Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G25/00—Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents
  • C10G25/003—Specific sorbent material, not covered by C10G25/02 or C10G25/03

Definitions

• the invention relates to the use of porous inorganic moldings which have been treated and / or loaded with acid for removing basic nitrogen compounds, in particular ammonia or basic nitrogen-hydrocarbon compounds, from mixtures containing ammonia and / or hydrocarbons.
• ion exchanged resins in the H form are used in the refineries as adsorbents for removing nitrogenous basic compounds, such as pyridine, from xylene, lubricating oils or petroleum distillates, which are said to have a much higher adsorption capacity than clays.
• these resins have to be regenerated periodically with hydrochloric acid, which often brings with it a poisoning problem for downstream catalysts or a plant-specific corrosion problem. (Yan, TY; Shu, P., Ind. Eng. Chem. Res., 1987, 26, pp. 753-755).
• DE-A-41 40 455 discloses abrasion-resistant and porous composite moldings which contain an inorganic, highly porous filler material (e.g. Y zeolite in the H form) and a matrix material consisting essentially of carbon.
• the moldings are used as adsorbents for benzene vapors.
• EP-A-0 278 694 discloses a process for removing basic nitrogen compounds from extracted oils using acidic polar adsorbents and for regenerating the adsorbents.
• H-Y zeolites are used as adsorbents, about whose degree of acid loading nothing has been said.
• JP-A-59 206486 discloses the removal of nitrogen-containing impurities from hydrocarbons, the oil containing the impurities being hydrogenated and the impurities subsequently being extracted with acid.
• the oil can also be treated with an acidic adsorbent, but the nature of which has not been said.
• SU-A-652202 (Derwent-Abstracts, Ref. 79-88839B / 49) discloses the removal of nitrogen-containing compounds from petroleum products by adsorption on a sulfonic acid cationite in the H form and in the Sn form. None is said about the nature of the nitrogen-containing compounds.
• Adsorbents are generally used industrially as shaped articles, since these e.g. in fixed bed reactors in continuous processes over powders have the advantage that they oppose the currents to be treated with a lower flow resistance. This is technically incisively reflected in a lower pressure drop. In addition, attention should be paid to the lowest possible abrasion value of the moldings.
• the invention was based on the object of providing substances for removing ammonia or basic nitrogen-hydrocarbon compounds from mixtures containing ammonia and / or hydrocarbons which on the one hand have a large adsorption capacity and on the other hand show a high abrasion resistance under reaction conditions.
• the invention relates to the use of porous, inorganic moldings which have been treated and / or loaded with acid for removing basic nitrogen compounds, in particular ammonia or basic nitrogen-hydrocarbon compounds, from mixtures containing ammonia and / or hydrocarbons.
• the basic nitrogen-hydrocarbon compounds preferably contain about 1 to 20, in particular 1 to 12, carbon atoms.
• the moldings used can be referred to quite generally as "solid acids" and also include, for example, moldings made of non-porous carrier particles, in the intermediate grain volume of which acid is contained. Mixtures of inorganic carriers with solid acids such as heteropolyacids, boric acid or organic sulfonic acids are useful.
• the carbon content of the shaped bodies is generally less than 2% by weight, in particular less than 1% by weight.
• the moldings are preferably formed from porous substances, such as silicas, layered silicates, clays, zeolites, titanium dioxide, zirconium dioxide and mixtures thereof, which are loaded with liquid or solid acids.
• the acid can also be loaded by replacing the alkali ions with protons.
• Two-layer or three-layer silicates which are preferably acid-activated, are preferably used as starting materials for the acid-laden porous moldings.
• kaolin should be mentioned in particular.
• Three-layer silicates are, for example, montmorillonite, hectorite, beidellite, saponite, antigorite, vermicullite, etc.
• Other useful silicates are, for example, sepiolite and attapulgite.
• the layer silicates containing montmorillonite bentonite and the so-called "Fuller's Earth” are particularly worth mentioning. Since these minerals are of natural origin, their composition can vary.
• Starting materials for the silicas used according to the invention are amorphous chain, ring and branch-forming polysilicic acids.
