Biogas Combustion Research Articles

ВЛИЯНИЕ ТЕПЛОФИЗИЧЕСКИХ СВОЙСТВ ПРОДУКТОВ СГОРАНИЯ БИОГАЗА НА ТЕПЛОВЫЕ ПАРАМЕТРЫ ВОДОГРЕЙНЫХ КОТЛОВ

The combustion products of biogas and natural gas differ in the content of components, which affects their heat content and heat exchange in boilers. To determine the possibility of using biogas in boilers designed for burning natural gas, the work compares the thermophysical properties of the combustion products of natural gas and biogas and their influence on the results of boiler calculations. Methods were obtained for calculating the thermal conductivity and viscosity of a mixture of gases depending on their composition and temperature. The comparison showed that the calorimetric and thermophysical properties of biogas combustion products differ from the properties of natural gas combustion products by up to 4 %, and the difference from the reference properties of combustion products given in the standard method for calculating boiler units is on average 6 %. A comparison has been made of the results of verification thermal calculations of low-power hot water boilers KVMG-1.0 and KSV-1.0 using the properties of combustion products given in the standard method for calculating boiler units, and when calculating them using the proposed equations. Calculations have shown that the results of calculations based on reference data of the standard method lead to higher values of exhaust gas temperatures and fuel consumption. It can be concluded that natural gas in boilers can be replaced by biogas without the need to reconstruct the boiler, but for thermal calculations it is necessary to take into account changes in the composition and properties of fuel combustion products.

Development of membrane bioreactor for conversion of flue Gas-CO2 to C1 and C2 biomolecules

The capture and utilization of CO2 (CCU) from flue gases constitute a novel carbon feedstock for producing renewable chemicals and fuels. To lower the energy demand of CCU, Bio-Integrated Carbon Capture and Utilization (BICCU) was recently presented, where CO2-consuming microorganisms simultaneously desorb and convert CO2 captured from flue gas by methyl diethanolamine (MDEA) with H2 from water-electrolysis as the electron donor. The limiting factor is the microbial toxicity of MDEA, which restricts the capacity of the process. Furthermore, producing soluble molecules like the C2 platform molecule acetate is not possible without contaminating the product with capture agent. To resolve both challenges, we here propose a three-phase membrane system, where the MDEA and microorganisms are separated by a CO2-permeable membrane. Biological batch experiments with a mixed mesophilic culture confirmed the increased capacity of the BICCU-process for producing both methane and acetate when introducing a CO2-permeable membrane to the system to alleviate microbial inhibition by the capture agent and avoid contamination of soluble bioproducts. When using O2-rich flue gas from a biogas combustion engine, the CO2 conversion rate decreased by 18.0 % compared to a clean 20:80 CO2:N2 gas mixture, yet anaerobic metabolisms were still active in the mixed inoculum. Abiotic experiments furthermore showed that the microbial CO2 consumption maintained the gradient across the membrane and enhanced the CO2-flux by a factor of 3.1 ± 0.3. The membrane-based BICCU concept is expected to hold great promise particularly for producing acetate from flue gas-CO2, as the in situ separation eliminates the need for costly downstream separation.

Effect of rotating gliding discharges on the lean blow-off limit of biogas flames

This study investigates the effect of a rotating gliding discharge on synthetic biogas combustion at atmospheric pressure. Synthetic biogas was produced by mixing methane and carbon dioxide. Three mixtures were considered: 100%/0%, 70%/30%, and 50%/50% of methane and carbon dioxide, respectively. The plasma effect was investigated in a low-swirl-number burner equipped with a high-voltage electrode to produce gliding discharges. The effect of plasma on the stability limits of the flame is reported for several electrical powers. During plasma-assisted combustion, the lean blow-off limits of biogas-air flames were significantly improved, which agrees with what can be found in the literature for other fuels. The electrical parameters of the discharge and the plasma emissions were measured using electric probes and emission spectroscopy, respectively. The mixture with the CO2 dilution was associated with a higher reduced electric field and higher ion production. A better understanding of the excited-species concentration evolution during plasma is necessary and will be investigated in future work.

