Design and Evaluation of a Porous Burner for the Mitigation of Anthropogenic Methane Emissions

Abstract

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.

Thermodynamic Assessment of Heat Recovery from a Fluidized-Bed Ventilation Air Methane Abatement Unit

“…Ancillary uses replace combustion air with VAM, while principal uses consider the VAM as a primary fuel source. 3 Technologies for VAM abatement include thermal flow reversal reactors (TFRRs), 5 catalytic flow reversal reactors (CFRRs), 5 chemical looping combustion, 6 fluidized-bed reactors, 7 lean-fuel gas turbines, 8 porous burners, 9 and biofiltration. 10 Commercial installations of the VAM abatement technology are limited to TFRRs.…”

Site Trials and Demonstration of a Novel Pilot Ventilation Air Methane Mitigator

“…The development of CMR technology has ceased due to its practical applicability compared with CFRR. The porous burner is equipped with a porous matrix to thermally oxidize VAM, requiring a minimum methane concentration of 2.3% . It is unlikely to be suitable for VAM abatement as the VAM concentration is usually below 1%.…”

“…The porous burner is equipped with a porous matrix to thermally oxidize VAM, requiring a minimum methane concentration of 2.3%. 10 It is unlikely to be suitable for VAM abatement as the VAM concentration is usually below 1%. The rotary recuperative thermal oxidizer (RTO) units have been applied for volatile organic compound (VOC) destruction.…”

Stone Dust Looping for Ventilation Air Methane Abatement: A 1 m3/s Pilot-Scale Study

“…The most mature VAM abatement technologies are based on regenerative thermal oxidizers (RTOs), which were originally used for the oxidation of volatile organic compounds. Numerous researchers have studied thermal and catalytic RTOs for VAM abatement. − A variety of other technologies have been investigated for VAM abatement, including biofiltration, , porous burners, catalytic lean fuel engines, catalytic reactors, and chemical looping …”

“…Numerous researchers have studied thermal and catalytic RTOs for VAM abatement. 5−14 A variety of other technologies have been investigated for VAM abatement, including biofiltration, 15,16 porous burners, 17 catalytic lean fuel engines, 18 catalytic reactors, 19 and chemical looping. 20 An alternative to fixed bed RTOs is fluid bed abatement processes.…”