摘要 :
Article presents the results of investigations on the pyrolytic process of utilisation of sewage sludge originated from the municipal-industrial sewage treatment plant. The products received during the process of the pyrolysis wer...
展开
Article presents the results of investigations on the pyrolytic process of utilisation of sewage sludge originated from the municipal-industrial sewage treatment plant. The products received during the process of the pyrolysis were subject to the detailed qualitative and quantitative analyses as far as their energetic usefulness is concerned.
收起
摘要 :
Current research and development on mine methane mitigation and utilisation focuses on methane emitted from underground coal mines,in particularventilation air methane (VAM).This is because (1) it represents most of the methane em...
展开
Current research and development on mine methane mitigation and utilisation focuses on methane emitted from underground coal mines,in particularventilation air methane (VAM).This is because (1) it represents most of the methane emitted from coal mines;and (2) it is most difficult to capture and use,asthe air volume is large and the methane resource is dilute and variable in both concentration and flow rate.It is estimated in China that over 70% of the drainagegas has a methane concentration of less than 30%,and this should be targeted for the mitigation and utilisation as well. VAM mitigation/utilisation requires either treatment in its dilute state,or concentration up to levels that can be used in conventional gas fuelled engines.This paper reviews most of the existing and developing VAM technologies,and discusses potential technical issues for their applications at mine sites.Then,based on fundamental thermodynamic laws the paper analyses methods for the concentration and oxidisation of methane in mine ventilation air to gain insightinto the effect of methane concentration.They are simplified as far as possible to allow conclusions to be drawn as to the limits of what is possible withventilation air methane.The analytic results are summarised to provide a guide on thermodynamic limitations for each technical process.
收起
摘要 :
Current research and development on mine methane mitigation and utilisation focuses on methane emitted from underground coal mines,in particularventilation air methane (VAM).This is because (1) it represents most of the methane em...
展开
Current research and development on mine methane mitigation and utilisation focuses on methane emitted from underground coal mines,in particularventilation air methane (VAM).This is because (1) it represents most of the methane emitted from coal mines;and (2) it is most difficult to capture and use,asthe air volume is large and the methane resource is dilute and variable in both concentration and flow rate.It is estimated in China that over 70% of the drainagegas has a methane concentration of less than 30%,and this should be targeted for the mitigation and utilisation as well. VAM mitigation/utilisation requires either treatment in its dilute state,or concentration up to levels that can be used in conventional gas fuelled engines.This paper reviews most of the existing and developing VAM technologies,and discusses potential technical issues for their applications at mine sites.Then,based on fundamental thermodynamic laws the paper analyses methods for the concentration and oxidisation of methane in mine ventilation air to gain insightinto the effect of methane concentration.They are simplified as far as possible to allow conclusions to be drawn as to the limits of what is possible withventilation air methane.The analytic results are summarised to provide a guide on thermodynamic limitations for each technical process.
收起
摘要 :
CO_2 reforming of methane was studied over a bed of coal char in a fixed bed reactor at temperatures between 1073 and 1223 K and atmospheric pressure with a feed composition of CH4/CO_2/N_2 in the ratio of 1:1:8. Experimental resu...
展开
CO_2 reforming of methane was studied over a bed of coal char in a fixed bed reactor at temperatures between 1073 and 1223 K and atmospheric pressure with a feed composition of CH4/CO_2/N_2 in the ratio of 1:1:8. Experimental results showed that the char was an effective catalyst for the production of syngas with a maximum H_2/CO ratio of one. It was also found that high H_2/CO ratios were favoured by low pressures and moderate to high temperatures. These results are supported by thermodynamic calculations. A mechanism of seven overall reactions was studied and three catalytic reactions of CH_4 decomposition, char gasification and the Boudouard reaction was identified as being of major importance. The first reaction produces carbon and H_2, the second consumes carbon, and the third (the Boudouard reaction) converts CO_2 to CO while consuming carbon. Equilibrium calculations and experimental results showed that any water present reacts to form H_2 and carbon oxides in the range of temperatures and pressures studied. Carbon deposition over the char bed is the major cause of deactivation. The rate of carbon formation depends on the kinetic balance between the surface reaction of the adsorbed hydrocarbons with oxygen containing species and the further dissociation of the hydrocarbon.
