Integrated thermal and catalytic cracking for olefin production

Patent metadata

Field	Value
Publication number	US-10669492-B2
Application number	US-201816039205-A
Country	US
Kind code	B2
Filing date	Jul 18, 2018
Priority date	Jul 18, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

Embodiments disclosed herein relate to systems and processes for producing olefins and/or dienes. The processes may include: thermally cracking a hydrocarbon containing feed to produce a cracked hydrocarbon effluent containing a mixture of olefins and paraffins; and catalytically cracking the cracked hydrocarbon effluent to produce a catalytically cracked effluent containing additional olefins and/or dienes. The systems may include a reaction zone for thermally cracking a hydrocarbon containing feed to produce a cracked hydrocarbon effluent containing a mixture of olefins and paraffins; and, a catalytic cracking reaction zone for catalytically cracking the cracked hydrocarbon effluent to produce a catalytically cracked hydrocarbon effluent containing additional olefins and/or dienes.

First claim

What is claimed:

1. A process for producing olefins and/or dienes, the process comprising:
thermally cracking a hydrocarbon containing feed comprising C5+ hydrocarbons at a temperature in the range from about 550° C. to about 750° C. to produce a cracked hydrocarbon effluent containing a mixture of olefins and paraffins, wherein a conversion of hydrocarbons in the hydrocarbon containing feed is in a range from about 20% to less than 40%, on a molar basis;
catalytically cracking the cracked hydrocarbon effluent to produce a catalytically cracked effluent containing additional olefins and/or dienes.

2. The process of claim 1 , wherein the cracked hydrocarbon effluent is not separated prior to the catalytically cracking step.

3. The process of claim 1 , further comprising cooling the cracked hydrocarbon effluent via direct or indirect heat exchange.

4. The process of claim 1 , further comprising separating the catalytically cracked effluent into one or more fractions selected from a hydrogen fraction, a methane fraction, a C2 fraction, an ethylene fraction, an ethane fraction, a C3 fraction, a propylene fraction, a propane fraction, a C4 fraction, a butadiene fraction, a butene fraction, a butane fraction, and a C5+ containing fraction.

5. The process of claim 1 , further comprising mixing steam, carbon dioxide, and/or nitrogen with the hydrocarbon containing feed to form a diluted feed mixture.

6. The process of claim 5 , wherein the diluted feed mixture has a steam to hydrocarbon ratio in the range from about 0.05 to 0.2, by weight.

7. A process for producing olefins and/or dienes, the process comprising:
heating a hydrocarbon feedstock, comprising one or more C5+ hydrocarbons, in a convection zone of a pyrolysis reactor to form a heated hydrocarbon mixture;
mixing the heated hydrocarbon mixture with steam to form a mixed feedstock having a steam to hydrocarbon ratio in the range from 0.04 to 0.2;
heating the mixed feedstock in the convection zone of the pyrolysis reactor;
reacting the mixed feedstock in the radiant zone of the pyrolysis reactor at a temperature in the range from about 550° C. to about 750° C. to convert a portion of the hydrocarbons to produce a cracked hydrocarbon effluent containing a mixture of olefins and paraffins;
feeding the entirety of the cracked hydrocarbon effluent to a catalytic cracking reaction zone for catalytically cracking the cracked hydrocarbon effluent to produce a catalytically cracked hydrocarbon effluent containing additional olefins and/or dienes;
separating the catalytically cracked hydrocarbon effluent to recover one or more fractions selected from a hydrogen fraction, a methane fraction, a C2 fraction, an ethylene fraction, an ethane fraction, a C3 fraction, a propylene fraction, a propane fraction, a C4 fraction, a butadiene fraction, a butene fraction, a butane fraction, and a C5+ containing fraction.

8. The process of claim 7 , wherein the catalytic cracking reaction zone comprises a riser reactor.

9. The process of claim 8 , further comprising feeding a naphtha fraction to the riser reactor.

10. The process of claim 7 , wherein the catalytic cracking reaction zone comprises two or more fixed beds in parallel operated in a staggered fashion.

11. The process of claim 7 , further comprising cooling the cracked hydrocarbon effluent via direct or indirect heat exchange.

Assignees

• Lummus Technology Inc

Inventors

• Sundaram Kandasamy Meenakshi

Classifications

• C10G9/28

  with preheated moving solid material · CPC title

• C10B53/00

  Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form (wet carbonising of peat C10F) · CPC title

• C10G11/05

  Crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C10G11/185

  Energy recovery from regenerator effluent gases · CPC title

• C10G51/06 Primary

  plural parallel stages only · CPC title