JP4424586B2 - Method for desulfurization of liquid hydrocarbons containing organic sulfur compounds - Google Patents

Description

  The present invention relates to a desulfurization method using an adsorbent for removing a liquid hydrocarbon containing an organic sulfur compound, particularly petroleum-based fuel oil, or a sulfur compound contained in a base material thereof, and an adsorbent selection method therefor About.

In the 21st century automobiles and their fuels, dealing with environmental issues is a major issue. From the viewpoint of reducing CO ₂ emissions, which are a global warming gas, and so-called automobile exhaust emissions, such as NO _X , fuel sulfur There is an increasing demand for reductions in minutes. Specifically, the sulfur content of gasoline and diesel oil is expected to be regulated to sulfur-free (10 ppm or less) in the near future, and fuel oil with a low sulfur content, that is, zero sulfur (sulfur content 1 ppm or less) It has been demanded. Also, with the widespread use of fuel cells such as on-board reforming fuel cell vehicles, there is a possibility that further low-sulfur petroleum liquid fuel oil may be required, and desulfurization technology to ultra-low sulfur has been actively researched. . On the other hand, in the petrochemical field, efficient removal of sulfur is required because a small amount of sulfur affects the catalytic reaction.

  In order to remove the sulfur compounds remaining in the fuel oil and reduce the sulfur content to 10 ppm or less, and further to 1 ppm or less by using the hydrodesulfurization method that is a desulfurization technique that has been mainly used in the past, a huge amount of catalyst And the cost increases due to the amount of hydrogen consumed. Further, in the case of a low-temperature liquid hydrocarbon, it is necessary to cool it again after heating to high temperature and desulfurization, resulting in a large energy loss. Furthermore, since gasoline is hydrogenated to the olefin content, the octane loss is large. As for diesel oil, the hue of the product is expected to deteriorate and the yield will drop significantly due to decomposition.

  Thus, in order to reduce the sulfur content of liquid hydrocarbons obtained from crude oil, it is necessary to have a simple facility and a technology for desulfurizing liquid hydrocarbons containing a sulfur content of several ppm to several hundred ppm with low operating costs. ing. The present invention solves such problems, and an object of the present invention is to use an adsorptive desulfurization agent that can sufficiently remove sulfur over a long period of time with relatively low equipment cost and operation cost for desulfurization of liquid hydrocarbons. The object is to provide a method for selecting a desulfurization method or an adsorptive desulfurization agent.

  As a result of diligent research to solve the above-mentioned problems, the present inventor selected a suitable adsorbent according to the type and the aromatic content of the organic sulfur compound contained in the liquid hydrocarbon, thereby forming a liquid hydrocarbon. The inventors have conceived that trace amounts of organic sulfur compounds contained can be effectively removed.

  That is, the present invention relates to a desulfurization method for removing an organic sulfur compound contained in a liquid hydrocarbon by bringing the liquid hydrocarbon into contact with an adsorbent, in a mercaptan, a chain sulfide, a cyclic sulfide, a thiophene, a benzo The adsorbent selection index C determined from the content of each organic sulfur compound classified into thiophenes and dibenzothiophenes, the aromatic content contained in the liquid hydrocarbon, and the specific surface area of the adsorbent is 100 or more. Specifically, the following adsorbents can be used.

  When the organic sulfur compound is mainly composed of mercaptans, the adsorbent contains a metal-based adsorbent, an X-type zeolite adsorbent, or a Y-type zeolite adsorbent if the aromatic content of the liquid hydrocarbon is less than 20% by mass. When the aromatic content is 20% by mass or more, the adsorbent contains a metal-based adsorbent or an X-type zeolite adsorbent.

When the organic sulfur compound is mainly composed of chain sulfides, if the aromatic content of the liquid hydrocarbon is less than 20% by mass, the adsorbent contains Na X type zeolite adsorbent or Na Y type zeolite adsorbent. When the aromatic content is 20% by mass or more, the adsorbent contains an X-type zeolite adsorbent, a ferrierite adsorbent, a mordenite adsorbent, or a silica gel type adsorbent.

  When the organic sulfur compound is mainly composed of cyclic sulfides, the adsorbent contains X-type zeolite adsorbent, Y-type zeolite adsorbent or silica gel adsorbent if the aromatic content of the liquid hydrocarbon is less than 20% by mass. However, at 20 mass% or more, the adsorbent contains an X-type zeolite adsorbent, a silica gel adsorbent, or an activated carbon adsorbent.

  When the organic sulfur compound is mainly composed of thiophenes, if the aromatic content of the liquid hydrocarbon is less than 20% by mass, the adsorbent contains an X-type zeolite adsorbent or a Y-type zeolite adsorbent, and the aromatic content Is 20 mass% or more, the adsorbent contains an X-type zeolite adsorbent or an activated carbon adsorbent.

  When the organic sulfur compound is mainly composed of benzothiophenes, the adsorbent contains X-type zeolite adsorbent, Y-type zeolite adsorbent or activated carbon adsorbent if the aromatic content of the liquid hydrocarbon is less than 20% by mass. When the aromatic content is 20% by mass or more, the adsorbent contains an X-type zeolite adsorbent or an activated carbon adsorbent.

  When the organic sulfur compound is mainly composed of dibenzothiophenes, if the aromatic content of the liquid hydrocarbon is less than 20% by mass, the adsorbent contains a Y-type zeolite adsorbent or activated carbon adsorbent, and the aromatic content is In 20 mass% or more, an adsorbent contains activated carbon adsorbent.

  When the proportion of mercaptans and dibenzothiophenes in the organic sulfur compound is less than 5% in terms of sulfur content, the adsorbent is an X-type zeolite adsorbent if the aromatic content of the liquid hydrocarbon is less than 20% by mass. , Y-type zeolite adsorbent or activated carbon adsorbent is contained, and when the aromatic content is 20% by mass or more, the adsorbent contains X-type zeolite adsorbent, activated carbon adsorbent or silica gel adsorbent.

When the ratio of mercaptans, chain sulfides, and cyclic sulfides in the organic sulfur compound is less than 5% in terms of sulfur content, the adsorbent is less than 20% by mass of the aromatic content of the liquid hydrocarbon. An X-type zeolite adsorbent, a Y-type zeolite adsorbent or an activated carbon adsorbent is contained. When the aromatic content is 20% by mass or more, the adsorbent contains an X-type zeolite adsorbent or an activated carbon adsorbent.
The proportions of chain sulfides, cyclic sulfides, and dibenzothiophenes in the organic sulfur compound are each less than 5% in terms of sulfur content, the aromatic content of the liquid hydrocarbon is 20% by mass or more, and the adsorbent is X Type zeolite adsorbent or activated carbon adsorbent. Alternatively, the ratio of cyclic sulfides, benzothiophenes, and dibenzothiophenes in the organic sulfur compound is less than 5% in terms of sulfur content, the aromatic content of the liquid hydrocarbon is less than 20% by mass, and the adsorbent is X-type zeolite adsorbent, Y-type zeolite adsorbent or L-type zeolite adsorbent is contained.

  The method for selecting an adsorbent according to the present invention is as follows. (A) The content of organic sulfur compounds contained is classified into mercaptans, chain sulfides, cyclic sulfides, thiophenes, benzothiophenes, and dibenzothiophenes. , (B) measuring the aromatic content contained in the liquid hydrocarbon, (c) preparing a plurality of adsorbents and measuring their specific surface area, (d) selecting the adsorbent for each adsorbent from these measurement results The index C is calculated, and (e) the adsorbent having the largest adsorbent selection index C is selected. Preferably, the plurality of adsorbents are an oxidation transition metal-supported alumina-based adsorbent, zinc oxide-based adsorbent, Y-type zeolite adsorbent, X-type zeolite adsorbent, L-type zeolite adsorbent, mordenite adsorbent, ferrierite adsorbent. , At least two selected from amorphous activated carbon adsorbent, fibrous activated carbon adsorbent, alumina-based adsorbent, and silica gel-based adsorbent. Further, in the desulfurization method of the present invention, the adsorbent selected by this selection method and the liquid hydrocarbon are brought into contact with each other to remove the organic sulfur compound contained in the liquid hydrocarbon.

