Method of recovering heat in hydrocarbon hydrogenating conversion process

Abstract

The present invention relates to method of recovering heat in hydrocarbon hydrogenating conversion process. The low temperature heat absorbing oil and the reaction resultant are heat exchanged to form high temperature heat absorbing oil, which enters to the bottom of the fractionating tower so as to mix with the liquid phase material flow inside the fractionating tower before being shunt into low temperature heat absorbing oil for reuse. The process is especially suitable for hydrogenating conversion of coal tar, and has the advantages of high heat utilizing rate, reduced hydrogen circulating system scale and reduced the scale of reboiling furnace in the fractionating tower. In addition, the heat absorbing oil heat exchanger may be used as the heater for starting the reactor or sulfurizing to reduce heat load of the heating furnace.

Description

technical field [0001] The invention relates to a heat recovery method in the hydrogenation conversion process of high hydrogen consumption hydrocarbons; in particular, the invention relates to a heat recovery method in the coal tar hydrogenation conversion process. Background technique [0002] As we all know, the hydroconversion process of hydrocarbon feedstock oil is the conversion process of hydrocarbon feedstock in the presence of catalyst and hydrogen, and is widely used in oil upgrading. The high-pressure separator hydrocarbon liquid produced by the hydroconversion process is composed of conventional liquid hydrocarbons and conventional gaseous hydrocarbons and non-hydrocarbon components such as H 2 S, H 2 O, NH 3 、H 2 and so on. Usually, the hydrocarbon liquid in the high-pressure separator first enters the low-pressure separator, and at a pressure of 0.5-4.0 MPa and a temperature of 35-60° C. 2 and C 1 、C 2 Low-partition gas composed of hydrocarbons and mainl...

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Problems solved by technology

The disadvantages of the heat recovery methods described above are:

[0003] ① The heat recovery method of the intermediate reaction effluent uses cold hydrogen or cold oil, which increases the scale of the cold hydrogen circulation system or increases the cold oil circulation system, which increases investment and converts high-temperature heat energy (such as 410-370°C heat energy) at the same time It is lower temperature heat energy (such as 410-50°C heat energy), of which 180-50°C heat energy cannot be recovered (usually cooled by air cooler or water cooler), and 410-180°C heat energy recovery process uses heat exchanger and intermediate reaction effluent Compared with direct use of heat exchangers, the investment in high-pressure heat exchangers is greatly increased due to the substantial reduction in temperature;

[0004] ②The heat recovery method of the final reaction effluent is to heat the raw material oil, hydrogen, low-fraction oil and excess heat energy to generate steam, but the heat energy utilization rate of the generated steam is lower than that of directly heating the process material or directly heating the reboiling liquid at the bottom of the fractionation tower

[0005] For the hydroconversion process of hydrocarbons with high hydrogen consumption, such as the hydroconversion process of coal tar or shale oil, due to the high hydrogen consumption and the large heat release of the reaction, there is a large amount of excess heat energy in the effluent in the middle of the reaction; The disadvantages of conventional hydroconversion process heat recovery methods are more obvious

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