Partial hydrogenation of benzene process method capable of recycling catalysts

Abstract

The invention discloses an optimized partial hydrogenation of benzene process method capable of recycling catalysts. The process method includes that after raw materials of benzene and hydrogen, and catalysts and additives enter a reactor and reaction products flow through a separator, an oil phase reaction liquid mixing with the catalysts and aqueous phase enters a flash tank; an oil water separating tank is added behind the flash tank, a pipeline through which discharge of the flash tank enters a waste water treatment system is connected to a first pipeline to be connected into the oil water separating tank, the discharge is pumped into a catalyst regenerator through a centrifugal pump from the oil water separating tank, and is sent back to the reactor along with the regenerated catalysts through a metering pump; a second pipeline is further arranged at an outlet of the centrifugal pump behind the oil water separating tank and connected with an inlet of the flash tank, and the flash tank, the oil water separating tank, newly added pipelines and pumps are made of stainless steel lining Poly tetra fluoro ethylene (PTFE). According to the partial hydrogenation of benzene process method, loss of hydrogenation catalysts and zinc sulfate is reduced, use amount of catalysts and additives are saved greatly, and production cost is reduced effectively.

Description

technical field [0001] The invention belongs to the technical field of partial hydrogenation of benzene, and in particular relates to a partial hydrogenation process of benzene with a recyclable catalyst. Background technique [0002] Currently, the partial hydrogenation of benzene to produce cyclohexene adopts the following process: [0003] The benzene outside the boundary area enters the device and is pumped into the reactor together with the benzene circulating in the device. In addition to benzene entering the reactor, hydrogen and catalyst are also injected into the reactor. Wherein the catalyst is a ruthenium-based noble metal catalyst in the form of spherical solid particles. The reactor is equipped with a stirrer to fully contact the three phases of gas, liquid and solid. In addition, zinc sulfate solution as an auxiliary agent should be injected into the reactor to adjust its pH value, so as to keep the catalyst in the best working condition. After the reaction...

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Problems solved by technology

[0006] 2. Since the reactor is injected with zinc sulfate solution to adjust the pH value, zinc sulfate is water-soluble, so zinc sulfate will be discharged together with the wastewater at the flash tank, resulting in a large waste of zinc sulfate

[0007] 3. Catalyst and zinc sulfate are both metal salts, which are discharged to the wastewater treatment system and cannot be treated by conventional methods such as neutralization and biochemistry, which increases the difficulty of treatment and operating costs

[0008] Currently there is no effective method for catalyst recovery in the partial hydrogenation process of benzene

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