. In 2021 the processing of biological waste at the Basirih TPA will produce 0.00584 Gg/year of GHG emissions and 0.38876 Gg/year of greenhouse gas emissions resulting from waste collection activities. The average amount of increase in greenhouse gas emissions in the last 10 years is 0.02615 Gg/year with a percentage of 13.01 % / year. Keywords: Biological waste processing, emissions, methane, landfilling, waste.

Extracting phytocompounds from Mucuna pruriens leaves as potential ruminant feed additives using different solvents

Some secondary metabolites of plants could serve as ruminant feed additives. They primarily preserve protein from rumen breakdown, reduce rumen protozoa population, and decrease methane gas production. The current study aimed to identify the phytocompounds content of extracted Mucuna pruriens leaves using the Microwave-assisted extraction method using three different solvents of methanol 70% (EM), aquadest (EA), and combinations of EM and EA (EK). The phytocompounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Some phytocompounds identified in the Mucuna pruriens substances from GC-MS curve proportion area of EM were 10.35% inositol, 3.1% quinazoline, 4.72% anthraquinone, 3.76% Coptisine, 2.06% isoquinoline, 2.18% D-gluconic acid, 2.83% D-Fructose, 3.91% D-glucose, and 4.59% butanedioic acid. The phytocompounds for EK were 17.22% inositol, 6.36% Niclosamide, 1.4% Acetamide, 1.32% Aniline, 55.97% 4-Amino-2-(4-methoxyphenyl)-5,6,7,8-tetrahydrofuro[2,3-b] quinoline-3-carbonitrile, 17.22% inositol. Furthermore, 22.73% inositol, 6.55%, ribonoic acid, 5.58%, silanol, 21.27% butanodioic acid, 2.88% Fluoroquinoxaline, 5,31%, glycerol, 1,64%, D- gluconic acid were found in the EA. The EA had high inositol content, the EK had high quinoline content, and the EM showed moderate results for all phytobiotics. The total phenolics, flavonoids, tannins, and saponins content significantly differed among the three solvents. The EA yielded the highest concentrations of total phenolics, flavonoids, and tannins, but the lowest concentration of total saponins. In contrast, the EM yielded the lowest total phenolics, flavonoids, and tannins content, but the highest total saponins content. Meanwhile, the EK yielded modest results for all phytocompounds, with values between EA and EM. In conclusion, the methanolic extract of Mucuna pruriens substance had the highest phytocompounds and bioactive potential as ruminant feed additives.

Multi-parameter control-based operation strategy for mainstream deammonification in an integrated anaerobic biofilm reactor-step feed MBR

The mainstream deammonification of municipal wastewater has been recognized as one of the greatest challenges in wastewater engineering. The conventional activated sludge process has disadvantages of high energy input and sludge production. To tackle this situation, an innovative A-B process, where an anaerobic biofilm reactor (AnBR) functioned as the A stage for energy recovery, and a step-feed membrane bioreactor (MBR) functioned as the B stage for mainstream deammonification, was constructed for carbon-neutral wastewater treatment. For addressing the challenge associated with selective retention of ammonia-oxidizing bacteria (AOB) over nitrite oxidizing bacteria (NOB), a multi-parameter control-based operation strategy was developed with synergistic control of influent COD redistribution, dissolved oxygen (DO) concentration and sludge retention time (SRT) in the innovative AnBR – step-feed MBR system. Results showed that more than 85% of wastewater COD could be removed with the direct production of methane gas in the AnBR. A relatively stable partial nitritation, which is a prerequisite of anammox, was achieved with the successful suppression of NOB, leading to 98% of ammonium-N and 73% of total nitrogen removed. Anammox bacteria could well survive and enrich in the integrated system, and the contribution of anammox to the total nitrogen removal was more than 70% at optimal conditions. Reactions network involved in the nitrogen transformation in the integrated system was further constructed through the mass balance and microbial community structure analyses. Consequently, this study demonstrated a practically feasible process configuration with high operation and control flexibility towards stable mainstream deammonification of municipal wastewater.

