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

<p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">Hydrogen fuel is at the forefront of the heating sector in achieving the Net Zero agenda, and industries are in the <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">race to develop hydrogen-ready burners for the industrial space heating applications. The transition from natural <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">gas to hydrogen is not straightforward, and some of the challenges faced in developing hydrogen-ready industrial <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">burners are addressed in this study. The experimental investigation of hydrogen-enriched fuel mixtures in indus- <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">trial burners (i.e., the PHOTON10 unit) has been conducted to address these challenges, including combustion and <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">emission characteristics. The hydrogen-enriched G20 (i.e., a test fuel with 99.99% natural gas) was introduced to <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">the burner to identify key challenges, such as flame stability, flame flashback, and flame thermal runaway. Hy- <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">drogen has unique burning characteristics compared to natural gas, resulting in unique challenges. The primary <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">challenge is to overcome flame rectification, as a 100% hydrogen flame is almost imperceptible to the naked eye in <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">daylight. Conventionally, the burner requires higher hydrogen consumption to meet its rated power output. Finally, <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">emission characteristics were analysed for every hydrogen blend up to 100% hydrogen (% by vol.), and the results <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">were in excellent agreement with CO2, NO, and NOx reductions. Flame temperature decreased with increasing <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">hydrogen-enriched G20 gas blend fuels. Fuel consumption increased up to three times to meet the PHOTON10’s <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">rated power output for 100% hydrogen. All the hydrogen- enriched G20 blend fuels exhibited lower values than <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">the emission thresholds for CO, CO2, NO, and NOx. The PHOTON10 unit requires minimal modifications to <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">achieve fuel-lean combustion for the air intake speed and diameter. During closed operation of PHOTON10, the <p class="p1" style="margin: 0px; font-width: normal; font-size: 9px; line-height: normal; font-family: Helvetica; font-size-adjust: none; font-kerning: auto; font-variant-alternates: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-position: normal; font-feature-settings: normal; font-optical-sizing: auto; font-variation-settings: normal;">flue gas temperature and UV cell flame rectification serve as the sole parameters for flame visualisation.