Ethylene
원료
Hydrocarbon feedstock
생산물
ethylene
적용
To produce polymer-grade ethylene and propylene, a butadiene-rich C4 product, an aromatic-rich raw pyrolysis gasoline, a hydrogen product and fuels, by steam pyrolysis of hydrocarbons, ranging from ethane to vacuum gas oils.
설명
Description:
The schematic flow design shown is typical for the production of ethylene and other coproducts by the pyrolysis of a liquid hydrocarbon feedstock.
In the pyrolysis furnaces (1) the feedstock is combined with steam and subjected to high-temperature cracking to produce an olefinic-rich gas. Kellogg's cracking furnaces incorporate low reaction times below 0.1 second with high outlet temperature of 1,600-1,700℉. This is known as Millisecond technology. These conditions are more selective to olefin forming reactions and thus produce higher olefin yields.
Pyrolysis gases are cooled in steam generating facilities (2), and further cooled in the pyrolysis fractionator (3). where fuel oil is separated from the main gas stream.
Cooled gases are then compressed in a multistage centrifugal compressor (4) with interstage cooling and liquid removal between stages. Vapors then pass to acid gas removal and drying system (5), prior to the demethanizer feed system (6) where a hydrogen-rich stream is removed. A portion of this hydrogen-rich stream is ultra-purified (7) for use in catalytic converters.
The demethanizer (8) and subsequent fractionation columns distil the mixture of hydrocarbons into the final product streams of a methane-rich fuel gas (8), polymer grade ethylene (11), chemical or polymer grade propylene (14, 15), a mixed C4 stream (13) suitable for butadiene extraction and a gasoline stream rich in aromatics. Prior to the ethylene purifiction tower (15), acetylene can be hydrogenated (14) or extracted s a further chemical product. Methyl acetylene and propadiene are hydrogenated (10) prior to the propylene purifiction tower. Ethane is recycled to the furnaces for pyrolysis.
Refrigeration is supplied by an external propylene-ethylene cascade system and by process gas expansions.
In the pyrolysis furnaces (1) the feedstock is combined with steam and subjected to high-temperature cracking to produce an olefinic-rich gas. Kellogg's cracking furnaces incorporate low reaction times below 0.1 second with high outlet temperature of 1,600-1,700℉. This is known as Millisecond technology. These conditions are more selective to olefin forming reactions and thus produce higher olefin yields.
Pyrolysis gases are cooled in steam generating facilities (2), and further cooled in the pyrolysis fractionator (3). where fuel oil is separated from the main gas stream.
Cooled gases are then compressed in a multistage centrifugal compressor (4) with interstage cooling and liquid removal between stages. Vapors then pass to acid gas removal and drying system (5), prior to the demethanizer feed system (6) where a hydrogen-rich stream is removed. A portion of this hydrogen-rich stream is ultra-purified (7) for use in catalytic converters.
The demethanizer (8) and subsequent fractionation columns distil the mixture of hydrocarbons into the final product streams of a methane-rich fuel gas (8), polymer grade ethylene (11), chemical or polymer grade propylene (14, 15), a mixed C4 stream (13) suitable for butadiene extraction and a gasoline stream rich in aromatics. Prior to the ethylene purifiction tower (15), acetylene can be hydrogenated (14) or extracted s a further chemical product. Methyl acetylene and propadiene are hydrogenated (10) prior to the propylene purifiction tower. Ethane is recycled to the furnaces for pyrolysis.
Refrigeration is supplied by an external propylene-ethylene cascade system and by process gas expansions.
Yields: Ethylene yields of up to 35% for naphthas and 30% for gas oils may be achieved depending on feedstock.
Properties in KDB
Component Names and Formula
ID
184
Name
ETHYLENE
Synonyms
ETHENE, ACETENE, ELAYL
CAS No.
74-85-1
Formula
C2H4
CH2CH2
