JPH03277693A - Removal of trace amount of chlorine from hydrocarbon-based oil - Google Patents

Abstract

PURPOSE:To remove selectively and effectively trace amounts of chlorine (compounds) from chlorine (compounds)-containing hydrocarbon-based oil over a long period of time without adversely affecting the subsequent steps by bringing the oil into contact with alumina under heating in the presence of hydrogen. CONSTITUTION:Hydrocarbon-based oil containing 1-1,000ppm chlorine (compounds) is brought into contact with a catalyst at 100-400 deg.C under a pressure of 5-50kg/cm<2>G, the catalyst comprising alumina having a surface area of 100m<2>/g or above and a pore volume of 0.1cc/g or above by use of 1.0ml/hr to 6l/hr hydrogen gas as carrier gas on a basis of 100ml/hr of the oil.

Description

[Detailed description of the invention] <Industrial application field> When hydrocarbon oil such as naphtha is cracked or reformed to produce useful components such as ethylene, propylene, benzene, etc., hydrocarbon oil If chlorine and/or chlorine compounds (hereinafter sometimes referred to as "chlorines") are present as impurities in the process, problems such as corrosion inside the process system and poisoning of catalysts and the like in subsequent steps will occur.

The present invention relates to a method for removing chlorine mixed in hydrocarbon oil, and in particular, it selectively and efficiently removes minute amounts of chlorine by contacting the rice hydrocarbon oil to be treated with a catalyst in the presence of hydrogen. Regarding how to remove.

<Conventional technology> There are many conventional technologies for removing trace amounts of chlorine, including technologies for removing chlorine from waste gas from the combustion of plastic waste and technologies for removing and reducing polychlorinated biphenyls (PCBs). Disclosed.

US Pat. No. 7,857,06 discloses a technique for collecting and removing hydrogen chloride by bringing a scavenger in which 0.5 to 45 wt % of an alkaline earth metal is supported on alumina into contact with a hydrogen chloride-containing gas.

US Pat. No. 6,846,44 discloses a technique for thermally decomposing solid organic waste at a temperature of 315 to 1100° C. and then coagulating and separating chlorine by cooling the thermally decomposed gas in multiple stages.

US Patent USP 326011 discloses a mixture of 110 wt% or more of ZnO, 5 wt% or more of a basic compound of calcium, and 5 wt% or more of an inert binder as an adsorbent for adsorbing hydrogen chloride at a temperature of 148.9-537.8°C. .

On the other hand, the following is disclosed as a method for removing chlorine compounds from hydrocarbon oil.

US Pat. No. 2,481,300 discloses a method for removing organic chlorides by contacting a catalyst comprising activated carbon with an alkali metal/alkaline earth metal and a hydrocarbon oil.

US Pat. No. 2,951,804 discloses a method for removing chlorine by contacting a hydrocarbon-based oil reforming feed with alumina impregnated with alkali metal hydroxide/alkaline earth metal hydroxide.

US Pat. No. 3,278,266 discloses a technique for removing chlorine compounds by contacting a hydrocarbon-based oil with a diacid base deposited on a porous carrier. Here, the diacid bases include Mg and Ca.

It is an oxide or hydroxide of Sr or Ba.

US Pat. No. 5,447,88 discloses a method of heating transformer oil containing polychlorinated biphenyls with an alkali in a sulfoxide solvent. The alkalis used are alkali metal alcoholades, mixtures of alkali metal hydroxides and alcohols.

US Patent No. 8,200,749 discloses a technique for extracting and separating chloride from a solution containing polychlorinated biphenyls using polyethylene glycol.

Canadian Patent CA-408116 discloses a method for removing organic halides from hydrocarbon-based oils using molten sodium particulates (80% particulates less than 10 μm) at 100-160°C.

Italian patent IT-22215 describes a decontamination technique in which a polyhalide-containing solution is brought into contact with a reaction bed consisting of a carbonate or bicarbonate of an alkaline earth metal salt on which a liquid film of polyethylene glycols has been adsorbed. Disclose.

