Papers by Keyword: Methane

Abstract: The research was performed with the aim of obtaining new data on effective methanogenesis during the fermentation of sugar production waste with the addition of lignocellulosic raw materials. Amaranth crops of different varieties were used as raw materials. After analyzing the component composition of fresh amaranth and dry raw materials according to standard methods, the samples were subjected to microbiological processing in the presence of an enzyme preparation in laboratory and industrial conditions. It was determined that when using the vegetative mass of amaranth plants with waste from sugar production in the processes of methanogenesis, the yield of biogas and its caloric content increase.

Abstract: A complete set-up of obtaining bio-hydrogen from palm oil mill effluent (POME) was successfully demonstrated in this study. The proposed set-up is a combination of upflow anaerobic sludge blanket (UASB) bioreactor (POME is digested to obtain methane) and subsequent a dry reforming tubular reactor (conversion of methane into bio-hydrogen). The UASB reactor with 10 litres working volume was operated in continuous operation at mesophilic temperature (38 °C), pH was maintained between 6.5 and 7.2 by adding buffering solution containing of 5 gL^-1 of calcium oxide (CaO) and hydraulic retention time (HRT) was set at 1 day. Prior to feeding of POME, the UASB reactor was inoculated with sludge taken from anaerobic pond at Lepar Hilir Palm Oil Mill. Then, the reactor was continuously fed with the raw POME with COD concentration of 7,773 mgL^-1 and organic loading rate (OLR) of 7.61 g CODL^-1d^-1. Meanwhile the dry reforming fixed-bed tubular reactor was operated at 750 °C and 0.1 g catalyst type Ni/SBA-15. Biogas produced from the UASB reactor was fed into the tubular reactor and gas samples were collected at the inlet and outlet and analyzed using GC-TCD. On average, the UASB reactor produced about 32 Ld^-1 biogas containing of 80 % methane and removing 67 % of COD. This biogas was fed into the dry reforming rector and the reaction took place in the reactor produced about 32 % of H₂, 0.24 % of CH₄, 28 % of CO₂ and 39 % of CO. This result yielded a H₂/CO ratio close to 1, demonstrated an efficient route for producing bio-hydrogen gas. Meanwhile, CH₄ conversion was recorded at 99.7 %.

Abstract: The 2 stroke single cylinder (63 cc) engine of 750 watt electric generator is very popular in the application because providing enough amount of electricity for small house hold with compact size, light weight with reasonable price. Usually this type of electric generator is fuelled with gasoline that mixed with oil as lubricant. The cylinder volume of the engine is usually around 63 cc. This type of engine can be fuelled with biogas with addition component to mix biogas together with air and lubricant, and set the compression pressure at 10 bar. Biogas mainly contain methane (CH4), carbon dioxide (CO2), moisture (H2O), and hydrogen sulfide (H2S). The CH4 is combustible gas and can be used as a fuel for internal combustion engine. Moisture and H2S are easily removed from biogas. To remove CO2 from biogas is about difficult and costly, therefore acceptable content of CO2 in the biogas should be investigate related with the fuel consumption. This research is conducted to understand the influent of ratio CH4 and CO2 in the biogas to fuel consumption of the 2 stroke single cylinder engine of 750 watt electric generator. The variations ratio of CH4 and CO2 were obtained from anaerobic digester with batch system. The results indicate that the CH4 and CO2 ration in the range 1.667-1.967 will yield optimum efficiency that reach biogas consumption in the range of 9.1-9.8 liter/minute.

Abstract: The luminescent sensory systems based on manganese-doped zinc sulfide quantum dots were developed for aqueous environment monitoring. The structural, optical and sensory characteristics of quantum dots were investigated. The mechanism of ZnS:Mn²⁺ interaction with methane in the aqueous media, as well as factors that have a primary influence on the formation of the sensory response in the reaction with methane, were determined.

Abstract: A simple aqueous based synthesis technique at room temperature was performed for preparation manganese-doped zinc sulfide quantum dots. Under 4 eV excitation quantum dots show photoluminescence bands at 2.11 and 3.1 eV corresponded to Mn²⁺ and intrinsic ZnS emission respectively. ZnS quantum dots were used as the luminescent sensing element for methane detection in aqueous media. The luminescent sensor response occurs due to photoinduced electron transfer from QDs to methane molecule resulting in QD luminescence quenching.