Thermo-enviro-economic analyses of a landfill biogas-fed polygeneration process combined with a liquefied natural gas cold energy utilization unit

Landfill biogas offers a promising opportunity to supply society’s energy requirements, following the waste-to-energy approach, which issuitable for sustainable production. However, structural modification for its utilization is the main gap, requiring additional research efforts. Considering this issue, the current study aims to design an eco-friendly polygeneration method for landfill biogas utilization for a cutting-edge heat recovery system that integrates a cold energy recovery and utilization unit for liquefied natural gas. The liquefied natural gas recovery section, the organic Rankine cycle with a zeotropic mixture, and the Kalina cycle are all started using the flue gas from the combustion of biogas in a cascade process. In addition, the waste heat of the Kalina cycle is recovered by a single-effect desalination cycle and liquefied natural gas recovery section. Also, a water electrolysis process is integrated into the whole system. As a result, the products include hydrogen, electricity, natural gas, hot and cold water, and freshwater. The Aspen HYSYS software is utilized to design the system and investigate its thermodynamic, environmental, and economic aspects. The results demonstrate an energy efficiency of 57.54 % and an exergy efficiency of 18.78 %. Also, the carbon dioxide footprint associated with the system equals 0.34 kg/kWh, and the specific cost of products is 73.96 $/GJ. An optimal exergy efficiency of 25.8 % and a specific cost of products of 69.7 $/GJ are obtained by means of an intelligent optimization approach that ultimately makes use of non-dominated sorting genetic algorithm-II and artificial neural networks.

Characterization of fresh biowastes for biogas production and environmental health in Niger Delta, Nigeria

BackgroundEnvironmental pollution is a public health problem in Niger Delta, Nigeria. Therefore, the aims of the present study were to: identify the major fresh biowastes in Bayelsa State, Niger Delta; quantify the biogas yields from mono-digestion and co-digestion of identified biowastes; determine the first day of biogas production during hydraulic retention time; assess pH variations during anaerobic digestion; and evaluate biogas flame colours.MethodsFifteen communities in Bayelsa State were randomly selected, and on-the-spot assessment and quantification of the biowastes found in each community were carried out daily per week. Mono-digestion of 20 kg of each biowaste and co-digestion of 10 kg of animal waste with 10 kg of plant waste were carried out respectively under anaerobic conditions. Cumulative biogas yield and pH were measured using a pH meter and weighing scale respectively. Biogas flame colours during combustion were visually assessed.ResultsExactly 120.61 metric ton of fresh biowastes was found to be generated per week in Bayelsa State, Niger Delta. Industrial biowastes were the highest [47.6 tonnes, (39.46%)], followed by abattoir biowastes [33 tonnes (27%)], market and roadside sellers biowastes [25.5 tonnes (21.14%)], and farm biowastes [14.51 (12.03%)]. Biogas yields (kg) were: 0, 0, 0, 0, 0, 17, 14, 2, 18, 16, 17, 15 and 1 kg for palm oil mill effluent (POME), orange fruit waste (OFW), pineapple peels (PP), plantain peels, cassava mill effluent (CME), rumen digesta (RD), cow dung, sewage, PP-RD, plantain peels-cow dung, POME-rumen digesta, OFW-cow dung, and CME-sewage respectively. The first day of biogas production for RD, cow dung, sewage, PP-RD, plantain peels-cow dung, POME-RD, OFW-cow dung, and CME-sewage was on the 6th, 32nd. 56th, 1st, 26th, 18th, 25th, and 60th day of hydraulic retention time respectively. A dominant blue flame colour mixed reddish yellow or orange flames were found during biogas combustion. A slight increase in pH was found in all the biodigester media.ConclusionsIn the present study, a variety of biowastes yielding various quantities and qualities of biogas were identified in Bayelsa State, Niger Delta. The study’s findings have provided evidence-based data that might be explored as a road map and catalyst for policy creation against inadequate biowaste management and as sustainable alternatives to the expensive liquefied petroleum gas. The potential of current research study to be scaled up for commercial use is implicated in the present study.

