Design and evaluation of a porous burner for the mitigation of anthropogenic methane emissions.
Methane constitutes 15% of total global anthropogenic greenhouse gas emissions. The mitigation of these emissions could have a significant near-term effect on slowing global warming, and recovering and burning the methane would allow a wasted energy resource to be exploited. The typically low and fluctuating energy content of the emission streams makes combustion difficult; however porous burners-an advanced combustion technology capable of burning low-calorific value fuels below the conventional flammability limit-are one possible mitigation solution. Here we discuss a pilot-scale porous burner designed for this purpose. The burner comprises a cylindrical combustion chamber filled with a porous bed of alumina saddles, combined with an arrangement of heat exchanger tubes for preheating the incoming emission stream. A computational fluid dynamics model was developed to aid in the design process. Results illustrating the burner's stable operating range and behavior are presented: stable ultralean combustion is demonstrated at natural gas concentrations as low as 2.3 vol%, with transient combustion at concentrations down to 1.1 vol%; the system is comparatively stable to perturbations in the operating conditions, and emissions of both carbon monoxide and unburned hydrocarbons are negligible. Based on this pilot-scale demonstration, porous burners show potential as a methane mitigation technology.
Wood
Susie
S
School of Chemical and Biomolecular Engineering, The University of Sydney, NSW 2006, Australia. s.wood@usyd.edu.au
Fletcher
David F
DF
Joseph
Stephen D
SD
Dawson
Adrian
A
Harris
Andrew T
AT
D000393:Air Pollutants / Q000737:chemistry*; D000818:Animals; D002516:Ceramics; D003198:Computer Simulation; D017752:Greenhouse Effect; D006801:Humans; D017745:Incineration / Q000295:instrumentation* / Q000379:methods; D008422:Materials Testing; D008697:Methane / Q000737:chemistry*; D008956:Models, Chemical; D012037:Refuse Disposal / Q000295:instrumentation / Q000379:methods; D013696:Temperature
D000393:Air Pollutants; D008697:Methane