• a special case for the amorphous silicas are the diatomaceous earths, which are water-containing silicon dioxide compounds that result from natural sediment deposits from diatoms. They consist of very varied, microscopic silica frameworks with many small grooves and channels, which therefore have good adsorption properties.
• organic or inorganic binders such as starch, cellulose derivatives, clays, hydraulic cements, etc. can be added.
• Acid activation of the silicates is not absolutely necessary if the starting material has already been subjected to an acid treatment or if it already has a high pore volume and an acid surface.
• the zeolites can be used in the H+ form without prior acid activation because they already have a relatively wide pore structure.
• the average pore diameter of zeolites of the ZSM5 type is about 0.5 nm, for faujasite about 1 nm. Mixtures of non-acid-treated starting materials and solid or liquid acids are also possible.
• catalyst supports based on acid-activated three-layer silicates can also be used as already acid-activated and shaped starting materials, e.g. the so-called KA carriers (commercial products from Süd-Chemie AG).
• KA carriers commercial products from Süd-Chemie AG.
• three-layer silicates are activated by treatment with acids, in particular with mineral acids, such as hydrochloric acid and sulfuric acid, filtered and washed usually free of salts and acids.
• the filter cake is shaped into shaped bodies by extrusion, granulation or pelletizing.
• the moldings are then treated thermally, as described below.
• the respective starting substance is reacted with any inorganic and / or organic acid, preferably a mineral acid, such as hydrochloric acid, sulfuric acid or phosphoric acid.
• the acid activation can also be carried out at elevated temperature and at reduced or elevated pressure. This generally involves an increase in the specific surface area, which in general also increases the adsorption capacity brings with it. In addition, there is an expansion of the lattice, which manifests itself in an increase in the pore volume and the average pore diameter.
• an additional chemical treatment for example silanizing the surface, can also be carried out.
• the moldings can be subjected to a thermal treatment before being loaded with acid.
• the thermal treatment includes drying, optionally vacuum drying or spray drying and / or calcination, which is preferably carried out at temperatures of about 200 to 600 ° C.
• the thermal treatment leads to a solidification of the expanded lattice structure and thus to an increase in the abrasion resistance.
• the thermal treatment can be carried out under oxidizing, reducing or inert conditions and in the presence of water vapor. Thermal treatment can also be carried out before acid activation.
• the pore volume of the shaped bodies is preferably approximately 0.1 to 2, in particular approximately 0.3 to 1 ml / g, the average pore radius approximately 0.2 to 6000 nm, in particular approximately 0.2 to 5500 nm.
• mercury is pressed under a pressure of 1 to 4000 bar onto the moldings not yet loaded with acid.
• the injected mercury volume based on the pore mass (ml / g) as the ordinate as a function of the pore radius as the abscissa (in logarithmic representation), gives the graphical representation of the pore size distribution.
• the gaps between the particles are included as pores if they are filled with mercury at a pressure of 1 bar. With this method, only pores down to a radius of about 2 nm (Macro and mesopores) recorded.
• the micropores formed by the channels of the zeolite lattice with pore radii of about 0.2 to 2, preferably 0.25 to 0.7 nm (intracrystalline pore radii) are also effective.
• the radii of these pores are generally determined by evaluating the X-ray diffraction spectra.
• the mesopores and macropores, which are formed by the intergranular interstices with pore radii of about 4 to 500, preferably about 5 to 300 nm, are effective in the zeolites. These are determined using the mercury intrusion method.
• the adsorptive effect of the micropores is negligible.
• These moldings preferably have an average pore radius of about 4 to 6000, in particular of about 5 to 5500 nm, which is also determined by the mercury intrusion method.
• the degree of acid loading depends on the pore volume. About 2% to about 95%, in particular about 5% to about 95%, of the pores should be loaded with acid; preferably they are about 20 to 80% acidic.
• Sulfuric acid is preferably used for the acid loading since it only boils at 338 ° C. There is therefore no danger that the equipment will corrode and the downstream catalysts will be inactivated.
• Phosphoric acid is also well suited because it is even less corrosive than sulfuric acid; however, the adsorption capacity of phosphoric acid for basic nitrogen-hydrocarbon compounds is somewhat lower than that of sulfuric acid.
• the adsorbents can also be loaded with organic sulfonic acids or other organic acids with higher boiling points.
