Catalytic or thermal reversed flow combustion of coal mine ventilation air methane: What is better choice and when?

Abstract The paper presents a comparison of the two options of reverse flow reactors destined for the utilization of coal mine ventilation air methane by catalytic (CFRR) or thermal (TFRR) combustion. It has been shown that both solutions have advantages and drawbacks. The use of the catalyst significantly decreases reactor temperature and makes the operation becomes to be autothermal for methane concentrations lower than in TFRR (even as low as over 0.06 vol.%). On the other hand when methane is combusted, particularly if average concentration is higher than ca. 0.4 vol.% the maximum temperature in the reactor appears to be too high for available cheap catalysts, while the use of the noble metals as active components (e.g. Pd) is not economically viable. Moreover lifetime of the catalysts is much lower than of the inactive heat exchange packing. For TFRR autothermicity threshold is higher (ca. 0.2 vol.%) but it enables cost-effective heat recovery if CH 4 concentration is higher than approx. 0.4 vol.%. In conclusion, the paper states that for lower VAM concentrations, when only greenhouse gas mitigation is an aim of combustion CFRR can have some advantages over TFRR. Should the heat recovery be seriously taken into account the TFRR is economically and technically the most advantageous solution, however.

[1]  Hua Guo,et al.  An assessment of mine methane mitigation and utilisation technologies , 2005 .

[2]  J. M. Somers,et al.  Thermal oxidation of coal mine ventilation air methane , 2008 .

[3]  G. Bunimovich,et al.  Reverse-Flow Operation in Fixed Bed Catalytic Reactors , 1996 .

[4]  Krzysztof Gosiewski.  Effective approach to cyclic steady state in the catalytic reverse-flow combustion of methane , 2004 .

[5]  C. W. Mallett,et al.  Progress in developing ventilation air methane mitigation and utilisation technologies. , 2003 .

[6]  M. Kubíček,et al.  Modelling of a tubular catalytic reactor with flow reversal , 1992 .

[7]  M. Jaschik,et al.  Thermal combustion of lean methane–air mixtures: Flow reversal research and demonstration reactor model and its validation , 2012 .

[8]  A. Boronin,et al.  Phase transformations in the thermoactivated MnOx–Al2O3 catalytic system , 2002 .

[9]  Ulrich Nieken,et al.  Control of the ignited steady state in autothermal fixed-bed reactors for catalytic combustion , 1994 .

[10]  Shi Su,et al.  Catalytic combustion of coal mine ventilation air methane , 2006 .

[11]  M. Jaschik,et al.  A study on thermal combustion of lean methane–air mixtures: Simplified reaction mechanism and kinetic equations , 2009 .

[12]  V. S. Sal’nikov,et al.  Deep Oxidation of Methane on Alumina–Manganese and Pt-Containing Catalysts , 2001 .

[13]  K. Gosiewski,et al.  Simplified Kinetic Model for Thermal Combustion of Lean Methane–Air Mixtures in a Wide Range of Temperatures , 2013 .

[14]  Dan Luss,et al.  Complex dynamic features of a cooled reverse‐flow reactor , 1998 .

[15]  Johannes Khinast,et al.  Dependence of Cooled Reverse-Flow Reactor Dynamics on Reactor Model , 1999 .

[16]  Min Chen,et al.  Efficient Synthesis of 1-Acetylpyrene Using [Bmim]Cl–FeCl3 Ionic Liquid as Dual Catalyst and Solvent , 2013 .

[18]  Dan Luss,et al.  Mapping regions with different bifurcation diagrams of a reverse‐flow reactor , 1997 .

[19]  K. Gosiewski.  Efficiency of heat recovery versus maximum catalyst temperature in a reverse-flow combustion of methane , 2005 .

[20]  G. Bunimovich,et al.  Control of Volatile Organic Compounds by the Catalytic Reverse Process , 1995 .

[21]  Deo,et al.  Mitigation of methane emissions from coal mine ventilation air , 1999 .

[22]  Andrew G. Salinger,et al.  The direct calculation of periodic states of the reverse flow reactor—II. Multiplicity and instability , 1996 .

[23]  Gerhart Eigenberger,et al.  Autothermal fixed-bed reactor concepts , 2000 .

[24]  Krzysztof Gosiewski,et al.  Homogeneous vs. catalytic combustion of lean methane—air mixtures in reverse-flow reactors , 2008 .

[25]  Robert E. Hayes,et al.  Heat Extraction from a Flow Reversal Reactor in Lean Methane Combustion , 2005 .

[26]  Is it economically feasible to use heterogeneous catalysts for VOC control in regenerative oxidizers , 1996 .