The adsorbent selection index C [−] is defined by the following equation.
[Equation 1]
C = Qa * Ra + Qb * Rb + Qc * Rc + Qd * Rd + Qe * Re + Qf * Rf
However,
Ra: Ratio of sulfur content of mercaptans to total sulfur content [-]
Rb: Ratio of sulfur content of chain sulfides to total sulfur content [-]
Rc: Ratio of sulfur content of cyclic sulfides to total sulfur content [-]
Rd: Ratio of sulfur content of thiophene to total sulfur content [-]
Re: Ratio of sulfur content of benzothiophenes to total sulfur content [-]
Rf: Ratio of sulfur content of dibenzothiophenes to total sulfur content [-]
Qa: Adsorption capacity index of mercaptans [-]
Qb: Adsorption capacity index of chain sulfides [-]
Qc: Adsorption capacity index of cyclic sulfides [-]
Qd: adsorption capacity index of thiophenes [-]
Qe: Adsorption capacity index of benzothiophenes [-]
Qf: Adsorption capacity index of dibenzothiophenes [-]

Here, the adsorption capacity index Q _x when the adsorbent is a combination of m kinds of adsorbents is expressed by the following equation.
[Equation 2]
Q _x = ((Q _x1 ² + Q _x2 ² + Q _x3 ² +... + Q _xm ² ) / m) ^1/2

The adsorption capacity indexes Qa to Qf are defined by the following equations.
[Equation 3]
Qa = Pa * X * e- ^{Y / Ta * Za}
[Equation 4]
Qb = Pb × X × e ^{−Y / Tb × Zb}
[Equation 5]
Qc = Pc * X * e- ^{Y / Tc * Zc}
[Equation 6]
Qd = Pd × X × e ^{−Y / Td × Zd}
[Equation 7]
Qe = Pe × X × e ^{−Y / Te × Ze}
[Equation 8]
Qf = Pf * X * e- ^{Y / Tf * Zf}

X is the maximum selection index [−] determined from the specific surface area S [m ² / g] by the adsorbent classification, and in the case of a metal-based adsorbent (oxidized transition metal-supported alumina-based adsorbent, zinc oxide-based adsorbent)
[Equation 9]
X = 0.3 × S + 120
In the case of zeolite-based adsorbent (Y-type zeolite adsorbent, X-type zeolite adsorbent, L-type zeolite adsorbent, mordenite adsorbent, ferrierite adsorbent),
[Equation 10]
X = 0.4 × S
In the case of carbon-based (amorphous activated carbon adsorbent, fibrous activated carbon adsorbent), alumina-based and silica gel-based adsorbent,
[Equation 11]
X = 0.15 × S + 50
It is.

  Y is an aromatic influence index [−] specific to various adsorbents; Y = 0.02 for metal adsorbents, Y = 0.5 for Y-type zeolite adsorbents, X-type zeolite adsorbents Y = 0.1 for L-type zeolite adsorbent, Y = 0.035 for L-type zeolite adsorbent, Y = 0.015 for mordenite adsorbent, Y = 0.003 for ferrierite adsorbent In the case of the system and alumina type adsorbents, Y = 0.02, and in the case of the silica gel type adsorbent, Y = 0.05.

Z is an aromatic content influence coefficient [-] specific to various adsorbents depending on the aromatic content A [mass%]
[Equation 12]
Za = A ^Ua , Zb = A ^Ub , Zc = A ^Uc , Zd = A ^Ud , Ze = A ^Ue , Zf = A ^Uf
It is represented by here,
Ta, Ua: Aromatics influence coefficient on the adsorption of mercaptans [-]
Tb, Ub: Aromatic influence coefficient [−] on adsorption of chain sulfides
Tc, Uc: Aromatic content influence coefficient [−] on adsorption of cyclic sulfides
Td, Ud: Aromatic influence coefficient [−] on adsorption of thiophenes
Te, Ue: Aromatic influence coefficient [−] on adsorption of benzothiophenes
Tf, Uf: Aromatic content influence coefficient [−] on adsorption of dibenzothiophenes
It is.

For metal adsorbents:
Ta = 8, Tb = 2, Tc = 2, Td = 1, Te = 2, Tf = 2
Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1

For zeolite adsorbents:
Ta = 1, Tb = 2, Tc = 5, Td = 3, Te = 2, Tf = 5
For Y-type zeolite and X-type zeolite,
Ua = 0.5, Ub = 0.5, Uc = 0.8, Ud = 0.8, Ue = 0.8, Uf = 0.8
In L-type zeolite, mordenite and ferrierite,
Ua = 1, Ub = 1, Uc = 1.6, Ud = 1.6, Ue = 1.6, Uf = 1.6

For carbon-based adsorbents:
Ta = 2, Tb = 1, Tc = 2, Td = 1, Te = 2, Tf = 6
Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1

For alumina adsorbent:
Ta = 2, Tb = 2, Tc = 2, Td = 1, Te = 2, Tf = 2
Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1

For silica gel type adsorbent:
Ta = 2, Tb = 8, Tc = 5, Td = 1, Te = 2, Tf = 2
Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1

here,
Pa: Adsorption capacity coefficient of mercaptans [-]
Pb: Adsorption capacity coefficient of chain sulfides [-]
Pc: Adsorption capacity coefficient of cyclic sulfides [-]
Pd: Adsorption capacity coefficient of thiophenes [-]
Pe: Adsorption capacity coefficient of benzothiophenes [-]
Pf: Adsorption capacity coefficient of dibenzothiophenes [-]
It is.

For transition metal supported alumina adsorbent:
Pa = 1, Pb = 0.3, Pc = 0.3, Pd = 0.3, Pe = 0.5, Pf = 0.1
For zinc oxide adsorbent:
Pa = 1, Pb = 0.1, Pc = 0.05, Pd = 0.05, Pe = 0.05, Pf = 0.1

For Y-type zeolite adsorbent:
Pa = 1, Pb = 0.8, Pc = 1, Pd = 1, Pe = 1, Pf = 1
For X-type zeolite adsorbent:
Pa = 1, Pb = 0.8, Pc = 1, Pd = 0.8, Pe = 1, Pf = 0.5
For L-type zeolite adsorbent:
Pa = 1, Pb = 1, Pc = 0.8, Pd = 0.8, Pe = 0.8, Pf = 0.3
For mordenite adsorbent:
Pa = 0.5, Pb = 1, Pc = 0.3, Pd = 0.3, Pe = 0.1, Pf = 0.05
For ferrierite adsorbent:
Pa = 0.5, Pb = 1, Pc = 0.1, Pd = 0.1, Pe = 0.05, Pf = 0.03

For irregular activated carbon adsorbent:
Pa = 0.4, Pb = 0.3, Pc = 0.4, Pd = 0.4, Pe = 0.7, Pf = 1
For fibrous activated carbon adsorbent:
Pa = 0.2, Pb = 0.3, Pc = 0.3, Pd = 0.4, Pe = 0.7, Pf = 1

For alumina adsorbent:
Pa = 1, Pb = 0.6, Pc = 0.3, Pd = 0.6, Pe = 1, Pf = 0.3
For silica gel type adsorbent:
Pa = 0.8, Pb = 0.8, Pc = 1, Pd = 0.7, Pe = 1, Pf = 0.1

In the present invention, the type of the adsorbent that functions efficiently depends on the type of the organic sulfur compound that is the adsorbed substance and the content of the aromatic component that is the competing substance having the greatest influence in the liquid hydrocarbon. By paying attention and selecting an adsorbent from a predetermined group, sulfur in the liquid fuel can be efficiently removed.
More specifically, the present invention relates to the content of each organic sulfur compound obtained by classifying organic sulfur compounds in liquid hydrocarbons containing a small amount of sulfur into specific types, aromatic content, and desulfurization of liquid hydrocarbons. Since the adsorbent selection index C is determined from the specific surface area of the adsorbent used, a selection method for selecting an adsorbent having a large value, and a desulfurization method using the adsorbent obtained by the selection method, the liquid carbonization to be desulfurized. An adsorbent suitable for hydrogen can be selected, and a trace amount of organic sulfur compound contained in the liquid hydrocarbon can be effectively removed.

  In the desulfurization method according to the present invention, one kind of adsorbent is selected from among a group of adsorbents that function efficiently depending on the kind of sulfur compound that is the adsorbed substance and the content of the aromatic substance that is the most influential competitor By selecting above, all the sulfur compounds contained in the liquid hydrocarbon can be efficiently removed.

[Adsorbent Selection Method] The effective adsorbent differs depending on whether the aromatic content in the liquid hydrocarbon containing the organic sulfur compound is 20% by mass or more or less than 20% by mass. Further, the effective adsorbent differs for each of the six types of sulfur compounds. Therefore, in selecting one or more adsorbents used for desulfurization of liquid hydrocarbons containing organic sulfur compounds, the aromatic content and organic sulfur compounds contained in the liquid hydrocarbons are measured, and the organic sulfur compounds are mercaptans, chains The above-mentioned adsorbent selection index C [-] is calculated for each adsorbent or a combination thereof, and is classified into large sulfides, cyclic sulfides, thiophenes, benzothiophenes, and dibenzothiophenes. One or more adsorbents are selected. It is preferable to use an adsorbent having an adsorbent selection index C of 150 or more, particularly 200 or more.

[Liquid hydrocarbon] The liquid hydrocarbon to be desulfurized is a liquid hydrocarbon containing a sulfur compound such as a petroleum fraction. The petroleum fraction is a liquid mainly composed of hydrocarbons obtained by purifying crude oil through purification processes such as distillation, cracking, hydrogenation, and isomerization, and the boiling point of the hydrocarbons mainly contained is 30 to 400 ° C. And the sulfur content is preferably 500 ppm or less, particularly 200 ppm or less. A petroleum fraction having a low content of nitrogen compounds that inhibit the adsorption of sulfur compounds, for example, 10 ppm or less is preferred. Examples of such petroleum fractions preferably used include a light oil fraction, a kerosene fraction, and a gasoline fraction. These fractions are used as raw materials for petroleum products such as light oil, kerosene, gasoline, and hydrocarbon fuel for fuel cells.

The light oil fraction is mainly composed of hydrocarbons having about 16 to 20 carbon atoms. It has a density (15 ° C.) of 0.820 to 0.880 g / cm ³ and a boiling point range of about 140 to 390 ° C., and is rich in paraffinic hydrocarbons. The kerosene fraction is mainly composed of hydrocarbons having about 12 to 16 carbon atoms. It has a density (15 ° C.) of 0.790 to 0.850 g / cm ³ and a boiling point range of about 150 to 320 ° C., and is rich in paraffinic hydrocarbons.

