JP2017519857A - Process for preparing high purity Fischer-Tropsch gas oil fraction - Google Patents

Abstract

The present invention is a method for preparing a high purity Fischer-Tropsch gas oil fraction comprising: a) supplying a Fischer-Tropsch derived gas oil feedstock containing one or more contaminants; b) Fischer-Tropsch derived Of gas oil feedstock to a fractionation zone and fractionating a Fischer-Tropsch derived gas oil feedstock into two or more Fischer-Tropsch gas oil fractions having different boiling ranges, wherein at least one Fischer-Tropsch gas oil fraction A fraction is a pollutant-enriched Fischer-Tropsch gas oil fraction in which one or more pollutants are enriched relative to the feedstock, c) at least one pollutant-enriched Fischer-Tropsch gas oil fraction To the absorption zone containing the most absorbent material and absorb the pollutant-enriched Fischer-Tropsch gas oil fraction. The step of absorbing at least a portion of the contaminants into contact with the material, and d) contaminants from the absorption zone refining Fischer are depleted - comprising the step of recovering Tropsch gas oil fraction, a method. The present invention further provides a further method for preparing a high purity Fischer-Tropsch gas oil fraction and the use of a refined Fischer-Tropsch gas oil fraction.

Description

  The present invention relates to a process for preparing a high purity Fischer-Tropsch gas oil fraction and its use as a solvent or functional fluid.

  In the last 20 years, there has been an increasing interest in synthetic paraffinic hydrocarbon products. Such synthetic paraffinic products are produced, for example, in the so-called Fischer-Tropsch process, and the synthesis gas, ie the mixture in which hydrogen and carbon monoxide are dominant, is converted into higher hydrocarbon compounds containing paraffins.

  A particularly important synthetic paraffinic product is light oil from Fischer-Tropsch. Because of its synthetic origin, these Fischer-Tropsch gas oils have very low levels of aromatics, naphthenic compounds and impurities relative to their crude oil counterparts. In addition, Fischer-Tropsch derived light oil has properties that are advantageous in solvent and functional fluid applications requiring low viscosity.

  US 2012/0048775 describes a process for producing middle distillates from paraffinic raw materials produced by Fischer-Tropsch synthesis, in which an initial boiling point in the range of 150 ° C. to 400 ° C. and a temperature of 300 ° C. to 450 ° C. Contaminants are removed by passing an intermediate fraction having a final boiling point in the range over the ion exchange resin and optionally over a guard bed. US 2004/152793 describes a process for preparing an olefinic naphtha, in which the olefinic naphtha stream is isolated from a Fischer-Tropsch hydrocarbon stream and purified on metal oxides at elevated temperatures. US 2004/152793 discloses that the non-olefinic paraffin of naphtha is predominantly n-paraffin. US 5906727 discloses a Fischer-Tropsch derived solvent having a boiling range of about 160 to 370 ° C. According to US 5906727, the solvent is odorless and colorless (+30 Saebold color number). There is a need in the art for Fischer-Tropsch derived solvents that have a narrower boiling range than the solvents disclosed in US5906727.

US Patent Application Publication No. 2012/0048775 US Patent Application Publication No. 2004/152793 US Pat. No. 5,906,727

(Summary of the Invention)
The present invention provides a method for preparing a refined Fischer-Tropsch gas oil fraction. When a Fischer-Tropsch derived light oil having a relatively broad boiling range, for example, in the range of about 150 to 450 ° C., is fractionated into two or more fractions having a narrower boiling range, at least one fraction is It has been discovered that it exhibits increased odor and / or discoloration. These disadvantageous side effects that occur when fractionating a substantially odorless and colorless Fischer-Tropsch light oil have not been known. It has now been discovered that this problem can be solved by the method described in the present invention.

Thus, the present invention is a first method for preparing a refined Fischer-Tropsch gas oil fraction comprising:
a) supplying a Fischer-Tropsch derived gas oil feedstock containing one or more pollutants, the Fischer-Tropsch derived gas oil having 9 to 25 carbon atoms relative to the total amount of Fischer-Tropsch derived paraffin A fluid comprising paraffins, including isoparaffins and linear paraffins having an alkyl chain length ranging from 7 to 30 carbon atoms, comprising at least 70% by weight of Fischer-Tropsch derived paraffins;
b) supplying the raw material to a fractionation zone and fractionating the raw material into two or more Fischer-Tropsch gas oil fractions having different boiling ranges, wherein at least one Fischer-Tropsch gas oil fraction is one or more A contaminant-enriched Fischer-Tropsch gas oil fraction, wherein the contaminant of is enriched relative to the feedstock,
c) supplying the pollutant-enriched Fischer-Tropsch gas oil fraction to an absorption zone comprising at least one absorbent material and contacting the pollutant-enriched Fischer-Tropsch gas oil fraction with the absorbent material to produce one or more pollutants. Absorbing at least a portion of the material, and d) a refined Fischer-Tropsch gas oil fraction in which the contaminants are dramatically reduced relative to the pollutant-enriched Fischer-Tropsch gas oil fraction as a high purity Fischer-Tropsch gas oil fraction. A method is provided comprising the step of recovering from the absorption zone.

  A refined Fischer-Tropsch gas oil fraction having a narrower boiling range than the gas oil raw material derived from Fischer-Tropsch, the preparation source, and having use as a solvent, a diluent and a functional fluid is prepared by the method described in the present invention. It becomes possible to do.

  The method described in the present invention further enables the preparation of a refined Fischer-Tropsch gas oil fraction having desired odor characteristics and / or color specifications and having use as a solvent, diluent and functional fluid. .

  The method described in the present invention removes contaminants using a relatively simple, inexpensive and safe absorption method, for example for treatment with strong acids such as concentrated sulfuric acid or for complex and expensive hydroprocessing. It becomes even more possible.

In a further aspect, the present invention is a second method for preparing a refined Fischer-Tropsch gas oil fraction comprising:
i) a Fischer-Tropsch gas oil fraction having a final boiling point of 260 ° C. or less, wherein said contaminant-containing Fischer-Tropsch gas oil fraction comprising more than 50% by weight of isoparaffin is fed to an absorption zone comprising an absorbent material; Contacting the contaminant-containing Fischer-Tropsch gas oil fraction with the absorbent material to absorb at least a portion of the contaminant, and ii) refining wherein the contaminant is depleted relative to the contaminant-containing Fischer-Tropsch gas oil fraction. A method is provided comprising recovering a Fischer-Tropsch gas oil fraction from the absorption zone as a high purity Fischer-Tropsch gas oil fraction.

In a further aspect, the present invention is a third method for preparing a high purity Fischer-Tropsch gas oil fraction comprising:
v) supplying a contaminant-containing Fischer-Tropsch gas oil fraction having an initial boiling point above 260 ° C. to the absorption zone containing the absorbent material, and contacting the contaminant-containing Fischer-Tropsch gas oil fraction with the absorbent material to Absorbing at least a portion, and vv) a refined Fischer-Tropsch gas oil fraction depleted in contaminants from a contaminant-containing Fischer-Tropsch gas oil fraction as a high purity Fischer-Tropsch gas oil fraction from the absorption zone. A method is provided that includes the step of collecting.

  In another aspect, the present invention provides the use of a refined Fischer-Tropsch gas oil fraction produced by the method according to the present invention as a solvent, diluent or functional fluid.

  The present invention provides a first method for preparing a refined Fischer-Tropsch gas oil fraction. Such Fischer-Tropsch gas oil fractions are particularly suitable for use as a solvent, diluent or functional fluid, and in particular for the applications described herein.

  In the process according to the invention, the fraction is prepared by feeding and fractionating a gas oil derived from Fischer-Tropsch. The light oil derived from the Fischer-Tropsch described in the present invention is a synthetic light oil derived from the Fischer-Tropsch process. Fischer-Tropsch derived light oils are known in the art. The term “Fischer-Tropsch derived” means that the light oil is or is produced from a synthetic product of the Fischer-Tropsch process. In the Fischer-Tropsch process, synthesis gas is converted to a synthesis product. Syngas or syngas is a mixture that is dominated by hydrogen and carbon monoxide obtained by converting hydrocarbonaceous feedstock. Suitable feedstocks include natural gas, crude oil, heavy oil fraction, coal, biomass or lignocellulosic biomass and lignite and lignite. Fischer-Tropsch derived light oil can also be referred to as GTL (gas to liquid) light oil. Fischer-Tropsch derived gas oils are processed at high temperatures on supported catalysts consisting of one or more Group VIII metals such as cobalt, ruthenium, iron, etc. Characterized by the product of the Fischer-Tropsch process. Preferably, at least a portion of the Fischer-Tropsch product comprises one or more metals, a hydrogenation component and an acidic oxide support component that are active in producing both hydrocracking and hydroisomerization reactions. Is contacted with hydrogen under hydrocracking / hydroisomerization conditions over one or more bifunctional catalysts. At least a portion of the resulting hydrocracked / hydroisomerized Fischer-Tropsch product can be supplied as a Fischer-Tropsch derived gas oil.