Improved combustion stability of biogas at different CO2 concentrations using inhomogeneous partially premixed stratified flames

Biogas is a renewable and clean energy source that plays an important role in the current environment of low- carbon transition. If high-content CO2 in biogas can be separated, transformed, and utilized, it not only realizes high-value utilization of biogas but also promotes carbon reduction in the biogas field. To improve the combustion stability of biogas, an inhomogeneous, partially premixed stratified (IPPS) combustion model was adopted in this study. The thermal flame structure and stability were investigated for a wide range of mixture inhomogeneities, turbulence levels, CO2 concentrations, air-to-fuel velocity ratios, and combustion energies in a concentric flow slot burner (CFSB). A fine-wire thermocouple is used to resolve the thermal flame structure. The flame size was reduced by increasing the CO2 concentration and the flames became lighter blue. The flame temperature also decreased with increase in CO2 concentration. Flame stability was reduced by increasing the CO2 concentration. However, at a certain level of mixture inhomogeneity, the concentration of CO2 in the IPPS mode did not affect the stability. Accordingly, the IPPS mode of combustion should be suitable for the combustion and stabilization of biogas. This should support the design of highly stabilized biogas turbulent flames independent of CO2 concentration. The data show that the lower stability conditions are partially due to the change in fuel combustion energy, which is characterized by the Wobbe index (WI). In addition, at a certain level of mixture inhomogeneity, the effect of the WI on flame stability becomes dominant.

Integration of an Autothermal Outer Electrified Reformer Technology for Methanol Production from Biogas: Enhanced Syngas Quality Production and CO2 Capture and Utilization Assessment

Biogas has emerged as a valid feedstock for biomethanol production from steam reforming. This study investigates an alternative layout based on an auto-thermal electrified reforming assuming a 1 MW equivalent anaerobic digestion plant as a source for methanol synthesis. The process considers an oxy-steam combustion of biogas and direct carbon sequestration with the presence of a reverse water–gas shift reactor to convert CO2 and H2 produced by a solid oxide electrolyzer cell to syngas. Thermal auto-sufficiency is ensured for the reverse water–gas shift reaction through the biogas oxy-combustion, and steam production is met with the integration of heat network recovery, with an overall process total electrical demand. This work compares the proposed process of electrification with standard biogas reforming and data available from the literature. To compare the results, some key performance indicators have been introduced, showing a carbon impact of only 0.04 kgCO2/kgMeOH for the electrified process compared to 1.38 kgCO2/kgMeOH in the case of biogas reforming technology. The auto-thermal electrified design allows for the recovery of 66.32% of the carbon available in the biogas, while a similar electrified process for syngas production reported in literature reaches only 15.34%. The overall energy impact of the simulated scenarios shows 94% of the total energy demand for the auto-thermal scenario associated with the electrolyzer. Finally, the introduction of the new layout is taken into consideration based on the country’s carbon intensity, proving carbon neutrality for values lower than 75 gCO2/kWh and demonstrating the role of renewable energies in the industrial application of the process.

Anaerobic digestion of municipal solid waste produced by the city of Algiers using life cycle assessment

This study analyses the life cycle assessment of anaerobic digestion process of municipal solid waste management (MSWM) produced by Algiers city. Some keys parameters of the processes are then modified to analyze the "hot spots" and perform a sensitivity analysis to identify their influence on the results. Data for the inventory came from actual city facilities, and background process information came from Eco invent version 3.1 of SimaPro 8.1 software. The analyzed process contribution indicates that the global warming potential is affected by the anaerobic digestion because of the NOx and CO emissions from the thermal processes of biogas burning and fuel oil combustion for digesters heating. Furthermore, plastics recycling is environmentally beneficial because of net savings. The energy valorization of biogas produces the least amount of environmental damage, eliminating 403.06 kg CO2 eq/ton of waste, saving 18.2 E+09 MJ/ton of fossil fuels, and producing 2.8 E+08 kWhel/year, or 6% of the city's annual electricity consumption.