The gasoline fraction is mainly composed of hydrocarbons having about 4 to 11 carbon atoms. The density (15 ° C.) is 0.783 g / cm ³ or less and the boiling range is about 30 to 220 ° C. For use in automobiles and other similar gasoline engines, fractions with a high octane number are obtained by catalytic cracking, catalytic reforming, alkylation, and the like. In general, aromatic and low-boiling isoparaffins and olefins have a high octane number.

  Aromatic compounds are strongly adsorbed by the adsorbent even at the molecular level and become competitively adsorbed with sulfur compounds, but many petroleum fractions contain about several to 50%, so the influence is great. In particular, when the total aromatic content is greater than about 20% by mass, the influence of the aromatic content is extremely large, and the amount of adsorption of NaY-type zeolite or the like is remarkably reduced. On the other hand, the olefin content is also competitively adsorbed with the sulfur compound, but the effect is small compared to the aromatic content. Therefore, the aromatic content was used as an index, and it was found that the type of effective adsorbent differs depending on whether the aromatic content is greater than 20% by mass or less.

  The method for measuring aromatics is JIS K 2536 (Japanese Industrial Standards) (this standard is a method for measuring hydrocarbon components in petroleum products by using saturated fluorescent, olefinic and aromatic hydrocarbons by the fluorescent indicator adsorption method. A method for quantifying by classification into three types of hydrocarbons, and a method for quantifying benzene, toluene, xylene, methanol, methyl tertiary butyl ether, etc. in gasoline by gas chromatography), Japan Petroleum Institute ) Standard JPI-5S-52-99 (gasoline-total composition analysis method-capillary column gas chromatogram method, generally referred to as PONA analysis), Petroleum Institute standard JPI-5S-49-97 (petroleum product-hydrocarbon type test method- High performance liquid chromatograph), The Institute of Petroleum (The Institute) of Petroleum) standard IP standard method 391/95 (analysis of aromatic hydrocarbons in middle distillate by high performance liquid chromatograph using a refractive index detector).

  Since the aromatic compound is strongly adsorbed to the adsorbent even at the molecular level and becomes competitively adsorbed with the sulfur compound, it is preferable to remove the aromatic compound as much as possible before the organic sulfur compound is adsorbed and removed. For example, the aromatic content in the liquid hydrocarbon is less than 20% by mass by separation operation such as distillation separation, membrane separation, solvent extraction, adsorption separation, chemical reaction such as hydrogenation reaction, dilution with non-aromatic hydrocarbon, etc. In addition, it is preferable to desulfurize with an adsorbent after the content is preferably reduced to 10% by mass or less, particularly preferably 5% by mass or less.

  In the present invention, organic sulfur compounds contained in liquid hydrocarbons are classified into six types: mercaptans, chain sulfides, cyclic sulfides, thiophenes, benzothiophenes, and dibenzothiophenes. The organic sulfur compound contained in the liquid hydrocarbon needs to be classified into any of these six types. For sulfur compounds that are difficult to classify because the structure of the organic sulfur compound is complex, it is possible to assign to a plurality of types and to select an effective adsorbent for both types.

  For the analysis of sulfur compounds, a method using a gas chromatograph (GC) equipped with a sulfur compound detector is preferred. Such detectors include a chemiluminescence detector (SCD), an atomic emission detector (AED), a flame photometric detector (FPD), and a mass detector (Mass). Although a selective detector (MSD) is mentioned, a chemiluminescence detector is preferable. In the analysis by GC-SCD, by classifying each peak and obtaining the area of each classification with respect to the total area, the sulfur content of the sulfur compounds belonging to each classification with respect to the total sulfur content (the weight of sulfur element contained in all organic sulfur compounds) The ratio of (the weight of elemental sulfur contained in the organic sulfur compound) is determined. It should be noted that the fact that a certain type of organic sulfur compound is the main component usually means that the ratio is 0.3 or more, preferably 0.5 or more, more preferably 0.7 or more.

Mercaptans are sulfur compounds RSH (R is a hydrocarbon group such as an alkyl group or an aryl group) having a mercapto group (—SH), and are also called thiols or thioalcohols. Mercapto groups are highly reactive and react particularly easily with metals. Representative mercaptans include methyl mercaptan, ethyl mercaptan, propyl mercaptan, butyl mercaptan (including tertiary butyl mercaptan), pentyl mercaptan, hexyl mercaptan, heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan, thiophenol (phenyl mercaptan) , Phenthiol, molecular formula C ₆ H ₆ S, molecular weight 110), thiocresol (mercaptotoluene, molecular formula C ₇ H ₈ S, molecular weight 124), thiolenol (mercaptoxylene, dimethylphenyl mercaptan, molecular formula C ₈ H ₁₀ S, molecular weight) 138) and thiocarbachlor (2-mercapto-p-cymene, 5-isopropyl-2-methylthiophenol, molecular formula C ₁₀ H ₁₄ S, Molecular weight 166), dithiocatechol (o-phenylene dimercaptan, o-mercaptobenzene, 1,2-disulfhydrylbenzene, molecular formula C ₆ H ₆ S ₂ , molecular weight 142) and dithiohydroquinone (dithiohydroquinone, p-phenylene dimercaptan, p-dimercaptobenzene, 1,4-disulfhydrylbenzene, molecular formula C ₆ H ₆ S ₂ , molecular weight 142) and dithioresorcin (m-phenylene dimercaptan, m-dimercaptobenzene, 1,3-disulfhydrylbenzene, molecular formula C ₆ H ₆ S ₂ , molecular weight 142), dithiol (toluene-3,4-dithiol, 3,4-dimercaptotoluene (molecular formula C ₇ H ₈ S ₂ , molecular weight 156) and trithiophloroglucin (C ₆ H ₆ S _3, molecular weight 166) thiopheno such as Le such Ar-SH (Ar is an aryl group), thionaphthol (naphthyl mercaptan, mercapto naphthalene, molecular formula _C 10 _H 8 S, molecular weight 160), thio benzhydrol (benzhydryl mercaptan, alpha-mercapto-diphenylmethane, molecular formula _{C 13} H ₁₂ S, molecular weight 200) and derivatives thereof.

  Sulfides, also called thioethers, are generic names for alkyl sulfides and aryl sulfides, and are sulfur compounds represented by the general formula R—S—R ′ (where R and R ′ are hydrocarbon groups such as alkyl groups and aryl groups). . This is a compound in which two hydrogen atoms of hydrogen sulfide are substituted with an alkyl group or the like. Disulfides are also included in the sulfides. Disulfide means disulfide. It is a general term for alkyl disulfide and aryl disulfide, and is a sulfur compound represented by the general formula R—S—S—R ′ (R and R ′ are hydrocarbon groups such as alkyl groups). A disulfide bond (S—S) is one of the oxidation steps of a mercapto group (—SH), and is naturally present in proteins.

  Sulfides are classified into chain sulfides and cyclic sulfides. In particular, since the adsorption characteristics of mordenite are greatly different between chain sulfides and cyclic sulfides, it is necessary to classify them into two types.

The chain sulfides are sulfur compounds that do not have a heterocyclic ring containing a sulfur atom as a heteroatom among the sulfides. Typical chain sulfides include dimethyl sulfide, methyl ethyl sulfide, methyl propyl sulfide, diethyl sulfide, methyl butyl sulfide, ethyl propyl sulfide, methyl pentyl sulfide, ethyl butyl sulfide, dipropyl sulfide, methyl hexyl sulfide, ethyl pentyl sulfide. , Propyl butyl sulfide, methyl heptyl sulfide, ethyl hexyl sulfide, propyl pentyl sulfide, dibutyl sulfide, dimethyl disulfide, methyl ethyl disulfide, methyl propyl disulfide, diethyl disulfide, methyl butyl disulfide, ethyl propyl disulfide, methyl pentyl disulfide, ethyl butyl disulfide, di Propyl disulfide, methylhexyl Sulfide, ethyl pentyl disulfide, propyl butyl disulfide, methyl heptyl disulfide, ethylhexyl disulfide, propyl pentyl disulfide, dibutyl disulfide, thioanisole (sulfide methylphenyl, molecular formula C _{7 H} 8 _S, molecular weight 124), Chiofenetoru (sulfide ethylphenyl, Thiocoketones RCSR ′ (R and R ′ are hydrocarbon groups such as alkyl groups and aryl groups) such as molecular formula C ₈ H ₁₀ S, molecular weight 138), thiobenzophenone (molecular formula C ₁₃ H ₁₀ S, molecular weight 198) and derivatives thereof Is mentioned.

Cyclic sulfides have a heterocyclic ring containing at least one sulfur atom as a heteroatom among sulfides and have no aromaticity (a penta- or hexa-atom ring and two double bonds). It is a sulfur compound that does not have a heterocyclic ring. Typical cyclic sulfides include tetrahydrothiophene (tetramethylene sulfide, molecular formula C ₄ H ₈ S, molecular weight 88.1), thiochroman (dihydrobenzothiopyran, molecular formula C ₉ H ₁₀ S, molecular weight 150), thiaadamantane (molecular formula) C ₉ H ₁₄ S, molecular weight 154), thioketones RCSR ′ (R and R ′ are hydrocarbon groups such as alkyl and aryl groups) such as trithioacetone and dithioacetone, thiobenzaldehyde (molecular formula C ₇ H ₆ S, molecular weight 122) trimer, 1,4-dithiane (diethylene disulfide, molecular formula C ₄ H ₈ S ₂ , molecular weight 120), dithiolane (molecular formula C ₃ H ₆ S ₂ , molecular weight 106) and derivatives thereof.

