Fractionation process for cracking gas from oxidation pyrolysis of gaseous hydrocarbon

Abstract

The invention provides a fractionation technique for the cracking gas obtained through the oxidation thermal decomposition of gaseous hydrocarbon and used for preparing acetylene. The cracking gas obtained through the oxidation thermal decomposition of gaseous hydrocarbon and used for preparing acetylene first goes through an oil washing tower to remove higher alkyne, C3 hydrocarbon and carbon black, and is pressurized to 0.4MPa to 1.5MPa through a compressor and deoiled through an activated carbon adsorption tower, thus dissolving acetylene and a few other indissoluble components through an absorbed solvent in the adsorption tower; the rest gases go in an ethylene separation tower to recycle concentrated ethylene products and tail gas is taken as synthesis gas; after the solvent dissolving acetylene and a few other indissoluble components enters a flashing tower to remove the indissoluble components, crude acetylene gas is obtained through the separation of an acetylene desorption tower; the indissoluble components are cycled before returning to the compressor and pure acetylene products are obtained after the crude acetylene gas is refined in a carbon dioxide tower; the wash oil saturated with higher alkyne, C3 hydrocarbon and carbon black goes back to normal pressure, flows to a wash oil purifying tower and higher alkyne and C3 hydrocarbon are obtained at the top of the tower and return to serve as gaseous hydrocarbon raw material.

Description

1. Technical field [0001] The invention relates to a cracking gas classification and separation process for producing acetylene by oxidation and pyrolysis of gaseous hydrocarbons, which belongs to the field of petrochemical industry. 2. Background technology [0002] Oxidative pyrolysis of methane-rich gaseous hydrocarbons such as natural gas, coal bed methane, refinery dry gas, and oilfield associated gas to produce acetylene is currently the main acetylene production process other than the calcium carbide method. Oxygen enters the multi-tube burner plate acetylene furnace. At 1500°C, methane is cracked to produce about 8% dilute acetylene, and then concentrated with N-methylpyrrolidone to produce 99% acetylene product. In addition to acetylene, the cracked gas of gaseous hydrocarbon oxidation pyrolysis to acetylene also contains hydrogen, methane, ethylene, carbon monoxide, acetylene homologues, ethane, propylene, propane, etc. With the different quenching liquids, the co...

AI Technical Summary

Problems solved by technology

However, the existing separation methods fail to consider the overall and comprehensive utilization of the main components of the acetylene production plant from the oxidation and pyrolysis of gaseous hydrocarbons. Acetylene is recovered under pressure, and ethylene and synthesis gas (collectively called hydrogen and carbon monoxide) are taken into account. As a low-value-added fuel, the cost of acetylene is high, and a large amount of useful main wind is not wasted

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