West German patent DT-3621172 applies to hydrocarbon oil from 06 to
A technique for dehalogenation by treatment with an alkali metal alcoholade having a C25 alkyl group at 12.0 to 140 t is disclosed.

JP-A-52-6704 discloses a crude oil neutralizing agent containing monoisopropanolamine and diisopropanazine as active ingredients.

JP-A No. 49-39602 discloses that raw oil mixed with low-quality oil or plastic waste is heated and vaporized, reducing hydrogen is blown into it, sulfur is converted to hydrogen sulfide, chlorine is converted to hydrogen chloride, and then the mixture is heated and vaporized in caustic soda or the like. Discloses a method for removing sulfur and chlorine by passing an aqueous solution containing a Japanese additive.

<Problem to be solved by the invention> However, in order to remove chlorine from hydrocarbon oil, alkali metals/alkaline earth metals or metal salts thereof are supported on porous adsorbents such as alumina and activated carbon. Although some chlorine compounds are removed when using a chlorine adsorbent, the overall removal rate of chlorine is 0 to 15 wt%.
And it's not enough.

When using oxygen-containing compounds such as wood, polyethylene glycol, and alcoholado, nitrogen-containing compounds such as amines, or molten metal sodium, these processing agents may remain in trace amounts in the raw hydrocarbon oil and may be catalyzed in the subsequent process. There are problems such as it being a poisonous ingredient.

In the method of cooling pyrolysis gas in multiple stages and condensing and separating chlorine, the removal efficiency is poor when the concentration of chlorine contained is trace.

Therefore, there is a need for a method to selectively and efficiently remove trace amounts of chlorine contained in hydrocarbon oils such as naphtha oil and liquefied natural gas (NGL) without leaving any problems in subsequent processes. There is.

That is, an object of the present invention is to provide a method for selectively, long-term, and efficiently removing trace amounts of chlorine from hydrocarbon oil without leaving any adverse effects as impurities in subsequent processes.

Means for Solving the Problems> The present invention uses a solid-liquid contact method to remove chlorine from a liquid hydrocarbon oil using alumina or a metal or metal compound supported on a carrier (hereinafter referred to as these). (sometimes referred to as a catalyst) under heating conditions in the presence of hydrogen to remove chlorine from hydrocarbon oil.

The reaction mechanism by which chlorine is removed is unknown, but
It is thought that chlorine is hydrogenolyzed and becomes, for example, hydrogen chloride and hydrocarbons.

Furthermore, as will be described later, in the case of alumina, it is also possible to adsorb and remove chlorine.

As solid state catalysts it is also possible to use alumina, carrier-supported cobalt, nickel and/or molybdenum metals or metal compounds.

In addition, metals or metal compounds of platinum, palladium, rhodium and/or ruthenium supported on a carrier may also be used.

At least one carrier selected from the group consisting of alumina, silica-alumina, silica, diatomaceous earth, zeolite, activated carbon, and clay is used.

Heating conditions are 100 to 400°C, and hydrogen is equivalent to 100 g of hydrocarbon oil + [/h]
It is preferable to set it to 1.0 to 6 sf/hr for r.

Further, after the hydrocarbon oil is brought into contact with the catalyst under the above conditions, the removal effect is improved if the oil is brought into contact with a collection substance containing alumina and/or an alkaline earth metal salt.

Contact with the collection substance is preferably carried out at a temperature of 20 to 400°C.

The mechanism of action of the scavenger is not clear, but when it contains alumina, the main adsorption is hydrogen chloride, but when it contains alkaline earth metal salts, the main action is the adsorption of hydrogen chloride and the metal salt. Guessed.

The configuration of the present invention will be explained in detail below.

The hydrocarbon oil to which the method of the present invention is applied is not particularly limited as long as it is a hydrocarbon that can be handled as a liquid.

