Pilot scale demonstration of potential for decarbonisation of industrial heating processes using hydrogen cofiring

This paper aims to evaluate whether cofiring hydrogen and natural gas mixtures are suitable as industrial furnace fuels and to identify further characteristics that need more detailed understanding to enable successful implementation of fuel switching. The outcome of this research and further investigations will ensure that the full capability of fuel switching becomes available to energy-intensive process operators. Co-firing natural gas and hydrogen leading to dedicated hydrogen combustion are pathways to decarbonise industrial processes and can enable future hydrogen utilisation and interoperability with fossil fuels. The key observations from pilot-scale industrial furnace trials at the University of Sheffield Energy Innovation Centre included: (1) Radiant heat flux depended primarily upon furnace temperature with no relationship measured with varying fuel composition. (2) The chamber geometry, radiant heat flux from solid surfaces and control temperature achieved were more significant to the furnace heat exchange than the fuel mixture. (3) Firing with natural gas and hydrogen mixtures did not affect furnace temperature or uniformity beyond variations attributable to other process conditions. (4) Gas temperatures and species were distributed uniformly within the fully mixed atmosphere, which represented 2/3 of the chamber volume. (5) Gas temperature and species distributions were not affected by fuel composition, therefore measurements from the centre of the chamber were representative of the mean conditions in the fully mixed atmosphere. (6) CFD modelling of the gas and temperature distributions within the furnace enabled thermodynamic and fluid dynamic characteristics to be understood and afforded confidence in experimental and model outcomes. Co-firing hydrogen with natural gas and dedicated hydrogen firing as an interoperable fuel to substitute for natural gas could be a key means to decarbonise hard to abate foundation industries, whilst making continued use of existing capital assets. This investigation demonstrated that understanding hydrogen firing and co-firing will enable the mitigation of perceived risks arising from decarbonisation of energy-intensive industries with low and zero carbon fuels.