  Fischer-Tropsch derived light oil is different from crude oil derived light oil. Despite having a similar boiling range, the unique molecular composition of Fischer-Tropsch derived gas oils, among other things, improves viscosity characteristics, improves pour point, improves density characteristics, and in particular the desired specific A combination of flash point characteristics and any of the above characteristics may be possible. For example, a Fischer-Tropsch derived gas oil can combine low volatility with a high flash point, but the Fischer-Tropsch derived gas oil has a viscosity that is similar to that of light oil derived from crude oil having similar volatility and flash point. It can be lower than the viscosity. Despite the above, Fischer-Tropsch derived light oil is a complex molecular mixture that is incomparable to pure paraffinic molecules such as pure n-dodecane.

  The characteristics of Fischer-Tropsch derived diesel oil, which differ from crude oil derived diesel oil, are generally characterized by specific weight ratio (i / n ratio) of isoparaffin and linear paraffin, relative amount of monomethyl branched isoparaffin and molecular weight distribution of paraffin And the absence of substantial levels of aromatics and naphthenes.

  A particular advantage of Fischer-Tropsch derived gas oils is that they exhibit very little odor and are almost colorless. The color used herein is the Saybolt color as measured by the Saybolt number (ASTM D156: Standard Test Method for Sailor Color of Petroleum Products). A high Saybolt number, +30, indicates a colorless fluid, while a lower Saybolt number, specifically less than zero, indicates a discoloration. A Saebold number less than 25 already indicates the presence of a discoloration that can be visually observed. Fischer-Tropsch derived light oil usually has the highest Saybolt number, ie +30. High purity, low odor and minimal color characteristics combined with the improvements in viscosity, pour point, density and flash point properties described above make Fischer-Tropsch derived gas oils suitable for solvent, diluent and functional fluid applications. Make it very suitable.

  Such low odor and minimal color characteristics are due, in part, to the fact that contaminants are present in Fischer-Tropsch derived gas oil feedstocks, but the concentration of such contaminants in Fischer-Tropsch derived gas oil is relatively low. Is caused. This is due to the nature of the Fischer-Tropsch process for making Fischer-Tropsch derived light oil, where the raw material to the Fischer-Tropsch process contains little or no sulfur and the process consists of unsaturated compounds, For example, it produces very little aromatics, oxygenates and nitrites. It is now possible to satisfy the specific requirements of the specific use of Fischer-Tropsch gas oil by fractionating it into two or more fractions with different boiling ranges. Was discovered. By fractionating gas oil derived from Fischer-Tropsch, isoparaffin and linear paraffin are distributed unevenly in two or more fractions, and Fischer-Tropsch having a different i / n ratio from the gas oil feed derived from Fischer-Tropsch A light oil fraction can be obtained. Also the relative amount of monomethyl branched isoparaffin and the molecular weight distribution of paraffin can be different. As a result, the viscosity, pour point, density and flash point properties of the Fischer-Tropsch derived gas oil fraction can vary beyond those expected based on fractionation based solely on the boiling range.

  In the process according to the invention, a Fischer-Tropsch derived gas oil feed is fed to the fractionation zone. The fractionation zone in this specification refers to one or more separation means for separating a Fischer-Tropsch derived gas oil feed into two or more fractions having different boiling ranges. Examples of suitable separation means include, but are not limited to, distillation units. Preferably, the Fischer-Tropsch derived gas oil feed is fractionated by distillation. Fischer-Tropsch derived gas oil feed can be fractionated in a single distillation column or two or more distillation columns. The Fischer-Tropsch derived gas oil feed is preferably fractionated in one or more distillation columns.

  In the fractionation zone, the gas oil feed derived from Fischer-Tropsch is fractionated into two or more gas oil fractions derived from Fischer-Tropsch. Each has a different boiling range. Preferably, the Fischer-Tropsch derived gas oil feedstock is fractionated into three or more, more preferably four or more, each Fischer-Tropsch gas oil fraction having a different boiling range. Preferably, at least one, more preferably at least two, Fischer-Tropsch gas oil fractions have a final boiling point of 260 ° C. or lower, preferably 250 ° C. or lower, more preferably 215 ° C. or lower. As used herein, final boiling point refers to the higher limit of the boiling range of the Fischer-Tropsch gas oil fraction, which is the initial boiling point and final boiling point measured under atmospheric conditions as determined by ASTM D86. Defined as the range between.

  Equally preferably, at least one, more preferably at least two, of the Fischer-Tropsch gas oil fraction has an initial boiling point above 260 ° C, preferably at least 300 ° C, more preferably at least 310 ° C. As used herein, initial boiling point refers to the lower limit of the boiling range of the Fischer-Tropsch gas oil fraction, which is the initial boiling point and final boiling point measured under atmospheric conditions as determined by ASTM D86. Defined as the range between.

  When fractionating Fischer-Tropsch derived light oil, the contaminants present in the Fischer-Tropsch derived light oil feed are not evenly distributed in more than one fraction, albeit at a low level. In particular, it has been observed that smaller molecular weight and / or more volatile contaminants may accumulate in the lower boiling fraction rather than stay in the higher boiling fraction. These contaminants are believed to cause an undesirable odor and, optionally, discoloration of the fraction not observed in Fischer-Tropsch derived gas oil feedstocks.

  In particular, it has been observed that larger molecular weight and / or less volatile contaminants may accumulate in the higher boiling fraction rather than stay in the lower boiling fraction. These contaminants are believed to cause exclusively unwanted discoloration of the fraction.

  Contaminants herein are non-paraffinic and non-naphthenic compounds. As used herein, the term pollutant refers to a compound selected from the group consisting of oxygenated compounds, unsaturated hydrocarbon compounds, sulfur-containing compounds and nitrogen-containing compounds.

  As used herein, the term unsaturated hydrocarbon compound refers to a compound having one or more unsaturated bonds, including aromatic compounds.

  In this specification, the term oxygen-containing compound refers to an oxygen-containing hydrocarbon compound. Examples of oxygenates include but are not limited to alcohols, ketones, aldehydes, ethers, epoxides and acids.

  As used herein, the term aromatic compound refers to aromatic compounds and compounds having one or more aromatic groups, including polycyclic aromatic compounds.

  More preferably, the term pollutant herein refers to a compound selected from the group consisting of oxygenated compounds and aromatic compounds. This is because such compounds are believed to contribute most significantly to the odor and discoloration of the pollutant enriched Fischer-Tropsch gas oil fraction.

  In the present specification, the term pollutant concentration is expressed in ppm by weight, unless otherwise indicated, and is a Fischer-Tropsch derived light oil, a pollutant enriched Fischer-Tropsch gas oil fraction or a refined Fischer-Tropsch gas oil fraction, respectively. Refers to the pollutant concentration calculated based on the total amount of and the total weight of the pollutant.

  Thus, in the method according to the invention, at least one Fischer-Tropsch gas oil fraction prepared in step (b) is a pollutant in a Fischer-Tropsch derived gas oil feedstock in the prepared Fischer-Tropsch gas oil fraction. Is a pollutant enriched Fischer-Tropsch gas oil fraction due to the uneven distribution of The contaminant-enriched Fischer-Tropsch gas oil fraction herein refers to a Fischer-Tropsch gas oil fraction that contains one or more contaminants at a higher concentration than a Fischer-Tropsch derived gas oil feedstock. In particular, the pollutant-enriched Fischer-Tropsch gas oil fraction may comprise at least one pollutant selected from the group consisting of oxygenates and aromatics.

  The effect of contaminant accumulation in the pollutant-enriched Fischer-Tropsch gas oil fraction is that the Saybolt number of the pollutant-enriched Fischer-Tropsch gas oil fraction is lower than that of the Fischer-Tropsch derived gas oil feedstock, i.e. It may be that the coloring of the minute has increased. This undesirable discoloration is particularly observed in the higher boiling Fischer-Tropsch gas oil fraction. While not wishing to be bound by any particular theory, in particular, more complex and conjugated molecules are believed to affect light emission and absorption. Such complex and conjugated molecules are likely to have higher molecular weights. It has been observed that discoloration of lower fractions may also occur to a lesser extent.

