Currently, I do not have any oven that fulfill the need of high temperature.
To convert biogas (that is CH4) to H2, you need to perform the following chemical process engineering steps:
1) React CH4 with steam to produce Syngas (CO + H2). This process is called Steam-Methane Reforming (SMR).
2) Perform a water-gas shift (WGS) reaction: CO + H2O => CO2 + H2
This step will require a catalyst like platinum (Pt).
3) Separate the gaseous mixture (CO2 + H2) to obtain H2 gas. For the separation process, you need to use a membrane that is selective for H2 gas. Alternatively, you could use the pressure swing process.
Hope this helps answer your question.
Professor Yehia Khalil, Yale University, USA
Fellow of the University of Oxford, UK
Prof Kahlil has it mostly right except commercial H2 plants use Fe for High temperature (700 F) sift reactors and Cu for Low temperature shift reactor (400F) Pt is too expensive to use for this application.. Also membranes are not used in SMR H2 plants (but they could be useful for a lab scale plant). Pressure Swing Adsorption (PSA) is used for most new H2 plants, Many older plant scrub out the CO2 and methanate (CO +3H2 CH4 + H2O) the small amount of remaining CO in a fixed bed reactor to produce 95-97% pure H2.
Most PSA based H2 plants only have one shift reactor with Fe based catalyst because it is difficult to justify the cost of a low temperature shift reactors.
Stem methane reforming reactors are furnaces with tubes filled with Ni catalyst that typically operate around 1500 F (815 C). High tempertures are require
Fortunately Steam methane reforming is proven technology that has been used on a large scale commercially for more than 75 years so there really isn't any compelling need to demonstrate it in the lab.
Thanks Prof. Khalil and Prof. Manner for very detailed and informative answer. Actually, I am interested to convert biogas (from anaerobic digestion of garbage) to electricity through its conversion to H2. What type of Fe, I should use to achieve the high temperature? There is no need to separate the H2 I will directly convert it to electrical energy by microbial fuel cell/fuel cell.
Regards.
DR. KHAN
Dr Khan,.
This article could be useful to you:
Rick Manner (not a Prof or a PHD)
I'm not usually a fan of producing H2 and using it as fuel because commercial H2 sells for about double the its heating value (compared to natural gas) and its not a very efficient fuel (low adiabatic flame temperature).but your application is interesting to me. How efficiently can you convert H2 to electricity? I know of at least one landfill gas to syngas (H2 + CO) project that was a technical success but an economic failure (not enough gas produced) landfill gas production may not be as predictable as you think
Pass steam and convert CH4 into CO+ H2 ( Use catalyst). But it depends on steam rate too. 3 to 25 bar pressure is required. The best way but it is different from purview of bio-chemical processing. Using thermo-chemical process, you will get CO + H2.
Thanks dear Alok, which catalyst I should use for steam reforming of CH4?
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