Experimental Study and Challenges of Hydrogen-NaturalGas Mixture Combustion for Industrial Premixed Burners

Hydrogen fuel is at the forefront of the heating sector in achieving the Net Zero agenda, and industries are in the

race to develop hydrogen-ready burners for the industrial space heating applications. The transition from natural

gas to hydrogen is not straightforward, and some of the challenges faced in developing hydrogen-ready industrial

burners are addressed in this study. The experimental investigation of hydrogen-enriched fuel mixtures in indus-

trial burners (i.e., the PHOTON10 unit) has been conducted to address these challenges, including combustion and

emission characteristics. The hydrogen-enriched G20 (i.e., a test fuel with 99.99% natural gas) was introduced to

the burner to identify key challenges, such as flame stability, flame flashback, and flame thermal runaway. Hy-

drogen has unique burning characteristics compared to natural gas, resulting in unique challenges. The primary

challenge is to overcome flame rectification, as a 100% hydrogen flame is almost imperceptible to the naked eye in

daylight. Conventionally, the burner requires higher hydrogen consumption to meet its rated power output. Finally,

emission characteristics were analysed for every hydrogen blend up to 100% hydrogen (% by vol.), and the results

were in excellent agreement with CO2, NO, and NOx reductions. Flame temperature decreased with increasing

hydrogen-enriched G20 gas blend fuels. Fuel consumption increased up to three times to meet the PHOTON10’s

rated power output for 100% hydrogen. All the hydrogen- enriched G20 blend fuels exhibited lower values than

the emission thresholds for CO, CO2, NO, and NOx. The PHOTON10 unit requires minimal modifications to

achieve fuel-lean combustion for the air intake speed and diameter. During closed operation of PHOTON10, the

flue gas temperature and UV cell flame rectification serve as the sole parameters for flame visualisation.