Energy-saving sulfur-tolerant shift system and process with small system resistance and low comprehensive consumption

Abstract

The invention belongs to the technical field of synthetic ammonia production processes, and particularly relates to an energy-saving sulfur-tolerant shift system and process with small system resistance and low comprehensive consumption, which comprises a raw gas shift reaction and shift gas cooling treatment, an isothermal shift furnace and an adiabatic shift furnace in a shift process flow are matched and connected in parallel for use, and high-grade steam is recovered; a process gas path is optimized among the multi-stage conversion furnaces, and the system resistance is reduced; and the system energy recovery mode is optimized, the steam grade number is reduced, the steam supplementing amount is reduced through whole-process optimization, and comprehensive consumption is reduced.

Description

technical field [0001] The invention belongs to the technical field of synthetic ammonia production process, and in particular relates to an energy-saving sulfur-resistant conversion system and process with small system resistance and low comprehensive consumption. Background technique [0002] CO shift is an important process in the ammonia production process. The conversion devices with high water-gas ratio and high CO water-gas phase such as pulverized coal pressurized gasification, coal-water slurry pressurized gasification, and natural gas conversion must not only complete the CO conversion task, but also take into account the heat brought into the conversion system by completing the previous process Especially in recent years, with the progress of nitrogen fertilizer production process and the popularization and application of new coal gasification technology, continuous gasification technology has achieved unprecedented development, and the CO content in the shift gas...

AI Technical Summary

Problems solved by technology

Due to the high concentration of CO and high water-gas ratio, if the amount of catalyst in the first shift furnace is increased during production, the catalyst in the first shift furnace will be burnt accidentally; reducing the amount of catalyst in the first shift furnace solves the problem of overheating, but The service life of the catalyst is short, and it needs to be replaced once a year. The operation period of the catalyst is short, which does not meet the requirements of large-scale equipment; at present, most of the conversion of pressurized gasification water gas is four-stage adiabatic, and the first conversion furnace is divided into two stages in parallel. There are 24 sets of air intake and static equipment in the system, including 10 sets of heat exchange equipment. With hot water at 220°C, the cooling water consumption per ton of ammonia is as high as 7800Kg

The system has more low-grade heat energy and high energy consumption for operation

[0003] Although the conversion process of coal-water slurry gasification has a lower CO concentration, the conversion technology adopted is still a three-stage or four-stage adiabatic reaction process. The recovery of sensible heat and latent heat in each stage of water gas or shift gas requires a separate machine. Indirect heat exchange equipment, Shell shell, aerospace furnace pulverized coal gasification process conversion process have the same problems as coal water slurry conversion, all of which have defects such as long process route, large project investment, large system resistance, low-grade heat energy and high energy consumption. As coal prices continue to rise, conversion devices have become the main process for various coal chemical companies to reduce comprehensive energy consumption and product costs

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