Flexibility improvement of a coal-fired power plant by the integration of biogas utilization and molten salt thermal storage

This study presents a novel method to enhance the flexibility of coal-fired power plant (CFPP). The suggested integrated system comprises a CFPP integrated with molten salt thermal storage system and a biogas combustion and its waste heat utilization system. Molten salt can be used to heat high-pressure feedwater and expel steam into the turbine, quickly increasing the output of CFPP. The waste heat from biogas combustion is used to charge the molten salt, and further waste heat is recovered by ORC. Comparative analyses reveal compelling advantages. The power generation can be rapidly increased by 6.8 %. A substantial 1,342.45 kW increase in power generation and an impressive 9.52 % enhancement in energy efficiency. Exergy analysis demonstrates a notable 9.52 % improvement in overall exergy efficiency. The system yields an annual net income of 10,083.51 k$, boasting an exceptionally low dynamic payback period of 1.798 years and a substantial net present value of 51,427.34 k$ over its 10-year operational span. This research enhances understanding of the use of molten salt thermal storage to increase the flexibility of CFPPs and the biogas utilization.

Waste-to-Energy Processes as a Municipality-Level Waste Management Strategy: A Case Study of Kočevje, Slovenia

The escalating challenge of waste management demands innovative strategies to mitigate environmental impacts and harness valuable resources. This study investigates waste-to-energy (WtE) technologies for municipal waste management in Kočevje, Slovenia. An analysis of available waste streams reveals substantial energy potential from mixed municipal waste, biodegradable waste, and livestock manure. Various WtE technologies, including incineration, pyrolysis, gasification, and anaerobic digestion, are compared. The results show that processing mixed municipal waste using thermochemical processes could annually yield up to 0.98 GWh of electricity, and, separately, 3.22 GWh of useable waste heat for district heating or industrial applications. Furthermore, by treating 90% of the biodegradable waste, up to 1.31 GWh of electricity and 1.76 GWh of usable waste heat could be generated annually from biodegradable municipal waste and livestock manure using anaerobic digestion and biogas combustion in a combined heat and power facility. Gasification coupled with a gas-turbine-based combined heat and power cycle is suggested as optimal. Integration of WtE technologies could yield 2.29 GWh of electricity and 3.55 GWh of useable waste heat annually, representing an annual exergy yield of 2.98 GWh. Within the Kočevje municipality, this amount of energy could cover 23.6% of the annual household electricity needs and cover the annual space and water heating requirements of 10.0% of households with district heating. Additionally, CO2-eq. emissions could be reduced by up to 20%, while further offsetting emissions associated with electricity and district heat generation by 1907 tons annually. These findings highlight the potential of WtE technologies to enhance municipal self-sustainability and reduce landfill waste.

Emissions of Gases and Dust into the Air as a Result of the Conversion of Landfill Gas into Electricity and Heat in a Cogeneration Plant

The consequence of landfilling is biogas production in the waste bed, the main parameter of which is methane. The capture of biogas and its energetic use in a cogeneration system is the optimal solution for both environmental and energetic aspects. Nevertheless, the emission of gases and dust into the air from the cogeneration plant as a result of the combustion of biogas poses a potential threat not only to the surrounding ecosystem but also poses a serious risk to human health, especially to the respiratory system, leading to a variety of diseases. The gas and dust emission tests performed in the study showed significant values for CO2 173.08 [kg ∙ h-1] and for CO 0.7545 [kg ∙ h-1], NO2 0.7129 [kg ∙ h-1], SO2 0.3958 [kg ∙ h-1] and total dust 0.0013 [kg ∙ h-1] respectively. The work aims to demonstrate the actual emissions of gases and dust into the air as a result of the combustion of landfill gas and to use them to calculate fees for the use of the environment. Since no emission standards have been defined for this type of installation and there is no need to use reducing devices, it is crucial to regularly monitor pollutant emissions by installation operators to optimize the biogas combustion process and reduce emissions. Replacing the reference values with measurement data regarding air emissions will make the actual impact of the cogeneration installation on the environment more realistic.