  A further effect of the accumulation of contaminants in the pollutant enriched Fischer-Tropsch gas oil fraction may be an increase in odor emitted by the Fischer-Tropsch gas oil fraction. This undesirable odor is particularly observed in the lower boiling Fischer-Tropsch gas oil fraction. While not wishing to be bound by any particular theory, in particular, more volatile low molecular weight molecules are believed to be odorous.

  Fischer-Tropsch derived light oil and in particular, Fischer-Tropsch derived paraffin has an odor in nature. Thus, references herein to terms such as no odor, low odor, or low odor refer to odors that are qualitatively equal or qualitatively similar to the odor of a Fischer-Tropsch derived light oil or paraffin. As used herein, references to terms of increased odor, stronger odor and undesirable odor or similar attributes refer to odors that are qualitatively different from the light oil or paraffin odor derived from Fischer-Tropsch. This difference in odor can be characterized by comparing the odor of the Fischer-Tropsch gas oil fraction, optionally enriched in pollutants, with the gas oil feed derived from Fischer-Tropsch and classifying the difference, i.e. 1 is qualitatively equal to the Fischer-Tropsch derived light oil feed (good odor characteristics), while 5 is qualitatively very different from the Fischer-Tropsch derived light oil feed (bad odor characteristics).

  Preferably, the Fischer-Tropsch derived gas oil feed is fractionated into at least two Fischer-Tropsch gas oil fractions, at least one of the at least two Fischer-Tropsch gas oil fractions being 260 ° C. or less, preferably A pollutant enriched Fischer-Tropsch gas oil fraction having a final boiling point of 250 ° C. or lower, more preferably 215 ° C. or lower. Likewise preferably, the Fischer-Tropsch derived gas oil feed is fractionated into at least two Fischer-Tropsch gas oil fractions, at least one of which is at least 260 ° C. Preferably, a pollutant enriched Fischer-Tropsch gas oil fraction having an initial boiling point of at least 300 ° C, more preferably at least 310 ° C. Usually, the Saybolt number of the pollutant-enriched Fischer-Tropsch gas oil fraction with an initial boiling point above 260 ° C. may be less than 30, in particular at least 2 and optionally at least 5, derived from Fischer-Tropsch It may be smaller than the Saybolt number of the light oil raw material.

  If more than one pollutant enriched Fischer-Tropsch gas oil fraction is produced, the above characteristics of the pollutant enriched Fischer-Tropsch gas oil fraction apply to at least one pollutant enriched Fischer-Tropsch gas oil fraction But can also be applied to other contaminant-enriched Fischer-Tropsch gas oil fractions.

  Both the above discoloration and increased odor are undesirable properties and do not provide an advantage for the use of the Fischer-Tropsch gas oil fraction in solvent, diluent or functional fluid applications. In order to make the Fischer-Tropsch gas oil fraction suitable for a wide range of solvent, diluent or functional fluid applications, the pollutant-enriched Fischer-Tropsch should undergo further processing to reduce odor and / or discoloration It is.

  Accordingly, the method according to the invention further comprises the step of supplying a pollutant enriched Fischer-Tropsch gas oil fraction to the absorption zone. The absorption zone includes at least one absorbent material that is suitable for absorbing at least a portion of the contaminant. In this specification, an absorbent material refers to an absorbent material and an adsorbent material. Absorbing herein refers to absorbing and adsorbing. Absorption herein refers to absorption and adsorption.

  Preferably, the absorption zone is a molecular sieve material comprising magnesium silicate and 4A or 5A molecular sieve, zeolite X, zeolite 13X, zeolite Y, dealuminated zeolite Y, ultrastabilized Y, ZSM-12, mordenite And at least one absorbent material selected from the group consisting of zeolite beta, zeolite L, and zeolite omega.

  While not wishing to be bound by any particular theory, in particular, absorbent materials having larger pore sizes, i.e., greater than 0.5 nm (5 angstroms) or larger, can contain oxygenated compounds and other It is believed that relatively large aromatic compounds can be absorbed in addition to contaminants. In particular, the absorbent material having a smaller pore size predominantly absorbs non-aromatic compounds including oxygen-containing compounds.

  Thus, the absorption zone is greater than 0.5 nm (5 angstroms), more preferably at least 0.55 nm (5.5 angstroms), even more preferably at least 0.6 nm (6 angstroms), even more preferably at least It is particularly preferred to include at least one absorbent material comprising pores having a pore size of 0.65 nm (6.5 angstroms). Preferably, the absorption zone is zeolite X, zeolite 13X, zeolite Y, dealuminated zeolite Y, ultrastable Y, ZSM-12, mordenite, zeolite beta, zeolite L, zeolite omega, more preferably zeolite. At least one molecular sieve material selected from the group consisting of X, zeolite 13X, zeolite Y, dealuminated zeolite Y, ultrastabilized Y, ZSM-12, mordenite, zeolite beta, zeolite L, zeolite omega Even more preferably, the absorbent material is zeolite 13X, which is the sodium form of zeolite X. Where the absorption zone comprises at least one molecular sieve absorbent material, the at least one molecular sieve absorbent material is greater than 0.5 nm (5 angstroms), more preferably at least 0.55 nm (5.5 angstroms), and More preferably, it has a channel structure in one or more directions having a diameter of at least 0.6 nm (6 angstroms), and even more preferably at least 0.65 nm (6.5 angstroms).

  The absorption zone can contain two or more absorbent materials, preferably two or more selected from the above-mentioned absorbent materials. As a preferred combination of absorbent materials, zeolite 13X and magnesium silicate can be mentioned. Another preferred combination of absorbent materials can include zeolite 13X and activated carbon. Absorbent combinations more efficiently absorb a wider range of contaminants, such as contaminants of both larger and smaller molecular diameters, such as oxygenates and aromatics or polar and nonpolar contaminants May be possible.

  The molecular sieves used as the absorbent material in the process of the present invention are preferably based on acidic molecular sieves in which the molar ratio of backbone silica to alumina is less than 100, more preferably more than 10, for example 20 to 50. . A material with less silica has more sites for adsorption sites available and may therefore be more efficient than a molecular sieve material with more silica.

  The absorbent material used in the absorption zone of the method of the invention can be provided in the form of particles, for example extruded bodies, spheres or pellets. The particles can also include an absorbent material alone or together with a binder material or filler material to improve the strength of the particles. The binder or filler material may be an amorphous metal oxide including, for example, alumina, silica, zirconia and titania. Preferably, the binder or filler material is alumina.

  Preferably, the pollutant enriched Fischer-Tropsch gas oil fraction contacts the absorbent material in the absorbent zone at a temperature in the range of 0 to 150 ° C. The lower limit of the temperature range in which the pollutant-enriched Fischer-Tropsch gas oil fraction contacts the absorbent material in the absorption zone is that the absorption is diffusion-limited, temperatures below 0 ° C. are the pollutant-enriched Fischer-Tropsch gas oil fraction This is related to the fact that it can cause an undesirable decrease in the rate of diffusion of contaminants from the minute to the absorbent material. As the contact temperature increases, i.e., above 0 ° C., the diffusion rate can increase. By maintaining temperatures below 150 ° C., the formation of by-products is reduced. This is important because these by-products may have undesirable effects on the application of the resulting Fischer-Tropsch gas oil fraction.

  More preferably, the pollutant enriched Fischer-Tropsch gas oil fraction is contacted with the absorbent material in the absorbent zone at a temperature in the range of 10 to 40 ° C, most preferably in the range of 10 to 30 ° C.

  Preferably, the pollutant enriched Fischer-Tropsch gas oil fraction is contacted with the absorbent material in the absorption zone at a pressure in the range of 1 to 75 bar, preferably 1.1 to 50 bar.

  The pollutant enriched Fischer-Tropsch gas oil fraction can be contacted with the absorbent material in a batch or continuous manner. The pollutant enriched Fischer-Tropsch gas oil fraction is preferably contacted with the absorbent material under turbulent flow conditions to stimulate fluid / solid material interactions. In the case of a continuous mode, the absorption zone can preferably comprise a fixed bed reactor comprising at least one fixed bed of absorbent material. Preferably, the pollutant enriched Fischer-Tropsch gas oil fraction is contacted with the absorbent material under continuous or inductive mixing, which is particularly preferred in the case of batch mode operation.