Phase equilibrium data for clathrate hydrates formed in the systems of urea + (methane or carbon dioxide) + water

Subsea methane hydrates are expected as a potential natural gas resource. To develop gas production methods for the subsea methane hydrates, flow assurance technologies are necessary. Urea is one of the environmentally-friendly thermodynamic hydrate inhibitors (THIs) which is expected to be applicable for subsea methane hydrate systems. To evaluate its performance as a THI, a set of phase equilibrium data are necessary. In this study, we report phase equilibrium data for systems of urea + methane + water and urea + carbon dioxide + water in the range of aqueous compositions of urea up to its solubility limits. The present data for urea + methane + water ranged in pressures from 5 to 13 MPa and in urea mass fractions from 0.05 to 0.5. The comparison with the literature found that the inhibition effect of urea is a few kelvin weaker than that of methanol in the present measurement range. With the dense urea solutions, the system reached four phase equilibrium, i.e., solid urea–aqueous solution–gas–hydrate. At 13 MPa, approximately 13 K of inhibition temperature was obtained with 0.500 of feed mass fraction where solid urea was precipitated from the aqueous phase. In the urea + carbon dioxide + water systems, urea also worked as a THI. The maximum inhibition temperature was approximately 10 K with 0.400 of urea mass feed fraction at the four phase equilibrium. Based on the present equilibrium data and seafloor conditions of the subsea methane hydrates, it was found that urea can be used for the both systems of the methane gas production and the hydrate based carbon capture and storage.

Molecular characterization of microorganisms with industrial potential for methane production in sludge from Kangemi sewage treatment plant, Nyeri county–Kenya

Microbial consortia under anaerobic conditions are involved in oxidizing organic matter in the sludge to produce methane gas. However, in developing countries like Kenya, these microbes have not been fully identified to target them for the efficient harnessing of biofuel. This study collected wet sludge from two anaerobic digestion lagoons 1 and 2 that were operational during sampling at Kangemi Sewage Treatment Plant, in Nyeri County, Kenya. DNA was extracted from samples using commercially available ZymoBIOMICS™ DNA Miniprep Kit and sequenced using Shotgun metagenomics. Samples were analyzed using MG-RAST software (Project ID: mgp100988), which allowed for identifying microorganisms directly involved in various stages of methanogenesis pathways. The study found hydrogenotrophic methanogens, such as Methanospirillum (32%), Methanobacterium (27%), Methanobrevibacter (27%), and Methanosarcina (32%), being predominant in the lagoon communities, whereas acetoclastic microorganisms such as the Methanoregula (22%) and the acetate oxidazing bacteria such as Clostridia (68%) were the key microbes for that pathway in the sewage digester sludge. Furthermore, Methanothermobacter (18%), Methanosarcina (21%), Methanosaeta (15%), and Methanospirillum (13%) carried out the methylotrophic pathway. In contrast, Methanosarcina (23%),Methanoregula (14%), methanosaeta (13%), and methnanoprevibacter (13%) seemed to play an important role in the final step of methane release. This study concluded that the sludge produced from the Nyeri-Kangemi WWTP harbors microbes with significant potential for biogas production. The study recommends a pilot study to investigate the efficiency of the identified microbes for biogas production.

DESIGN OF HOUSEHOLD-SCALE BIODIGESTER FROM COW MANAGEMENT

Biogas is one solution to overcome community difficulties due to rising fuel prices and the scarcity of LPG gas, this technology can be immediately applied, especially for cattle breeders. Utilizing cow dung that is processed anaerobically in a digester which will produce methane gas as an alternative energy. In planning this household-scale biogas device, there are several components designed including a digester with a volume capacity of 400L with a filling capacity of 2/3 of the digester volume, the material used is HDPE plastic (High Density Polyethylene) and a holding capacity of 147 L which produces a flash time. fire for 20.01 minutes for 15 days of the fermentation process. Where the lowest pressure is obtained on the 3rd day with a pressure of 104.668,73 N/m2, and the maximum pressure is on the 12th day with a maximum pressure of 107.201,85 N/m2i. simulation using solidwork software results in the digester construction which is planned to be used because it has a fairly good level of security

Application of a Full-Scale Horizontal Anaerobic Digester for the Co-Digestion of Pig Manure, Food Waste, Excretion, and Thickened Sewage Sludge

