Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
This paper presents heat exchanger technology that is the key technology in three processes i.e. hydrogen and oxygen production using high temperature steam electrolysis; Brayton power cycle where sCO2 is recycled to the combustor in aim to reduce high temperature achieved after natural gas is combusted in oxygen and methanol production. These processes are combined into one process that enables methanol and electricity production with 100% carbon capture.
Industrial hydrogen has been used in many different applications e.g. oil refineries, ammonia and methanol production with demand that has been increasing continuously and expect to rise in days to come. To date, Steam Methane Reforming (SMR) process where methane (natural gas) reacts with steam at high temperature in an endothermic reaction has been adopted as the conventional way to produce industrial hydrogen.
However, there are other processes developed to produce hydrogen with electrolysis of steam being one of them. Steam electrolysis includes few different cell types with Solid Oxide Electrolysis Cell (SOEC) that operates at high temperatures being considered in this paper. It needs to be noted that hydrogen produced by steam electrolysis is of highest purity.
As steam electrolysis requires electricity which can be provided by either renewable or non-renewable energies, this paper is considering electricity provided by renewable energies (wind, solar or hydro) and electricity produced by Brayton power cycle, so hydrogen is produced without Green House Gas (GHG) emission.
To reduce electricity requirement for steam electrolysis diffusion bonded heat exchangers are employed to use heat from turbine exhaust gas and heat realized during hydrogenation of CO2 in methanol production.