收起
摘要 :
CO2 reforming of methane was studied over a bed of coal char in a fixed bed reactor at temperatures between 107.3 and 1223 K and atmospheric pressure with a feed composition of CH4/CO2/N2 in the ratio of 1:1:8 Experimental results...
展开
CO2 reforming of methane was studied over a bed of coal char in a fixed bed reactor at temperatures between 107.3 and 1223 K and atmospheric pressure with a feed composition of CH4/CO2/N2 in the ratio of 1:1:8 Experimental results showed that the char was an effective catalyst for the production of syngas with a maximum H2/CO ratio of one. It was also found that high H2/CO ratios were favoured by low pressures and moderate to high temperatures. These results are supported by thermodynamic calculations, A mechanism of seven overall reactions was studied and three catalytic reactions of CH4 decomposition, char gasification and the Boudouard reaction was identified as being of major importance The first reaction produces carbon and H2, the second consumes carbon, and the third (the Boudouard reaction) converts CO2 to CO while consuming carbon. Equilibrium calculations and experimental results showed that any watei present reacts to form H2 and carbon oxides in the range of temperatures and pressures studied. Carbon deposition over the char bed is the major cause of deactivation. The rate of carbon formation depends on the kinetic balance between the surface reaction of the adsorbed hydrocarbons with oxygen containing species and the further dissociation of the hydrocarbon.
收起
摘要 :
CO_2 reforming of methane was studied over a bed of coal char in a fixed bed reactor at temperatures between 1073 and 1223 K and atmospheric pressure with a feed composition of CH4/CO_2/N_2 in the ratio of 1:1:8. Experimental resu...
展开
CO_2 reforming of methane was studied over a bed of coal char in a fixed bed reactor at temperatures between 1073 and 1223 K and atmospheric pressure with a feed composition of CH4/CO_2/N_2 in the ratio of 1:1:8. Experimental results showed that the char was an effective catalyst for the production of syngas with a maximum H_2/CO ratio of one. It was also found that high H_2/CO ratios were favoured by low pressures and moderate to high temperatures. These results are supported by thermodynamic calculations. A mechanism of seven overall reactions was studied and three catalytic reactions of CH_4 decomposition, char gasification and the Boudouard reaction was identified as being of major importance. The first reaction produces carbon and H_2, the second consumes carbon, and the third (the Boudouard reaction) converts CO_2 to CO while consuming carbon. Equilibrium calculations and experimental results showed that any water present reacts to form H_2 and carbon oxides in the range of temperatures and pressures studied. Carbon deposition over the char bed is the major cause of deactivation. The rate of carbon formation depends on the kinetic balance between the surface reaction of the adsorbed hydrocarbons with oxygen containing species and the further dissociation of the hydrocarbon.
收起
摘要 :
About 28 billion m~3 of methane is emitted per year to the atmosphere from coal mining activities around the world. The mitigation and utilisation of the fugitive coal mine methane is very difficult because its concentration is ve...
展开
About 28 billion m~3 of methane is emitted per year to the atmosphere from coal mining activities around the world. The mitigation and utilisation of the fugitive coal mine methane is very difficult because its concentration is very low and variable of 0.1%～1%, and it is contained in large air flow rate of 150～400 m~3/s. This paper overviews the existing and developing technologies for the mitigation and utilisation of the fugitive mine methane, and then presents a ventilation air methane catalytic turbine (VAMCAT) technology we developed, which can be powered with about 1% methane in air.
收起
摘要 :
Reliable mine gas prediction is not only essential for effective gas drainage and control,improvement of mining safety and reduction of coalproduction costs,but also important to mine gas production assessment for gas utilisation ...
