What is the role of the desalination water pipeline in methanol synthesis?
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This post was last edited by Tianya Langji on 2009-8-23 07:11. Our company is working on a coal-to-methanol project with an annual capacity of 600,000 tons; the methanol synthesis process employs the DeWitt process. In the preliminary design documents, a desalination water pipeline with a DN50 diameter is specified to be installed between the syngas compressor and the first inlet/outlet heat exchanger. The pressure of this desalinated water is 9.3 MPa, and its flow rate is 875.5 Kg/h. The flow rate of syngas exiting the syngas compressor is 217,900 Nm3/h. After the first inlet/outlet heat exchanger, there is a syngas purification tank that uses porous magnesium-aluminum spinel adsorbents. What is the purpose of installing this desalination water pipeline?
The process you’re talking about is quite rare; I haven’t seen such a design in any of the three methanol projects. Including the second-phase project, that makes five projects in total. Brother, by desalinated water you mean the one that comes out of the synthesis outlet, after passing through the methanol separator, right? There is indeed such a design – it involves an alcohol absorption tower that uses desalinated water to absorb a portion of the methanol present in the liquefied gas that results from synthesis cooling.
Remove most of the methanol from the gas to prevent it from affecting the adsorbent
Injecting deionized water helps to condense methanol in the gas, facilitating separation and reducing the methanol content in the gas entering the tower
It has similarities to CASALE’s process; it seems to be used for converting COS into H2S. After the inlet and outlet heat exchangers, the deionized water is vaporized into steam, which reacts with COS at the porous adsorbent to produce H2S; the H2S is then adsorbed and removed.
What the user mentioned above refers to the gas scrubbing tower, and our facility also has one of that type. The desalination water pipeline I’m talking about is located at the outlet of the syngas compressor; the gas contains very little methanol. I’ve asked many people about this, and they all say they’ve never seen such a thing.
At that time, I also considered hydrodesulfurization – breaking down organic sulfur into hydrogen sulfide and then removing the sulfides further in order to protect the synthesis catalyst. However, it seems that porous magnesium-aluminate spinel does not have the ability to adsorb sulfides; therefore, I think it is reasonable to consider this process as a hydrodesulfurization process. I wonder if there are any other explanations! ! !
Is there only porous magnesium-aluminum spinel in your purification tank? Is the function of porous magnesium-aluminum spinel described in the process package? Could you explain the role of porous magnesium-aluminum spinel, to help everyone understand the function of demineralized water?
Have any of the colleagues mentioned above come into contact with the Puraspec 2020 type desulfurizer? This type of desulfurizer is used in the syngas purification unit. The desalination water pipeline mentioned should be designed for the precise desulfurization of syngas. I’m not entirely familiar with the performance of this catalyst at the moment, but it’s certain that the desalination water pipeline is intended for desulfurization purposes!
This is not for desulfurization; it is used for washing wax
It is used for precise desulfurization, primarily to convert COS into H2S. We also have this pipeline in our process. I’m sure.