Chemistry: fischer-tropsch processes; or purification or recover – Plural zones each having a fischer-tropsch reaction
Reexamination Certificate
2001-08-23
2004-03-09
Parsa, J. (Department: 1621)
Chemistry: fischer-tropsch processes; or purification or recover
Plural zones each having a fischer-tropsch reaction
C518S700000, C518S714000, C518S715000, C585S310000, C585S322000, C585S323000
Reexamination Certificate
active
06703429
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a process for producing hydrocarbonaceous products from synthesis gas.
BACKGROUND OF THE INVENTION
Various processes for converting synthesis gas into hydrocarbonaceous products are well known. For example, Fischer-Tropsch synthesis is a well known method for the conversion of remote natural gas into salable products such as liquefied petroleum gas (LPG), condensate, naphtha, jet fuel, diesel fuel, other distillate fuels, lube base stock, and lube base stock feedstock. The Fischer-Tropsch synthesis process produces products that are predominantly linear hydrocarbons. These linear hydrocarbons are desirable for use in distillate fuels and as a lube base stock feedstock because they do not contain cyclic hydrocarbons. The linear structure of the hydrocarbons give them excellent burning properties when used as fuels and a high viscosity index when used as a lube base stock. The non-paraffinic linear hydrocarbons produced from the Fischer-Tropsch synthesis (e.g., olefins and alcohols) can be converted into linear paraffins by hydrogenation (e.g., hydrotreating, hydrofinishing, and/or hydrocracking).
The products from the Fischer-Tropsch process are not ideal, however, for use as a gasoline blend stock or in petrochemical operations. These uses require the presence of either aromatics or highly branched iso-paraffins, the production of which requires the use of naphtha reforming and/or alkylation processes. The low molecular weight products of the Fischer-Tropsch process that are rich in linear olefins could be converted to high octane alkylate if a source of iso-butane were available. Although iso-butane could be made from a conventional Fischer-Tropsch process by saturation of a butane stream followed by isomerization, the process would be expensive.
Another process for converting synthesis gas into hydrocarbonaceous products is the dual functional syngas conversion process. This process was developed from Isosynthesis, a process developed in Germany in the 1930's with the objective of making low molecular weight iso-paraffins using Thoria catalysts at high pressures. More recently, Isosynthesis has evolved to use at least two different types of catalysts that both make methanol and consume it. Iso-paraffins are again a major component of the product, and this dual functional syngas conversion process can also be referred to as modern Isosynthesis. The products from the modern dual functional syngas conversion reactor are a mixture of low molecular weight iso-paraffins and an aromatic-rich product.
However, the dual functional syngas conversion process does not make products that can readily be converted into jet fuel, diesel fuel, other distillate fuels, lube base stock, or lube base stock feedstock. Light gases produced by the dual functional syngas conversion process are rich in iso-butane, but it is not easy to convert this product into fuels because to do so would require the process steps of dehydrogenation, oligomerization, and alkylation.
Accordingly, there is a need in the art for an economic and efficient process for converting synthesis gas into a full range of hydrocarbonaceous products.
SUMMARY OF THE INVENTION
The present invention relates to processes for converting synthesis gas into hydrocarbonaceous products. In one aspect of the present invention, a process for converting synthesis gas into hydrocarbonaceous products is provided comprising the steps of (a) subjecting a first portion of synthesis gas to a dual functional syngas conversion process to form a first effluent comprising a first hydrocarbonaceous product including aromatics and iso-paraffins; (b) subjecting a second portion of synthesis gas to a Fischer-Tropsch synthesis process to form a second effluent comprising a second hydrocarbonaceous product including linear paraffins and linear olefins; and (c) alkylating the linear olefins with the iso-paraffins to produce high octane gasoline range alkylate.
