Conversion of synthesis gas to hydrocarbon mixtures utilizing dual reactors

• US 4,279,830 A
• Filed: 06/01/1979
• Issued: 07/21/1981
• Est. Priority Date: 08/22/1977
• Status: Expired due to Term

• Current Assignee: Kidde Limited (Carrier Global Corporation)
• Original Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Inventors: Huang, Tracy J., Haag, Werner O.
• Primary Examiner(s): MARS, HOWARD
• Application Number:
  US06/044,872
• Time in Patent Office: 781 Days
• Field of Search: 260/449.6 R, 260/449.6 M, 260/449 R, 260/449 M, 260/449 L, 260/450, 585/407, 585/408, 585/415, 585/322, 585/324, 208/46, 208/120, 208/950
• US Class Current: 518/700
• CPC Class Codes: C07C 1/046 Numerical values of parameters only to be used if no other subgroup of C07C1/04 is used
• CPC Class Codes: C07C 1/0485 Set-up of reactors or accessories; Multi-step processes
• CPC Class Codes: C07C 2523/04 Alkali metals
• CPC Class Codes: C07C 2523/745 Iron
• CPC Class Codes: C07C 2523/78 with alkali- or alkaline earth metals or beryllium
• CPC Class Codes: C10G 2300/1022 Fischer-Tropsch products
• CPC Class Codes: C10G 2300/4006 Temperature
• CPC Class Codes: C10G 2300/4012 Pressure
• CPC Class Codes: C10G 2300/4018 Spatial velocity, e.g. LHSV, WHSV
• CPC Class Codes: C10G 2300/805 Water
• CPC Class Codes: C10G 2400/02 Gasoline
• CPC Class Codes: C10G 3/49 containing crystalline aluminosilicates, e.g. molecular sieves
• CPC Class Codes: C10G 3/54 characterised by the catalytic bed
• CPC Class Codes: C10L 1/06 for spark ignition
• CPC Class Codes: Y02P 30/20 using bio-feedstock
• CPC Class Codes: Y10S 208/95 Processing of "fischer-tropsch" crude

Abstract

The conversion of less than 1 H₂ /CO ratio syngas to high yield of C₃ plus product is accomplished with a CO reducing catalyst comprising shift characteristics and the product of Fischer-Tropsch synthesis is converted to premium gasoline and distillate fuels by contact with acidic ZSM-5 zeolite.

The syngas conversion may be accomplished in any catalyst system permitting a very close temperature control on the exotherm encountered and the gasoline-distillate yield relationship may be varied as a function of temperature and pressure.

Claims

1. In a process for converting syngas to carbon compounds comprising oxygenates and hydrocarbon products wherein syngas is contacted with an iron-containing Fischer-Tropsch catalyst at a temperature with the range of 400°

to 600°

F. and a pressure within the range of 1-1500 psig so as to achieve high conversion of said syngas to substantial amounts of C₃ + carbon compounds comprising no more than 20% methane plus ethane, and all or a portion of the product of said syngas conversion is passed in contact with an acidic crystalline zeolite having a pore dimension greater than 5 Angstroms, a silica-to-alumina ratio of at least 12, and a constraint index within the range of 1-12 at a temperature of 530°

-850°

F., a pressure from about 1 atmosphere to about 800 psig, and at a space velocity of from about 0.2 to 30 WHSV so as to promote the formation of gasoline and distillate materials;

the improvement which comprises increasing the rate of syngas conversion by maintaining a H₂ /CO ratio in the range of 0.5 to 1 and achieving an overall syngas conversion of greater than 60%.

2. The process of claim 1 wherein the acidic crystalline zeolite is ZSM5.

3. The process of claim 2 wherein water is charged with the syngas passed in contact with the CO reducing catalyst.

4. The process of claim 2 wherein conversion of the syngas produces C₁ to C₄₀ carbon compounds and the total product effluent of the Fischer-Tropsch operation is passed in contact with the zeolite catalyst.

5. The process of claim 2 wherein the conversion of syngas is accomplished in more than one CO reduction zone and at least one zone employs the CO reduction catalyst suspended in a liquid medium.

6. The process of claim 2 wherein the products of Fischer-Tropsch synthesis comprise hydrocarbon and oxygenates which are separated and separately processed over said special zeolite catalyst to produce gasoline and distillate product.

7. The process of claim 2 wherein the high conversion of the syngas feed produces less than 20% methane plus ethane, the yield of C₃ plus products is at least 80% and the yield of C₅ plus products is at least 45%.

8. The process of claim 2 wherein the H₂ /CO ratio of the syngas is within the range of 0.6 to 0.8.

9. The process of claim 2 wherein the conversion of syngas by said Fischer-Tropsch catalyst is accomplished in an elongated reaction zone comprising suspended catalyst particles in a liquid medium.

10. The process of claim 2 wherein conversion of syngas by said Fischer-Tropsch catalyst is accomplished in the presence of a fixed bed of catalyst particles retained in an elongated tubular reaction zone surrounded by a heat exchange medium.

11. The process of claim 2 wherein the conversion of the low ratio syngas is effected in at least two separate catalyst zones in series and the removal of formed CO₂ is accomplished between catalyst zones.