Treatment method of Fischer-Tropsch synthesis recycle gas decarburization wastewater

Abstract

The invention relates to a treatment method of Fischer-Tropsch synthesis recycle gas decarburization wastewater, which comprises subjecting the wastewater to flash evaporation and striping, and specifically comprises: 1) feeding decarburization wastewater into a flash evaporation tank, carrying out reduced pressure flash evaporation, discharging the gas subjected to flash evaporation from the upper part of a flash evaporation tower, and discharging the wastewater subjected to flash evaporation from the bottom of the tower; 2) feeding the wastewater subjected to flash evaporation into a stripping tower through the upper part of the stripping tower, feeding hydrogen or carbon monoxide or a mixture of the hydrogen and the carbon monoxide into the stripping tower through the lower part of thestripping tower, performing stripping of the wastewater by stripping gas in the stripping tower, discharging water after stripping from the bottom of the tower, and discharging the stripped gas from the top of the tower and returning the discharged stripped gas to a reactor together with flash steam obtained in the step (1). According to the method disclosed by the invention, the comprehensive utilization of wastewater resources is realized while the emission of decarburization wastewater is reduced.

Description

technical field [0001] The invention belongs to the field of petrochemical comprehensive utilization, and in particular relates to a treatment method for Fischer-Tropsch synthesis cycle gas decarbonization wastewater. Background technique [0002] The Fischer-Tropsch synthesis process uses coal or natural gas as the raw material to indirectly synthesize liquid fuels. In the Fischer-Tropsch reaction, while H2 and CO generate hydrocarbon products on the reduced catalyst, water is simultaneously generated during the reaction process, and water and CO undergo water gas The conversion reaction produces a large amount of CO2. Therefore, after the products in the gas out of the synthesis reactor are separated, the remaining tail gas must be freed of CO2 before being recycled. Since the thermal potash method is used to remove CO2, the loss of hydrocarbons is the smallest. Therefore, this method is commonly used for decarburization of Fischer-Tropsch synthesis cycle gas. However, du...

AI Technical Summary

Problems solved by technology

For the steam stripping method, although most of the organic matter in the organic wastewater can be removed by gas, the waste water after the gas stripping still needs to be sent to the sewage for treatment, and the stripped product also needs to be designed separately. The treatment required by the whole process is difficult, and the investment is high. High operating costs; however, for the steam stripping method that adds multiple-effect evaporation and concentration steps, it has the disadvantages of high energy consumption and the need for sewage treatment after evaporation

On the other hand, the current wastewater treatment process only focuses on the control of wastewater discharge, and the wastewater resources and organic components in wastewater have not been effectively utilized, and secondary discharge pollution is still inevitable.

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