展开
Reliable mine gas prediction is not only essential for effective gas drainage and control,improvement of mining safety and reduction of coalproduction costs,but also important to mine gas production assessment for gas utilisation evaluation and planning. An integrated mine gas simulation system has been developed to predict strata conditions and methane gas emission during Iongwall mining.The system isused to assist selection and planning of suitable mining,gas management and utilisation strategies for new and existing mines.Several key mine gas assessmentprocesses,such as mine site gas and geotechnical characterisation,and fully coupled mechanical deformation-fluid flow computer simulation,have beenintegrated in the simulation system. Gas flow during mining is controlled by in situ gas content and geotechnical conditions,as well as the mining induced changes in the strata such as thoseof stress,fracture,pore pressure and permeability.The central part of the integrated simulation system is the new 3D code called COSFLOW that simulates thecomplex behaviour of rock,water and gas flow,and predicts gas emission during longwall development and retreat.The code is also capable of simulating gasdrainage performance and estimating gas production. This system was developed from a recently completed collaborative project entitled“Predevelopment Studies for Mine Methane Management andUtilisation”,between the New Energy and Industrial Technology Development Organization (NEDO) of Japan,the Japan Coal Energy Center (JCOAL),andthe Commonwealth Scientific and Industrial Research Organisation (CSIRO) of Australia. The integrated simulation approach is described in this paper and examples of mine site application are presented.
收起
摘要 :
Reliable mine gas prediction is not only essential for effective gas drainage and control,improvement of mining safety and reduction of coalproduction costs,but also important to mine gas production assessment for gas utilisation ...
展开
Reliable mine gas prediction is not only essential for effective gas drainage and control,improvement of mining safety and reduction of coalproduction costs,but also important to mine gas production assessment for gas utilisation evaluation and planning. An integrated mine gas simulation system has been developed to predict strata conditions and methane gas emission during Iongwall mining.The system isused to assist selection and planning of suitable mining,gas management and utilisation strategies for new and existing mines.Several key mine gas assessmentprocesses,such as mine site gas and geotechnical characterisation,and fully coupled mechanical deformation-fluid flow computer simulation,have beenintegrated in the simulation system. Gas flow during mining is controlled by in situ gas content and geotechnical conditions,as well as the mining induced changes in the strata such as thoseof stress,fracture,pore pressure and permeability.The central part of the integrated simulation system is the new 3D code called COSFLOW that simulates thecomplex behaviour of rock,water and gas flow,and predicts gas emission during longwall development and retreat.The code is also capable of simulating gasdrainage performance and estimating gas production. This system was developed from a recently completed collaborative project entitled“Predevelopment Studies for Mine Methane Management andUtilisation”,between the New Energy and Industrial Technology Development Organization (NEDO) of Japan,the Japan Coal Energy Center (JCOAL),andthe Commonwealth Scientific and Industrial Research Organisation (CSIRO) of Australia. The integrated simulation approach is described in this paper and examples of mine site application are presented.
收起
摘要 :
The United Utilities (UU) biomethane to grid plant provides a further outlet for the biogas which provides operational flexibility. This flexibility means UU can modulate biomethane and electricity production to maximise financial...
展开
The United Utilities (UU) biomethane to grid plant provides a further outlet for the biogas which provides operational flexibility. This flexibility means UU can modulate biomethane and electricity production to maximise financial performance and operate dynamically within the electricity and natural gas networks. This dynamic operation includes working on capacity market applications to manage demand to support the electricity performance of the grid. This supports longer term full smart grid developments. This aligns with the UK's focus to bring together policy to drive integrated strategies to realise environmental and sustainable benefits. In taking this project forward, UU have embraced new technology and achieved safe and efficient operation. By realising this future way of operation, which maximises value to customers, UU's integrated energy generation solutions sets a "blue print" for how UU and others can maximise financial, environmental and social benefits.
收起
原文获取