Among the heterocyclic compounds containing one or more sulfur atoms as heteroatoms, thiophenes are pentacyclic or hexaatomic and have aromaticity (two or more double bonds in the heterocyclic ring). And a sulfur compound in which the heterocyclic ring is not condensed with the benzene ring and derivatives thereof. Also included are compounds in which heterocycles are fused together. Thiophene, also called thiofuran, is a sulfur compound with a molecular weight of 84.1 that can be represented by the molecular formula C ₄ H ₄ S. Other typical thiophenes include methylthiophene (thiotolene, molecular formula C ₅ H ₆ S, molecular weight 98.2), thiapyran (pentthiophene, molecular formula C ₅ H ₆ S, molecular weight 98.2), thiophene (molecular formula C ₆ H ₄ S ₂ , molecular weight 140), tetraphenylthiophene (thionesal, molecular formula C ₂₀ H ₂₀ S, molecular weight 388), dithienylmethane (molecular formula C ₉ H ₈ S ₂ , molecular weight 180) and derivatives thereof.

Of the heterocyclic compounds containing one or more sulfur atoms as heteroatoms, benzothiophenes are pentacyclic or hexaatomic and have aromaticity (two double bonds in the heterocyclic ring). And a sulfur compound in which a heterocyclic ring is condensed with one benzene ring and derivatives thereof. Benzothiophene, also called thionaphthene or thiocoumarone, is a sulfur compound with a molecular weight of 134, which can be represented by the molecular formula C ₈ H ₆ S. Other representative benzothiophenes include methylbenzothiophene, dimethylbenzothiophene, trimethylbenzothiophene, tetramethylbenzothiophene, pentamethylbenzothiophene, hexamethylbenzothiophene, methylethylbenzothiophene, dimethylethylbenzothiophene, trimethylethylbenzo Thiophene, tetramethylethylbenzothiophene, pentamethylethylbenzothiophene, methyldiethylbenzothiophene, dimethyldiethylbenzothiophene, trimethyldiethylbenzothiophene, tetramethyldiethylbenzothiophene, methylpropylbenzothiophene, dimethylpropylbenzothiophene, trimethylpropylbenzothiophene, Tetramethylpropylbenzothiophene, pentame Le propyl benzothiophene, methyl ethyl propyl benzothiophene, dimethyl ethyl propyl benzothiophene, trimethyl ethylpropyl benzothiophene, alkyl benzothiophenes such as tetramethyl-ethylpropyl benzothiophene, Chiakuromen (Benzoa -γ- pyran, molecular formula C _{9 H} 8 _S, Molecular weight 148), dithiaphthalene (molecular formula C ₈ H ₆ S ₂ , molecular weight 166) and derivatives thereof.

Dibenzothiophenes are heterocyclic compounds containing one or more sulfur atoms as heteroatoms, and the heterocyclic ring is a penta- or hexa-atom ring and has aromaticity (two double bonds in the heterocyclic ring). And a sulfur compound in which a heterocyclic ring is condensed with two benzene rings and derivatives thereof. Dibenzothiophene is also called diphenylene sulfide, biphenylene sulfide, or diphenylene sulfide, and is a sulfur compound having a molecular weight of 184 that can be represented by the molecular formula C ₁₂ H ₈ S. 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene are well known as difficult desulfurization compounds in hydrorefining. Other typical dibenzothiophenes include trimethyldibenzothiophene, tetramethyldibenzothiophene, pentamethyldibenzothiophene, hexamethyldibenzothiophene, heptamethyldibenzothiophene, octamethyldibenzothiophene, methylethyldibenzothiophene, dimethylethyldibenzothiophene, trimethyl Ethyl dibenzothiophene, tetramethylethyl dibenzothiophene, pentamethylethyl dibenzothiophene, hexamethylethyl dibenzothiophene, heptamethylethyl dibenzothiophene, methyldiethyldibenzothiophene, dimethyldiethyldibenzothiophene, trimethyldiethyldibenzothiophene, tetramethyldiethyldibenzothiophene, penta Methyldiethyldibenzothi Phen, hexamethyldiethyldibenzothiophene, heptamethyldiethyldibenzothiophene, methylpropyldibenzothiophene, dimethylpropyldibenzothiophene, trimethylpropyldibenzothiophene, tetramethylpropyldibenzothiophene, pentamethylpropyldibenzothiophene, hexamethylpropyldibenzothiophene, heptamethylpropyl Alkyl dibenzothiophenes such as dibenzothiophene, methylethylpropyldibenzothiophene, dimethylethylpropyldibenzothiophene, trimethylethylpropyldibenzothiophene, tetramethylethylpropyldibenzothiophene, pentamethylethylpropyldibenzothiophene, hexamethylethylpropyldibenzothiophene, thianthrene Diphenylene disulfide, molecular formula _C 12 _H 8 _{S 2,} molecular weight 216), thioxanthene (dibenzo thiopyran, diphenylmethane sulfide, molecular formula _C 13 _{H 10} S, include molecular weight 198) and derivatives thereof.

  The adsorbent according to the present invention is selected from metal-based adsorbent, X-type zeolite adsorbent, Y-type zeolite adsorbent, activated carbon adsorbent, ferrierite adsorbent, mordenite adsorbent, silica gel adsorbent and the like. Hereinafter, each adsorbent will be outlined.

[Metal Adsorbent] A metal adsorbent, preferably a copper oxide-supported adsorbent, is capable of adsorbing all types of sulfur compounds, but is particularly excellent in the adsorption performance of mercaptans. Is selected when the liquid hydrocarbon contains mercaptans because it has low adsorption of aromatics and high adsorption performance even if the sulfur compound concentration is low. One of the adsorbents, one of the adsorbents selected preferably when the sulfur compound concentration is low, and one of the adsorbents that can be selected even when the aromatic content is 20% by mass or more. is there.

  Zinc oxide adsorbents are known as hydrogen sulfide adsorbents (chemical adsorbents, sorbents), but are also excellent in mercaptans adsorption performance, and have little influence on aromatics, Since it has high adsorption performance even when the sulfur compound concentration is low, it is one of the adsorbents selected when mercaptans are contained in the liquid hydrocarbon.

As the metal-based adsorbent, there can be used those in which a metal component is supported on a porous carrier such as alumina or activated carbon, or a molded product obtained by mixing alumina and the metal component. As the type of metal, silver, mercury, copper, cadmium, lead, molybdenum, zinc, cobalt, manganese, nickel, platinum, palladium, iron, and oxides thereof can be used. From the viewpoint of safety and economy, copper, zinc, and nickel are preferable. Among these, copper is inexpensive and has excellent performance for adsorption of sulfur compounds in a wide temperature range from near room temperature to about 300 ° C., in the state of copper oxide without reduction treatment, and in the absence of hydrogen. This is particularly preferable. An adsorbent having a specific surface area of 150 m ² / g or more, preferably 200 m ² / g or more in which a copper component is supported on a porous carrier can be used. If used in the presence of hydrogen, adsorption of sulfur compounds other than mercaptans can be promoted. Moreover, the metal component chemically reacted with sulfur after use can be regenerated by reacting with oxygen at 800 to 900 ° C.

As the metal-based adsorbent, a refractory inorganic material having a specific surface area of 200 m ² / g or more can be used as the porous carrier, and alumina carrier, activated carbon and the like are particularly preferably used. The alumina carrier is a porous particle mainly composed of alumina, and is usually preferably a spherical particle having a diameter of 0.5 to 5 mm, particularly 1 to 3 mm. The spherical shape is advantageous in terms of diffusion in the pores of the adsorbed sulfur compound because the average distance from the outer surface to the adsorbent center is short and the average concentration gradient can be increased as compared with a cylinder type (columnar shape) or the like. It is preferable that the breaking strength is 3.0 kg / pellet or more, particularly 3.5 kg / pellet or more because the absorbent does not crack. Usually, the breaking strength is measured by a compressive strength measuring device such as a Kiya-type tablet breaking strength measuring device (Toyama Sangyo Co., Ltd.).

  The crystallinity and type of alumina constituting the porous carrier are not limited. However, in the case of γ-alumina generally used as a catalyst carrier, it is difficult to produce a carrier having a large specific surface area and pore volume and high fracture strength. An amorphous alumina carrier such as activated alumina is preferably used because of its low wear rate and low powder production.

  Activated carbon used as a porous carrier is porous particles mainly composed of carbon. Usually, it is mainly indefinite with an average diameter of 0.8 to 1.7 mm. It is preferable that the carrier has a breaking strength of 3.0 kg / pellet or more, particularly 3.5 kg / pellet or more, because the absorbent does not crack.

