Abstract:
A method for production of synthetic diesel and naphtha from a hydrocracker includes hydrocracking a synthetic heavy hydrocarbon feed comprising an a value to form a diesel and a naphtha; selecting a desired diesel-to-naphtha ratio; calculating, based on the feed a and the desired diesel-to-naphtha ratio, a target molar ratio of hydrocarbons exiting to hydrocarbons entering the hydrocracker; and adjusting at least one hydrocracking conversion promoting condition to achieve said target molar ratio. The present invention further relates to a method for adjusting the overall production of a syngas-to-synthetic hydrocarbons plant in response to market conditions, comprising adjusting at least one hydrocracking conversion promoting condition and/or at least one conversion promoting condition within a Fischer-Tropsch reactor so as to maintain the overall diesel-to-naphtha ratio or to maintain a diesel production rate within a predetermined range of a desired value.
Abstract:
A method for production of synthetic diesel and naphtha from a hydrocracker includes hydrocracking a synthetic heavy hydrocarbon feed comprising an a value to form a diesel and a naphtha; selecting a desired diesel-to-naphtha ratio; calculating, based on the feed a and the desired diesel-to-naphtha ratio, a target molar ratio of hydrocarbons exiting to hydrocarbons entering the hydrocracker; and adjusting at least one hydrocracking conversion promoting condition to achieve said target molar ratio. The present invention further relates to a method for adjusting the overall production of a syngas-to-synthetic hydrocarbons plant in response to market conditions, comprising adjusting at least one hydrocracking conversion promoting condition and/or at least one conversion promoting condition within a Fischer-Tropsch reactor so as to maintain the overall diesel-to-naphtha ratio or to maintain a diesel production rate within a predetermined range of a desired value.
Abstract:
The present invention is generally related towards methods for preparing and using a more stable synthesis catalysts. In particular, the present invention is directed towards treating synthesis catalysts with low levels of oxygen to deactivate the smaller more unstable metal crystallites present in the catalyst matrix. The process can be carried out either prior to and/or simultaneously with the synthesis reaction.
Abstract:
Methods for reducing the average molecular weight of liquid hydrocarbons in a Fischer-Tropsch reactor are disclosed. The preferred embodiments of the present invention are characterized by feeding a hydrocarbon stream, which lowers the average molecular weight of the hydrocarbon liquids inside the reactor, and more preferably by recycling a portion of low-molecular weight hydrocarbon products back into the reactor. Lowering the molecular weight of the hydrocarbon liquids inside the reactor increases the mass transfer and solubility, and diffusivity of the reactants in the hydrocarbons present in the slurry.
Abstract:
An amorphous support, methods for making the same and methods of using, particularly in hydrocracking. A method of making may comprise mixing a first amorphous material and a second amorphous material of different acidities to form a mixture, and treating by either separately treating the first and second amorphous materials before mixing or treating the mixture, so as to form an amorphous catalyst support. Treating preferably includes calcining. The acidity of the amorphous support may be modified by the different acidities of the precursor amorphous materials, their proportions in the mixture, and/or the order of the mixing and treating steps. A method of use may comprise reacting a hydrocarbon fraction with hydrogen over a hydrocracking catalyst comprising the amorphous catalyst support to form a hydrocracked product. Further embodiments include the first and second amorphous materials comprising silica-alumina, and/or differing in Brönsted acidity, Lewis acidity, or acidity index.
Abstract:
A stabilized catalyst support having improved hydrothermal stability, catalyst made therefrom, and method for producing hydrocarbons from synthesis gas using said catalyst. The stabilized support is made by a method comprising treating a crystalline hydrous alumina precursor in contact with at least one structural stabilizer or compound thereof. The crystalline hydrous alumina precursor preferably includes an average crystallite size selected from an optimum range delimited by desired hydrothermal resistance and desired porosity. The crystalline hydrous alumina precursor preferably includes an alumina hydroxide, such as crystalline boehmite, crystalline bayerite, or a plurality thereof differing in average crystallite sizes by at least about 1 nm. The crystalline hydrous alumina precursor may be shaped before or after contact with the structural stabilizer or compound thereof. The treating includes calcining at 450oC or more. Preferred structural stabilizers can include cobalt, magnesium, manganese, manganese, zirconium, boron, aluminum, barium, silicon, lanthanum, oxides thereof, or combinations thereof.
Abstract:
This invention relates to methods and apparatus for separating liquid products and catalyst particles from a slurry used in a Fischer-Tropsch reactor system. The preferred embodiments of the present invention are characterized by a separation system that uses a sedimentation chamber, which contains at least one inclined channel that enhances the settling of particles within the slurry. The enhanced settling separates the slurry into a catalyst-rich bottom stream and a catalyst-lean overhead stream. The catalyst-rich bottom product stream is preferably recycled to the reactor, while the catalyst-lean overhead stream can be further processed by a secondary separation system to produce valuable synthetic fuels. The inclined channel may be provided by a structure selected from the group consisting of tube, pipe, conduit, sheets, trays, walls, plates, and combinations thereof.
Abstract:
The present invention provides an apparatus and method for controlling the hydrodynamics within a gas agitated multiphase reactor at a given gas linear velocity. The embodiments of the present invention involve novel configurations of the multiphase reactor internal structures. In general, the configurations comprise a plurality of discrete reaction flow zones created by arranging the internal structures of a multiphase reactor.
Abstract:
A process for producing hydrocarbons comprises providing a multi-tubular reactor having at least 100 tubes units containing a catalyst, each tube being between 2 and 5 meters tall and in thermal contact with a cooling fluid; feeding hydrogen and carbon monoxide to each tube at a linear gas superficial velocity less than about 60 cm/s; and converting the gas feedstream to hydrocarbons on the catalyst, wherein the yield of hydrocarbons in each tube is greater than 100 (kg hydrocarbons)/hr/(m 3 reaction zone). Each tube may have an internal diameter greater than 2 centimeters. The catalyst may be active for Fischer Tropsch synthesis and may comprise cobalt or iron. The maximum difference in the radially-averaged temperature between two points that are axially spaced along the reactor is less than 15°C, preferably less than 10°C. The catalyst loading or intrinsic activity may vary along the length of the reactor.
Abstract:
The present invention is generally related towards enhancing the yield and/or cold-flow properties of certain hydrocarbon products, increasing the degree of isomerization in a diesel product and/or increasing the production rate of a diesel product. The embodiments generally include reducing the residence time of lighter hydrocarbon fractions during hydrocracking, thereby decreasing secondary cracking, by various configurations of introducing at least two hydrocarbon feedstreams of different boiling ranges at different entry points in a hydrocracking unit. A method further includes forming a hydrocarbons stream comprising primarily C5+ Fischer-Tropsch hydrocarbon products; fractionating hydrocarbons stream to form at least a wax fraction and an intermediate fraction which serve as separate feedstreams to a hydrocracking unit comprising at least two hydroconversion zones. One embodiment comprises the use of a bifunctional catalyst in one of the hydrocracking zones so as to favor hydroisomerization of hydrocarbons to favor the formation of branched paraffins boiling in the diesel range.