Options to reduce fouling in MTO downstream recovery

Patent metadata

Field	Value
Publication number	US-9452957-B2
Application number	US-201414313539-A
Country	US
Kind code	B2
Filing date	Jun 24, 2014
Priority date	Jun 24, 2014
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

A process is presented for removing the fouling problems associated with the product recovery in a methanol to olefins conversion process. The process includes passing the quenched MTO process stream to a product separator, wherein an intermediate stream is generated and includes water and heavier hydrocarbons. The intermediate stream is processed to remove the buildup of heavier hydrocarbons.

First claim

What is claimed is:

1. A process for reducing fouling in an MTO process, comprising:
passing a product effluent stream comprising olefins, solid materials, and highly substituted aromatic hydrocarbons including hexamethylbenzene and pentamethyl benzene from an MTO reactor to a quench tower to generate a first overhead stream comprising olefins and said highly substituted aromatics, and a first bottoms stream comprising waste water;
passing the first overhead stream to a product separator unit to generate a second overhead stream comprising olefins and water, a second bottoms stream comprising waste water, and an intermediate stream comprising water and highly substituted aromatic hydrocarbons;
passing the second overhead stream to a product treatment and recovery system to separate the second overhead stream, in compression and separation steps, into a hydrocarbon stream and a water stream and a light hydrocarbon stream comprising olefins;
passing the water stream from the product treatment and recovery system to an oxygenate stripper;
cooling a portion of the intermediate stream and passing a portion of the cooled portion of the intermediate stream as reflux to the top of the product separator unit and the remainder to a water stripper to generate a water overhead stream for use in the product separator unit and a water bottom stream for passing to a water treatment unit;
passing another portion of the intermediate stream to a second separation unit to generate a hydrocarbon stream containing highly substituted aromatic hydrocarbons a second bottoms stream comprising waste water;
passing the first bottoms stream comprising waste water, second bottoms stream comprising waste water, and second bottoms stream comprising waste water to the water stripper;
passing the hydrocarbon stream and the stream containing highly substituted aromatic hydrocarbons to wash column to generate and a washed hydrocarbon stream comprising C4 and higher hydrocarbons and a wash stream comprising methanol and water; and
passing the washed hydrocarbon stream to an olefin cracking process.

2. The process of claim 1 further comprising passing the wash stream to an oxygenate stripper to generate an oxygenate stream and a second water stream.

3. The process of claim 1 wherein the second separation unit is a coalescing unit.

4. The process of claim 1 wherein the second separation unit is a settling unit.

5. The process of claim 1 further comprising passing the intermediate stream to a filtration system.

6. The process of claim 1 wherein the separation step comprises collecting the intermediate stream from the product separator and skimming the hydrocarbon stream from the top layer of the collected intermediate stream and drawing of the water stream from the bottom of the collected intermediate stream.

7. The process of claim 6 further comprising adding a clean hydrocarbon stream to the product separator to facilitate the skimming of the hydrocarbons into the hydrocarbon stream.

Assignees

• Uop Llc

Inventors

• Senetar John J
• Montalbano Joseph A
• Kauff Daniel A

Classifications

• C10G75/00

  Inhibiting corrosion or fouling in apparatus for treatment or conversion of hydrocarbon oils, in general (C10G7/10, C10G9/16 take precedence) · CPC title

• C10G21/00

  Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents (C10G17/00, C10G19/00 take precedence) · CPC title

• C10G3/00

  Production of liquid hydrocarbon mixtures from oxygen-containing organic materials, e.g. fatty oils, fatty acids (production from non-melting solid oxygen-containing carbonaceous materials C10G1/00) · CPC title

• C07C1/20

  starting from organic compounds containing only oxygen atoms as heteroatoms · CPC title

• C10G31/06

  by heating, cooling, or pressure treatment · CPC title