Many laboratory- and pilot-scale studies on anaerobic co-digestion have been conducted in Republic of Korea; however, studies on full-scale demonstration facilities are lacking. This study aimed to present a successful case of a large-scale anaerobic co-digestion facility in Republic of Korea for biogas generation from four organic wastes (pig manure, food waste, excretion, and thickened sewage sludge) using a horizontal anaerobic digester. A preliminary biochemical methane potential test was performed for the individual and mixed organic waste to design a treatment facility for 320 m3/day of organic waste generated in Seosan City. Subsequently, a horizontal anaerobic digester with a 35 day-retention time (based on 320 m3/day input) was constructed. Each organic waste was placed in an anaerobic reactor after pretreatment. The input was gradually increased after the first seeding, and the operation continued for 158 days. Total and volatile solids made up 4.1% and 3.3%, respectively. Throughout the operating period, the digester temperature was maintained at 35–40 °C for mesophilic digestion, and the pH was maintained at 7–8. The average organic matter removal efficiency (volatile solids basis) was 64% and the methane gas production rates were 0.35, 0.6, 0.26, 0.28, and 0.39 Nm3CH4/kg vs. for pig manure, food waste, excretion, thickened sewage sludge, and mixed waste, respectively, resulting in an average methane content of the biogas 68.8%.

Analysis of The Utilization of Tofu Liquid Waste as a Biogas Electricity Power Plant (Case Study of BK Tofu Industry at Payakumbuh City West Sumatra)

The increase in population from year to year causes an increase in the need for food such as Tofu. This also has an impact on the number of tofu industries in Indonesia. The tofu industry is a food industry that is in great demand by the public, raw materials are easy to find, and processing is easy. Nevertheless, it arises that the environmental problems posed by the tofu industry are waste generated from the liquid tofu waste manufacturing process. When discharged into the environment, it can cause a foul odour and pollute the environment. The utilization of tofu liquid waste into electrical resources is one of the steps that can be developed in reducing pollution and increasing electrification. Being the first step, it is necessary to study the use of biomass as a source of electricity, which includes studying the potential of resources. This study aims to determine the potential value of tofu liquid waste and electrical energy for PLTBG fuel as an effort to apply clean technology. For the method in this study using anaerobic fermentation with SuperPro Designer simulation. As a result of this study, tofu liquid waste produces methane gas (CH4) of 141.97 m3 per day and total electrical energy of 129.03 kWh. It can be concluded from this study, tofu liquid waste can be used as biogas for generator set fuel with an output power of 12,000 Watts which meets industrial electricity needs for 11.73 hours.

Observation-derived 2010-2019 trends in methane emissions and intensities from US oil and gas fields tied to activity metrics

The United States is the world's largest oil/gas methane emitter according to current national reports. Reducing these emissions is a top priority in the US government's climate action plan. Here, we use a 2010 to 2019 high-resolution inversion of surface and satellite observations of atmospheric methane to quantify emission trends for individual oil/gas production regions in North America and relate them to production and infrastructure. We estimate a mean US oil/gas methane emission of 14.8 (12.4 to 16.5) Tg a-1 for 2010 to 2019, 70% higher than reported by the US Environmental Protection Agency. While emissions in Canada and Mexico decreased over the period, US emissions increased from 2010 to 2014, decreased until 2017, and rose again afterward. Increases were driven by the largest production regions (Permian, Anadarko, Marcellus), while emissions in the smaller production regions generally decreased. Much of the year-to-year emission variability can be explained by oil/gas production rates, active well counts, and new wells drilled, with the 2014 to 2017 decrease driven by reduction in new wells and the 2017 to 2019 surge driven by upswing of production. We find a steady decrease in the oil/gas methane intensity (emission per unit methane gas production) for almost all major US production regions. The mean US methane intensity decreased from 3.7% in 2010 to 2.5% in 2019. If the methane intensity for the oil/gas supply chain continues to decrease at this pace, we may expect a 32% decrease in US oil/gas emissions by 2030 despite projected increases in production.

Fermentation of increasing ratios of grain starch and straw fiber: effects on hydrogen allocation and methanogenesis through in vitro ruminal batch culture.

Grain starch has a faster rate of rumen fermentation than straw fiber and causes a rapid increase in ruminal molecular hydrogen (H2) partial pressure, which may promote other H2 sinks to compete H2 away from methanogenesis. The study was designed to investigate the effects of increasing ratios of grain starch to straw fiber on hydrogen allocation and methanogenesis through in vitro ruminal batch incubation. Corn grain and corn straw were employed as starch and fiber source respectively. Seven treatments were the ratios of corn grain to corn straw (RGS) being 0:6, 1:5, 2:4, 3:3, 4:2, 5:1, and 6:0. Elevating RGS increased dry matter (DM) degradation and decreased methane (CH4) and hydrogen gas (gH2) production relative to DM degraded. Elevating RGS increased volatile fatty acid (VFA) concentration, propionate molar percentage and microbial protein (MCP) concentration, decreased acetate molar percentage, acetate to propionate ratio and estimated net metabolic hydrogen ([H]) production relative to DM degraded. Elevating RGS decreased the molar percentage of [H] utilized for CH4 and gH2 production. In summary, increasing ratios of grain starch to straw fiber altered rumen fermentation pathway from acetate to propionate production, reduced the efficiency of [H] production with the enhancement of MCP synthesis, and led to a reduction in the efficiency of CH4 and gH2 production.

