Experimental investigation of the co-combustion of LPG-hydrogen blends on LPG-fueled systems

The need for sustainable and less pollutant heating solutions has started an energy transition process. Some of the short-term alternatives proposed are based on the use of hydrocarbon-hydrogen blends in conventional combustion systems. In this work, LPG-H2 blends are studied in (a) a gas heater, (b) a water heater and (c) a porous media burner. Thermal and emission behavior, as well as thermal efficiency, are studied for different fractions of H2 in the fuel blend. Stable combustion was sustained for H2 volume fractions up to (a) 44%, (b) 68% and (c) 58%, for the above-mentioned appliances, respectively. Both gas and water heaters showed an overall reduction in thermal efficiency and temperatures as H2 presence was increased. On the other hand, higher temperatures, and thermal efficiencies, along with a 30% reduction in CO emissions were registered for the porous media burner for large H2 fractions in the fuel blend. In conclusion, the technical feasibility of adding H2 to the LPG feed lines of conventional combustion systems was demonstrated, through the stable operation of the 3 appliances studied.