RU1770265C - Method of hydrogen-containing gas production - Google Patents

Abstract

The invention relates to methods for producing synthesis gas for the production of ammonia, methanol, higher alcohols. The purpose of the invention is to reduce energy consumption. To achieve this goal in the two-stage catalytic conversion of hydrocarbon feeds by decomposing it in the first stage in the presence of water vapor by indirect heat exchange with the decomposition products of the second stage, carried out in the presence of an oxygen-containing gas mixture heated to a temperature of 700-900 ° C; , according to the invention, the oxygen-containing gas mixture is mixed with the heat carrier in the ratio of heat carrier / oxygen equal to 0.5-30 before heating. 1 tab.

Description

The invention relates to a process for producing synthesis gas for the production of ammonia, methanol, higher alcohols and hydrogen from hydrocarbons, such as natural gas, by a 2-stage steam-oxygen or steam-oxygen conversion method

The aim of the invention is to reduce energy consumption.

PRI me R 1.

Technological natural gas containing, 65%, At-4.00%. , 34% under a pressure of 4.3 MPa and a temperature of 380 ° C is mixed-in the mixer with water vapor, in a ratio of 1: 2.5 and with a temperature of the mixture 320 ° C it enters the heat exchanger, where due to indirect heat exchange with the converted gas after the secondary reforming is heated to a temperature of 450 ° C. With this temperature, the gas-vapor mixture enters the reaction tubes of the tube converter, where, due to the heat of the converted gas, it is heated after the secondary reforming and the conversion process proceeds with the formation of the converted gas of the following composition,% vol: С02 - 4.54, СО - 10.44, Na - 50.29, N2 - 0.28. CH4 - 4.72. H20 - 20.73, which enters the mixer of the shaft converter. Process air compressed in a compressor to a pressure of 4 MPa, saturated with moisture in a mixer up to a ratio of / ngo / / o2 30 and inflated in a gas turbine compressor heat exchanger up to a temperature of a steam-air mixture of 700 ° C, is also supplied with a ratio of / ooz: / sn4 1.354. The temperature of the converted gas after the mine conveyor is 950 ° C, and the composition of the wet gas:

С02 СО On N2 СНл HzO 4.44 2.10 20.34 747 0.01 65.64 The composition of the converted gas after a two-stage methanol conversion has

Xi

vj

Oh Yu Oh

ate

ratio / H2 + CO / N2 3.00. After cooling in the converter, heat exchanger, and steam generator, the converted gas enters the carbon monoxide converter. After pre-conversion of carbon monoxide, purification from dioxide and methanation, ad-interest ammonia can be used,

P RL .. M @ p, as in example 1, but t% htol6 |: air, cleaned by the plug in the mixer-up cooi carried by VHjO / VdT OS, is heated in the preheater to 900 ° C and is supplied with this temperature into the mine converter.

The ratio of technological air: natural, 73. The temperature of the converted gas at the outlet of the mine converter is 950 ° C. Dry converted gas has the following composition;

, 99%, СО-12.27%,, 04%,, 77%,, 93%, which corresponds to the ratio after the stages of carbon monoxide conversion, washing from carbon dioxide and methanation, 044. After the methanation step, a low temperature block of excess nitrogen is established in which the energy of the excess nitrogen is used to cover the loss of cold. The energy balance of the low temperature unit is covered at a H2 / Na ratio of 2.05. With a higher ratio, additional cold must be supplied, and with a lower ratio, the energy of excess nitrogen is not used to cover the loss of cold.

After the low-temperature block, the nitrogen-hydrogen mixture with the ratio is fed to the synthesis of ammonia.

PRI me R 3.

The same as in Example 2, but oxygen is used instead of the process air, which is mixed with carbon dioxide in the mixer to the Vcoj / Vo ratio. Heats up in heaters up to 800 ° C and with this temperature enters the shaft converter. The temperature of the converted gas at the outlet of the mine reactor is 950 ° C, and the dry, convected gas has the following composition1

, 63%, СО-31.01%. 6%,, 3%,, 46%.

After washing the converted gas from COa and with a ratio of H2 / CO 1, it is sent to the synthesis of higher alcohols.

Below is a table of comparative data of the proposed method with the prototype.

The table shows that the claimed technical solution allows to reduce the energy intensity of the process compared to the prototype method by 1 t. NH3 by 0.02-0.326 gcal. At extreme values of the ratio of coolant to oxygen

a reduction in energy consumption does not occur. With a larger ratio of heat carriers to oxygen, an excess of heat occurs, which does not lead to an improvement in technological parameters. So, when the ratio of coolant to oxygen is greater than 30, the H2 / N ratio after methane conversion becomes 3.2, which requires the withdrawal of a part of hydrogen in the form of purge gases with an irrevocable loss of energy with heating of the vapor-oxygen mixture. When the ratio of coolant to oxygen is less than 0.5, the composition of the converted gas has an H2 / N2 ratio of less than 2, which is associated with an additional expense

rzpduha and the need to remove excess Na from the low-temperature unit with an irrational loss of pressure.

Claims (1)

SUMMARY OF THE INVENTION A method for producing a hydrogen-containing gas, comprising steam conversion of hydrocarbon feed in a tube converter and pre-conversion in a shaft reactor in the presence of an oxygen mixture pre-heated to 700-900 ° C. and gas obtained in the pre-conversion stage, are fed into the annulus of the tube converter, after which withdrawn from the process, characterized in that in order to reduce energy consumption, the oxygen mixture is mixed with water vapor or carbon dioxide in a volume ratio of 0.5-30 respectively. Name Unit Measure Expenses: Natural gas c, - 8100 gccl / h nm / tM, 700.5 5.674 60ti, 3 4.895 6E64.6 5.627 6044.892 Steam consumption for those ports (without Saturation) T / TNH, 0.613 0.4 0.672 0.515 0.607 0.465 0.677 0.518 Air compressor power kWh / tNI, D8l, 8 0.64 179.6 0,, 6 0.61 178.3 0.409 Natural gas consumption for heating pivot / hour 32.9 0.267 113.3 0.918 4l, 5 0.336 101, "0.82 Total 7.0586,, 0386.639