Direct supply of catalytic reforming feedstock
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That company has experience in providing raw materials directly for reprocessing; what are the specific plans and procedures, and what issues need to be taken into consideration? Please share your valuable opinions
What does direct supply mean? Go straight into the reactor without pretreatment?
It should refer to feedstock supplied directly after pre-hydrogenation. The most important thing is the separation of fractions from the upstream units; regular analyses of the raw material’s boiling range and impurities should be carried out, with an increased frequency for such analyses.
Direct supply has two disadvantages: first, the feed volume is unstable; second, the raw material has a high water content. Both of these affect the operation of the pre-distillation section.
After the direct feeding of material, a buffer tank is required before pre-distillation; it serves two purposes: one is dehydration, which is the main function, and the other is buffering to stabilize the feed flow. At the same time, increase the frequency of analysis on the materials supplied directly from upstream units to identify issues promptly.
The raw material buffer tanks in regular installations are not large enough; we use the large tanks in the tank farm, with material being added and removed continuously. However, this is only done when there is a shortage of raw materials, as it introduces unnecessary risks.
Whether it is the pre-hydrogenation feed for the reforming system or the direct feed from the reforming unit, the following is required: 1. The quality of the raw materials must meet the standards； 2. Stable supply volume ； 3. The raw material is fed into a sufficiently large buffer tank to remove unnecessary impurities (such as carbon powder, rust, etc.) and moisture.
Thank you all for your suggestions. However, we plan to feed the crude gasoline directly into the pre-distillation tower without using a buffer tank. The raw material pump is not able to supply enough volume, so we intend to add a coalescer before the feed enters the tower. We’re not sure what shortcomings this approach might have
I strongly object to direct supply without a buffer tank; if you have to purge the tower once during vacuum distillation, you’ll be very busy!
I think direct supply has too much of an impact on this device!
Coagulators are used to remove trace amounts of water. Can they remove large amounts of water? Are coagulators prone to clogging?
Ours uses direct feeding with cracking, and thermal feeding helps save energy
One more question: Has anyone analyzed the water content in atmospheric and vacuum distillation naphtha that has not been subjected to sedimentation or dehydration? What is it approximately? We are currently using a live tank feeding method, with the inlet and outlet of the large tank being very close to each other; based on an approximate estimation from the water removal amount at the top of the pre-distillation tower, the value is above 250 ppm.
Supplying directly without a buffer tank means you’ll run into problems as soon as you perform vacuum distillation in the column