Investigations on a Spark Ignition Engine, Part II: Impact of Hydrogen Addition and Compression Ratio on a Biogas-Fuelled Engine

Performance, emissions and combustion were studied using a spark ignition engine modified from a single-cylinder diesel engine with varying compression ratios and hydrogen addition. When the compression ratio increases, there is a slight increase in brake power and thermal efficiency. There is a small increase in brake power and brake thermal efficiency when the compression ratio is above 13:1. Increased emissions of nitric oxide, hydrocarbon, and carbon monoxide were observed at compression ratios above 13:1. Leaner mixtures, brake power and brake thermal efficiency are lowered. Spark timing is retarded as the compression ratio rises which results in high peak pressure and rate of heat release. At a compression ratio of 13:1, a small amount of hydrogen (15% on an energy basis) was added along with biogas. The lean limit of biogas combustion and the combustion rate are greatly increased by the addition of hydrogen. In addition, there was a rise in brake power and thermal efficiency. The levels of hydrocarbons were significantly reduced. Nitric oxide emissions did not rise as a result of the use of the retarded ignition timing. The effect of two throttle conditions on spark ignition engines using biogas as fuel is presented as Part I of this study.

Efficient reactive adsorption of hexamethyldisiloxane on MCM-41 supported sulfuric acid

Volatile methyl siloxanes (VMSs), which are converted to silica sediments during biogas burning, are regarded as the most problematic VMSs in existing biogas cleaning systems. However, the majority of methods for VMS removal, including cryogenic condensation, physical absorption, chemical absorption and porous material adsorption have been constrained by these methods' intrinsic drawbacks. Here, we present an alternate method for removing VMS from gas streams that are based on the materials supported by H2SO4. Simple incipient wetness impregnation was used to create MCM-41-supported H2SO4 (SSA/MCM) materials, which showed high reactive adsorption property for hexamethyldisiloxane (L2) elimination in the temperature range of 80–160 °C with the peak reactivity at 100 °C. With maximum QB and Qm values of 191.3 and 365.6 mg g−1, respectively, dynamic adsorption findings showed the significance of altering the intake concentration, gas flow rate, adsorbent mass, relative humidity, as well as H2SO4 loading in determining the L2 removal efficacy. Furthermore, it was established that the L2 reactive adsorption was caused by the polymerization of L2 by supported H2SO4, which produced the creation of polysiloxane. The findings offer an important foundation for creating a cutting-edge biogas cleaning method.

The Use of the Autotrophic Culture of Arthrospira platensis for CO2 Fixation from Biogas Combustion

The increased concentration of CO2 in the atmosphere has a strong impact on global warming. Therefore, efficient technologies must be used to reduce CO2 emissions. One of the methods is the biofixation of CO2 by microalgae and cyanobacteria. This is now a widely described technology that can improve the economics of biomass production and reduce CO2 emissions. There are no reports on the possibility of using it to clean exhaust gases from biogas combustion. The aim of the research was to determine the possibility of using Arthrospira platensis cultures to remove CO2 from biogas combustion. The efficiency of biomass production and the effectiveness of biological CO2 fixation were evaluated. The use of exhaust gases led to a more efficient increase in cyanobacterial biomass. The growth rate in the exponential phase was 209 ± 17 mgVS/L·day, allowing a biomass concentration of 2040 ± 49 mgVS/L. However, the use of exhaust gases led to a decrease in the pH of the culture medium and a rapid decline in the Arthrospira platensis population. The cyanobacteria effectively fixed CO2, and its concentration was limited from 13 ± 1% to 1.3 ± 0.7%. There was no influence of the exhaust gases on changes in the qualitative composition of the cyanobacterial biomass. In the culture fed with exhaust gas, the A. platensis population quickly entered the death phase, which requires close monitoring. This is an important indication for potential operators of large-scale photobioreactors.

