Urea production process of high-efficiency condensation, low-mounting height CO2 air stripping method and high-voltage lamp type full condensation reactor

Abstract

The invention discloses a CO2-stripping process for urea with efficient condensation and low installation height and a high pressure tube condensation reactor. Problems of a traditional urea process are solved, including high civil construction framework, high device investment and hard operation, management and maintenance. With the specific high pressure tube condenser adopted, gas and liquid are separated, unreacted gas in the high pressure tube condensation reactor is directly sent to a scrubber, and simultaneously reacted liquid is sent to a synthesizing tower by a high pressure ejector. Compared with the traditional urea civil construction framework, the height of the framework of the process is lowered by 20-25m. The process has the advantages of simple modification, energy-saving property, lowered energy consumption, lowered investment, convenient operation and convenient maintenance and overhauling.

Description

technical field [0001] The invention relates to an industrial urea production process and its special equipment, in particular to a high-efficiency condensation, low installation height CO 2 Gas stripping urea production process and high-pressure tubular full condensation reactor. Background technique [0002] Industrial urea production is based on CO 2 Gas and liquid ammonia are used as raw materials, which are processed into solid urea products through high-pressure synthesis, medium-pressure or / and low-pressure decomposition and recovery, vacuum concentration, and granulation. [0003] At present, the production processes of urea plants at home and abroad mainly include the following types: Netherlands Stamicarbon (Stamicarbon) CO 2 Air stripping process, Italian Snamprogetti ammonia stripping process, Japan TEC's ACES21 process, Swiss Casale's high-efficiency synthesis process, aqueous solution full circulation process, etc. Among them, the carbon dioxide stripping pr...

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Problems solved by technology

[0005] There are following problems in the above-mentioned urea production process: 1, because the reaction liquid that urea synthesis tower comes out is to utilize potential difference to return to the top of high-pressure stripping tower, so just require The feed inlet at the bottom of the urea synthesis tower is at least 10m higher than the liquid feed inlet at the top of the high-pressure stripping tower; 2. Since the high-pressure condenser adopts the falling film type, methylammonium liquid and stripping gas (CO2 and NH 3) enters from the top, and the reaction liquid and gas are discharged from the bottom and sent to the urea synthesis tower by using the pressure difference. Therefore, the bottom of the high-pressure condenser must be arranged at the same height as the bottom of the urea synthesis tower. As a result, urea The synthesis tower (bottom) and high-pressure methylammonium condenser (bottom) must be arranged on a plane with a height of about 20m, thus making its civil framework as high as 50-70m

The high-pressure process materials go through the tube side. Because the gas and liquid go down, the liquid forms a film on the tube wall, and the gas travels in the tube, so that the residence time of the process material in the tube is very short. The steam pressure is low, generally 0.44MP(A), which is difficult to use rationally

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