A copper component is supported on the copper oxide-supported adsorbent that is preferably used. It is preferable that the copper component is contained in an amount of 0.1 to 15% by weight, particularly 1 to 10% by weight, based on the weight of the absorbent. It is preferable that only copper is supported, and it is preferable that 70% by weight or more, particularly 95% by weight or more of the transition metal contained in the adsorbent is a copper component. In order to prevent segregation of copper to the outer surface of the adsorbent particles, the weight of the copper component per unit specific surface area is preferably 0.7 mg / m ² or less, particularly 0.5 mg / m ² or less. In order to increase the adsorption capacity of mercaptans, it is preferable that the copper component is large, and it is particularly preferable that the weight of the copper component per unit specific surface area is 0.3 to 0.7 mg / m ² . Moreover, it is also possible to carry | support further components other than copper as needed. Zinc and iron can be supported as components other than copper. However, when the amount other than copper is less, for example, the other metal component has a weight of metal element of 0.1 mg / m ² or less, in particular, 0.2. It is preferably 02 mg / m ² or less.

  The alumina support in which copper is supported in the support pores takes on a green color due to the interaction between copper and alumina. When the concentration of copper is too high with respect to the specific surface area, black copper oxide is obtained without any interaction with alumina. Since this black copper oxide is easily detached, it may be detached during use and poison the downstream catalyst, and it is necessary to prevent black copper oxide from being generated. Accordingly, the supported copper preferably exhibits a green color, and the use of an absorbent exhibiting a black color is not preferable. Specifically, the proportion of black particles contained in the absorbent is preferably 10% or less, particularly 5% or less.

The specific surface area of the copper oxide-carrying adsorbent is 150 m ² / g or more, preferably 200 m ² / g or more. When the specific surface area is less than 200 m ² / g, the adsorption capacity of alkylthiophenes among the sulfur compounds is remarkably reduced. Therefore, the specific surface area of the adsorbent may be 200 m ² / g or more, particularly 250 m ² / g or more. preferable. In order to obtain mechanical strength, the macropore volume, which is the volume of pores having a pore diameter of 0.1 μm or more, is preferably 0.2 ml / g or less, particularly preferably 0.15 ml / g or less. In general, the specific surface area and the total pore volume are measured by a nitrogen adsorption method, and the macropore volume is measured by a mercury intrusion method. The nitrogen adsorption method is simple and commonly used, and is described in various documents. For example, Kazuhiro Hagio: Shimazu review, 48 (1), 35-49 (1991), ASTM (American Society for Testing and Materials) Standard Test Method D 4365-95.

As the zinc oxide adsorbent, a zinc oxide content of 90% by mass or more, a specific surface area of 10 m ² / g or more, and a spherical or cylinder type (columnar) adsorbent, which is generally used as a hydrogen sulfide adsorbent, can be used.

[Zeolite] X-type zeolite adsorbent, preferably NaX-type zeolite adsorbent, can adsorb all types of sulfur compounds, but in particular mercaptans, chain sulfides, cyclic sulfides, thiophenes, Adsorption performance of benzothiophenes is excellent, and since the influence of aromatics is relatively small, liquid hydrocarbons include mercaptans, chain sulfides, cyclic sulfides, thiophenes, and benzothiophenes. It is one of the adsorbents selected when it is present, and is one of the adsorbents that can be selected even when the aromatic content is 20% by mass or more.

  Y-type zeolites, preferably NaY-type zeolite adsorbents and L-type zeolite adsorbents, preferably KL-type zeolite adsorbents, can adsorb all types of sulfur compounds. Is big. One of the adsorbents selected when the aromatic content is less than 20% by mass, preferably 5% by mass or less, but is not selected when the aromatic content is 20% by mass or more.

  Mordenite adsorbents, preferably Na mordenite adsorbents and ferrierite adsorbents, preferably K ferrierite adsorbents, can adsorb mercaptans, chain sulfides, cyclic sulfides, thiophenes. In particular, the adsorption performance of chain sulfides is excellent, and since the pore size is smaller than that of NaY-type zeolite, the influence of aromatics is relatively small, so liquid hydrocarbons contain chain sulfides. It is one of the adsorbents that can be selected when the aromatic content is 20% by mass or more.

Zeolite has the general formula: xM _{2 / n} O · Al ₂ O ₃ · ySiO ₂ · zH ₂ O (where n is the valence of the cation M, x is a number of 1 or less, y is a number of 2 or more, z is a general term for a crystalline hydrous aluminosilicate represented by a number of 0 or more. Structure of the zeolite is shown in detail in such Structure Commission homepage http://www.iza-structure.org/ the International Zeolite Association (IZA), of SiO ₄ or AlO ₄ around the Si or Al The tetrahedral structure is a three-dimensionally ordered structure. Since the tetrahedral structure of AlO ₄ is negatively charged, charge compensating cations such as alkali metals and alkaline earth metals are held in the pores and cavities. The charge compensating cation can be easily exchanged for another cation such as a proton. In addition, due to the acid treatment or the like, the SiO ₂ / Al ₂ O ₃ molar ratio is increased, the acid strength is increased, and the solid acid amount is decreased. Since acid strength does not significantly affect the adsorption of sulfur compounds, it is preferable not to reduce the amount of solid acid.

In the faujasite type zeolite (FAU), the structural unit of the skeleton structure is a 4-membered ring, a 6-membered ring and a 6-membered double ring. The micropores have a three-dimensional structure, the entrance is a circle formed by a non-planar 12-membered ring, and the crystal system is cubic. The faujasite stone, which is a faujasite type natural zeolite, is represented by the molecular formula (Na ₂ , Ca, Mg) ₂₉ • Al ₅₈ Si ₁₃₄ O ₃₈₄ • 240H ₂ O and the like, and the micropore diameter is 7.4 × 7. The size of the unit cell is 24.74 cm. As faujasite type synthetic zeolite, there are X type and Y type. NaX-type zeolite is represented by Na ₈₈ [(AlO ₂ ) ₈₈ (SiO ₂ ) ₁₀₄ ] · 220H ₂ O and can adsorb molecules having an effective diameter of about 10 mm. NaY-type zeolite can adsorb molecules having an effective diameter of up to about 8 mm. The faujasite type zeolite preferably used in the present invention is represented by the general formula: xNa ₂ O.Al ₂ O ₃ .ySiO ₂ , and X <1 and y <10 are preferably used. The SiO ₂ / Al ₂ O ₃ molar ratio is preferably 10 mol / mol or less.

In mordenite (MOR), the structural unit of the skeleton structure is a 4-membered, 5-membered or 8-membered ring. The micropores have a one-dimensional structure and a three-dimensional structure, the entrance is an ellipse formed of a non-planar 12-membered ring and an 8-membered ring, and the crystal system is orthorhombic. The mordenite is a natural zeolite, there are mordenite, expressed in such molecular formula _{Na 8 Al 8 Si 40 O 96} · 24H 2 O, one-dimensional 6.5 × 7.0 Å in micropore diameter of 12-membered ring The structure and the 8-membered ring have two channels of 2.6 × 5.7 mm three-dimensional structure, both are connected, and the unit cell size is 18.1 × 20.5 × 7.5 mm. . Mordenite also exists as a synthetic zeolite. Na mordenite can adsorb molecules with an effective diameter of up to about 7 mm. The mordenite preferably used in the present invention is represented by the general formula: xNa ₂ O.Al ₂ O ₃ .ySiO ₂ , and X <1 and y <20. The SiO ₂ / Al ₂ O ₃ molar ratio is preferably 20 mol / mol or less.

L-type zeolite (LTL) was developed by the Linde Division of Union Carbide. The code name of IZA is changed from Linde Type L to LTL. The structural units of the skeleton structure are a 4-membered ring, a 6-membered ring and an 8-membered ring. The micropore has a one-dimensional structure, the entrance is a circle formed by a 12-membered ring, and the crystal system is a hexagonal crystal. It is represented by the molecular formula (K ₆ , Na ₃ ) · Al ₉ Si ₂₇ O ₇₂ · 21H ₂ O, and the like. Typically, the micropore diameter is 7.1 × 7.1 mm, and the unit cell size is 18.40. X 18.40 x 7.52 mm. The KL type zeolite is represented by the formula K ₉ Al ₉ Si ₂₇ O ₇₂ · xH ₂ O and the like, and the KL zeolite can adsorb molecules having an effective diameter of about 8 mm.

Ferrierite (FER) has a 5-, 6- and 8-membered skeletal structural unit. The micropore has a one-dimensional structure, the entrance is an ellipse formed of a 10-membered ring and an 8-membered ring, and the crystal system is orthorhombic. Ferrierite stone, which is a ferrierite-type natural zeolite, is represented by the molecular formula (Mg ₂ , Na ₂ ) ₂₉ .Al ₆ Si ₃₀ O ₇₂ .18H ₂ O and the like, and the micropore diameter is 4.2 with a 10-membered ring. It has two channels of a one-dimensional structure of × 5.4 mm and an eight-membered ring and a one-dimensional structure of 3.5 × 4.8 mm, both are connected, and the unit cell size is 19.156 × 14. 127 × 7.489cm. K ferrierite can adsorb molecules up to about 4 mm in effective diameter.

The properties of the zeolite used in the present invention include a crystallinity of 80% or more, particularly 90% or more, a crystallite size of 5 μm or less, particularly 1 μm or less, and an average particle size of 30 μm or less, particularly 10 μm or less. The specific surface area is preferably 300 m ² / g or more, particularly preferably 400 m ² / g or more.

