Who can explain the process of coal-to-methanol production?
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I would like to understand the process of coal-to-methanol production. For example, what is removed during low-temperature methanol washing, and what is the main function of those various devices?
Give me an email address and I can tell you.
There are several major units, including air separation, gasification, conversion, low-temperature methanol washing, sulfur recovery, and methanol synthesis. Air separation: it involves separating air to obtain high-purity nitrogen and oxygen, with some argon being produced as a by-product； Gasification: Production of gas (such as CO, H2, etc.). Conversion: CO is converted to obtain more H2; the reaction is CO + H2O → H2 + CO2. Carbon removal: Excess CO2 and acidic gases such as H2S are removed from the feed gas, the hydrogen-to-carbon ratio is adjusted to around 2, and acidic gas of suitable quality (with a concentration of over 25%) is produced for sulfur recovery. Sulfur recovery: Treatment of acidic gas; in some cases, ammonia-containing gas obtained through gas lifting also needs to be treated, which requires a furnace temperature of over 1250 degrees. Methanol synthesis: Production and purification of methanol
The brother on the third floor is absolutely right; in low-temperature methanol washing, the main task is to remove carbon dioxide and hydrogen sulfide
For coal-to-methanol production, the main function of low-temperature methanol washing is to remove all sulfides as well as most of the CO2 from the process gas. It is required that the sulfur content at the outlet of the methanol washing tower be below 0.1PPM, while the CO2 content should be around 3% (this is determined by the methanol synthesis catalyst). First, there are the air separation and gasification units； Then there is the transformation process; the CO content at the outlet of the transformed gas is around 20% (Shell gasifiers are used for coal gasification) ； Low-temperature methanol washing unit ； Sulfur recovery unit: primarily recovers hydrogen sulfide from the acid gas obtained during methanol regeneration in the low-temperature methanol washing process ； Methanol synthesis unit (including syngas recycle compressor) ； Finally, there is the distillation unit.
The main task of the conversion section is to achieve a ratio of (H2-CO2)/(CO+CO2) equal to 2.05–2.1 through partial conversion and gas mixing, in order to meet the requirements of the methanol synthesis reaction. The task of the low-temperature methanol washing unit is to remove excess CO2 (while ensuring that the carbon dioxide content in the purified gas is 2.5%), as well as hydrogen sulfide, and to provide an acidic gas with a concentration of at least 40% for the sulfur recovery section.
Low-temperature methanol washing is a method for removing carbon dioxide