US 12,172,952 B2 · Ethylene maximization with propylene metathesis

Abstract

Systems and processes herein improve the conversion of propylene to ethylene via metathesis. On a mass basis, embodiments herein may be used to convert greater than 40% propylene, on a mass basis, to ethylene, such as 43% to 75%, on a mass basis. In one aspect, processes for the conversion of propylene to ethylene herein may include introducing a propylene feed stream to a metathesis reactor, and contacting the propylene with a metathesis catalyst in the metathesis reactor to convert the propylene to ethylene and 2-butene. An effluent from the metathesis reactor may be recovered, the effluent including ethylene, 2-butene, and unconverted propylene. The effluent may then be separated in a fractionation system to recover an ethylene fraction, a propylene fraction, a c4 fraction, and a C5+ fraction. The propylene fraction and the C4 fraction may then be fed to the metathesis reactor to produce additional ethylene.

Claims19

Dependent claims

A system for the conversion of propylene to ethylene, the system comprising:

a feed stream for providing a propylene feed;
a metathesis reactor containing a metathesis catalyst to convert the propylene to ethylene and 2-butene, and produce a metathesis reactor effluent comprising ethylene, 2-butene, and unconverted propylene, 2-pentene, and 2-hexene;
a first fractionation system for separating the ethylene, 2-butene, and unconverted propylene in the metathesis reactor effluent to recover an ethylene fraction, a propylene fraction, a C4 fraction, and a C5+ fraction;
one or more flow lines for feeding the propylene fraction and the C4 fraction to the metathesis reactor to produce additional ethylene;
a second fractionation system for separating the C5+ fraction into a C5 fraction, a C6 fraction, and a C6+ fraction;
and
a steam cracker for cracking at least a portion of one or more of the C6+ fraction, C6 fraction, or a hydrogenated product thereof to produce a cracker effluent comprising ethylene, propylene, butenes, and/or pentenes.

4 more elements

A system for the production of ethylene, comprising:

a metathesis reactor containing a metathesis catalyst, the metathesis reactor configured for receiving a mixed feed stream comprising a propylene feed stream and one or more C3-C5 hydrocarbon containing fractions, and contacting the mixed feed stream with the metathesis catalyst to produce a reaction effluent comprising ethylene, unconverted propylene, 2-butene, 2-pentene, and 2-hexene;
a first flow line for feeding the reaction effluent to a deethylenizer to separate the reaction effluent into an ethylene product stream and a C3+ fraction;
a second flow line for feeding the C3+ fraction to a depropanizer to separate the C3+ fraction into a C3 fraction and a C4+ fraction;
a third flow line for feeding the C4+ fraction to a debutanizer to separate the C4+ fraction into a C4 fraction and a C5+ fraction;
a fourth flow line for feeding the C5+ fraction to a depentanizer to separate the C5+ fraction into a C5 fraction and a C6+ fraction;
and
a steam cracker for cracking the C6+ fraction to produce a cracker effluent comprising one or more of ethylene, propylene, butenes, and pentenes;
and
a fifth flow line for feeding the steam cracker effluent to the first flow line with the reaction effluent;
wherein an overall system is configured for converting propylene to ethylene at greater than 40% on a mass basis.

7 more elements

A system for the production of ethylene, comprising:

a metathesis reactor containing a metathesis catalyst, the metathesis reactor configured for receiving a mixed feed stream comprising a propylene feed stream and one or more C3-C5 hydrocarbon containing fractions, and contacting the mixed feed stream with the metathesis catalyst to produce a reaction effluent comprising one or more of ethylene, unconverted propylene, 2-butene, 2-pentene, and 2-hexene;
a fractionation system comprising a deethylenizer, a depropanizer, a debutanizer, and depentanizer configured for receiving the reaction effluent and producing an ethylene product fraction, a C3 fraction, a C4 fraction, a C5 fraction, a C6 fraction, and a C6+ fraction;
a steam cracker configured for cracking at least a portion of the C6 fraction, C6+ fraction, or both, to produce a cracker effluent comprising ethylene, propylene, butenes, pentenes, or a combination thereof;
and
a flow line for feeding the steam cracker effluent to the fractionation system for fractionation with the reaction effluent;
wherein the overall system is configured for converting greater than 40% of propylene to ethylene on a mass basis.

3 more elements

Dependencies are inferred from the claim text.

Ethylene maximization with propylene metathesis

Life of this patent

Ethylene maximization with propylene metathesis

Life of this patent

Abstract

Claims19