  NaX type zeolite, NaY type zeolite and Na mordenite are X type zeolite, Y type zeolite and mordenite whose charge compensating cation is sodium, KL type zeolite and K ferrierite are L whose charge compensating cation is potassium. Type zeolite, ferrierite. If the charge compensation cation is hydrogen, thiophenes, benzothiophenes, etc. react with sulfur compounds or aromatics such as toluene at room temperature to form oligomeric heavy substances, covering the adsorbent surface. This is not preferable because it inhibits adsorption of sulfur compounds. Charge compensation cations are alkaline metals such as lithium, sodium, potassium, rubidium, cerium, alkaline earth metals such as magnesium, calcium, strontium, barium, manganese, iron, cobalt, nickel, copper, zinc, ruthenium, lead, Transition elements such as silver and lanthanum are preferred. In particular, zeolite having an alkali metal ion as the charge compensating cation is preferably used.

  As the zeolite adsorbent, the above-mentioned zeolite can be used as it is, but a molded body containing 30% by weight or more, particularly 60% by weight or more of these zeolites is preferably used. As the shape, in order to increase the concentration gradient, a small shape, particularly a spherical shape, is preferable as long as the differential pressure does not increase. In the case of a spherical shape, the diameter is preferably 0.5 to 5 mm, particularly preferably 1 to 3 mm. In the case of a columnar shape, the diameter is preferably 0.1 to 4 mmφ, particularly 0.12 to 2 mmφ, and the length is preferably 0.5 to 5 times the diameter, and particularly preferably 1 to 2 times.

Since the specific surface area of the zeolite adsorbent greatly affects the adsorption capacity of the sulfur compound, it is preferably 200 m ² / g or more, particularly preferably 300 m ² / g or more. Regarding zeolite adsorbents, the maximum weight that can be adsorbed per unit weight of sulfur compounds that each adsorbent is likely to adsorb is the ratio, regardless of the type of zeolite, when there is no aromatic that is competitively adsorbed with sulfur compounds. It is approximately proportional to the surface area S [m ² / g]. From the inventor's experimental value, the maximum value of the sulfur compound that can be adsorbed on 1 kg of the adsorbent is represented by 0.4 × S [g]. The pore volume with a pore diameter of 10 mm or less is preferably at least 0.1 ml / g, particularly preferably at least 0.20 ml / g, in order to increase the adsorption capacity of sulfur compounds. In addition, the pore volume having a pore diameter of 10 mm or more and 0.1 μm or less should be 0.05 ml / g or more, particularly 0.10 ml / g or more in order to increase the diffusion rate of sulfur compounds in the pores. Is preferred. The pore volume having a pore diameter of 0.1 μm or more is preferably 0.3 ml / g or less, particularly preferably 0.25 ml / g or less, in order to increase the mechanical strength of the molded article.

  When zeolite is used as a molded article, as described in JP-A-4-198011, a semi-finished product may be molded and then dried and calcined, and a binder (binding agent) may be added to the zeolite powder as necessary. ) May be mixed and molded, followed by drying and baking.

  Examples of the binder include clays such as alumina and smectite, and inorganic binders such as water glass. These binders may be used to such an extent that they can be molded, and are not particularly limited, but usually about 0.05 to 30% by weight with respect to the raw material is used. Mixing inorganic fine particles such as silica, alumina, other zeolites, and organic substances such as activated carbon to improve the adsorption performance of sulfur compounds that are difficult for zeolite to adsorb, and increasing the abundance of mesopores and macropores. The diffusion rate of the compound may be improved. Moreover, you may improve adsorption | suction performance by compounding with a metal. In the case of particles, it is usually an irregular shape mainly having an average diameter of 0.8 to 1.7 mm, and the breaking strength of the carrier is 3.0 kg / pellet or more, particularly 3.5 kg / pellet or more. This is preferable because it does not cause cracking.

[Alumina Adsorbent] The alumina adsorbent is a porous particle composed mainly of alumina and preferably 95% by weight or more of aluminum oxide or hydrated oxide. Usually, a spherical shape having a diameter of 0.5 to 5 mm, particularly 1 to 3 mm is preferable. The spherical shape is advantageous in terms of the diffusion of adsorbed sulfur compounds in the pores because the average distance from the outer surface to the adsorbent center is short and the average concentration gradient can be increased as compared with a cylinder type (columnar shape) or the like. The specific surface area is preferably 200 m ² / g or more.
The crystallinity and type of alumina are not limited, but in the case of γ-alumina generally used as a catalyst carrier, it is difficult to produce a carrier having a large specific surface area and a large pore volume and high fracture strength. An amorphous alumina carrier such as activated alumina is preferably used because of its low wear rate and low powder production.

[Silica gel adsorbent] Silica gel adsorbents can adsorb mercaptans, chain sulfides, cyclic sulfides, thiophenes, and benzothiophenes, but have the ability to adsorb chain sulfides and cyclic sulfides in particular. It is one of the adsorbents selected when the liquid hydrocarbon contains chain sulfides and cyclic sulfides because it is excellent and has relatively little influence on the aromatic content. Is one of the adsorbents that can be selected even in the case of 20 mass% or more.

  Silica gel is a general term for amorphous porous aggregates of silicon dioxide. The surface of silica gel is covered with silanol groups (Si-OH), shows weak acidity, and has hydrogen bonding properties and polarity. This silanol group is classified into several groups depending on the physical properties and chemical reactivity of silica gel, but the free silanol group is an adsorption site and has high chemical reactivity. The hydrophilicity can be controlled by reaction with the surface modifier, and the surface covered with the surface hydrogen-bonding silanol group has low reactivity.

[Activated carbon] Fibrous activated carbon has excellent adsorption performance for thiophenes, benzothiophenes, and dibenzothiophenes. However, it has relatively high adsorption performance for benzothiophenes and dibenzothiophenes, especially for dibenzothiophenes. It is one of the adsorbents selected when the liquid hydrocarbon contains benzothiophenes and dibenzothiophenes because it is excellent and has little influence on the aromatic content. % Is one of the adsorbents that can be selected. Thus, since it became clear that each adsorbent is good and bad, almost all organic sulfur compounds can be removed by combining these adsorbents.

  Activated carbon is a carbon material with a developed pore structure, and is widely used industrially as an adsorbent and catalyst carrier, and can be classified into amorphous activated carbon and fibrous activated carbon based on its shape. Amorphous activated carbon is a porous body consisting of a disordered layered structure of carbon microcrystals. Basically, it is hydrophobic, and the adsorbed substance is physically adsorbed on the surface between the amorphous part and the crystallite. Amorphous activated carbon made from natural products contains about 5% by mass of oxygen, has an oxygen-containing functional group on the surface, and exhibits a slight hydrophilicity. The type and amount of this surface functional group are affected by the activation method during production.

  Although there are carbon materials that exhibit adsorption activity even if they are natural, such as anthracite, they are generally produced by carbonizing activated carbon raw materials that are organic (carbonaceous substances) and activating them as necessary. Is not limited. Many carbonaceous materials are conceivable as raw materials for activated carbon, and the production conditions differ depending on the type of raw material. As raw materials, plant-based wood, sawdust, coconut husk, pulp waste liquid and the like, fossil fuel-based coal, heavy petroleum oil, or pitch or coke obtained by pyrolyzing them can be used. Fibrous activated carbon uses a fiber obtained by spinning a synthetic polymer, tar pitch or petroleum pitch as a starting material. Coal is classified into lignite, bituminous coal, and anthracite depending on the degree of coalification. Examples of the synthetic polymer include phenol resin, furan resin, polyvinyl chloride resin, polyvinylidene chloride resin, and waste plastic.

  Carbonization is a general term for a wide variety of chemical reactions in which carbon is enriched, such as bond breakage caused by heat changes of organic substances, and decomposition, polycondensation, and aromatic cyclization that result in recombination into more stable bonds. is there. The raw material can be heat-treated to obtain coke and char. During this carbonization reaction, water, carbon oxide, and light hydrocarbons volatilize and at the same time a liquid is distilled out. The pore structure that greatly affects the adsorption properties of activated carbon changes with the carbonization temperature. In general, in the production of activated carbon, carbonization is performed in the range of 600 to 800 ° C. to produce a carbonaceous material (carbonized material), but the conditions are not particularly limited.

  Examples of the activation method after carbonization in the production of activated carbon include gas activation and chemical activation. In Japan, the gas activation method using water vapor is the mainstream, but the chemical activation method using zinc chloride is still used in the production of powdered activated carbon. In recent years, an alkali activation method, which is a new chemical activation method, has also been reported.

  The gas activation method is also called physical activation, and is a method for producing fine porous activated carbon by causing a carbonaceous material to contact and react with water vapor, carbon dioxide, oxygen or the like at a high temperature. The activation process is thought to proceed in two stages.In the first heating process, unstructured parts are selectively decomposed and consumed, and the fine pores closed between the carbon crystals are released, resulting in a specific surface area. Increases rapidly. In the gasification reaction process in the second stage, carbon crystals and the like are consumed and mesopores and macropores are formed.

  The chemical activation method is a method for producing fine porous activated carbon by dehydration and oxidation reaction of chemicals by impregnating raw materials evenly with an activation chemical and heating and baking in an inert gas atmosphere. Activating chemicals are zinc chloride, sulfuric acid, boric acid, nitric acid, hydrochloric acid, phosphoric acid, sodium phosphate, calcium chloride, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, calcium carbonate, potassium sulfate, sodium sulfate, sodium sulfate Potassium nitrate, potassium chloride, potassium permanganate, potassium sulfide, potassium thiocyanate and other dehydrating, oxidizing and eroding chemicals are used. In chemical activation, the mass ratio of the chemical to be impregnated with respect to the carbonaceous raw material is an important measure of activation. When the mass ratio is small, micropores are generated, and as the mass ratio increases, the pore diameter increases. The pore volume is increased.

