Process for the oxidative dehydrogenation of N-butenes to butadiene

Patent metadata

Field	Value
Publication number	US-10144681-B2
Application number	US-201414150239-A
Country	US
Kind code	B2
Filing date	Jan 8, 2014
Priority date	Jan 15, 2013
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A process for the oxidative dehydrogenation of n-butenes to butadiene is disclosed herein, in which the formation of butadiene peroxides from butadiene in the work-up of the product gas mixture from the oxidative dehydrogenation is effectively prevented.

First claim

The invention claimed is:

1. A process for preparing butadiene from n-butenes, which comprises the following steps:
A) providing a feed gas stream (a) comprising n-butenes;
B) introducing the feed gas stream (a) comprising n-butenes and an oxygen-comprising gas into at least one dehydrogenation zone and oxidatively dehydrogenating the n-butenes to produce a product gas stream (b) comprising butadiene, n-butenes, water vapor, oxygen, low-boiling hydrocarbons selected from the group consisting of methane, ethane, ethene, propane, propene, butane, and isobutane;
C) cooling and compressing the product gas stream (b) in at least one compression stage to produce both a gas stream (c2) and at least one condensate stream (c1) comprising water, wherein the gas stream (c2) comprises butadiene, n-butenes, water vapor, oxygen, low-boiling hydrocarbons selected from the group consisting of methane, ethane, ethene, propane, propene, butane, and isobutane;
D) absorbing butadiene and n-butenes from the gas stream (c2) into an absorption medium comprising aromatic hydrocarbons in an absorption column to produce an absorption medium stream loaded with butadiene and n-butenes and a second gas stream (d2) comprising oxygen and low-boiling hydrocarbons selected from the group consisting of methane, ethane, ethene, propane, propene, butane, and isobutane;
E) removing oxygen and a portion of butadiene and n-butenes from the absorption medium stream loaded with butadiene and n-butenes by stripping with an inert gas in a stripping column;
F) recycling the portion of butadiene and n-butenes removed by said stripping into the absorption medium stream loaded with butadiene and n-butenes by passing the portion of butadiene and n-butenes removed by said stripping through the absorption column;
G) desorbing the butadiene and n-butenes from the absorption medium stream loaded with butadiene and n-butenes to produce a C 4 product gas stream (d1) comprising the desorbed butadiene and n-butenes, wherein the C 4 product gas stream (d1) comprises less than 100 ppmw of oxygen;
H) separating the C 4 product gas stream (d1) by extractive distillation with a solvent which is selective for butadiene into a stream (e1) comprising butadiene and the selective solvent and a stream (e2) comprising n-butenes; and
I) distillation of distilling the stream (e1) comprising butadiene and the selective solvent to produce a stream (f1) consisting essentially of the selective solvent and a stream (f2) comprising butadiene.

2. The process according to claim 1 , wherein the inert gas is nitrogen.

3. The process according to claim 1 , wherein the C4 product gas stream (d1) comprises less than 20 ppmw of oxygen.

4. The process according to claim 1 , wherein the inert gas is methane or nitrogen.

5. The process according to claim 4 , wherein the inert gas is nitrogen.

6. The process according to claim 4 , wherein the inert gas is methane.

Assignees

• Basf Se

Inventors

• Josch Jan Pablo
• Weck Alexander
• Giesa Sonja
• Bütehorn Steffen
• Balegedde Ramachandran Ragavendra Prasad
• Benfer Regina
• Weber Markus

Classifications

• C07C7/11

  by absorption, i.e. purification or separation of gaseous hydrocarbons with the aid of liquids · CPC title

• C07C7/08

  by extractive distillation · CPC title

• C07C11/167

  1, 3-Butadiene · CPC title

• C07C5/48 Primary

  with oxygen as an acceptor · CPC title

• B01J2208/00663

  Concentration · CPC title