Hydrocarbon oils include crude oil, straight-run naphtha, kerosene, gas oil, vacuum distillate, atmospheric residual oil, pyrolysis gasoline produced as a by-product in the pyrolysis unit of an ethylene plant, and naphtha distillate produced in the catalytic cracker. Examples include oil and recycled oil.

Hydrocarbon oils are treated in a liquid state, but low-boiling components are treated under pressure, and even hydrocarbon compounds that are solid at room temperature must be heated and treated in a liquid state.

The chlorine contained in the hydrocarbon oil to be removed by the method of the present invention may be present in any form such as simple chlorine, hydrogen chloride, or an organic chlorine compound, or may be a mixture thereof.

The concentration of chlorine in hydrocarbon oil is not particularly limited, but is 1 to 11,000 pp, preferably 1 to 10
If it is 0 ppm, the removal efficiency is good.

If necessary, it is preferable to filter the sludge etc. in the hydrocarbon oil using a filter or the like in advance to remove chlorine which can be separated by filtration together with the sludge.

The catalyst to be used is preferably alumina alone, or a metal or metal compound of cobalt, nickel and/or molybdenum supported on a carrier. Among them, cobalt, nickel and molybdenum are preferred because they can maintain the chlorine removal rate for a long period of time. preferable.

Alumina as a catalyst has a surface area of 100 m'/g or more, preferably 200 m'/g or more, and a pore volume of 0.1
CC78 or higher is used.

Cobalt, nickel and/or molybdenum are preferably used in their elemental state, and when supported as oxides, nitrates, etc., they are used after being reduced in a hydrogen stream.

Furthermore, it can also be used in a reduced state in a hydrogen stream containing hydrogen sulfide.

These elements or compounds supported may be used alone or as a mixture. Cobalt as a mixture
Examples include molybdenum, nickel-molybdenum, and nickel-cobalt-molybdenum. The composition ratio of these mixtures can be freely selected.

As a carrier, alumina, silica-alumina, silica,
Diatomaceous earth, zeolite, activated carbon or clay are used.

Alumina is more preferred.

When alumina is used as a carrier, the specific surface area measured by the BET method is usually 150 to 600 m'/g, preferably 200 to 400 m'7g, and the pore volume is 01 to 0.9.
cc/g, preferably in the range of 0.2 to 0.8 cc/g.

The supported amount is preferably 0.05 to 35 wt% based on the total amount of catalyst.

An example of preparing a catalyst using alumina as a carrier is given below.

(1) Cobalt/Alumina Catalyst A carrier (alumina) is added to an aqueous solution of cobalt nitrate [Co (NO3) 2 .6H20], and after immersion for about 15 hours, the catalyst is collected. After drying the collected catalyst, it is calcined at 350° C. for 5 hours in the presence of air.

(2) Cohert-molybdenum/alumina catalyst cobalt nitrate [co (Nosl 2 ・6H20)* m liquid,
Sodium molybdate [Na2M0O4・2H201
An aqueous solution is added, and the resulting cobalt molybdate is washed with water and then dried. Alumina powder is added to dried cobalt molybdate and molded into granules. After molding, it is fired again at 350°C for 5 hours.

When used, it is reduced at 350 to 550'e under a hydrogen stream. To reduce hydrogen sulfide in a hydrogen stream,
After aerating a mixed gas of hydrogen and hydrogen sulfide in a ratio of 99.1:0.1 or more, preferably about 6=4, at 150 to 250°C for 2 to 10 hours, the temperature is roughly brought to 250 to 350°C, and 2 to 1
Ventilate for 0 hours.

(3) Nickel-molybdenum/alumina catalyst A carrier (alumina) is added to an aqueous solution of nickel nitrate [Ni (NO5h.6Hzo), immersed for about 15 hours, and then calcined at 350°C for 5 hours.Next, ammonium molybdate [(N
H4) 6MO7024] immersed in an aqueous solution for about 15 hours,
Bake at 00°C for 5 hours.

