University of Edinburgh researchers have developed a new low carbon process to improve the production yield of ultrapure hydrogen from coal-like materials
Academics at the University of Edinburgh have developed the new high purity hydrogen (H2) process in collaboration with researchers at Yonsei University, South Korea.
This breakthrough will provide a significant step-change for a broad range of chemical engineering and industrial applications where there is significant demand for the gas, in, for example, low carbon hydrogen-based heat and power production, across large-scale industrial plants, or powering the next generation of hydrogen fuel cells used in hybrid and electric vehicles.
The University of Edinburgh’s commercialisation arm, Edinburgh Research & Innovation (ERI), is now seeking industry partners to license this technology for development into commercially viable application.
Until now, the primary form of hydrogen production has been by natural gas (methane) steam reforming. During this process, the hydrocarbons in the gas are converted at high temperature into a hydrogen-rich mixture of gases. The hydrogen is then separated out during an additional process step.
Natural Gas is generally used as raw material for the production of commercial, ultrapure hydrogen (99.9+ % H2 purity). However, the demands to produce high purity hydrogen from cheaper raw materials such as coal and biomass continue to increase.
The University of Edinburgh research found that such solid-to-H2 processes is not economically feasible against the conventional methane-to-H2 process due to an intrinsically very low hydrogen yield.
Moreover, this is required to produce low carbon hydrogen by implementing a carbon capture unit to fossil fuels H2 plants.
Dr Hyungwoong Ahn, a Senior Lecturer in Chemical Engineering from the University of Edinburgh’s School of Engineering, reveals how, through a series of adopted processes, the research uncovered ways to produce the low carbon hydrogen from coal that improves on this ultra-pure hydrogen yield:
“By integrating a coal‐to‐hydrogen process with carbon capture, the hydrogen yield per unit coal feed can be greatly improved using the carbon capture unit used on a synthesis gas stream generated by coal gasification. This helps to improve the hydrogen yield by greater and more efficient use of the H2 Pressure Swing Absorption (PSA) tail gas – an important separation process for gases and applied widely in gas purification and gas recovery.”
The research team identified the core invention was to split the PSA tail gas into three sub-streams and use them accordingly (i) as a supplementary fuel for a carbon gas capture unit to improve its sorbent regeneration; (ii) as an additional feed to shift reactors to boost the hydrogen yield by converting more carbon to hydrogen and (iii) as fuel from drying coal instead of using synthesis gas.
John Jeffrey, ERI’s business development executive, comments:
“This breakthrough now allows us to look for industrial and commercialisation partners who see the clear advantages in this research. The production of high-purity hydrogen and the efficiency of the process, from start to finish, will amount to an improvement in hydrogen production yield by more than 2% further to what would be expected of a solid-to-H2 process with CO2 capture and a total auxiliary power consumption reduction by around 7%. These can be viewed as significant savings depending on the output of the processing plant.”