• Hydrochloric acid is less suitable for loading because it evaporates easily and causes corrosion problems.
• hydrochloric acid vapors can inactivate the noble metal catalysts in the subsequent catalytic treatment of the purified hydrocarbons (cracking, reforming).
• the process steps for the production of the shaped bodies can be modified in such a way that a further acid activation is carried out after the acid activation and shaping. Acid activation can also be carried out after the thermal treatment if a further increase in the pore radius is desired. A further thermal treatment can follow the loading of the thermally treated moldings with acid, but this is not as intensive as the first thermal treatment, since evaporation of the acid should be avoided as far as possible.
• Shaping is generally done by agglomeration, e.g. by granulating, extruding, pelleting or tableting.
• the average agglomerate diameter of the shaped bodies is generally> 0.5 mm.
• the shaped bodies can be granules, spheres, extrudates, rings, cylinders, wire wheels, fancy shapes or honeycomb bodies.
• the finished moldings generally have an adsorption capacity of about 1 to 10% by weight (based on atomic nitrogen). This corresponds, based on the nitrogen-hydrocarbon compounds typically to be removed, to an adsorption capacity of approximately 3 to 50% by weight. These compounds generally have boiling points (at atmospheric pressure) of ⁇ 400 ° C.
• the processes for removing nitrogen-hydrocarbon compounds from hydrocarbon mixtures are preferred carried out continuously, but can also be carried out in batch mode, ie quasi-continuously.
• the composition and concentration of the adsorbed molecules, the pressure, the temperature and the space velocity are varied and adjusted in a suitable manner.
• adsorption processes take place either in a fixed bed or in a reactor with an agitator.
• adsorption can be carried out in cocurrent or in countercurrent.
• the moldings used according to the invention are advantageously used to remove basic nitrogen-hydrocarbon compounds from refinery streams, preferably from C2 to C20 streams, in particular from C3 to C12 streams, for. B. from LPG, naphtha, gasoline, kerosene, diesel, heating oil and gas oils used.
• the product and educt streams can be recycled via the adsorbent bed and diluted with gaseous and / or liquid substances under adsorption conditions.
• Paraffins, olefins, naphthenes and / or aromatics, and also hydrogen, inert gases and / or steam are generally used as dilution media.
• the moldings used according to the invention can be regenerated after use.
• the acid and the basic nitrogen-hydrocarbon compounds adsorbed therein can be removed by washing. Subsequently the acid-free moldings are dried and again loaded with acid.
• the moldings can also be regenerated by oxidation of the adsorbed basic nitrogen-hydrocarbon compounds. If the oxidation is carried out at elevated temperatures at which some of the acid is already evaporating, the evaporated acid is supplemented by impregnating the moldings with new acid.
• the calcined spheres are then mixed with 1000 liters of 20% hydrochloric acid and leached at 90 ° C. for 24 hours.
• the leached balls are then washed chloride-free with distilled water and dried at 200 ° C. for 10 hours.
• the calcined clay balls are placed in a suitable vessel in which there is a 50% sulfuric acid solution. The balls are completely saturated, then the excess sulfuric acid is allowed to drip off; the acid-impregnated balls are dried at 110 ° C. for 5 hours. Because of the evaporated water the degree of pore filling is about 40%.
• the granules are then placed on a pelletizing plate. Then the granules are sprayed with concentrated sulfuric acid. The impregnation is ended when the sulfuric acid absorption is 30% by weight. Pore filling degree: 73%.
• Diatomaceous earth is formed together with 100% phosphoric acid into extrusions with a diameter of 6 mm.
• the extrudates are heated at 400 ° C. for 10 minutes.
• the nominal composition of the adsorbent thus obtained is: SiO2 30 wt .-%; H3PO4 70 wt .-%.
• Pore volume of the loaded adsorbent 0.22 ml / g; average pore radius: 1300 nm.
• Nominal composition of the adsorbent SiO2 35 wt .-%; H3PO4 65 wt .-%.
• Example 3 The granules of acid-activated montmorillonite obtained according to Example 3 are loaded as in Example 3 with (a) 9 or (b) 35% by weight H3PO4. Pore filling degree: 16.5% (a), 90% (b).
