# US 8,785,703 B2 · Process for preparing ethylene and propylene

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,785,703 B2
- Document ID: US8785703B2
- Status: Granted
- Kind: B2
- Application number: 13/606,232
- Filed: 2012-09-07
- Published: 2013-09-19
- Granted: 2014-07-22
- Earliest claimed: 2011-09-07
- Assignees: Shell Oil Company
- Applicants: Sivakumar Sadasivan Vijayakumari; Jeroen Van Westrenen
- Inventors: Sivakumar Sadasivan Vijayakumari; Jeroen Van Westrenen
- Web page: https://patentgrep.com/patent/US8785703B2

## CPC

- C07C 1/22: by reduction
- C07C 1/20: starting from organic compounds containing only oxygen atoms as heteroatoms
- C07C 4/06: Catalytic processes {(C07C4/025 takes precedence)}
- C07C 29/48: by oxidation reactions with formation of hydroxy groups
- C07C 41/06: by addition of organic compounds only
- C07D 301/03: by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
- Y02P 30/20: using bio-feedstock
- Y02P 30/40: Ethylene production
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

The present invention provides a process for preparing ethylene and/or propylene, comprising the steps of contacting a stream comprising C4+ olefins with a zeolite-comprising catalyst at a temperature in the range of from 350 to 1000° C. and retrieving an olefinic product stream comprising: ethylene and/or propylene, and a C4+ hydrocarbon fraction, comprising paraffins, normal olefins and iso-olefins; The C4+ hydrocarbon fraction is recycled while part of the fraction is purged. The part of the C4+ hydrocarbon with is purged is treated to extract C4+ isoolefins as tert-alkyl ethers. At least part of tert-alkyl ethers are converted to further ethylene and propylene.

## Claims

### Claim 1

A process for preparing ethylene and/or propylene, comprising the steps of:
a) contacting a stream comprising C4+ olefins with a zeolite-comprising catalyst at a temperature in the range of from 350 to 1000° C. and retrieving an olefinic product stream comprising:
ethylene and/or propylene, and
a C4+ hydrocarbon fraction, comprising paraffins, normal olefins and iso-olefins;
a1) dividing the C4+ hydrocarbon fraction into a first part and a second part;
b) recycling a first part of the C4+ hydrocarbon fraction to step (a);
c) subjecting a second part of the C4+ hydrocarbon fraction to an etherification process with methanol and/or ethanol wherein at least part of the iso-olefins are converted with methanol and/or ethanol to an tert-alkyl ether, and retrieving an etherification product stream;
d) separating at least part of the etherification product stream into at least an ether-enriched stream and an iso-olefin-depleted C4+ hydrocarbon stream;
e) withdrawing at least part of the iso-olefin-depleted C4+ hydrocarbon stream from the process to purge part of the paraffinic C4+ hydrocarbons;
f) converting at least part of the tert-alkyl ether in the ether-enriched stream to ethylene and/or propylene by contacting at least part of the ether-enriched stream with a molecular sieve-comprising catalyst at a temperature in the range of from 350 to 1000° C.

### Claim 2 (depends on 1)

A process according to claim 1, wherein step (f) comprises recycling at least part of the ether-enriched stream to step (a).

### Claim 3 (depends on 1)

A process according to claim 1, further comprising providing an oxygenate-comprising stream to step (a) and contacting the oxygenate-comprising stream with the zeolite-comprising catalyst together with the C4+ olefins.

### Claim 4 (depends on 1)

A process according to claim 1, wherein part of the stream comprising C4+ olefins is obtained by converting an oxygenate-comprising feed to a product stream comprising:
ethylene and/or propylene, and —C4+ olefins.

### Claim 5 (depends on 4)

A process according to claim 4, wherein the oxygenate-comprising feed is converted by contacting the oxygenate-comprising feed with a molecular sieve-comprising catalyst at a temperature in the range of from 350 to 1000° C.

### Claim 6 (depends on 5)

A process according to claim 5, wherein the oxygenate-comprising feed comprises at least part of the ether-enriched stream.

### Claim 7 (depends on 4)

A process according to claim 4, wherein the molecular sieve-comprising catalyst comprises at least one SAPO, AlPO, or MeAlPO type molecular sieve.

### Claim 8 (depends on 1)

A process according to claim 1, wherein the zeolite-comprising catalyst comprises at least one zeolite selected from MFI, MEL, TON and MTT type zeolites.

### Claim 9 (depends on 1)

A process according to claim 1, wherein the iso-olefins include at least one of isobutene and isopentene.

### Claim 10 (depends on 1)

A process according to claim 1, wherein the iso-olefins are converted with methanol to the tert-alkyl ether by contacting the iso-olefin with methanol in the presence of an etherification catalyst at a temperature in the range of from 30 to 100° C.

### Claim 11 (depends on 10)

A process according to claim 10, wherein the etherification catalyst is a protonated cation-exchange resin catalyst.

### Claim 12 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)

A process according to claim 1, wherein an oxygenate-comprising feedstock is provided to an oxygenate-to-olefin process to produce a product stream comprising ethylene and/or propylene and C4+ olefins, at least part of which C4+ olefins are provided to step (a) of the process according to any one of claims 1 to 11, as part of the stream comprising C4+ olefins and wherein least part of the ether-enriched stream obtained in step (e) is provided to the oxygenate-to-olefin process together with or as part of the oxygenate-comprising feedstock.

### Claim 13 (depends on 1)

A process according to claim 1, wherein the olefinic product comprises ethylene and at least part of the ethylene is further converted into at least one of polyethylene, mono-ethylene-glycol, ethylbenzene and styrene monomer.

### Claim 14 (depends on 1)

A process according to claim 1, wherein the olefinic product comprises propylene and at least part of the propylene is further converted into at least one of polypropylene and propylene oxide.