Gas Hydrates Reserve Characterization Using Thermo-Hydro-Mechanical Numerical Simulation: A Case Study of Green Canyon 955, Gulf of Mexico

The Gulf of Mexico is a widely explored and producing region for offshore oil and gas resources, with significant submarine methane hydrates. Estimates of hydrate saturation and distribution rely on drilling expeditions and seismic surveys that tend to provide either large-scale estimates or highly localized well data. In this study, hydrate reserve characterization is done using numerical simulation at Green Canyon block 955 (GC955). In addition, coupled thermo-hydro-mechanical (THM) simulation results show that hydrate saturation and geobody distribution are determined by the thermodynamic conditions as well as reservoir structures, stratigraphic differences, and permeability differences. Hydrate formation due to upflow of free gas and dissociation due to gas production and oceanic temperature rise due to climate change are simulated. The abundance of free gas under the hydrate stability zone and favorable pressure and temperature meant little hydrate was depleted from the reservoir. Furthermore, the maximum displacement due to warming reached 0.5 m in 100 years and 4.2 m in 180 days based on a simulation of constant production of methane gas. The displacement direction and magnitude suggest that there is little possibility of slope failure. Therefore, the GC955 site studied in this paper can be considered a favorable site for potential hydrate exploitation.

Organic Solid Waste Management by Producing Eco-Enzymes from Fruit Skin in Permata Tembalang

The Ministry of Environment and Forestry in 2020 estimates that waste dumps in Indonesia will be 67.8 million tons. However, organic waste management in Indonesia is still relatively low. The accumulation of organic waste in the landfill, which usually causes unpleasant odors and potentially cause an explosion due to the production of methane gas from natural decomposition processes, can be avoided by prioritizing waste management from the source. An alternative way to handle organic waste is make eco-enzymes because it is efficient, economical, and environmentally friendly. This is the focus of the community service team. The community service method is carried out in three stages, including the preparation stage, the implementation stage, and the final stage. The preparation stage consists of doing a module for sorting organic waste and its utilization (making eco-enzymes). The next phase consists of socialization, education, and training on sorting organic waste and making the right eco-enzymes. The final stage consists of evaluation and making a final report. The expected result after education, socialization, or training has been carried out by the community service team, the community members, especially RT 04 RW 05 Permata Tembalang, know better and understand the sorting and utilization of organic waste.

Energy Recovery Analysıs of A Biomass Type of Installed Waste Water Treatment Plant

Energy production can also be obtained from plant, animal or sometimes human material, referred to be the biomass technology. The biomass raw material can be obtained from purposely grown energy crops, waste from food crops, wood or forest residues, horticulture, animal farming, food processing, or human waste from sewage plants. In this study, energy recovery analysis of an installed waste water treatment plant was conducted. The physical and chemical analyses of energy recovery that can be obtained from waste water treatment plant were clarified. In this regards, parameters including daily wastewater inlet water flow rate, wastewater inlet water 24 hourly average temperature, wastewater inlet water 24 hourly pH average, wastewater inlet water 24 hourly conductivity average, gas generator daily gas consumption, diesel generator daily energy generation, daily energy consumption from the city line, gas generator energy generation, total energy consumption of the water treatment plant, and daily gas generation of the treatment plant were identified. The plant has the duty of providing water treatment, so it is certain that noteworthy energy consumption in the plant can occur is an expected situation. However, the point that how much of the energy can be regained by the biomass technology provided by the burning processes conducted on the human waste is important. Namely, it is reported in this study that 78.29% of the total energy consumed by the plant was regained by these processes occurred in the treatment facility. On the other hand, this amount of recovered energy was reported to correspond a total of 14.200 GWh in this installed plant of Turkey. Apart from the amount of the recovered energy, the discharge of the amount of the methane gas which is responsible of the biomass energy generation was also analyzed according to the considered physical and chemical parameters. For instance, the analyses have shown that the increase of the waste water temperature causes decrease on the amount of the methane gas generation. On the other hand, the conductivity and the degree of acidity increase resulted the increase of the amount of the methane gas production.

