Discussion: What work is required to convert diesel hydroprocessing to wax oil hydroprocessing
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What changes are required to convert atmospheric-pressure hydrogenation to wax oil hydrogenation?
1. Ordinary diesel hydrogenation catalysts are not suitable for processing wax oil, and the catalyst needs to be replaced. 2. Paraffin oil has a high freezing point, so it is necessary to take measures to prevent freezing in the pipelines. 3. Wax oil and water are difficult to separate in the high-viscosity fractions designed as diesel, requiring the addition of demulsifiers. 4. Generally, the feed tanks in diesel hydrogenation plants are at normal temperature; whether to replace the feed tanks needs to be considered based on the temperature at which the wax oil is fed in.
Due to differences in the hydrogen-to-oil ratio and hydrogen consumption, it is necessary to consider the capacity of the new hydrogen and recycled hydrogen compressors; distillation also needs to be adjusted accordingly as the properties of the material change.
Firstly, diesel uses a cold high-pressure process, while wax oil should employ a hot high-pressure process. Other issues related to pumps and heat exchangers are not a problem, as the specific gravity of paraffin oil is similar to that of diesel fuel, or even lower. Additionally, the heat tracing for the wax oil pipeline must be installed as well; otherwise, condensation issues will arise. The diesel stripping tower at the rear also needs to be adjusted appropriately.
My factory also needs to undergo this renovation; come and take a look
In fact, wax oil hydrogenation is similar to diesel hydrogenation; the only difference is that the operating temperature is higher, and it is possible to replace the catalyst if conditions permit. Those without high heat values need to be added, to check whether the heat exchange between what enters the stripping tower and what exits the unit is appropriate, as well as whether the material of the heat exchangers meets the required standards. If it is not for heat exchange between tail oil and feed oil, consideration can be given to making modifications.