  Preferably, the pollutant enriched Fischer-Tropsch gas oil fraction is in contact with the absorbent material in the absorption zone for a time sufficient to absorb at least a portion of the pollutant. In the case of batch contact of the pollutant-enriched Fischer-Tropsch gas oil fraction and the absorbent material, the pollutant-enriched Fischer-Tropsch gas oil fraction is 1 to 48 hours, preferably 30 to 24 hours, more preferably The absorbent material can be contacted for any time in the range of 60 minutes to 24 hours. Preferably, in batch contact, the pollutant enriched Fischer-Tropsch gas oil fraction has a pollutant enriched Fischer in the range of 0.5 to 200, more preferably 1 to 175, even more preferably 5 to 125. -Contact with the absorbent material in a volume ratio of the Tropsch gas oil fraction to the absorbent material.

In the case of continuous contact of the pollutant-enriched Fischer-Tropsch gas oil fraction and the absorbent material, the pollutant-enriched Fischer-Tropsch gas oil fraction is from 1 minute to 48 hours, preferably from 30 minutes to 24 hours, more preferably from 60 minutes. Contact with any time-absorbing material in the range of 24 hours is possible. Preferably, the pollutant enriched Fischer-Tropsch gas oil fraction is 0.0001 to 0.01 s ⁻¹ , more preferably 0.0001 to 0.005 s ⁻¹ , even more preferably 0.0001 to 0.00. Contact the absorbent material in the absorption zone at 003 s ⁻¹ LHSV.

  The absorption zone can comprise one or more absorption sections. In one embodiment, the absorption zone can comprise two or more absorption sections in series. Optionally, the absorbent zone comprises two or more compartments, each containing a separate absorbent material. This has the advantage that different contaminants can be removed separately to the required extent. In one example, there may be a first compartment containing Mg silicate or similar absorbent material and a second compartment containing zeolite 13X or similar large pore molecular sieve absorbent material. This combination allows Mg silicate or similar absorbent material to absorb some oxygenates, so that most of the absorption capacity of zeolite 13X or similar large pore molecular sieve absorbent material is aromatic contamination. It has the advantage that it can be used for substances. Alternatively, the absorbent zone can include a mixture of two or more absorbent materials.

  In a further embodiment, the absorption zone can comprise two or more absorption compartments in parallel, preferably comprising the same absorbent material. The advantage of having parallel absorption zones is that this allows continuous operation of the absorption process, the absorption bed is regenerated alternately (as described in more detail herein below), while the remaining compartments It is a normal driving method.

  Other embodiments can comprise both parallel and serial absorption zones.

  In the process according to the invention, the refined Fischer-Tropsch gas oil fraction is recovered from the absorption zone as a high purity Fischer-Tropsch gas oil fraction. The refined Fischer-Tropsch gas oil fraction recovered from the absorption zone is depleted of contaminants, ie, the refined Fischer-Tropsch gas oil fraction is lower than the contaminant concentration of the contaminant-enriched Fischer-Tropsch gas oil fraction. Has a pollutant concentration. Preferably, at least one of the aromatic and oxygenate concentrations of the refined Fischer-Tropsch gas oil fraction is lower than the corresponding concentration of the contaminant-enriched Fischer-Tropsch gas oil fraction. More preferably, the aromatic and oxygenate concentrations of the refined Fischer-Tropsch gas oil fraction are lower than the corresponding concentrations of the contaminant-enriched Fischer-Tropsch gas oil fraction.

Preferably, the refined Fischer-Tropsch gas oil fraction according to the invention is
• 0 to 500 ppm by weight, more preferably 0 to 200 ppm by weight, even more preferably 0 to 100 ppm by weight, even more preferably 0 to 50 ppm by weight, based on the weight of the refined Fischer-Tropsch gas oil fraction Most preferably aromatic compounds in the range of 0 to 25 ppm by weight;
An oxygenate in the range from 0 to 30 ppm by weight, more preferably from 1 ppm by weight, calculated on the basis of the elemental oxygen in the oxygenate and the weight of the refined Fischer-Tropsch gas oil fraction;
0 to 3 ppm by weight calculated based on the weight of elemental sulfur in the sulfur-containing hydrocarbon compound and the weight of the refined Fischer-Tropsch gas oil fraction, more preferably from 1 ppm by weight, even more preferably, 0 to 1 calculated on the basis of the weight of sulfur-containing hydrocarbon compounds in the range from 0.2 ppm by weight and / or elemental nitrogen in the nitrogen-containing hydrocarbon compounds and refined Fischer-Tropsch gas oil fraction Contains nitrogen-containing hydrocarbon compounds in the weight ppm range.

More preferably, the refined Fischer-Tropsch gas oil fraction according to the invention is
• 0 to 500 ppm by weight, more preferably 0 to 200 ppm by weight, even more preferably 0 to 100 ppm by weight, even more preferably 0 to 50 ppm by weight, based on the weight of the refined Fischer-Tropsch gas oil fraction Most preferably aromatic compounds in the range of 0 to 25 ppm by weight;
An oxygenate in the range from 0 to 3 ppm by weight, more preferably from 1 ppm by weight, calculated on the basis of the elemental oxygen in the oxygenate and the weight of the refined Fischer-Tropsch gas oil fraction;
0 to 3 ppm by weight, more preferably from 1 ppm by weight, even more preferably from 0 to 3 ppm by weight, calculated on the basis of the weight of elemental sulfur and refined Fischer-Tropsch gas oil fraction in the sulfur-containing hydrocarbon-based compound. Sulfur-containing hydrocarbon compounds in the range from 2 ppm by weight, and • 0 to 1 ppm by weight calculated on the basis of the weight of elemental nitrogen in the nitrogen-containing hydrocarbon compound and the refined Fischer-Tropsch gas oil fraction Including nitrogen-containing hydrocarbon compounds. In the above, the concentration of the oxygen-containing compound, sulfur-containing hydrocarbon compound and nitrogen-containing hydrocarbon compound is determined based on the weight of oxygen, sulfur and nitrogen present in the gas oil, and includes such oxygen, sulfur and nitrogen atoms. Reference is made to elemental oxygen, elemental sulfur and elemental nitrogen to show that it has not been determined based on the weight of the complete molecule.

  If more than one pollutant enriched Fischer-Tropsch gas oil fraction is present, each pollutant enriched Fischer-Tropsch gas oil fraction is preferably fed to a separate absorption zone containing a separate absorbent material. More than one refined Fischer-Tropsch gas oil fraction is prepared. This is particularly true when the fractionation and absorption process steps are operated in a continuous manner. Each of the individual fractions of more than one refined Fischer-Tropsch gas oil fraction can preferably have its own specific contaminant concentration within the above-mentioned range.

  In addition to the purified Fischer-Tropsch gas oil fraction, contaminant-containing absorbent material can be recovered from the absorption zone. The contaminant-containing absorbent material can be recycled to the absorption zone, or in particular, when the sorption capacity of the absorbent material is reached, the contaminant-containing absorbent material can be regenerated. The absorbent material can be regenerated in any suitable manner that desorbs or otherwise removes contaminants from the absorbent material. For example, the absorbent material is removed by removal with a desorbent such as steam or nitrogen, or for example, contamination absorbed by heating the absorbent material in the presence of oxygen, oxygen-enriched air, air or a hydrogen-containing gas. The material can be regenerated by burning it or otherwise decomposing it. After regenerating the absorbent material, it can be recycled to the absorption zone.

  In addition to the pollutant enriched Fischer-Tropsch gas oil fraction, a non-polluted Fischer-Tropsch gasoline fraction can also be prepared in step (b). Such Fischer-Tropsch gasoline fractions that are not enriched in pollutants can be recovered directly from the process, i.e. without subjecting these fractions as further Fischer-Tropsch gasoline fractions to the absorption step (c). -Tropsch gasoline fraction.

  The high purity Fischer-Tropsch gasoline fraction recovered from the absorption zone as a purified Fischer-Tropsch gasoline fraction (step (d)) can be used for the desired application, optionally after further processing.

  In a further aspect, the present invention provides the use of a purified Fischer-Tropsch gas oil fraction with a functional fluid formulation or diluent as a solvent. The functional fluid formulation herein may be a formulation comprising a purified Fischer-Tropsch gas oil fraction that preferably further comprises an additive compound. Solvents, functional fluid formulations and diluents are typically used in many areas such as oil and gas exploration and production, process oils, agricultural chemicals, process chemicals, construction industry, food and related industries, paper, fabrics And leather and a variety of household and consumer products. Furthermore, the type of additive used in the functional fluid formulation described in the present invention depends on the type of fluid formulation. Additives for functional fluid formulations include, but are not limited to, corrosion and rheology control products, emulsifiers and wetting agents, drilling stabilizers, high pressure and antiwear additives, de- and antifoaming agents, pour point inhibitors, and antioxidants Agents.