When used, it is used under (2) 41 above under a hydrogen stream or after being reduced with a mixed gas of hydrogen and hydrogen sulfide.

When creating a catalyst with a high loading rate, nickel oxide [NiO] or nickel nitrate and molybdenum oxide [Mo03F] are added to alumina powder and compression molded.

Further, as a catalyst, platinum, palladium, rhodium and/or ruthenium metal or metal compound supported on a carrier may be used.

These catalysts are used in the elemental state, and when supported with oxides, nitrates, etc., they are used after being reduced in a hydrogen stream.

The carriers used are the same as in the case of cobalt, nickel and/or molybdenum.

Examples of catalyst preparation include the following.

(4) Platinum/alumina catalyst hexachloroplatinic acid [After adding a carrier (alumina) to the H2PtCjit al aqueous solution and immersing it for about 15 hours,
Collect the catalyst.

Next, after drying the collected catalyst, it was heated to 450 ml in the presence of air.
Bake at ℃ for about 5 hours. In actual use, reduction is carried out at 350 to 550°C under a hydrogen stream.

The following conditions are used to cause a catalytic reaction with a liquid hydrocarbon oil using the above solid catalyst.

The temperature in the reaction tank where the catalyst and hydrocarbon oil come into contact is usually 100 to 400°C, preferably 150 to 300°C.
It is.

As for the heating method, the reaction tank may be heated, or the hydrocarbon oil to be treated may be heated in advance.

The pressure inside the reaction tank is 5Kg/cm'G ~ 50Kg/
ca+2G preferably 20g/cff+2G
~40Kg/ca2G.

The liquid hourly space velocity (L-H-3-V) in the reaction tank is usually 0.
．． 5-10 hr-', more preferably 1.0-5.0
Set to hr-'. Within this range, the removal rate of chlorine is high.

The hydrogen gas used may be hydrogen gas alone, or N, , He
It may also be a mixture with other carrier gases such as.

The amount of hydrogen used may be sufficient as long as the reaction is sufficiently carried out, but it is 1 Omj2/hr to 6j2/hr in terms of hydrogen gas per 100 s+J2/hr of hydrocarbon oil.
, preferably 90 ml! /hr ~311/hr.

For the contact reaction between the catalyst and the hydrocarbon oil in the method of the present invention, various solid-liquid contact systems can be used, such as a fixed bed system, a moving bed system, or a fluidized bed system.

After the contacting step with the catalyst, a further contact can be made with a scavenging material containing alumina and/or alkaline earth metal salts. The decomposition products of chlorine produced in the step of contacting with the catalyst are adsorbed to the collection material and efficiently removed by this step.

When alumina itself is used as a catalyst, or a cobalt, nickel and/or molybdenum or platinum metal catalyst using alumina as a carrier is used and brought into contact with a hydrocarbon oil,
Since the reaction step with the catalyst and the collection step with the collection material can be performed simultaneously, the subsequent collection step with the collection material is not necessary, and the process is simplified.

Alumina as a collection substance may have the properties of alumina as a carrier as described above.

Alkaline earth metal salts as scavenging substances include calcium,
Examples include magnesium oxides, carbonates, and mixtures thereof, and calcium oxides are particularly preferred.

The contact conditions with the collecting substance vary depending on the contact conditions with the catalyst in the previous step, and are not particularly limited, but include a temperature of 20 to 40℃.
0°C, more preferably 30-300°C, LH5V0.
5 to 10 hr-', more preferably 1 to 5 hr-'.

Preferably, the following reaction apparatus is used, but the present invention is not limited thereto.

FIG. 1 shows an example of an apparatus for removing chlorine from hydrocarbon oil, which has a fixed bed 5 containing a catalyst supported on a carrier and a reaction tank 2 heated by a heat source 10.

