Papers by Keyword: Mine Gas

Abstract: A set of experimental system was self-designed and made for liquid phase catalytic oxidation of gas to methanol. It was used to investigate the impacts of catalyst and reaction conditions on catalytic oxidation of gas to methanol in acetic acid solution, and to analyze its reaction mechanism. It has been showed that the yield of the methanol is 1840 μmol under the catalysis of 0.5 g of 0.5% Pd-CuPc/Y and the following conditions: CH3COOH:H2O = 4:1 (v/v), 1000 μmol of p-benzoquinone; reaction time, 3 h; reaction temperature, 150°C; gas composition, 2.5MPa CH4+0.4MPaO2 +0.4MPa N2; in acetic acid solution, catalytic oxidation of mine gas to methanol follows mechanisms of electrophilic substitution and oxidation of reactive oxygen species (ROS).

Abstract: Mine gas composition is complex, and its main component is methane (CH4), followed by carbon dioxide (CO2) and nitrogen (N2), also contains a small amount or trace amount of heavy hydrocarbon gases (ethane, propane, butane, pentane, etc.) , Hydrogen (H2), carbon monoxide (CO), sulfur dioxide (SO2), hydrogen sulfide (H2S) and so on. For gas detection, the gas compositions above with listed behind CH4 becomes its interference noise. A second harmonic modulation of the fiber laser was used to achieve low concentration of coal mine gas monitoring against a multi-component-gas background noise, and an early warning can be accomplished.

Abstract: This article introduced control principles of a mine gas mixing control system; and expounded the realization methods, the steps of PID control algorithm and parameter setting in the Step7 by using configuration control system of Siemens PLC. In the industrial control computer IPC, PLC and human-computer interface HMI centered control system that realized steady control of the calorific value, and it has preferable reliability, advancement and adaptability.

Abstract: In our country, as the great threat caused by gas explosion or gas accident to the safety in coal mine production, the development of gas monitoring system is key to preventing accidents beforehand.. Putted into interferometer, the amplitude and the intensity of the incident ray carrying the information of gas concentration are divided many times by reflection and transmission, which results in many parallel beams in the form of the reflected light and the transmitted light. The concentration of the gas can be obtained by testing the light intensity signal . The experiment results show that an accurate measurement result which is capable for the gas concentration test in underground abominable conditions can be got by this mean. Particularly, based on multiplexing technique of optical fiber sensing, it is easy to build a sensor network. This method has an important significance and a good prospect of application and extension for gas monitoring and safety production in the coal mine.

Abstract: Methane (CH4) a potent greenhouse gas (GHG). Human activities, such as natural gas extraction, natural gas transportation and coal mining, result in emissions of the large amounts of CH4 into the atmosphere. Thus it is necessary to study the reduction of CH4 in these fields. The experiments of hydrates formation of CH4 and coal mine gas were respectively carried out using self-developed experiment apparatuses. The results show that the hydrates of CH4 and coal mine gas are prone to be formed under appropriate conditions. The strong storage stability of natural gas hydrates was approved by the experiments to determine the dissociation heat and the average dissociation rate of hydrates. At the same time, the technology flow for recovery and utilization of coal mine gas was proposed based on gas hydrate technology. The experiment results and the former literatures indicate that the reducing emission of CH4 using gas hydrates is feasible.

Abstract: This paper aims to design a sort of aqueous atomization absorbing material which can absorb mine gas under coal mine to decrease the methane concentration and reduce the explosion hazard. The material was composed of water as matrix, Span 80 as methane absorbent, and inorganic salt as additive. Methane the main component of mine gas was used as model of mine gas. The influence of concentration of inorganic salt on absorption and the effect of different compound materials made of Span 80 and inorganic salt on absorption were studied using Head Space Gas Chromatography to determine the content of methane absorbed. Explosion chamber was used as experiment system to simulate mine gas explosion. The explosion suppression effects of absorbing materials were studied preliminarily in explosion chamber using the maximum explosion pressure and residual methane content after explosion as parameters. The results indicate that the absorbing material can absorb more methane than water and can partly inhibit the explosion of the mixture of methane and air.