  Preferred solvents, diluents and / or functional fluid formulations using the refined Fischer-Tropsch gas oil fraction obtained by the method described in this invention as diluent oil or base oil include, but are not limited to drill fluid, heated fuel, Lamp oil, barbecue lighter, concrete demolding, pesticide spray oil, paints and coatings, personal care and cosmetics, consumer products, pharmaceuticals, industrial and institutional cleaning, adhesives, inks, air cleaners, sealants, explosives, water Treatment, cleaner, scouring powder, car dewaxing agent, discharger, transformer oil, process oil, process chemical, silicone varnish, 2-stroke motorcycle oil, metal cleaning, dry cleaning, lubricant, hardware construction fluid, aluminum roll oil , Explosives, chlorinated paraffin, heat-cured seal Ink, wood treatment, polymer processing oil, Sabitomeyu, shock absorbers, greenhouses fuels include destruction fluids and fuel additives formulations.

  Typical solvent, diluent and functional fluid applications are described in, for example, “The Index of Solvents”, Michael Ash, Irene Ash, Power publishing Ltd, 1996, ISBN 0-566-0784-8 and “Handbook of S”. George Wypych, Willem Andrew publishing, 2001, ISBN 0-8155-1458-1.

  The advantage of using the refined Fischer-Tropsch gas oil fraction as a solvent, diluent or in a functional fluid formulation is that the refined Fischer-Tropsch gas oil fraction has low viscosity, low pour point, but high flash point That's what it means. Such a combination of physical properties of the refined Fischer-Tropsch gas oil fraction is highly desirable for its use in functional fluid formulations combined with low viscosity requirements.

  For example, in drill fluid applications, the temperature of the drill fluid may decrease during use, which may result in an increase in drill fluid viscosity. High viscosity can be detrimental to the advantageous use of drill fluids. Thus, the refined Fischer-Tropsch gas oil fraction obtained from the process according to the invention having a low viscosity and a high flash point is highly desirable for its use in drill fluid applications.

  Use of the refined Fischer-Tropsch gas oil fraction as a diluent can include use as a diluent or base oil for solvent and / or functional fluid applications.

  The term diluent oil means an oil that is used to reduce viscosity and / or improve other properties of solvents and functional fluid formulations.

  The term base oil refers to an oil to which other oils, solvents or substances are added to produce a solvent or functional fluid formulation.

  Advantages of the use of a refined Fischer-Tropsch gas oil fraction as a diluent or base oil for solvent and / or functional fluid formulations include a refined Fischer-Tropsch gas oil fraction, and a functional fluid further comprising an additive compound In the case of a preparation, the same as above.

  In a further aspect, the present invention provides the use of a refined Fischer-Tropsch gas oil fraction obtained by the process according to the present invention to improve biodegradability and reduce toxicity in solvent and / or functional fluid applications. To do.

  As noted above, the refined Fischer-Tropsch gas oil fraction is preferably at a very low level of aromatics, sulfur, and nitrogen compounds, and preferably does not contain polycyclic aromatic hydrocarbons. Such low levels can result in, but are not limited to, low water toxicity, low sedimentation organism toxicity, low human and animal toxicity and low global environmental toxicity of the refined Fischer-Tropsch gas oil fraction. The molecular structure of the refined Fischer-Tropsch gas oil fraction can provide easy biodegradability of gas oil derived from Fischer-Tropsch.

  Any additional Fischer-Tropsch gas oil fraction obtained in step (b) of the process that is not pollutant enriched, as well as the refined Fischer-Tropsch gas oil fraction, is It can also be used in more than one way.

  The specific use of a particular Fischer-Tropsch gas oil fraction can depend on the exact composition and properties of such a particular Fischer-Tropsch gas oil fraction. The gas oil derived from Fischer-Tropsch supplied in step (a) of the method according to the present invention as a raw material is a synthetic light oil derived from a raw material other than crude oil such as methane, coal or biomass and produced by the Fischer-Tropsch method. . The preparation of Fischer-Tropsch derived gas oils, both of which are incorporated herein by reference, eg, WO 02/070628 and WO-A-9934917 (specifically the catalyst of Example III of WO-A-9934917). The method described in Example VII of WO-A-9934917 to be used). As mentioned above, such Fischer-Tropsch derived diesel oil has a different molecular composition and significantly different properties than crude oil derived diesel oil. Therefore, Fischer-Tropsch derived light oil can be clearly distinguished from crude oil derived light oil. A number of preferred properties of Fischer-Tropsch derived light oil are provided herein.

  Preferably, the Fischer-Tropsch derived light oil comprises more than 50% by weight, more preferably more than 70% by weight, and even more preferably more than 80% by weight isoparaffin. Preferably, the Fischer-Tropsch derived light oil is at least 2, more preferably at least 2.8, even more preferably at least 3.5, even more preferably at least 3.7, even more preferably at least 4 Even more preferably, it has an i / n ratio of at least 4.5.

  Preferably, the Fischer-Tropsch derived light oil is 20 to 40% by weight, preferably 21 to 37% by weight, more preferably 23 to 37% by weight, based on the total weight of isoparaffin in the Fischer-Tropsch derived light oil. In the range of monomethyl branched isoparaffins.

  Preferably, the Fischer-Tropsch derived light oil has an initial boiling point of at least 150 ° C. and a final boiling point of 450 ° C. or less under atmospheric conditions. Suitably, the Fischer-Tropsch derived light oil has an initial boiling point of at least 175 ° C. under atmospheric conditions, measured using ASTM D86. As used herein, it should be noted that the initial boiling point, final boiling point and boiling range indicated herein are the initial boiling point, final boiling point and boiling range determined by ASTM D86 when describing the present invention. . The initial boiling point, final boiling point and boiling range determined by ASTM D86 for all Fischer-Tropsch light oils are less than or greater than the initial boiling point of ASTM D86 and the final boiling point of ASTM D86 for all Fischer-Tropsch light oil, respectively. Note further that it does not exclude the presence of compounds or fractions having a true boiling temperature.

  Fischer-Tropsch derived gas oil feed preferably is 330 to 450 ° C., more preferably 331 to 370 ° C., even more preferably 332 to 365 ° C., 333 to 351 ° C., even more preferably under atmospheric conditions, It has a final boiling point of 336 to 348 ° C and even more preferably 339 to 345 ° C. Boiling point under atmospheric conditions means atmospheric boiling point, which is determined by ASTM D86.

  Fischer-Tropsch derived light oil, also called Fischer-Tropsch full range gas oil, has an alkyl chain length in the range of 7 to 30 carbon atoms, and includes paraffins including isoparaffins and linear paraffins, preferably 9 carbon atoms A Fischer-Tropsch derived gas oil is preferably composed of a Fischer-Tropsch derived paraffin having 7 to 30 carbon atoms relative to the total amount of Fischer-Tropsch derived paraffin. Preferably, at least 70 wt%, more preferably at least 85 wt%, more preferably at least 90 wt%, more preferably at least 95 wt%, even more preferably at least 98 wt%, relative to the amount. Has 9 to 25 carbon atoms Fischer - including paraffin Tropsch derived.

Additionally, Fischer - gas oil Tropsch derived, preferably, 774kg / ^{m 3} from 782kg / ^{m 3,} more preferably, 775 kg / ^{m 3} from 780 kg / ^{m 3,} even more preferably, 779kg / m from 776kg / ^{m 3 3} has a density at 15 ° C. as described in ASTM D4052.

  Suitably the Fischer-Tropsch derived diesel oil has a kinetic viscosity at 40 ° C. as described in ASTM D445 of 2.3 to 3.0 cSt, preferably 2.5 cSt to 2.9 cSt.

  Further, the pour point of Fischer-Tropsch derived light oil (as described in ASTM D97) is preferably less than −10 ° C., more preferably less than −15 ° C., more preferably less than −17 ° C., more preferably Less than −20 ° C., more preferably less than −22 ° C., even more preferably less than −27 ° C., and preferably more than −40 ° C.

  Suitably, the cloud point (as described in ASTM D2500) of light oil from Fischer-Tropsch is preferably less than −10 ° C., more preferably less than −15 ° C., more preferably less than −18 ° C., more preferably Is less than −20 ° C., more preferably less than −22 ° C., and most preferably less than −27 ° C., and preferably more than −40 ° C.

  Preferably, the flash point of Fischer-Tropsch derived gas oil as described in ASTM D93 is at least 60 ° C, more preferably 70 ° C, even more preferably at least 80 ° C, and even more preferably at least 85 ° C. .