The reaction tank 2 is equipped with a raw material delivery line 4 for transporting the hydrocarbon oil as the raw material 1 via a pump 6, a heat exchanger 3, and a preheater 17, and a gas line 8 for introducing hydrogen gas 7. . The reaction tank 2 is maintained at a predetermined temperature by a heat source 10, and is provided with a take-out line 9 for removing hydrocarbon oil from which chlorine has been removed. It communicates with a product line 12 that takes out the system oil as a product, and a part of it is connected to a gas-liquid separation tank 15.

The heat exchanger 13 is cooled by cooling water 14.

The gas-liquid portion 111ai15 includes a gas separation line 11 that separates and discharges hydrogen gas from the reaction product introduced by the product line 12, and the gas separation line 11 is connected to the gas line 8 via a compressor 16. Also,
The gas-liquid component M4W15 includes a product line 12 for extracting hydrocarbon oil from the reaction product introduced by the product line 12.
2 is provided.

The product lines 12 and 122 are equipped with a collection tank 20 as necessary.
will be communicated to. The collection unit 4!20 has a fixed bed 50 containing a collection substance, and further performs a collection process on the hydrocarbon oil treated in the reaction tank 2 using the collection substance.

<Example> The present invention will be specifically explained below using examples.

(Example 1) Naphtha oil containing 150 ppm of chlorine was used as a stock solution to remove chlorine.

equipped with a fixed bed with a volume of 50 m1 and heated to 250 °C,
The chlorine removal equipment shown in Fig. 1, which has a reaction tank with a volume of 280 mj2, is supplied with a stock solution of 100 mρ/hr (L HS V
= 2 hr-') and hydrogen gas 1.21/hr
passed.

Table 1 shows the chlorine concentration and chlorine removal rate in the hydrocarbon oil 8 hours after the start of liquid passage.

The catalyst used was as follows.

Al2O, specific surface area 340 ya2/g pore volume
0.50cc/g PT, 0.5 wt% supported on the above A1 mountain.

Above ^120. Pd0.5wt% what was carried.

Rh0.5wt% in the above AJ2203 mutually compatible.

Ni10wt% in the above Al1203 what was carried.

Above ^120. to C010wt% what was carried.

Co-Mo/^1203 Above^120. niCo-M
10 wt% of O (of which 5 wt% of Co) was supported.

PL/8! To 0°Pd/8A to 20°Rh/8! He03 Ni/A42203 Co/AJ2.0° (Example 2) The following steps were carried out except that a commercially available catalyst containing nickel, cobalt, and molybdenum shown in Table 2 was used, and naphtha oil containing chlorine at a concentration of 258 ppm was used as the stock solution. Chlorine in naphtha oil was removed in the same manner as in Example 1.

Table 2 shows the chlorine concentration and chlorine removal rate in the naphtha oil 8 hours after starting the liquid passage.

Furthermore, the chlorine concentration and chlorine removal rate in the naphtha oil were measured 32 hours after the start of liquid passage under the same conditions as above, but compared to the case 8 hours later, the No change,
It was found that there was no deterioration in catalyst activity.

Table 2 Main item (◆l), (*2) Made by Institut Français du Bétrol (IFP) ■, (Middle 3), (Umbrella 4) Made by Toyo CCI (CCI) ■, (◆5) Specially made by JGC Universal, (◆ 6) LD-145 from (◆2) was treated with 10% hydrogen sulfide-hydrogen mixed gas at 250°C for 5 hours, and then further heated at 350°C.
It was treated for 3 hours.

(Tsubaki 7) C20-06 of (*4) was treated in the same manner as (No. 6).

(Example 3) In Example 1, 0.5 wt% was added to the catalyst used in the fixed bed.
Using Pt/A1203 (manufactured by Engelhard Japan), chlorine was removed by changing the reaction temperature, LHSV (liquid hourly space velocity), and reaction time. Table 3 shows the removal rate of chlorine after 8 hours.

