Partial conversion system for carbonic oxide and process control method thereof

Abstract

The invention discloses a partial conversion system for carbonic oxide and a process control method thereof. The system comprises a converted gas-liquid separator, two pre-converting furnaces which are connected in parallel, a converting furnace, a purified gas heater, a feed gas heater and an auxiliary feed gas heater. The process control method of partial conversion of carbonic oxide comprises the following steps: (1) diversion of the feed gas which is separated by the converted gas-liquid separator; (2) removal of carbon dust in the pre-converting furnaces; (3) diversion and heat exchange of feed gas to complete partial conversion of carbonic oxide; and (4) diversion of gas after mixing. The system and the method have the following advantages: maintenance of the feed gas heater can be completed on line, thus the continuous operation of the device is not affected; at the later stage of the operation of converting catalyst, the inlet gas temperature of the converting furnace can be increased by virtue of the auxiliary feed gas heater, thus the long-period steady operation of the device can be realized.

Description

Technical field: [0001] The invention relates to a carbon monoxide conversion system and a process control method thereof, in particular to a carbon monoxide partial conversion system and a process control method thereof. Background technique: [0002] The carbon monoxide shift process is under the action of a catalyst, and at a certain temperature (higher than the initial activity temperature of the catalyst), CO and water vapor react to convert CO into hydrogen and carbon dioxide. Its function is to provide the post-system with H that meets the process requirements. 2 / CO ratio. [0003] The main task of the carbon monoxide conversion device is to partially convert CO into H 2 , to meet the hydrogen-carbon ratio required by the post-system, due to the H in the crude syngas 2 The ratio of / CO is high, in order to effectively control the synthesis gas H of the carbon monoxide shift unit 2 / CO ratio, the shift device adopts a partial shift process, and about 1 / 3 of the cr...

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Problems solved by technology

[0004] At present, most carbon monoxide conversion devices use a single heat exchanger to heat the feed gas at the inlet of the converter furnace. Often, the pressure difference increases due to fouling of the feed gas heater, and the carbon monoxide conversion device is shut down to exhaust the gas.

In addition, at the end of the use of the conversion catalyst, the catalyst activity decreases, the CO conversion rate is low, and the H 2 The ratio of / CO cannot well meet the requirements of the post-system, which is not conducive to the stable operation of the device under high load, and the product output decreases

In addition, the activity of the shift furnace catalyst is relatively good at the initial stage of use, and the inlet temperature of the shift furnace is controlled to operate at a relatively low temperature, so the heat entering the feed gas heater is correspondingly reduced. It is difficult to reduce the heat entering the feed gas heater with current operating methods. The raw gas outlet temperature of the raw gas heater is too high, resulting in fouling of the tube side tubes of the raw gas heater operating at a higher temperature

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