  Fischer-Tropsch derived light oil has a smoke point as described in ASTM D1322 of greater than 50 mm.

Usually, the gas oil derived from Fischer-Tropsch supplied as a raw material to the method according to the present invention is:
From 0 to 300 ppm by weight, more preferably from 0 to 200 ppm by weight, even more preferably from 0 to 100 ppm by weight, even more preferably from 0 to 50 ppm by weight, based on the weight of light oil derived from Fischer-Tropsch, Most preferably, the aromatic compound is in the range of 0 to 25 ppm by weight,
An oxygenate in the range of 0 to 3 ppm by weight, more preferably 0 to 1 ppm by weight, calculated on the basis of the weight of elemental oxygen in the oxygenate and the weight of light oil from Fischer-Tropsch,
0 to 3 ppm by weight, more preferably 0 to 1 ppm by weight, even more preferably calculated based on the weight of elemental sulfur in the sulfur-containing hydrocarbon-based compound and the weight of light oil derived from Fischer-Tropsch, Sulfur-containing hydrocarbon compounds in the range of 0 to 0.2 ppm by weight;
A nitrogen-containing hydrocarbon compound in the range of 0 to 1 ppm by weight calculated on the basis of the weight of elemental nitrogen in the nitrogen-containing hydrocarbon compound and the weight of Fischer-Tropsch-derived light oil, and / or Fischer- A naphthenic compound in the range of 0 to 2% by weight with respect to the weight of light oil derived from Tropsch, and at least one of an aromatic compound, an oxygen-containing compound, a sulfur-containing hydrocarbon compound, and a nitrogen-containing hydrocarbon compound Is contained in a Fischer-Tropsch derived gas oil feed, i.e. at least one of the above concentrations is not zero. Specifically, at least one of aromatics and oxygenates is included in a Fischer-Tropsch derived gas oil feedstock, ie, at least one of the above aromatic and oxygenates concentrations is not zero .

Preferably, the Fischer-Tropsch derived gas oil supplied as a feed to the process according to the invention is
From 0 to 300 ppm by weight, more preferably from 0 to 200 ppm by weight, even more preferably from 0 to 100 ppm by weight, even more preferably from 0 to 50 ppm by weight, based on the weight of light oil derived from Fischer-Tropsch, Most preferably, the aromatic compound is in the range of 0 to 25 ppm by weight,
An oxygenate in the range of 0 to 3 ppm by weight, more preferably 0 to 1 ppm by weight, calculated on the basis of the weight of elemental oxygen in the oxygenate and the weight of light oil from Fischer-Tropsch,
0 to 3 ppm by weight, more preferably 0 to 1 ppm by weight, even more preferably calculated based on the weight of elemental sulfur in the sulfur-containing hydrocarbon-based compound and the weight of light oil derived from Fischer-Tropsch, Sulfur-containing hydrocarbon compounds in the range of 0 to 0.2 ppm by weight;
A nitrogen-containing hydrocarbon compound in the range of 0 to 1 ppm by weight calculated on the basis of the weight of elemental nitrogen in the nitrogen-containing hydrocarbon compound and the weight of light oil derived from Fischer-Tropsch, and derived from Fischer-Tropsch A naphthenic compound in the range of 0 to 2% by weight based on the weight of the diesel oil, and at least one of an aromatic compound, an oxygen-containing compound, a sulfur-containing hydrocarbon compound and a nitrogen-containing hydrocarbon compound is -Contained in a light oil feedstock derived from Tropsch, i.e. at least one of the above concentrations is not zero. Specifically, at least one of aromatics and oxygenates is included in a Fischer-Tropsch derived gas oil feedstock, ie, at least one of the above aromatic and oxygenates concentrations is not zero . In the above, the concentration of oxygen-containing compounds, sulfur-containing hydrocarbon compounds and nitrogen-containing hydrocarbon compounds is determined on the basis of the weight of oxygen, sulfur and nitrogen present in the gas oil, and the complete concentration including these oxygen, sulfur and nitrogen atoms is determined. Reference is made to elemental oxygen, elemental sulfur and elemental nitrogen to show that they are not determined on the basis of the weight of a particular molecule.

  Furthermore, the Fischer-Tropsch derived light oil is preferably less than 300 ppm by weight polycyclic aromatic hydrocarbon, more preferably less than 25 ppm by weight, based on the weight of Fischer-Tropsch derived gas oil. It contains aromatic hydrocarbons, most preferably less than 1 ppm by weight of polycyclic aromatic hydrocarbons. Further, Fischer-Tropsch derived light oil contains n-paraffins and can contain cyclic alkanes.

  In step (b) of the method according to the invention, the Fischer-Tropsch derived gas oil feedstock is more than one Fischer-Tropsch gas oil fraction, preferably more than two Fischer-Tropsch gas oil fractions, more preferably It is fractionated into four or more Fischer-Tropsch gas oil fractions. In particular, the at least one Fischer-Tropsch gas oil fraction, in particular the pollutant-enriched Fischer-Tropsch gas oil fraction obtained in step (b), has a stronger odor than a Fischer-Tropsch derived gas oil feedstock. There is a case.

  Preferably, at least one of step (b), or Fischer-Tropsch gas oil fraction obtained ultimately in (d) if a Fischer-Tropsch gas oil fraction is fed to step (c), It has a final boiling point of 260 ° C. or lower, preferably 250 ° C. or lower, more preferably 215 ° C. or lower. Preferably, the at least one Fischer-Tropsch gas oil fraction is (1) a Fischer-Tropsch gas oil fraction having a final boiling point of 180 ° C. or less, preferably 170 ° C. or less, (2) at least 160 ° C., preferably at least Fischer-Tropsch gas oil fraction having an initial boiling point of 170 ° C. and a final boiling point of 190 ° C. or less, preferably 190 ° C. or less, (3) at least 180 ° C., preferably at least 190 ° C. initial boiling point and 225 ° C. or less, preferably A Fischer-Tropsch gas oil fraction having a final boiling point of 215 ° C. or lower, and (4) an initial boiling point of at least 205 ° C., preferably at least 215 ° C. and a final boiling point of 260 ° C. or lower, preferably 250 ° C. or lower. Selected from the group consisting of Fischer-Tropsch gas oil fractions Fischer is - a Tropsch gas oil fraction, boiling point, is determined using ASTM D86, measured under atmospheric conditions.

  In particular, at least one of step (b) or, if the Fischer-Tropsch gas oil fraction is fed to step (c), ultimately the Fischer-Tropsch gas oil fraction obtained in (d) is (1) a Fischer-Tropsch gas oil fraction having a final boiling point of 180 ° C. or lower, preferably 170 ° C. or lower, (2) an initial boiling point of at least 160 ° C., preferably at least 170 ° C. and 200 ° C. or lower, preferably Fischer-Tropsch gas oil fraction having a final boiling point of 190 ° C. or lower, and (3) Fischer having an initial boiling point of at least 180 ° C., preferably at least 190 ° C. and a final boiling point of 225 ° C. or lower, preferably 215 ° C. or lower. A Fischer-Tropsch gas oil fraction selected from the group consisting of Tropsch gas oil fractions. Well, boiling point, it is determined using ASTM D86, measured under atmospheric conditions.

  More particularly, at least one of step (b) or, if the Fischer-Tropsch gas oil fraction is fed to step (c), ultimately the Fischer-Tropsch gas oil fraction obtained in (d). (2) a Fischer-Tropsch gas oil fraction having an initial boiling point of at least 160 ° C., preferably at least 170 ° C. and a final boiling point of 200 ° C. or less, preferably 190 ° C. or less, (3) at least 180 ° C., preferably A Fischer-Tropsch gas oil fraction selected from the group consisting of a Fischer-Tropsch gas oil fraction having an initial boiling point of at least 190 ° C. and a final boiling point of 225 ° C. or less, preferably 215 ° C. or less, wherein the boiling point is ASTM Determined using D86 and measured under atmospheric conditions.

  Such Fischer-Tropsch gas oil fractions obtained in step (b), preferably having a lower final boiling point of 260 ° C. or less, are particularly prone to have undesirable odor characteristics, and therefore are free of contaminants that cause undesirable odors. It has been found that the absorption process in step (c) for removal is beneficial.

  Preferably, at least one of the above fractions obtained in step (b) is fed to step (c) as a contaminant enriched Fischer-Tropsch gas oil fraction.

  At least one of the Fischer-Tropsch gas oil fractions obtained in step (b), in particular the contaminant-enriched Fischer-Tropsch gas oil fraction, has a Saybolt number lower than that of the Fischer-Tropsch derived gas oil feedstock. May indicate the resulting color.