• the balls of acid-activated montmorillonite obtained according to Example 1 are loaded with 30% by weight H3PO4 as in Example 5. Pore filling degree: 33%.
• the extrudates are cut to a length of 3 mm with a cutting device, dried at 100 ° C. and then calcined at 600 ° C. for 5 hours.
• Pore volume (after mercury porosimetry): 0.40 ml / g. Average pore radius: 170 nm.
• Micropore volume of the zeolite portion (x-ray): 0.53 ml / ml; Pore radius: 0.35 nm.
• 1000 g of the extrudates obtained are immersed in 1300 ml of sulfuric acid with a concentration of 1346 g H2SO4 / liter for 30 min at room temperature.
• the extrudates are filtered through a suction filter and then dried at 100 ° C. Pore filling degree: 72%.
• Nominal composition of the adsorbent alpha-Al2O3 70 wt .-%; H2SO4 30 wt .-%.
• Nominal composition of the adsorbent TiO2 65 wt .-%; H2SO4 35 wt .-%.
• Nominal composition of the adsorbent SiO2 70 wt .-%; H2SO4 30 wt .-%. Pore filling degree: 33.5%.
• Nominal composition of the adsorbent ZrO2 80 wt .-%; H2SO4 20 wt .-%.
• adsorbents according to the examples given above were examined for their absorption capacity with regard to nitrogen-containing bases.
• Table I Adsorbent example no. MAXIMUM CAPACITY *) g pyridine / 100 g g N / 100 g 1 19.6 3.5 2nd 31.0 5.5 3rd 26.2 4.6 4th 14.3 2.5 5 12.1 2.1 6 (a) 6.4 1.1 6 (b) 12.1 2.1 7 12.1 2.1 8th 14.1 2.5 9 16.4 2.9 10th 18.6 3.3 11 13.0 2.3 12th 19.4 3.4 13 28.2 5.0 14 29.0 5.1 *) after 24 hours
• Example 2 The adsorbent of Example 2 is examined for its absorption capacity with regard to nitrogen-containing bases at different temperatures.
• Example 2 The adsorbent of Example 2 is examined for its absorption capacity with regard to nitrogenous bases when using different feed streams.
• Feed 1 100 g hexadecane 5 g pyridine
• Feed 2 100 g hexadecane 5 g pyridine 2
• witch-1 Feed 3
• H2O Feed 4
• Table III Feed no. TURNOVER PYRIDINE * (%) MAX.
• Example 2 The absorbent of Example 2 is examined for its absorption capacity with regard to nitrogen-containing bases in the flow-through reactor at different temperatures and different feed streams.
• the nitrogen is heated to the desired temperature (50 ° C or 100 ° C).
• the feed is pumped over the adsorber bed.
• analysis is carried out for pyridine breakthrough by gas chromatography, and the runtime or the absorption capacity until the breakthrough is determined.
• Example 2 The adsorbent of Example 2 is examined for its absorption capacity with regard to nitrogen-containing bases in the presence of thiophene in a flow reactor with different feed streams.
• the nitrogen is heated to the desired temperature of 50 ° C.
• the feed is pumped over the adsorber bed.
• the runtime or the absorption capacity until the breakthrough is determined.
• the thiophene conversion is 0%.
• Example 2 The adsorbent of Example 2 is examined for its absorption capacity with regard to nitrogen-containing bases in the presence of thiophene in a flow reactor in a long-term test under pressure.
• the mixture is heated to the desired temperature of 100 ° C. in a stream of hydrogen.
• the feed is pumped over the adsorber bed.
• analysis is carried out for pyridine breakthrough by gas chromatography.
• a conversion of pyridine of 100% is achieved over the test period of 153 hours.

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
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• Organic Chemistry (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)

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• 1994
  • 1994-08-20 DE DE4429643A patent/DE4429643A1/de not_active Withdrawn
• 1995
  • 1995-08-12 EP EP95112751A patent/EP0697454B1/fr not_active Expired - Lifetime
  • 1995-08-12 ES ES95112751T patent/ES2147249T3/es not_active Expired - Lifetime
  • 1995-08-12 DE DE59508247T patent/DE59508247D1/de not_active Expired - Fee Related

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