Bioenergy production from bacteria (Methanogens)

The research deals with anaerobic fermentation and creating the conditions for bacteria (Methanogens) to carry out the process of hydration, acidification and production of methane gas. The study included the design of an anaerobic reactor made of thick glass (12) mm, with dimensions (of 35 x 35 x 35) cm, with a thermal heater inside it and a temperature set at (45) ℃, and then filled with Dairy wastewater. The Treatment period of the reactor reached two months, during which water samples were taken (72hrc) for laboratory tests (pH, COD). The laboratory tests began on 1/1/2021 and ended on 1/3/2021. COD removal of 87.12% was achieved with a neutral pH at the beginning of the second month of treatment. Biogas was obtained in this anaerobic reactor by fermentation and in the presence of bacteria (Methanogens), and its amount during the treatment period was 1.6 m3. Keywords: Bioenergy, Dairy waste Water, anaerobic reactor, Fermentation, bacteria (Methanogens)

In Vitro Evaluation of Feed Quality of Fermented Tithonia diversifolia with Lactobacillus bulgaricus and Persea americana miller Leaves as Forages for Goat

Fermented Tithonia diversifolia and Persea americana miller or avocado leaves as local alternative forages for goats are potential as protein, mineral, and energy sources. Therefore, this study aimed to evaluate the effect of fermented Tithonia diversifolia (FTD) and avocado leaves (AL) combination on in vitro nutrient digestibility, rumen fluid characteristics, and methane production. This study consisted of 3 trials. Trial 1 evaluated FTD’s nutrient content with Lactobacillus bulgaricus with different durations of fermentation arranged in a completely randomized design consisting of five treatments and four replications. The treatments were T. diversifolia without fermentation and fermentation of T. diversifolia for 2, 3, 4, and 5 days. Trial 2 was in vitro evaluation on different days of fermented T. diversifolia in a completely randomized design consisting of four treatments and four replications. Trial 3 was in vitro evaluation of FTD for 5 days and AL combination, which consisted of four combinations. FTDAL1 = 20% FTD+80% AL; FTDAL2 = 40% FTD+60% AL; FTDAL3 = 60% FTD+40% AL; and FTDAL4 = 80% FTD+20% AL. Experimental diets were incubated using Tilley and Terry method. Fermentation of T. diversifolia using L. bulgaricus significantly increased nutrient components (p<0.01), nutrient digestibility (p<0.01), and rumen fluid characteristics (p<0.05). In vitro evaluation of FTD and AL combination significantly increased nutrient digestibility, total volatile fatty acid, ammonia concentration, total gas production, and methane production (p<0.05), but insignificantly affected pH rumen fluid. It is concluded that the combination of 80% fermented T. diversifolia and 20% avocado leaves has the potential to increase dry matter, organic matter, crude protein, cellulose digestibility, and rumen fluid characteristics, but it is not optimum to decrease total gas and methane gas production.

Estimasi Produksi Gas Metana Untuk Pemanfaatan Sebagai Sumber Energi Di TPA Talang Gulo, Jambi

Landfills (TPA) are a significant source of methane emissions into the atmosphere. In Indonesia, the estimation of methane gas production from a landfill has not been widely carried out. The purpose of this research is to measure production and measure the concentration of methane gas emitted into the atmosphere, assess methane gas emissions as an energy source, and analyze the potential costs and benefits of electrical energy that can be generated from methane gas emissions at the Talang Gulo TPA. The emission data obtained can be used as material for analysis to create a project for developing a gas processing system from a landfill. This estimation approach is carried out in three ways, namely prediction with LandGEM-v302 software, field measurements with methane flux and utilization of methane gas production as an energy source. The LandGEM-v302 simulation results obtained a total landfill gas of 29.96 Gg/year consisting of CH4 of 8.002 Gg/year, CO2 of 21.96 Gg/year and NMOC (non-methane organic compounds) of 0.344 Gg/year. The results of field measurements on the surface of the closed chamber TPA obtained CH4 emissions from TPA Talang Gulo of 4.75 Mg/year. The different characteristics of the landfill surface greatly affect the gas emissions released into the atmosphere. Moisture conditions or water content in the waste also affect the methane emission rate. The electricity potential from methane gas is 15.718 MW so that the cost benefit analysis shows an NPV of Rp. 6,028,622,852.18, B/C Ratio of 0.00196 and IRR of 2.445%.