In another aspect of the invention, a process for converting synthesis gas into hydrocarbonaceous products is provided comprising the steps of (a) providing a synthesis gas; (b) subjecting at least a portion of the synthesis gas to a dual functional syngas conversion process to form a first effluent comprising unreacted synthesis gas and a first hydrocarbonaceous product including aromatics and iso-paraffins; (c) subjecting the unreacted synthesis gas to a Fischer-Tropsch synthesis process to form a second effluent comprising a second hydrocarbonaceous product including linear paraffins and linear olefins; and (d) alkylating the linear olefins with at least a portion of the iso-paraffins to produce high octane gasoline range alkylate.
In a further aspect of the present invention, a process for converting synthesis gas into hydrocarbonaceous products is provided that comprises the steps of (a) providing a synthesis gas; (b) subjecting at least a portion of the synthesis gas to a dual functional syngas conversion process to form a first effluent comprising a first portion of unreacted synthesis gas, carbon dioxide, a first portion of water, and a first hydrocarbonaceous product including aromatics and iso-butane; (c) separating the first hydrocarbonaceous product into a light gas fraction, an iso-butane-containing stream, and a high octane aromatic gasoline blend component; (d) subjecting the unreacted synthesis gas to a Fischer-Tropsch synthesis process to form a second effluent comprising a second portion of water, a second portion of unreacted synthesis gas, and a second hydrocarbonaceous product including linear paraffins and linear olefins; (e) separating the second hydrocarbonaceous product into a light gas stream, a C
3
-C
4
olefin-containing stream, a C
3
-C
4
alcohol-containing stream, and a C
5
+
stream; (f) combining the C
3
-C
4
olefin-containing stream and the C
3
-C
4
alcohol-containing stream to form a combined stream; (g) reducing the oxygen content of the combined stream to below 4000 ppm by dehydration; and (h) alkylating the combined stream with the iso-butane-containing stream to produce high octane iso-paraffinic gasoline range alkylate.
Unless otherwise stated, the following terms used in the specification and claims have the means given below:
“Aromatic” means a molecular species that contains at least one aromatic function.
“Jet fuel” means a material suitable for use in turbine engines for aircraft or other uses meeting the current version of at least one of the following specifications:
ASTM D1655-99
DEF STAN
91-91/3
(DERD 2494), TURBINE FUEL, AVIATION, KEROSINE TYPE, JET A-1, NATO CODE: F-35
International Air Transportation Association (IATA) “Guidance Material for Aviation Turbine Fuels Specifications”, 4th edition, March 2000
United States Military Jet fuel specifications MIL-DTL-5624 (for JP-4 and JP-5) and MIL-DTL-83133 (for JP-8)
“Diesel fuel” means a material suitable for use in diesel engines and conforming to the current version at least one of the following specifications:
ASTM D 975—“Standard Specification for Diesel Fuel Oils”
European Grade CEN 90
Japanese Fuel Standards JIS K 2204
The United States National Conference on Weights and Measures (NCWM) 1997 guidelines for premium diesel fuel
The United States Engine Manufacturers Association recommended guideline for premium diesel fuel (FQP-1A)
“Gasoline” means a material suitable for use in spark-ignition internal-combustion engines for automobiles and light trucks (motor gasoline) and in piston engine aircraft (aviation gasoline) meeting the current version of at least one of the following specifications:
ASTM D4814 for motor gasoline
European Standard EN 228 for motor gasoline
Japanese Standard JIS K2202 for motor gasoline
ASTM D910 for aviation gasoline
ASTM D6227 “Standard Specification for Grade 82 Unleaded Aviation Gasoline”.
UK Ministry of Defense Standard 91-90/Issue 1 (DERD 2485), GASOLINE, AVIATION: GRADES 80/87, 100/130 and 100/130 LOW LEAD
“Distillate fuel” means a material containing hydrocarbons with boiling points between approxim
Kibby Charles L.
O'Rear Dennis J.
Burns Doane Swecker & Mathis L.L.P.
Chevron U.S.A. Inc.
Parsa J.
LandOfFree
Process for converting synthesis gas into hydrocarbonaceous... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for converting synthesis gas into hydrocarbonaceous..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for converting synthesis gas into hydrocarbonaceous... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3224160