Wastewater issues in methanol production
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The alcohol-containing wastewater generated in our plant after methanol distillation has a strong odor, contains a lot of oily substances, and is difficult to treat; as a result, the plant area becomes very unpleasant to be in, which is quite troublesome. I was wondering if there are any good ways to reduce the amount of wastewater produced or effective methods for treating it. (Our factory uses the Lurgi technology for gas production.)
For aldehyde-alcohol wastewater, biochemical methods are generally used to remove high concentrations of COD; as for odors and oily substances, filtration or air flotation can be employed. Recently, there has been considerable interest in the applications of ozone in water treatment, especially in nitrogen fertilizer industries, and it is likely that it can also be effective in dealing with methanol wastewater! However, the operating costs are quite high!
The COD value of the alcohol-water mixture in our factory is generally below 300, and when it is sent for biochemical treatment, it doesn’t have such a strong odor as you mentioned. It’s possible that the distillation efficiency in your facility isn’t very good; improving the process parameters related to distillation might solve the problem.
I also think it’s a problem with distillation; try controlling the parameters appropriately
Send it to the boiler wastewater or coal yard for burning:
The fifth floor has good points! Burning is a good method, but how exactly should it be done? If not handled properly, it can result in thick smoke and an overwhelming smell.
I can only share my views based on the actual conditions of our plant: We use three-column distillation, along with a recovery column. First, we focus on improving the distillation process, particularly in the atmospheric pressure column and the recovery column. The alcohol content in the bottom stream is below 1000 ppm; in practice, it can generally be kept between 100 and 500 ppm. This stream is then sent to the conversion gas stripping column using an alcohol-containing water pump. The steam resulting from this stripping process is combined with fresh steam to serve as process steam for the first stage of conversion. The alcohol content in the bottom stream after stripping is below 8 ppm, and it is sent to the chemical treatment unit. The COD level after treatment is less than 60 mg/L.
Control distillation properly; the wastewater can be sent for coal grinding or biochemical treatment
Our factory uses the steam from the gas generation boiler jacket for vaporizing substances as gas generation agents