Effect of H2 produced through steam methane reforming on CHP plant efficiency

Abstract

In-situ hydrogen production is carried out by a catalytic reformer kit set up into exhaust gases for a CHP plant based on spark ignition engine running under lean conditions. An overall auto-thermal reforming process is achieved.Hydrogen production is mainly dependent on O 2 content in exhaust gases. Experiments are conducted at constant speed at 2 air/fuel ratios and 4 additional natural gas flow rates. H 2 content varies in the range 6% to 10% in vol. H 2 content effect is analyzed with respect to performance and emissions. Comparing with EGR shows an increasing of electrical efficiency of 1% whilst heat recovery decreases by 1%. NO and HC decrease by 18% and 12%, but CO increases by 14%, respectively. The results show that: (i) graphite joints were destroyed under effect of H 2 and high temperature; (ii) a cold spot appeared in the RGR line, and condensation has as consequence a carbon deposit; and (iii) no back-fire or knock occurred.

Transport characteristic study of methane steam reforming coupling methane catalytic combustion for hydrogen production

“…4. As a result, it is also different from the conventional steam reforming process which not coupling the methane catalytic combustion for heat source [4,5,27]. With the increase of inlet temperature, hydrogen mass fraction ðu H2 Þ decreases firstly, and then it increases.…”

Effects on CHP plant efficiency of H2 production through partial oxydation of natural gas over two group VIII metal catalysts

“…Le Corre et al [1] highlighted the effect of air-fuel ratio on the H 2 production for a CHP plant. The higher the air-59 fuel ratio, the greater is the H 2 content in the reformed gases.…”

“…The higher the air-59 fuel ratio, the greater is the H 2 content in the reformed gases. For example, Le Corre et al [1] reported that the 60 difference of H 2 content is 2% for air-fuel ratios of 1.5 and 1. For a CHP plant fuelled by natural gas, the O 2 content in the exhaust gases is around 7-8% by vol.…”

“…In the configuration with reformed exhaust gas 214 recirculation (denoted RGR), where exhaust gas is blended with additional natural gas before entering the 215 reformer, Le Corre et al [1] have shown that H 2 production yields a concentration in the reformed gas of only 216 10-14%. The AGRC improves significantly H 2 production by promoting the partial oxidation of methane, at 217 temperatures around 775 K. This temperature is not the most favorable for H 2 production (the ideal 218 temperature for H 2 production is around 1000 K); but the exhaust gases exiting the turbocharger are 219 available at 775 K for use and are otherwise emitted as wastes.…”