SU1472437A1 - Method of producing gas for ammonia synthesis - Google Patents

Abstract

The invention relates to gas production processes for ammonia synthesis and can be used in the chemical industry. To produce gas for ammonia synthesis, the method involves preparing a methane conversion stage by heating the catalyst bed with a heated gas, a two-stage methane conversion and a two-stage carbon monoxide conversion, and the catalyst’s exhaust gas containing at least 40% by volume hydrogen is used to heat the catalyst temperature of 200-250 °, which is initially fed to the first stage of the conversion of carbon monoxide, then to the stage of catalyst heating, after which it is returned to the stage of methane conversion . The residual CO content is reduced to 0.1–0.15 wt%, and the energy consumption is 50–60 nm ^s / _t . 1 tab.

Description

one

This invention relates to gas production processes for ammonia synthesis. and can find a new application in the chemical industry.

The purpose of the invention is to increase the conversion rate by reducing the residual content of carbon monoxide and reducing the energy consumption per process.

Example. The purge gas production of methanol, containing,%: H 81.2; CO, 1.5; WITH 8.0; Nj 5.8; CH4 3, 5, in the amount of 20,000 nm / h with a temperature and pressure of 28 kgf / cm, is fed to a first-stage carbon monoxide converter, the catalyst is heated to 200 C. Here, too, steam with a temperature of 380 C in an amount of 1000 with a pressure of 40 kgf / cm in a volume ratio of steam: gas of 0.5: 1. The temperature in the converter rises to 330 ° C. The residual CO content in the converted gas is 2.5 vol.%.

Next, the converted gas is fed to the CO stage II converter, the catalyst is heated to 200 ° C, the residual CO content in the converted gas is 0.1%.

After the second stage of conversion, the converted gas is fed to CO removal.

Purified gas content, vol.%: Hi 89,7; N / 6.5; CH 3.8; CO 5 CO 2 ppm, served partially in the amount of 5000 nm / s for mixing with natural gas supplied to the desulfurization, and the rest in the amount up to 13000 nm / hour for heating the first-stage methane conversion catalyst. After warming up the catalyst to 200 ° C

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50,000 steam is supplied for conversion. After heating the catalyst to 750 ° C, natural gas is supplied at the I stage of conversion after desulfurization. On a nickel catalyst, methane is converted at a steam: gas ratio of 3.7: 1 to a residual CH content of 10-11%.

After the primary reformer, nga is fed into the secondary reforming reactor.

17АОО purified gas with the content: Н 67.2%; CH I8% j N4 14.8%;

CO 5 ppm; ppm, is fed to the mix with natural gas entering the desulfurization in the amount of 5,000 im / h and for heating the first-stage methane conversion catalyst in the amount of I2AOO nm / h and then proceeding

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air and raise the temperature to .1000-1. When this occurs, the vapor conversion of methane is carried out in a manner similar to Example 1,

Comparative data on the effectiveness of the process are presented in the table.

As can be seen from the table, in the proposal

Kunocjji-inn i-i -itiiiti f- - „„ „

its content is 0.35%. Further, the 15th degree method is increased. „“ L, tt. - "tl-alaymst PPGT P MJA -

the converted gas is fed to further stages of ammonia production, and the purified purge gas is fed to the CH II converter of the stage II, stopping its supply to the CH4 converter of the I stage.

PRI mme R 2. The method is carried out analogously to example 1. The content of H in the purge gas is 40%, temperature. The amount of gas is 20,000 nm 7h. Gas composition: H, 40%; WITH 13%; WITH 18.5%; CH 15%; 0.6%; N 12.9%. The purge gas enters the CO stage I converter, heats the catalyst to 250 ° C, and steam is supplied at a temperature of 380 ° C in an amount of 10,000. The temperature in the converter is increased to 330 C. At the same time, carbon monoxide is converted to a residual CO content of 3.5% by volume. Next, the converted gas is fed to the CO stage II converter, heated to 250 ° C. The residual CO content in the converted gas is 0.15%. Then the converted gas is purified with CO 2 and CO in a known manner. Received in quantity

the CO version by reducing the CO content in the gas by 2.5-3 times and the energy consumption is reduced by 50-60 nm / ton.

Claims (1)

20 claims A method for producing gas for ammonia synthesis, including the preparation of a methane conversion stage by heating a catalyst bed, blowing it with heated gas, a two-stage methane conversion and a two-stage carbon monoxide conversion, characterized in that in order to increase the conversion 30 by reducing the residual - content of carbon monoxide and reduction of energy consumption, as a gas for heating the catalyst, use the waste purge gas of methanol production, containing not less than 40% by volume of hydrogen with a temperature of 200-250 ° C, which Initially, it is fed to the first stage of the conversion of carbon monoxide, then to the 40th stage of catalyst heating, and then it is returned to the methane convection stage. "" 17АОО purified gas with the content: Н 67.2%; CH I8% j N4 14.8%; CO 5 ppm; ppm, is fed to the mix with natural gas entering the desulfurization in the amount of 5,000 im / h and for heating the first-stage methane conversion catalyst in the amount of I2AOO nm / h and then proceeding is carried out analogously to example 1, Comparative data on the effectiveness of the process are presented in the table. As can be seen from the table, the proposed „„ „ degree method increases con. „“ L, tt. - "tl-alaymst PPGT P MJA - the CO version by reducing the CO content in the gas by 2.5-3 times and the energy consumption is reduced by 50-60 nm / ton. Invention Formula A method for producing gas for ammonia synthesis, including the preparation of a methane conversion stage by heating a catalyst bed, flushing with heated gas, a two-stage methane conversion and a two-stage carbon monoxide conversion, characterized in that in order to increase the conversion rate by reducing the residual carbon monoxide content and reduce energy consumption, as the gas for heating the catalyst, use the exhaust purge gas from methanol production, containing at least 40% by volume of hydrogen with a temperature of 200-250 ° C, th original is fed to the first stage of conversion of carbon monoxide, then - at the step of heating the catalyst, after which the methane is recycled to the conversion step.