Application of Wobbe Index Analyser for Energy Efficiency Optimisation of Combustion Process Control

Abstract

The increasing needs to optimise the cost of operation for the oil and gas industry has put more signifcant demand for Engineers to seek innovative technology and enhanced process design application to save energy. One of the key areas to improve energy efciency is combustion equipment which consumes a signifcant amount of fuel gas. The conventional method of air-fuel ratio control using excess oxygen at the exhaust stack is the most common mean of combustion control. This method is efective if the fuel gas composition is stable with minimum fuctuation in Gross heating value. In practice, most modern refneries, gas processing plants, and petrochemical plants have multiple fuel gas sources from fash gas or residue of-gas generated by the intermediate process. The composition can vary widely, making it challenging for conventional air-fuel ratio control via access oxygen. A sudden change of the fuel gas composition can potentially result in unpredictability combustion, leading to equipment inefciency and the possibility of causing damage to the equipment & product quality, thus leading to economic loss. Wobbe index analyser can determine the exact heating value of fuel gas used for combustion and thus eliminate unstable fuel gas composition issues. The Wobbe index analyser provides compensated value to fuel gas control system to enhance the air-fuel ratio control, leading to more efcient energy management of combustion control equipment.