Pinch, energy, and exergy analysis for a power-hydrogen cogeneration system fueled by biogas

This paper presents a combined heating, power, and hydrogen system production by utilizing biogas energy. A novel methodology is proposed to identify thermodynamic cycle conditions and reform processes by using biogas as the energy source. Biogas steam and dry reforming methods are considered based on equilibrium data employing the EES program. It is found that biogas has two principal roles for combustion and reforming processes simultaneously. The thermal energy from the combustion of biogas causes its reforming and improves the efficiency of the system by 74%. The exergy efficiency, the overall exergy destruction, and hydrogen efficiency are calculated for various electric powers ranging from 5 to 40 MW. It is found that the combustion chamber has the maximum exergy destruction of about 51%. The parametric study of the system is performed to assess the optimum conditions for producing hydrogen. The optimal condition corresponds to CO2/CH4 = 0.50–0.66, H2O/CH4 = 2–3.6, and the reforming temperature range of 965–1036 K. The conversion of methane and carbon dioxide shows the reduction of the greenhouse gases.

Experimental Investigation on Microsecond Pulsed Plasma Supported Biogas Combustion

Abstract This paper evaluates the effect of a microsecond pulsed plasma (MPP) on the stabilization and emission characteristics of non-premixed biogas/air flames with various CO2 contents. The MPP is generated by a unique DC-pulsed power generator providing high voltage (HV) pulses over a wide range of pulse repetition frequencies (PRFs). The burner configuration is made up of two concentric tubes in which a swirler is placed inside the annular part, ensuring the oxidizer's rotation. The central tube delivers the fuel through an injector placed close to the burner exit. Electrical diagnostics, including voltage, were performed. OH* chemiluminescence measurements were done to describe the structure and stability of the flame. Results showed that plasma generated by microsecond HV pulses can improve flame stability. In this regard, the distribution of key active species in the burner was studied via optical emission spectroscopy (OES). The results revealed that the pulsed plasma generates chemically active species such as excited N2*, CH*, OH* molecules, and H* and O* atoms, thereby improving flame stability. The dependence of the emitted species intensities on plasma parameters was investigated in detail. It is demonstrated that MPP can drastically enhance the dynamic flame stability of swirling non-premixed biogas flames, especially at lean operating conditions. In addition, NOx and CO emissions were studied over a wide range of pulse repetition frequencies. It is seen that the pulsed plasma increases NOx emission slightly and significantly reduces CO concentration in the flue gases.

Life Cycle Environmental and Economic Assessment of Different Biogas and Biogas Residue Operation Models

The utilization of biogas and biogas residues is an important objective of animal manure resource management. Regarding the environmental friendliness and economic suitability of utilization modes, previous studies have evaluated and compared biogas or biogas residue individually, which may lead to incomplete environmental and economic assessments. In this study, the environmental and economic aspects of six integrated biogas and digestate operation modes, i.e., biogas utilization (direct combustion, cogeneration, and purification) and biogas residue utilization (field return and composting), were analyzed via life cycle assessment (LCA) and the net present value (NPV) method, with an animal manure biogas plant in Tangshan City as the study object. The results of LCA showed that biogas cogeneration + biogas residue composting disposal was superior to other models in most environmental indicators. NPV analysis showed that direct biogas combustion + biogas residue composting was the best, breaking even in the 3rd year with a cumulative profit of 250 million CNY. With increased environmental costs and benefits, the biogas cogeneration + biogas residue composting model had the best performance in terms of efficiency ratio at 2.58; the NPV of both operating models of biogas cogeneration increased, while the NPV of the other operating models decreased about 20%.