Table 3 Removal rate of chlorine (Comparative Example 1) Chlorine was removed in the same manner as in Example 1, except that a porous adsorbent was used as a fixed bed and the reaction temperature was set to room temperature.

The results are shown in Table 4.

(Example 4) Chlorine in naphtha oil was removed in the same manner as in Example 1, except that the type of catalyst and the type of carrier were changed as shown in Table 5, and the results are shown in Table 5.

In No. 28 and No. 30, after the above reaction, a fixed bed of alumina was added as a collection material to the reaction species having the same shape as in Example 1 to form a collection tank, and the contact temperature was 50° C. and the contact time was 30 minutes. The collection process was carried out. The results are shown in Table 5. The alumina used has a surface area of 340 m'/
g, and the pore volume was 0.6 cc/g.

(Comparative Example 2) Caustic soda (alkali metal hydroxide) and barium hydroxide (a 5N aqueous solution of alkaline earth metal hydroxide was used as a catalyst), the chlorine-containing naphtha oil used in Example 2, and the volume The mixture at a ratio of 1:1 was kept in contact for 1.0 hour at room temperature using a shaker. Table 6 shows the chlorine concentration and chlorine removal rate in the obtained naphtha oil.

<Effects of the Invention> Since the method of the present invention heats chlorine contained in hydrocarbon oil in the presence of hydrogen and brings it into contact with a specific catalyst, trace amounts of chlorine contained in hydrocarbon oil can be removed. It can be removed efficiently over a long period of time. Hydrocarbon oil from which chlorine has been removed by this method does not corrode other reaction equipment, etc., and does not contain catalyst poisoning components such as oxygen-containing compounds, nitrogen-containing compounds, and trace alkalis. Therefore, it can be widely used in catalytic reactions such as hydrogenation and polymerization.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus for carrying out the method of the present invention. Explanation of symbols! ...Raw material, 2.Reaction tank, 3.13.Heat exchanger, 4.Doping loading line, 5.50.Fixed bed, 6.Pump, 7. Hydrogen gas, 8...Gas line, 9...Takeout line, 10...Heat source, 11...Gas separation line, 12.22.122...Product line, 14...Cooling water, 15 ... Gas-liquid fraction 11f waste, 16... Compressor, 17... Preheater tank, 20... Collection waste

Claims (6)

[Claims] (1) A method for removing trace chlorine from hydrocarbon oil, which comprises bringing a hydrocarbon oil containing chlorine and/or chlorine compounds into contact with alumina under heating conditions in the presence of hydrogen. (2) Hydrocarbon oil containing chlorine and/or chlorine compounds is applied to a cobalt,
1. A method for removing trace amounts of chlorine from hydrocarbon oil, the method comprising contacting under heating conditions with at least one metal or metal compound selected from the group consisting of nickel and molybdenum. (3) Hydrocarbon oil containing chlorine and/or chlorine compounds is mixed with at least one metal or metal compound selected from the group consisting of platinum, palladium, rhodium, and ruthenium supported on a carrier in the presence of hydrogen. , a method for removing trace amounts of chlorine from hydrocarbon oil, which is characterized by contacting under heating conditions. (4) The carrier in the hydrocarbon oil according to claim 2 or 3, wherein the carrier is at least one selected from the group consisting of alumina, silica-alumina, silica, diatomaceous earth, zeolite, activated carbon, and clay. How to remove trace chlorine. (5) Heating in contact with the metal or metal compound supported on the alumina or carrier is performed at a temperature of 100 to 400
The method for removing trace chlorine from hydrocarbon oil according to any one of claims 1 to 4, which is carried out at <RTIgt;C. (6) The hydrogen is 100ml/hr of the hydrocarbon oil
In contrast, when hydrogen is used alone, the flow rate is 1.0 ml/h.
The method for removing trace chlorine from hydrocarbon oil according to any one of claims 1 to 5, wherein the method is used at a rate of r to 6 l/hr.