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US 12,030,849 B2Granted
Liquid isomerization for methathesis process
AssigneeTechnip Process Technology, Inc.
InventorsSteven Evitt, Cornelis F. Van Egmond, Veronique Reich, Yvon Simon, Bruno Destour
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Abstract
The present disclosure relates to processes for improved yields of propylene via metathesis, primarily from the conversion of C4 and C5+ olefins obtained from steam or fluid catalytic cracking of hydrocarbons. In particular, the present disclosure relates to processes for preparing propylene by improved isomerization of 1-butene to 2-butene relative to the metathesis reaction.
Claims21
A method for the production of propylene from ethylene and butene comprising:
- (i) isomerizing under liquid phase conditions a hydrocarbon stream in an isomerization reactor vessel, thereby producing an isomerized hydrocarbon stream;
- (ii) providing a feedstock comprising the isomerized hydrocarbon stream to a metathesis reactor vessel without distilling the isomerized hydrocarbon stream before the metathesis reactor vessel;
- and
- (iii) contacting the feedstock comprising the isomerized hydrocarbon stream with a metathesis catalyst in the metathesis reactor vessel to form a product stream,
- wherein (1) the isomerization reactor vessel that converts a portion of 1-butene to 2-butene is located on a butene concentrated recycle stream for making the feedstock to the metathesis reactor vessel comprising a Raffinate mixture, ethylene and the isomerized hydrocarbon stream, the Raffinate mixture having 2-butene/1-butene mole ratio between 10 and 20, or (2) the isomerization reactor vessel that converts a portion of 1-butene to 2-butene is located on a fresh feed stream for making the feedstock to the metathesis reactor vessel comprising a Raffinate mixture, ethylene and the isomerized hydrocarbon stream, the Raffinate mixture having 2-butene/1-butene mole ratio less than 10,
- wherein the hydrocarbon stream comprises n-butenes and paraffins in which butadiene is limited to a maximum of about 0.5 weight percent and isobutylene is limited to maximum of about 10 weight percent, and
- wherein the isomerization reactor vessel is external and separate from the metathesis reactor vessel.
4 more elements
A process for the production of propylene from ethylene and butene, the process comprising:
- (i) combining a hydrocarbon stream comprising n-butenes and paraffins in which butadiene is limited to a maximum of about 0.5 weight percent and isobutylene is limited to maximum of about 10 weight percent with an ethylene stream, thereby producing a combined hydrocarbon stream and ethylene stream;
- (ii) contacting a feedstock to the metathesis reactor vessel in a metathesis reactor vessel with a metathesis catalyst to form a product stream comprising ethylene, propylene, C4 olefins comprising 2-butene and 1-butene, heavier olefins, and paraffins;
- (iii) separating the ethylene from the product stream to provide a recycle ethylene stream and a bottoms stream comprising propylene, paraffins, C4 olefins comprising 2-butene and 1-butene, and C5+ hydrocarbons;
- (iv) fractionating the bottoms stream to provide at least (1) a propylene fraction, (2) a butene concentrated recycle stream fraction comprising paraffins, olefins, 2-butene, 1-butene, and C5 hydrocarbons, and (3) a C4+ hydrocarbon fraction;
- (v) recycling the recycle ethylene stream of step (iii) and the butene concentrated recycle stream fraction of step (iv) to step (i), thereby making a feedstock to a liquid phase isomerization reactor vessel comprising the combined hydrocarbon stream and ethylene stream of step (i), the recycle ethylene stream of step (iii), the butene concentrated recycle stream fraction of step (iv), and a Raffinate mixture having 2-butene/1-butene mole ratio less than 10;
- and
- (vi) isomerizing the feedstock to the liquid phase isomerization reactor vessel under liquid phase conditions in the liquid phase isomerization reactor vessel, thereby producing an isomerized hydrocarbon stream, the isomerized hydrocarbon stream is transported to the metathesis reactor vessel without distilling the isomerized hydrocarbon stream before the metathesis reactor vessel, the feedstock to the metathesis reactor vessel comprises the isomerized hydrocarbon stream,
- wherein the liquid phase isomerization reactor vessel is external and separate from the metathesis reactor vessel.
5 more elements
A process for the production of propylene from ethylene and butene, the process comprising:
- (i) combining a hydrocarbon stream comprising n-butenes and paraffins in which butadiene is limited to a maximum of about 0.5 weight percent and isobutylene is limited to maximum of about 10 weight percent with an ethylene stream, thereby producing a combined hydrocarbon stream and ethylene stream;
- (ii) contacting a feedstock to the metathesis reactor vessel in a metathesis reactor vessel with a metathesis catalyst to form a product stream comprising ethylene, propylene, C4 olefins comprising 2-butene and 1-butene, heavier olefins, and paraffins;
- (iii) separating the ethylene from the product stream to provide a recycle ethylene stream and a bottoms stream comprising propylene, paraffins, C4 olefins comprising 2-butene and 1-butene, and C5+ hydrocarbons;
- (iv) fractionating the bottoms stream to provide at least (1) a propylene fraction, (2) a butene concentrated recycle stream fraction comprising paraffins, olefins, 2-butene, 1-butene, and C5 hydrocarbons, and (3) a C4+ hydrocarbon fraction;
- (v) recycling the recycle ethylene stream of step (iii) to step (i), thereby making the feedstock to the metathesis reactor vessel comprising the combined hydrocarbon stream and ethylene stream of step (i), the recycle ethylene stream of step (iii), and a Raffinate mixture having 2-butene/1-butene mole ratio between 10 and 20;
- and
- (vi) isomerizing under liquid phase conditions in a liquid phase isomerization reactor vessel the butene concentrated recycle stream fraction prior to step (i), wherein the liquid phase isomerization reactor vessel is located on a butene concentrated recycle stream for producing an isomerized hydrocarbon stream to be combined with the feedstock to the metathesis reactor vessel and to be provided to the metathesis reactor vessel, and
- wherein the liquid phase isomerization reactor vessel is external and separate from the metathesis reactor vessel.
5 more elements
Dependencies are inferred from the claim text.