Process for forming ethylene and propylene by hydrocracking

Patent metadata

Field	Value
Publication number	US-9783465-B1
Application number	US-201715658879-A
Country	US
Kind code	B1
Filing date	Jul 25, 2017
Priority date	Nov 12, 2014
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A novel process and a novel catalyst for the production of light olefins. 1-butene is cracked in the presence of an acid- or base-modified silicalite-1 catalyst bed, wherein the modified silicalite-1 has a Si/Al ratio of greater than 1000. The modification procedures described herein increase the selectivity of the silicalite-1 catalyst toward light olefins such as ethylene and propylene. The catalytic cracking of 1-butene may be carried out in a fixed bed reactor or a fluidized bed reactor.

First claim

The invention claimed is:

1. A process for forming a mixture of ethylene and propylene from 1-butene, comprising:
distilling a C 4 -mixture to form a purified 1-butene;
treating silicalite-1 crystals to an acid washing and/or a base treatment to produce modified silicalite-1 crystals; and
contacting the purified 1-butene, in vapor form, in a fluidized bed reactor with the modified silicalite-1 crystals to catalytically crack the purified 1-butene to form the mixture of ethylene and propylene;
wherein the modified silicalite-1 crystals have an average particle size of 0.02 mm to 1.0 mm in diameter, an MFI framework, and a Si/Al ratio of 2035-2499.

2. The process of claim 1 , wherein the catalytic cracking is carried out at a reactor temperature within the range of 450° C. to 750° C.

3. The process of claim 1 , wherein the catalytic cracking is carried out at a hydrocarbon partial pressure within the range of 5 psia to 50 psia.

4. The process of claim 1 , wherein the catalytic cracking is carried out at a gas hourly space velocity of 600 h −1 to 10000 h −1 .

5. The process of claim 1 , wherein the silicalite-1 crystals are calcinated before and/or after the acid washing and/or the base treatment.

6. The process of claim 1 , wherein the process produces at least 50 wt. % total ethylene and propylene based on the total weight of the purified 1-butene.

7. The process of claim 1 , wherein the process produces a mixture of ethylene and propylene comprising ethylene and propylene in a ratio of ethylene to propylene of 1:2 to 1:3.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Al-Khattaf Sulaiman Saleh
• Palani Arudra
• Aitani Abdullah Mohammed

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• C07C4/06 Primary

  Catalytic processes {(C07C4/025 takes precedence)} · CPC title

• C07C4/02

  by cracking a single hydrocarbon or a mixture of individually defined hydrocarbons or a normally gaseous hydrocarbon fraction · CPC title