The sulfuric acid used is preferably concentrated sulfuric acid (concentration of about 30 to 40% by mass). Further, the heat treatment after impregnation is usually performed at about 200 to 300 ° C. for about 4 to 6 hours in a non-oxidizing atmosphere. In recent years, activated carbon having a specific surface area of 3,000 m ² / g or more is produced from petroleum coke by a special chemical activation method using KOH or the like, and it has been reported that the adsorption capacity is remarkably excellent (H. March, D. Crawford: Carbon, 20, 419 (1982), AN Wennerberg, TM O'Grady: US Patent 4082694). In Japan as well, research has been conducted on various carbon materials such as petroleum coke, petroleum pitch, coal pitch, and coconut shell, and high functionality of activated carbon is being studied. In particular, this is an effective method for soft carbon such as optically anisotropic pitch-based carbon fiber, which cannot generate pores by a method such as steam activation. This production method is characterized by the fact that an alkali (mainly KOH) that is about 1 to 5 times the mass of the carbonaceous material is used as the mass ratio, and the raw material mixture is set at a predetermined temperature of 400 to 900 ° C. in an activated gas atmosphere. It is activated by processing at the temperature. After the reaction, the content is taken out and washed thoroughly with water to elute the alkali and obtain activated carbon. The obtained activated carbon has a very large specific surface area and pore volume, and it may be possible to produce activated carbon having better adsorption performance than other activation methods. Such an activation method is also disclosed in, for example, Japanese Patent Laid-Open No. 5-247731.

  The adsorption characteristics by activated carbon are essentially determined by the contact between the surface of the activated carbon and adsorbate molecules and the in-situ interaction energy. Therefore, the strength of interaction is important depending on the relationship between the pore distribution and the adsorbate molecular diameter, and the structure and physical properties of the adsorbate molecule. Moreover, in many cases, liquid phase adsorption is multi-component competitive adsorption and is complicated due to the state of solute molecules in the solvent. The present inventors have found that the adsorption capacity of sulfur compounds is not simply proportional to the specific surface area. The fibrous activated carbon having a relatively small specific surface area has a larger adsorption capacity than the powdered activated carbon having a large specific surface area. Although various causes are considered, it is thought that the pore structure of activated carbon has influenced greatly.

  Fibrous activated carbon uses carbon fiber as a raw material for activated carbon. Compared with granular activated carbon, it has a very high adsorption rate, high adsorption at low concentrations, and can be processed into various shapes such as felt. It has features such as being. In general, carbon fiber is a pitch fiber obtained by melt spinning PAN (polyacrylonitrile) fiber, strong rayon, petroleum pitch, coal pitch, etc., and after performing a thermal oxidation crosslinking reaction in air at 200 to 400 ° C., then in nitrogen It is a graphitized fiber that has been heat-treated at 800-1500 ° C. and heat-treated at 2000 ° C. and has a high carbon content.

  The pitch includes an isotropic pitch and an anisotropic pitch. Carbon fiber produced from isotropic pitch is inexpensive, but has low strength due to poor molecular orientation. In contrast, carbon fibers produced from optically anisotropic (mesophase) pitch have a high degree of molecular orientation and exhibit excellent mechanical properties. In the optically anisotropic pitch-based carbon fiber, it is important to control the orientation of the graphite layer surface inside the fiber. This orientation is substantially controlled in the spinning process such as pitch viscosity at the time of spinning, spinning speed, cooling speed, nozzle structure and the like. In the optically anisotropic pitch-based activated carbon fiber for adsorbent use, the orientation of the graphite layer surface in the fiber is preferably so-called radial orientation. Examples of the spinning method include melt spinning, centrifugal spinning, vortex spinning, and melt blow spinning, and any method may be used.

Pitch is a thermoplastic organic compound, and in order to perform carbonization while maintaining the fiber form, the fiber is usually subjected to infusibilization after spinning to obtain infusible fibers. This infusibilization can be infusibilized continuously in a liquid phase or gas phase by a conventional method, but is usually carried out in an oxidizing atmosphere such as air, oxygen, or NO ₂ . For example, infusibilization in air is performed at an average temperature increase rate of 1 to 15 ° C./min and a processing temperature range of about 100 to 350 ° C.

  The infusibilized fiber can be used in the next activation treatment step as it is, but since it contains a large amount of low volatile matter, it is desirable to carry out a light carbonization treatment to obtain a light carbonized fiber. This treatment is performed in an inert gas such as nitrogen, but the treatment temperature range is 400 ° C. or more and 700 ° C. or less. Infusibilized fibers or lightly carbonized fibers can be activated and used as adsorbents even in the form of mats or felts, but they are ground (milled) before activation for uniform mixing with chemicals and surface uniformity due to activation reactions. It is also possible to If it is excessively fine, uniform activation becomes difficult, so the thickness is preferably 5 μm or more. As a milling method, it is effective to use a Victory mill, a jet mill, a cross flow mill, a high-speed rotating mill or the like. In order to perform milling efficiently, for example, a method of cutting fibers by rotating a rotor to which a blade is attached at high speed is appropriate.

  The activated carbon adsorbent of the present invention can be used in the form of granules, fibers, powders or molded products, but when used continuously and repeatedly regenerated, it should be used as a molded product of activated carbon. Is preferred. The shape can be granular, honeycomb, matte, felt or the like. When used in a granular form, a shape close to a small sphere of about 0.3 to 3 mm is preferable from the relationship of packing density, adsorption speed and pressure loss. When used as a molded product, the powder may be molded, then carbonized, and then activated, or may be molded after the activation, dried and fired. When molding, a binder (binding agent) can be used as necessary. Examples of the binder include tar pitch, tar compatible resin, expanded graphite, lignin, molasses, sodium alginate, carboxymethyl cellulose (CMC), a phenol resin, and other organic binders such as polyvinyl alcohol and starch, and smectite. Examples thereof include inorganic binders such as water glass. These binders may be used to such an extent that they can be molded, and are not particularly limited. Mixing inorganic substances such as silica, alumina, and zeolite to improve the adsorption performance of sulfur compounds that are difficult for activated carbon to adsorb, or increasing the amount of mesopores and macropores to improve the diffusion rate of sulfur compounds . Moreover, you may improve adsorption | suction performance by compounding with a metal. In the case of particles, the absorbent is usually indefinitely having an average diameter of 0.8 to 1.7 mm, and the fracture strength of the carrier is 3.0 kg / pellet or more, particularly 3.5 kg / pellet or more. This is preferable because it does not cause cracking.

  [Combination of adsorbents] As described above, there may be two or more kinds of adsorbents. Multiple types of adsorbents are placed in contact with hydrocarbons sequentially, adsorbents are physically mixed and then contacted, and when adsorbent particles are produced, they are mixed and contacted with the same particles. There is a method to make it.

    The method of sequentially contacting with hydrocarbons requires that adsorption of sulfur compounds that are difficult to adsorb and remove efficiently by arranging adsorbents for sulfur compounds that are easily adsorbed and removed, and that special adsorbents must be produced. It is preferably used because it does not exist. Whether adsorption removal is easy or not depends on the concentration of each sulfur compound, and because the differential pressure, the amount of adsorbent, and the ease of regeneration are also major factors, the order of the adsorbents cannot be said. However, since adsorption removal of mercaptans is often relatively easy, it is often preferable to first contact with an adsorbent for adsorption removal of mercaptans. Moreover, since the disulfides may be produced when the mercaptans come into contact with the metal-based adsorbent, the adsorbent for removing the mercaptans is preferably disposed upstream. Adsorption and removal after the mercaptans are often easy in the form of chain sulfides. Therefore, it is preferable to contact the adsorbent for adsorption removal of the chain sulfides next to the adsorbent for adsorption removal of the mercaptans. There are many cases. On the other hand, since it is thiophenes that are most difficult to remove by adsorption, it is often preferable that the adsorbent for adsorption removal of thiophenes is brought into contact last. Next, since it is difficult to use benzothiophenes, it is often preferable that the adsorbent for adsorbing and removing benzothiophenes be brought into contact immediately before the adsorbent for adsorbing and removing thiophenes.

The conditions for [Contact Conditions] contact, pressure is atmospheric pressure to 50 kg / ^cm 2 G, preferably normal pressure to 10 kg / ^cm 2 G, particularly 0.1~3kg / cm ² G are preferred. Flow rate, 0.1~100hr ^-1, particularly preferably 0.5～20Hr ^-1 in LHSV. The temperature at which the adsorption treatment is performed is preferably 150 ° C. or less, particularly preferably 0 to 100 ° C. Among the sulfur compounds, chain sulfides, cyclic sulfides, thiophenes, benzothiophenes, and dibenzothiophenes have a large adsorption capacity at a lower adsorption temperature. In particular, at a temperature higher than 150 ° C., the adsorption capacity of thiophenes is remarkably small. For mercaptans, a higher adsorption temperature is preferable for metal-based adsorbents and zinc oxide, but the effect on temperature is small for copper oxide-carrying alumina, so that it is sufficiently active even at room temperature.