Abstract: The objective of the study is to obtain suitable adsorbent to be applied for the purification of hydrogen from hydrogen-methane gas mixture. The application will be used to increase the efficiency of process in refinery unit focusing on hydrogen supply as the feed of hydrocracking unit. One of the promising technology is adsorption. In this study, adsorbent used is utilized by palm shell based bioadsorbent activated carbon which is a potential raw material among others due to its carbon and lignin content also its abundant supply. The activated carbon is going through chemical activation using H₃PO₄ to increase its surface area. Characteristic test of produced activated carbon is measured to obtain surface area which resulted in BET surface area of 414.91 m²/g and iodine number of 716 mg/g. In this case, a detailed experimental study has been made for the adsorption of pure methane, and pure hydrogen at 20°C and CH₄/H₂ gas mixture at 10, 20, and 30°C isothermal condition with pressure variation for each isothermal condition 1 – 6 bar. Measurement were made using volumetric technique coupled with gas chromatographic analysis. The result of adsorption test shows at 20°C adsorption of pure CH₄ was highest followed by mixture gas of CH₄/H₂ with 1.5% methane then pure H₂. The adsorption of gas mixture for any composition of gas were increased with increasing pressure at all temperatures. At the same pressure, adsorption of gas mixture that composed of 8.5% methane at 10 and 30°C increased in lower isothermal condition. Based on gas chromatograph analysis, in all conditions methane in gas mixture is all adsorbed to activated carbon. The trend of isothermal adsorption also fits the Langmuir model of isothermal adsorption.

Abstract: The analysis of sudden outbursts of coal and gas in coal mines is presented in the article. Phase transitions of gas to gashydrate state are investigated in the laboratory. Thermobaric parameters of phase transitions of mine methane are established. The new hypothesis is described of sudden outbursts of gas that is based on a gashydrate condition of methane in mines at depths (near 1000 m and more) and their explosion-like failure – Percy Bridgman’s effect.

Abstract: Bulk silicon carbide (SiC) as light emitter is less efficient due to its indirect bandgap. Therefore, nanosized SiC thin film fabrication approach enable emission wavelength shifts due to spatial confinement. The result of luminescent study of SiC thin film deposited via very high frequency plasma-enhanced chemical vapour deposition (VHF-PECVD) are presented. Precursor gasses used were silane and methane. Methane flow rate was varied from 8 sccm to 20 sccm while other parameters were maintained. Raman spectral analysis denotes the quantum confinement effect occurrence in proportion to the methane flow rate increment. The luminescence properties of the deposited SiC thin film ranging from highly green emission (~518 nm) to highly UVB emission (~294 nm) dominant luminescence. Broad blue emission band shifted toward higher wavelength with smaller FWHM as methane flow rate is increased. This results enable the possibility of luminescent SiC thin film applications in photonics and electronic integration as blue light sources.

Abstract: In order to decrease CO₂ level, converting the gas into hydrocarbon fuel gasses has been performed by using photoreduction method under TiO₂/SiO₂ photocatalysis. The silica (SiO₂) for TiO₂/SiO₂ preparation was purified from volcanic ash, that mixed with TiO₂ suspended in water. The photoreduction process of CO₂ was carried out in a batch technique, by exposing CO₂ and water vapor in the presence of TiO₂/SiO₂ photocatalyst with UV lamp for 24 h. The gasses produced from the photoreduction were determined by gas chromatography method. In the research, the effects of HCl and HNO₃ as hydrogen ion supplier were also evaluated. The research results indicate that the photoreduction of CO₂ with the water vapor over the photocatalyst of TiO₂/SiO_{2-volcanic ash} has successfully produced methane and ethylene as fuel gasses, while in the presence of TiO₂ no ethylene was resulted. The methane produced by TiO₂/SiO₂ was observed to be larger than by TiO₂ powder. The content of TiO₂ in TiO₂/SiO₂ with low level strongly influenced the yield of the products. In contrast, the yield was independent on the TiO₂ content in high level. The presence of the acids was found to increase the methane produced , and no ethylene was formed, but instead, methanol was resulted. The effect of HCl was higher than HNO₃.

Abstract: In this study, the principal possibility of methane formation from syngas (the mixture of hydrogen and carbon monoxide) in the dielectric barrier discharge plasma was shown. The results of syngas conversion under microsecond pulses (amplitude up to 12 kV and frequency of 1000Hz) treatment in the five-tube reactor were discussed. The dependence of the methane formation on the volume flow rate and the energy input were studied. Also effect of inert gases (by the example of nitrogen) addition in the initial gaseous mixture on the methane formation was investigated.