Why use methanol to produce hydrogen?
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Gasification produces hydrogen and carbon monoxide, which are used to synthesize methanol! Why use methanol to produce hydrogen again? Instead of synthesis, isn’t it better to produce hydrogen directly through gasification?
Methanol steam reforming for hydrogen production is more widely adopted due to its high hydrogen yield (the hydrogen content in the products can approach 75% as can be seen from the reaction equation), efficient energy utilization, simple process control, and ease of industrial operation.
Different plants have different considerations. For refineries, the overall efficiency of producing hydrogen from methanol is more convenient to consider; in coal chemical industries, hydrogen is produced as a by-product, and just like in catalytic reforming, the hydrogen generated can be purified using a PSA unit before it is put to use
I raised the same question as the original poster a few years ago. At that time, I was unemployed at home for three months and was helping an industrial gas company with the preliminary safety assessment for hydrogen production from methanol; I asked the same question. In fact, both refineries and coal chemical plants can produce hydrogen. The problem is transportation, with dispersed users and high overall costs. So this bowl of stew can only be watched as it is given to others.
Well, it’s just that there’s no other option – who has another gas source willing to be used for hydrogen production? The cost of producing hydrogen from methanol is a little over 1 yuan per cubic meter, while the cost of producing hydrogen from coke oven gas is less than 1 yuan. The key issue is that you need such a gas source available
What is the composition of hydrogen produced by gasification? What to do with CO? How much hydrogen is obtained? Is conversion necessary? How much is wasted?
The question raised by the poster is very good. In fact, the decision should be based on the conditions of surrounding enterprises and one’s own needs, especially regarding the quantity required. It is also necessary to take into account the local environmental regulations. Hydrogen production from coal is the most economical method, but it involves many procedures that need to be followed; the relevant authorities will certainly classify such projects as coal chemical projects, requiring a variety of complicated procedures. On the other hand, if only a small amount of hydrogen is needed, methanol cracking can suffice, and the procedures involved are simpler. Especially regarding environmental impact assessments, it’s difficult to handle coal-to-gas projects.
Hydrogen production from methanol is still reasonable from an investment perspective for small hydrogen production units
Whether to use methanol to produce hydrogen or coal to produce hydrogen should be considered comprehensively; just like with formaldehyde, it is also produced from methanol. Some companies use coal-based methanol, while others use methanol directly.