The main reactors are vertical vessels, each having expandable bed of an ion-exchange-resin-type catalyst. Methanol makeup, mixed with methanol recycle, is pumped from TK-001 by pump P-003, through methanol guard pots V-004 to remove basic and cationic compounds.
The C4 feed and a part of methanol respectively pumped through P-002 and P-003 under flow and flow ratio control are mixed with recycle before feeding the main reactors V-005 A/B. The two reactors are installed in series. The feed is heated with LP steam in feed preheaters E-002 and E-003. Interreactor cooler E-004 is used during EOR conditions of column catalyst to increase conversion.
The catalyst is fluidized by recycling a part of reactor effluent through P-005. The temperature of the reactor is controlled by cooling the recycled stream with cooling water in exchanger E-005, which removes the heat of reaction and heat added during preheat in E-003. Filters F-002/4/6 are installed at both reactor inlet and outlets to collect fine particles from the resins. The conversion in the reactors is up to 80%.
Cartridge filters with an acrylic wool fiber filter element are installed at the inlet of reactors to trap circulating resin particles of 75+ micron size. Similarly, strainers are placed at reactor outlets to trap circulating fine particles originating from the catalyst bed.
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