Powering shuttle kilns with compressed biomethane gas for the Thai ceramic industry

Small-scale ceramic kilns use two types of burners, a rocket type and a shower type. A mixing nozzle injects the fuel into the burner. This creates a natural draft which entrains the combustion air and both air and fuel exit at the burner head where ignition occurs. It is not possible to directly substitute CBG for LPG without making physical changes to these nozzles and adjusting the flow parameters. This research outlines a methodology for adapting the burners for CBG and experimentally verifying the predictions. Flame stability, temperature, emissions, and efficiency were measured and were equivalent to the LPG flames. Finally, the modified burners were tested inside a 0.1 m3 shuttle ceramic kiln and used to fire greenware. It is estimated that a cost savings of up to 30% can be obtained using CBG, with a payback period of a little over three and a half years, factoring in the cost of the changeover.