Crude benzene hydrofining process

Abstract

The invention relates to the technical field of chemical production, in particular to a crude benzene hydrofining process, which comprises the following steps: pretreating crude benzene, performing pressurizing by a pump, exchanging heat by a heat exchanger, and pumping the product into a hydrogen mixing tank; fully mixing a crude benzene full-fraction raw material, hydrogen and part of a recycledhydrogenation product in the hydrogen mixing tank, and fully dissolving the hydrogen in the raw material; sending a gas-liquid mixture discharged from the hydrogen mixing tank into a heating furnaceto be heated to 330-340DEG C, and then sending the product into an excessive hydrogen separation tank, and enabling the excessive hydrogen separated from the top of the excessive hydrogen separation tank to enter a tail gas treatment system; feeding the full-liquid-phase crude benzene raw material rich in dissolved hydrogen from the bottom of the excess hydrogen separation tank into a first-stagehydrogenation reactor, and carrying out a full-liquid-phase hydrogenation reaction under the catalytic action of a hydrogenation catalyst under the conditions of a pressure of 6-6.5MPa and a temperature of 340-345DEG C; flowing back one part of a hydrogenation product from the hydrogenation reactor to the hydrogen mixing tank, keeping the reflux quantity at 80% of the hydrogenation product, and subjecting the rest part to heat exchange with the raw material crude benzene, and then letting the rest part enter the gas-liquid separation tank. Therefore, the energy consumption is low, and the benefit is greatly improved.

Description

technical field [0001] The invention relates to the technical field of chemical production, in particular to a crude benzene hydrogenation refining process. Background technique [0002] Crude benzene is a complex mixture composed of various aromatic hydrocarbons and other compounds, of which benzene, toluene, and xylene content account for more than 90%, and important chemical products such as benzene, toluene, and xylene can be obtained through refining. Crude benzene is mainly refined by pickling and hydrotreating. The pickling method has simple process flow, flexible operation and low equipment investment, but serious pollution, low product yield and poor quality; hydrofining method has low pollution, high product yield and high quality, but the process process is more complicated and the investment is larger , is the current mainstream crude benzene refining technology. [0003] CN101519338A discloses a crude benzene hydrogenation method. In this method, the crude be...

AI Technical Summary

Problems solved by technology

Although this method can effectively avoid the coking problem of the device, the valuable heavy components in the crude benzene have not been effectively utilized, and the added value of the crude benzene is greatly reduced; in order to further suppress the coking of the crude benzene and meet the product property requirements, two or three stages are adopted Reactor reaction, the hydrogenation reaction is mainly in the gas phase, and the gas-oil ratio is high, so a large amount of hydrogen needs to be circulated, and the loss of hydrogen increases

In addition, the operation of pretreatment equipment, multiple reactors and recycle hydrogen compressors increases investment and energy consumption