SU579220A1 - Method of catalytic conversion of hydrocarbons - Google Patents

Description

one

The invention relates to a method for steam catalytic conversion of hydrocarbons, which is used in the chemical and petrochemical industries.

At present, in the preparation of source gases for the synthesis of methanol and ammonia, as well as for the production of hydrogen, the most widely used method is steam or steam-carbon dioxide catalytic conversion of hydrocarbons in pressure tube furnaces heated by reaction tubes with hot fumes l.

A known method of steam catalytic conversion of hydrocarbons under pressure in tubular furnaces on a catalyst at 750–950 ° C, including the process of heat exchange, mixing hydrocarbons with steam to a steam: gas ratio of 4: 1, steam catalytic conversion of hydrocarbons in tube furnaces under the action of heat from natural gas combustion in burners with air compressed in a compressor with intermediate cooling of air with cooling water and using the energy of compressed flue gases in waste heat boilers and in a gas turbine 1.2.

2

: The disadvantages of this method are the low degree of conversion and significant energy and energy costs.

In order to reduce the energy consumption, natural gas run-off for heating the reaction tubes of the tube furnace is carried out by compressed air containing 5–15 vol% water vapor.

Water vapor is introduced into the compressed air by partial evaporation of water heated in the intermediate air coolers of the air compressor.

The application of this method makes it possible to increase the efficiency of heat exchange in a tube furnace by 25–30% and, consequently, increase the degree of conversion of hydrocarbons. It is useful to use the energy expended in compressing the air in the first stages of the compressor, to compensate for the losses due to aerodynamic drag.

Example. Natural gas with a pressure of 15 atm is fed to the heater,

in which natural gas is heated to 400 ° C by the products of combustion of fuel. Then natural gas is cleaned from sulfur, after which it is mixed with water vapor streams and

Claims (2)

carbon dioxide to the ratio of pairs of pairs: gae: CO: e 3.3, 1: 0.27. The resulting mixture is introduced into the tubular space of a tubular furnace filled with a nickel-containing catalyst and heated through the walls of the reaction tubes with products of combustion of fuel fed into the annular space of the tube furnace. The conversion is carried out at 870 ° C, with the converted gases being obtained as follows: eleven; CO l7f-H "68.35; CH 3.5; 0.15. The resulting converted gases are sent for cooling to the boiler and then to the methanol synthesis compartment. Atmospheric air with a temperature of 20 ° C is compressed in the first stage of the compressor to a pressure of 4.6 atm (its temperature rises to 200 ° C) and sent to the intermediate air cooler to cool the air to 45 ° C before it enters the second stage of compression. Compressed air with a pressure of 12 atm and a temperature of 200 ° C is directed to a humidifier, in which air is saturated with water vapor up to 10% by volume. Water evaporation occurs mainly due to the heat of hot water () entering the humidifier from the intermediate air cooler, and partially due to the heat of compressed air, as the temperature of the humidified air decreases to 170 C. The non-evaporated water from the humidifier with a temperature of 65 ° C is pumped into the water heat exchanger, in which it is cooled to 30 ° C, and then into the intermediate air cooler. Compressed air saturated with water vapor, with a pressure of 12 atm and a temperature of 170 ° C, is supplied to the annular spaces of a tubular furnace for burning natural gas, where there is an intense heat exchange between flue gases of high-energy blackness. heat exchange, and reaction pipes in which steam-carbon dioxide conversion of natural gas takes place. The flue gases with a temperature of 1000 ° C after the tube furnace are sent to a heat recovery gel, in which they are cooled to 800 s. Thereafter, flue gases with the addition of 10.5 atm are directed to a gas turbine, where, as a result of the expansion of the gases, mechanical energy is generated to drive an air compressor and an electric generator. From the gas turbine, the flue gases with a temperature are directed to the catheater to produce water vapor. The proposed method will reduce the heat exchange surface of a tubular furnace by 10-15%, to obtain additional electricity generation by gas turbines in the amount of 300 kW of methanol. Claims The method of steam catalytic conversion of hydrocarbons at 750-950 ° C in tube furnaces heated by burning natural gas in burners with compressed air, characterized in that, in order to reduce energy costs, the burning of natural gas to heat the tube furnace is carried out with compressed air containing water vapor in the amount of 5-15%. Sources of information taken into account during the examination: 1. Reference book of a nitrogen worker. Chemistry, 1967, t. 1, p. 71, 118-121. 2. Authors certificate of the USSR 119174, cl. C 01 B 1/18, 7.07,58.