New green technology for hydrogen production

Hydrogen is a valuable feedstock for the petrochemical industry and it may play a big role in the energy supply of the future, as a green, non-polluting, and efficient energy carrier. If it is burnt, only water is formed. However, the conventional technology for hydrogen production from natural gas ('steam reforming') is a highly energy intensive process, operated at high pressures (up to 25 bar) and high temperature (850 degrees C), with multistage subsequent separation and purification units. Moreover, huge amounts of CO₂ have to be handled in post-processing steps.

TU Eindhoven has now developed a new and improved technology called "sorption enhanced catalytic reforming of methane," using novel catalyst/sorbent materials. Halabi, working in collaboration with the Energy Research Centre of the Netherlands (ECN), has demonstrated the feasibility of producing hydrogen through such a process at much lower temperatures (400 to 500 degrees Celsius).

The process is performed in a packed bed reactor using a Rhodium-based catalyst and a Hydrotalcite-based sorbent as a new system of materials. Hydrogen is produced on the active catalyst and the cogenerated CO₂ is effectively adsorbed on the sorbent, hence preventing any CO₂ emissions to the atmosphere.

Halabi: "Direct production of high purity hydrogen and fuel conversion greater than 99.5% is experimentally achieved at low temperature range of (400 -- 500 ºC) and at a pressure of 4.5 bar with a low level of carbon oxides impurities: less than 100 ppm." The enormous reduction of the reactor size, material loading, catalyst/sorbent ratio, and energy requirements are beneficial key factors for the success of the concept over the conventional technologies. Small size hydrogen generation plants for residential or industrial application operated at a relatively low pressure, of less than 4.5 bar, seem to be feasible.

Dr. Mohamed Halabi received his PhD on May 9, 2011, at TU Eindhoven based on his dissertation "Sorption Enhanced Catalytic Reforming of Methane for Pure Hydrogen Production -- Experimental and Modeling." He conducted his research at the laboratory of Chemical Reactor Engineering, under the supervision of Prof. Jaap Schouten.