A COMPARATIVE STUDY ON SAFETY, EXERGETIC, AND ENVIRONMENTAL ANALYSIS FOR BIOMETHANOL VIA BIOGAS REFORMING

The energy crisis and global warming caused by fossil fuel combustion have received increasing attention in recent years. Biomethanol is a clean and environmentally friendly energy produced by reforming biogas-derived syngas. To investigate the most suitable and efficient biomethanol production process, this paper compares the biomethanol production via three different biogas reforming processes, namely steam reforming, autothermal reforming, and tri-reforming using Aspen Plus simulator through safety index, energy and exergetic, and environmental analyses. For the process performance, the tri-reforming process achieved the highest energetic and exergetic efficiencies of 63.17% and 41.24%, respectively, due to producing the highest yield of methanol. In the environmental analysis, the steam reforming of the biogas process showed the lowest CO2 emission intensity of 3.16 ton CO2/ton methanol. The major source of CO2 emission is the combustion of biogas. The Dow Fire and Explosion Index was used for the safety aspect. The biomethanol reactor was discovered to be the most hazardous equipment.

Biogas untuk Menghasilkan Energi Listrik

Biogas is a methane gas produced from the fermentation of organic matter by anaerobic bacteria. Utilization of biogas as an energy source can be done by burning biogas directly, and indirectly by converting it into electrical energy. Biogas-fueled electric energy potential to be developed in the NTB area. The fundamental reason is: the government program "Earth One Million Cows" which is supposed to happen in 2013, rising prices of petroleum fuel and the scarcity of inorganic fertilizers. To realize the above research activities, will do the following steps: 1) Development of fixed-dome digester with a size of 8 m3, 2) the charging of organic materials in the digester to produce biogas, 3) perform gas reservoirs in the media that has been prepared, 4) integrate system are made, 5) test and measurement under load conditions. Test results on Biogas Power Plant in the laboratory EBT of the Engineering Faculty of Mataram Universit, with 8m3 digester produces biogas production at the effective time of 2.152 m3/day. Consumption of biogas to the generator at 200watt load is 0.133 m3 / 15, or the conversion of biogas into electricity coefficient is 2.4 m3/kwh. Production of biogas a day if converted to a 200Watt power burden to last about 4 hours.

Characterization of Biogas as an Alternative Fuel in Micro-Scale Combustion Technology

This study observes the flame characteristics of the biogas in micro/meso-scale (MSC) combustion technology, namely in a cylindrical MSC. For comparison, the fuel and combustor variations were carried out with backward-facing step size (bfs) as the flame holder in the combustor.The bfs are varied by changing the combustor's length of the inlet diameter. However, the size of the outlet diameter of the combustor is always constant to obtain a continuous combustion reaction zone. Biogas/methane (CH4), butane gas (C4H10), and a mixture of biogas-butane are used as fuel, with air as the oxidizing agent. The results showed that the type of fuel, reactant flow velocity, and equivalent ratio that occurred in the fuel variation and the bfs variation of the cylindrical msc influenced the flame characterization. Stable flame forms in the stoichiometric to rich equivalent ratio area and the medium to high reactant velocity area. The result shows that the equivalent ratio (φ) is 1.23 –1.44, the flame stability limit at the combustor ratio of 0.7, and biogas fuel has low flame stability compared to butane and the biogas-butane mixture. Moreover, the flame can be stable on butane fuel in the equivalent ratio (φ) 0.85 –1.43 and (φ) 0.86 –1.19 for the biogas-butane fuel mixture. Furthermore, when the D1/D2 increases, the flame stability of biogas tends to be wider than when the combustor ratio is 0.7, where the equivalent ratio (φ) is 0.98 –1.42. The result also shows that the flame can be stable on butane fuel in the equivalent ratio (φ) 0.71 –1.43, and for the biogas-butane fuel mixture, the flame can be stable in the equivalent ratio (φ) 0.69 –1.32. However, the best characterization of biogas combustion is formed in the variation of biogas treatment by mixing butane gas (biogas-butane). One of the methods used is called with a wider flame stability limit area. More varied flame visualization variations with a more widely distributed flame mode map, flame, and combustor wall temperature. The result shows that the combustor wall temperature of butane is around 225-250 °C, higher than the characterization of biogas combustion around 150°C, where it's without mixing butane gas for the possible test ranges.