  The high purity Fischer-Tropsch gas oil fraction recovered in step (d) as the refined Fischer-Tropsch gas oil fraction is enriched in contaminants supplied to step (c) to prepare the refined Fischer-Tropsch gas oil fraction. Has the same boiling range as the modified Fischer-Tropsch gas oil fraction.

  Preferably, at least one of step (b), or Fischer-Tropsch gas oil fraction obtained ultimately in (d) if a Fischer-Tropsch gas oil fraction is fed to step (c), It has an initial boiling point of greater than 260 ° C, preferably at least 300 ° C, more preferably at least 310 ° C. Preferably, the at least one Fischer-Tropsch gas oil fraction is (1) a Fischer-Tropsch gas oil having an initial boiling point of greater than 260 ° C, preferably at least 270 ° C and a final boiling point of 320 ° C or less, preferably 310 ° C or less. A fraction, (2) a Fischer-Tropsch gas oil fraction selected from the group consisting of a Fischer-Tropsch gas oil fraction having an initial boiling point of at least 310 ° C, preferably at least 330 ° C, more preferably at least 360 ° C; Boiling points are determined using ASTM D86 and measured under atmospheric conditions.

  In particular, at least one of step (b) or, if the Fischer-Tropsch gas oil fraction is fed to step (c), ultimately the Fischer-Tropsch gas oil fraction obtained in (d) is A Fischer-Tropsch gas oil fraction having an initial boiling point of at least 310 ° C., preferably at least 330 ° C., more preferably at least 360 ° C., the boiling point being determined using ASTM D86 and under atmospheric conditions Measured in

  The Fischer-Tropsch gas oil fraction obtained in step (b) and having an initial boiling point above 260 ° C. is particularly prone to discoloration, ie has a lower Savort number than a Fischer-Tropsch derived gas oil feedstock. Was found to have a Saybolt number of less than 30. Even more particularly, the pollutant-enriched Fischer-Tropsch gas oil fraction obtained in step (b) has an initial boiling point above 330 ° C., in particular above 360 ° C., and obtained in step (b) is , Less than 28, more specifically less than 27, and more particularly less than 25.

  Preferably, at least one of the above fractions obtained in step (b) is fed to step (c) as a contaminant enriched Fischer-Tropsch gas oil fraction.

  The high purity Fischer-Tropsch gas oil fraction recovered in step (d) as the refined Fischer-Tropsch gas oil fraction is enriched in contaminants supplied to step (c) to prepare the refined Fischer-Tropsch gas oil fraction. Has the same boiling range as the modified Fischer-Tropsch gas oil fraction.

  Preferably, at least one of the Fischer-Tropsch gas oil fraction obtained in step (b) or the refined Fischer-Tropsch gas oil fraction recovered in step (d) as a high purity Fischer-Tropsch gas oil fraction is 2 To an i / n ratio in the range of 6. Preferably, the majority of the Fischer-Tropsch gas oil fraction obtained in step (b) or (d), ie more than half, has an i / n ratio in the range of 2-6. A high i / n ratio may advantageously have an effect on the viscosity of the Fischer-Tropsch gas oil fraction, among other things. Increasing the relative concentration of isoparaffin may lower the overall viscosity of the Fischer-Tropsch gas oil fraction. By fractionating a Fischer-Tropsch derived light oil feedstock, a fraction having an improved i / n ratio can be obtained depending on the particular anticipated application.

  Preferably, at least one of the Fischer-Tropsch gas oil fractions obtained in step (b) or (d) is from 30 to 75% by weight, based on the total weight of isoparaffin in the Fischer-Tropsch gas oil fraction, Preferably, it contains monomethyl branched isoparaffin in the range of 35 to 70% by weight, more preferably 35 to 60% by weight.

  Preferably, the majority of the Fischer-Tropsch gas oil fraction obtained in step (b) or (d), ie more than half, is 30 to 75% by weight, based on the total weight of isoparaffin in the Fischer-Tropsch gas oil fraction. In the range of monomethyl branched isoparaffins. Preferably, at least one of the Fischer-Tropsch gas oil fraction obtained in step (b) or (d) is a higher weight percent monomethyl branch relative to the total weight of isoparaffin than the Fischer-Tropsch derived gas oil feedstock. Contains isoparaffin. More preferably, at least two, even more preferably three, of the Fischer-Tropsch gas oil fraction obtained in step (b) or (d) is based on the total weight of isoparaffins from the Fischer-Tropsch derived gas oil feedstock. Higher weight percent monomethyl branched isoparaffin.

  Monomethyl branched isoparaffins exhibit desirable biodegradability properties relative to other isoparaffins. A relatively high concentration of monomethylisoparaffin relative to other isoparaffins may advantageously be effective, inter alia, for the biodegradation properties of the Fischer-Tropsch gas oil fraction. By increasing the relative concentration of monomethylisoparaffin relative to other isoparaffins, the biodegradability characteristics of the Fischer-Tropsch gas oil fraction can be improved over the biodegradation characteristics of the Fischer-Tropsch derived gas oil feedstock.

In a further aspect, the present invention is a second method for preparing a refined Fischer-Tropsch gas oil fraction comprising:
i) A pollutant-containing Fischer-Tropsch gas oil fraction having a final boiling point of 260 ° C. or less, fed to an absorption zone containing at least one absorbent material, and the pollutant-containing Fischer-Tropsch gas oil fraction as an absorbent material Contacting and absorbing at least some of the contaminants;
ii) providing a process comprising the step of recovering a refined Fischer-Tropsch gas oil fraction from absorptive zone as a high-purity Fischer-Tropsch gas oil fraction as a high-purity Fischer-Tropsch gas oil fraction, wherein the pollutant-containing Fischer-Tropsch gas oil fraction is depleted in contaminants. To do.

  The limiting features described herein above for the first method according to the invention apply mutatis mutandis to the second method according to the invention. The limiting features described hereinabove for the contaminant-enriched Fischer-Tropsch gas oil fraction of the first method according to the present invention are the same as those described above for the contaminant-containing Fischer of the second method according to the present invention. -The same applies to the Tropsch gas oil fraction.

  The limiting features described herein above for each step (c) and (d) of the first method according to the present invention are the same as the step (i) of the second method according to the present invention. , (Ii) also applies mutatis mutandis.

  Preferably, in the second method according to the invention, the pollutant is selected from the group consisting of oxygenated compounds and aromatic compounds.

  Preferably, in the second method according to the invention, the absorbent material is a molecular sieve material, preferably zeolite X, zeolite 13X, zeolite Y, dealuminated zeolite Y, ultrastable Y, ZSM- 12, mordenite, zeolite beta, zeolite L, zeolite omega, preferably zeolite 13X.

  Preferably, in the second method according to the invention, the pollutant-containing Fischer-Tropsch derived gas oil is contacted with the absorbent material at a temperature in the range of 0 to 150 ° C.

  Preferably, in the second method according to the invention, the contaminant-containing Fischer-Tropsch gas oil fraction is contacted with the absorbent material in a fixed bed reactor comprising at least one fixed bed of absorbent material.

  The present invention also provides the use of the refined Fischer-Tropsch gas oil fraction obtained in the second method as a solvent, diluent or functional fluid.

In a still further aspect, the present invention is a third method for preparing a refined Fischer-Tropsch gas oil fraction comprising:
v) supplying a pollutant-containing Fischer-Tropsch gas oil fraction having a final boiling point above 260 ° C. to an absorption zone comprising at least one absorbent material and contacting the pollutant-containing Fischer-Tropsch gas oil fraction with the absorbent material Absorbing at least a portion of the contaminants, and vv) a refined Fischer-Tropsch gas oil fraction in which the contaminants are drastically reduced relative to the contaminant-containing Fischer-Tropsch gas oil fraction, a high purity Fischer-Tropsch gas oil fraction. As a method comprising the step of recovering from the absorption zone.

  The limiting features described herein above for the first method according to the invention apply mutatis mutandis to the third method according to the invention. The limiting features described hereinabove for the contaminant-enriched Fischer-Tropsch gas oil fraction of the first method according to the present invention are the same as those described above for the contaminant-containing Fischer of the third method according to the present invention. -The same applies to the Tropsch gas oil fraction.

  The limiting features described herein above for each step (c) and (d) of the first method according to the present invention are the same as the step (v) of the third method according to the present invention. , (Vv) also applies mutatis mutandis.

  Preferably, in the third method according to the present invention, the contaminant is selected from the group consisting of oxygenated compounds and aromatic compounds.

  Preferably, in the third method according to the invention, the absorbent material is a molecular sieve material, preferably zeolite X, zeolite 13X, zeolite Y, dealuminated zeolite Y, ultrastable Y, ZSM- 12, mordenite, zeolite beta, zeolite L, zeolite omega, preferably zeolite 13X.

  Preferably, in the third method according to the invention, the contaminant-containing Fischer-Tropsch gas oil fraction is contacted with the absorbent material at a temperature in the range of 0 to 150 ° C.

  Preferably, in the third method according to the invention, the pollutant-containing Fischer-Tropsch gas oil fraction is contacted with the absorbent material in a fixed bed reactor comprising at least one fixed bed of absorbent material.

  The present invention also provides the use of the refined Fischer-Tropsch gas oil fraction obtained in the third method as a solvent, diluent or functional fluid.

  The invention is further illustrated by the following non-limiting examples.

[Example 1]
By distillation, a Fischer-Tropsch derived gas oil having a boiling range of 185 to 350 ° C. as determined by ASTM D86 was fractionated into 7 fractions. The characteristics of the prepared Fischer-Tropsch gas oil fraction are shown in Table 1. Aromatic compound content was determined by UV absorption spectroscopy. The ratio of isoparaffin to linear paraffin and the concentration of monomethyl branched isoparaffin were determined using gas chromatography.

Odor test procedure:
The odor of the Fischer-Tropsch derived gas oil feed and the resulting contaminant-enriched and purified fractions were determined by a panel of 4 members using the following procedure:
(1) Prepare 30 mL of sample and store it in a 60 mL glass bottle with a screw lid.
(2) Remove the lid and immediately expose the panel member to the odor of the sample to record the odor characteristics of the sample,
(3) The lid was replaced immediately after the panel member was exposed to the odor of the sample.
The following conditions were observed during the odor test:
(A) All panel members must perform the test on the same day within 4 hours.
(B) Each panel member shall conduct an odor test and evaluate all samples in the same room at the same time.

  Immediately after exposure to individual samples, panel members submitted odor grades with 5 being a bad odor and 1 being a good odor. The reported odor quality is based on the majority of votes cast by panel members.

  The feed gas oil has a relatively low odor and a relatively low aromatic content.

  As can be seen from Table 1, aromatics accumulate in the lighter fraction during fractionation. In addition, the odor is most prominent in the lower boiling fraction, ie strong and different from the raw material.

[Example 2]
Three Fischer-Tropsch gas oil fraction samples, ie representative samples GS160, GS170 and GS190 from Example 1, were in contact with the absorbent material in the absorption zone. Each Fischer-Tropsch gas oil fraction was contacted separately with fresh absorbent material. The Fischer-Tropsch gas oil fraction sample was first contacted with the Mg silicate absorbent material followed by the zeolite 13X absorbent material. The volume ratio of the Fischer-Tropsch gas oil fraction to the absorbent material was 82 for zeolite 13X and 210 for Mg silicate. The Fischer-Tropsch gas oil fraction was in contact with the absorbent material under atmospheric pressure and atmospheric temperature. The properties of the refined Fischer-Tropsch gas oil fraction are shown in Table 2.

  As can be seen from Table 2, Mg silicate does not significantly remove aromatics from the pollutant enriched Fischer-Tropsch gas oil fraction. However, odor improvement is observed. This is due to the absorption of other pollutants, in particular oxygenates. Zeolite 13X certainly absorbs a significant portion of the aromatic compound and further improvement in odor is observed.

[Example 3]
A Fischer-Tropsch gas oil fraction sample, ie representative sample GS270 from Example 1, was in contact with the zeolite 13X absorbent material in the absorption zone. The properties of the refined Fischer-Tropsch gas oil fraction are shown in Table 3. As can be seen in Table 3, both the color and odor characteristics of the Fischer-Tropsch gas oil fraction sample were significantly improved after contacting the contaminant-enriched fraction with the absorbent material according to the present invention.

Claims (15)

A method for preparing a refined Fischer-Tropsch gas oil fraction comprising:
a) supplying a Fischer-Tropsch derived gas oil feedstock containing one or more pollutants, the Fischer-Tropsch derived gas oil having 9 to 25 carbon atoms relative to the total amount of Fischer-Tropsch derived paraffin A fluid comprising paraffins, including isoparaffins and linear paraffins having an alkyl chain length ranging from 7 to 30 carbon atoms, comprising at least 70% by weight of Fischer-Tropsch derived paraffins;
b) supplying a Fischer-Tropsch derived gas oil feed to a fractionation zone and fractionating the Fischer-Tropsch derived gas oil feed into two or more Fischer-Tropsch gas oil fractions having different boiling ranges, wherein at least 1 One Fischer-Tropsch gas oil fraction is a pollutant-enriched Fischer-Tropsch gas oil fraction in which one or more pollutants are enriched to the feedstock,
c) supplying a pollutant enriched Fischer-Tropsch gas oil fraction to an absorption zone comprising at least one absorbent material and contacting the pollutant enriched Fischer-Tropsch gas oil fraction with the absorbent material to at least one of the pollutants; And d) recovering the refined Fischer-Tropsch gas oil fraction from the absorption zone, the refined Fischer-Tropsch gas oil fraction being a contaminant against the pollutant-enriched Fischer-Tropsch gas oil fraction. Including a step in which there is a drastic reduction.   The method of claim 1, wherein the one or more contaminants are selected from the group consisting of oxygenates and aromatics.   At least one absorbent material is a molecular sieve material, preferably zeolite X, zeolite 13X, zeolite Y, dealuminated zeolite Y, ultrastable Y, ZSM-12, mordenite, zeolite beta, zeolite L, 3. A process according to claim 1 or 2, wherein the zeolite is omega, preferably zeolite 13X.   4. A method according to any one of claims 1 to 3, wherein the absorption zone comprises two or more absorbent materials, preferably at least zeolite 13X and magnesium silicate.   The process according to any one of claims 1 to 4, wherein the pollutant enriched Fischer-Tropsch gas oil fraction is contacted with the absorbent material at a temperature in the range of 0 to 150 ° C.   6. A process according to any one of the preceding claims, wherein the pollutant enriched Fischer-Tropsch gas oil fraction is contacted with an absorbent material in a fixed bed reactor comprising at least one fixed bed of absorbent material.   The process according to any one of claims 1 to 6, wherein the pollutant enriched Fischer-Tropsch gas oil fraction has a final boiling point of 260 ° C or lower.   7. A process according to any one of the preceding claims, wherein the pollutant enriched Fischer-Tropsch gas oil fraction has an initial boiling point greater than 260C.   9. A process according to any one of the preceding claims, wherein the pollutant enriched Fischer-Tropsch gas oil fraction has a Saybolt number of less than 30.   The process according to any one of claims 1 to 9, wherein the Fischer-Tropsch derived gas oil has a final boiling point of 450 ° C or less.   Use of the refined Fischer-Tropsch gas oil fraction obtained by the method according to any one of claims 1 to 10 as a solvent, diluent or functional fluid. A method for preparing a refined Fischer-Tropsch gas oil fraction comprising:
i) A Fischer-Tropsch gas oil fraction having a final boiling point of 260 ° C. or less, wherein the pollutant-containing Fischer-Tropsch gas oil fraction containing more than 50% by weight of isoparaffin is placed in an absorption zone comprising at least one absorbent material. Supplying and contacting the contaminant-containing Fischer-Tropsch gas oil fraction with the absorbent material to absorb at least a portion of the contaminant, and ii) depleting contaminants relative to the contaminant-containing Fischer-Tropsch gas oil fraction. Recovering the refined Fischer-Tropsch gas oil fraction from the absorption zone.   Use of the refined Fischer-Tropsch gas oil fraction obtained by the method according to claim 12 as solvent, diluent or functional fluid. A method for preparing a refined Fischer-Tropsch gas oil fraction comprising:
v) supplying a contaminant-containing Fischer-Tropsch gas oil fraction having an initial boiling point above 260 ° C. to an absorption zone comprising at least one absorbent material, and contacting the contaminant-containing Fischer-Tropsch gas oil fraction with the absorbent material. Absorbing at least a portion of the contaminants, and vv) recovering from the absorption zone a refined Fischer-Tropsch gas oil fraction that is depleted in contaminants relative to the contaminant-containing Fischer-Tropsch gas oil fraction. ,Method.   Use of the refined Fischer-Tropsch gas oil fraction obtained by the method according to claim 14 as solvent, diluent or functional fluid.