  The adsorbent preferably removes a small amount of adsorbed moisture as a pretreatment of the adsorbent. When moisture is adsorbed, not only the adsorption of sulfur compounds is inhibited, but moisture desorbed from the adsorbent immediately after the start of hydrocarbon introduction is mixed into the hydrocarbon. Zeolite, copper oxide-supported adsorbent, zinc oxide, silica gel, and alumina are preferably dried at about 130 to 500 ° C, preferably about 350 to 450 ° C. In the case of amorphous activated carbon and fibrous activated carbon, it is preferable to dry at about 100 to 200 ° C. in an oxidizing atmosphere such as air. Above 200 ° C., it reacts with oxygen and loses weight, which is not preferable. On the other hand, it can be dried at about 100 to 800 ° C. in a non-oxidizing atmosphere such as nitrogen. It is particularly preferable to perform the heat treatment at 400 to 800 ° C. because organic substances and oxygen contained therein are removed and the adsorption performance is improved.

  For adsorbent desorption regeneration, for zeolite, silica gel, alumina, amorphous activated carbon, and fibrous activated carbon, the adsorbent after adsorptive desulfurization is washed with a solvent such as toluene, alcohol, and acetone, heated in a nitrogen atmosphere, and decompressed. It can be easily desorbed and regenerated and reused by heating underneath. In particular, sufficient heating can be achieved in a short time by heating in a non-oxidizing atmosphere (usually under a nitrogen atmosphere) and / or under reduced pressure. Moreover, although it does not function directly as a desorbing agent, it is possible to use water or water vapor as a heating source. In the case of a metal-based adsorbent or zinc oxide, desorption regeneration by washing with a solvent, heating in a nitrogen atmosphere, heating under reduced pressure, or the like is limited. It is necessary to remove sulfur by reduction and / or oxidation.

  The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto.

[Oxidized Transition Metal-Supported Alumina Adsorbent] As the oxidized transition metal-supported alumina adsorbent, copper catalyst-supported alumina NK-311 manufactured by Orient Catalyst Co. (copper content: 7.6 mass%, specific surface area S: 264 m ² / g, X = 0.3 × S + 120 = 199, Y = 0.02, Ta = 8, Tb = 2, Tc = 2, Td = 1, Te = 2, Tf = 2, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 1, Pb = 0.3, Pc = 0.3, Pd = 0.3, Pe = 0.5, Pf = 0.1) (Hereinafter referred to as “copper oxide-supported alumina”) and nickel oxide-supported alumina (nickel oxide content: 50 mass%, specific surface area S: 50 m ^{2 /} g, X = 0.3 × S + 120 = 135, Y = 0.02, Ta = 8, Tb = 2, Tc = 2, Td = 1, Te = 2, Tf = 2, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 1, Pb = 0.3, Pc = 0.3, Pd = 0.3, Pe = 0. 5, Pf = 0.1) in powder form (hereinafter referred to as “nickel-supported alumina”).

[Zinc Oxide Adsorbent] As a zinc oxide adsorbent, a zinc oxide adsorbent NK-301H (Zinc oxide content: 99% by mass, specific surface area S: 10 m ^{2 /} g, X = 0.3 ×, manufactured by Orient Catalyst Co., Ltd. S + 120 = 123, Y = 0.02, Ta = 8, Tb = 2, Tc = 2, Td = 1, Te = 2, Tf = 2, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 1, Pb = 0.1, Pc = 0.05, Pd = 0.05, Pe = 0.05, Pf = 0.1) (hereinafter referred to as “powder”) "Zinc oxide") was used.

[Y-type zeolite adsorbent] As Y-type zeolite adsorbent, Tosoh Corporation NaY-type zeolite powder HSZ-320NAA (SiO ₂ / Al ₂ O ₃ ratio: 5.5 mol / mol, specific surface area S: 700 m ² / g, X = 0.4 × S = 280, Y = 0.5, Ta = 1, Tb = 2, Tc = 5, Td = 3, Te = 2, Tf = 5, Ua = 0.5, Ub = 0. 5, Uc = 0.8, Ud = 0.8, Ue = 0.8, Uf = 0.8, Pa = 1, Pb = 0.8, Pc = 1, Pd = 1, Pe = 1, Pf = 1) was used (hereinafter referred to as “NaY-type zeolite”).

[X-Type Zeolite Adsorbent] As X-type zeolite adsorbent, Wako Pure Chemical Industries, Ltd. NaX-type zeolite powder F-9 (SiO ₂ / Al ₂ O ₃ ratio: 2.5 mol / mol, specific surface area S: 591 m ² / G, X = 0.4 × S = 236, Y = 0.1, Ta = 1, Tb = 2, Tc = 5, Td = 3, Te = 2, Tf = 5, Ua = 0.5, Ub = 0.5, Uc = 0.8, Ud = 0.8, Ue = 0.8, Uf = 0.8, Pa = 1, Pa = 1, Pb = 0.8, Pc = 1, Pd = 0 0.8, Pe = 1, Pf = 0.5) (hereinafter referred to as “NaX-type zeolite”).

[L-Type Zeolite Adsorbent] As L-type zeolite adsorbent, KL type zeolite powder HSZ-500KOA manufactured by Tosoh Corporation (SiO ₂ / Al ₂ O ₃ ratio: 6.1 mol / mol, specific surface area S: 280 m ² / g) , X = 0.4 × S = 112, Y = 0.035, Ta = 1, Tb = 2, Tc = 5, Td = 3, Te = 2, Tf = 5, Ua = 1, Ub = 1, Uc = 1.6, Ud = 1.6, Ue = 1.6, Uf = 1.6, Pa = 1, Pb = 1, Pc = 0.8, Pd = 0.8, Pe = 0.8, Pf = 0.3) (hereinafter referred to as “KL-type zeolite”).

[Mordenite adsorbent] Na mordenite powder HSZ-642NAA manufactured by Tosoh Corporation as a mordenite adsorbent (SiO ₂ / Al ₂ O ₃ ratio: 18.3 mol / mol, specific surface area S: 360 m ² / g, X = 0.4 × S = 144, Y = 0.015, Ta = 1, Tb = 2, Tc = 5, Td = 3, Te = 2, Tf = 5, Ua = 1, Ub = 1, Uc = 1.6, Ud = 1.6, Ue = 1.6, Uf = 1.6, Pa = 0.5, Pb = 1, Pc = 0.3, Pd = 0.3, Pe = 0.1, Pf = 0.05) (Hereinafter referred to as “Na mordenite”).

[Ferrierite adsorbent] As a ferrierite adsorbent, K Ferrierite powder HSZ-720KOA manufactured by Tosoh Corporation (SiO ₂ / Al ₂ O ₃ ratio: 18.2 mol / mol, specific surface area S: 170 m ² / g, X = 0.4 × S = 68, Y = 0.003, Ta = 1, Tb = 2, Tc = 5, Td = 3, Te = 2, Tf = 5, Ua = 1, Ub = 1, Uc = 1. 6, Ud = 1.6, Ue = 1.6, Uf = 1.6, Pa = 0.5, Pb = 1, Pc = 0.1, Pd = 0.1, Pe = 0.05, Pf = 0.03) (hereinafter referred to as “K Ferrierite”).

[Amorphous Activated Carbon Adsorbent] As an irregular activated carbon adsorbent, an amorphous activated carbon powder Darco KB (specific surface area S: 1,500 m ^{2 /} g, X = 0.15 × S + 50 = 275, Y = 0.02, Ta = 2, Tb = 1, Tc = 2, Td = 1, Te = 2, Tf = 6, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 0.4, Pb = 0.3, Pc = 0.4, Pd = 0.4, Pe = 0.7, Pf = 1) (hereinafter referred to as “amorphous activated carbon”).

[Fibrous activated carbon adsorbent] As the fibrous activated carbon adsorbent, fibrous activated carbon A powder (specific surface area S: 2,669 m ² / g, total pore volume: 1.36 cm ³ / g, average pore diameter: 20 mm, micro Pore specific surface area: 2,630 m ² / g, micropore pore volume: 1.29 cm ³ / g, X = 0.15 × S + 50 = 450, Y = 0.02, Ta = ² , Tb = ^1, Tc = 2, Td = 1, Te = 2, Tf = 6, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 0.2, Pb = 0.3, Pc = 0.3, Pd = 0.4, Pe = 0.7, Pf = 1), fibrous activated carbon B powder (specific surface area S: 1,155 m ² / g, total pore volume: 0.44 cm ³ / g, an average pore size: 15 Å, micropore specific surface area: 1,137m ² / g, micropore pore volume: 0.40 cm ³ / g X = 0.15 × S + 50 = 223, Y = 0.02, Ta = 2, Tb = 1, Tc = 2, Td = 1, Te = 2, Tf = 6, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 0.2, Pb = 0.3, Pc = 0.3, Pd = 0.4, Pe = 0.7, Pf = 1), and , Short fibrous (fibrous activated carbon FR-25 manufactured by Kuraray Chemical Co., Ltd., specific surface area S: 2,749 m ² / g, total pore volume: 0.96 cm ³ / g, average pore diameter: 14 mm, Micropore specific surface area: 2,741 m ² / g, micropore pore volume: 0.94 cm ³ / g, X = 0.15 × S + 50 = 462, Y = 0.02, Ta = ^2, Tb = ^1, Tc = 2, Td = 1, Te = 2, Tf = 6, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 0.2, P = 0.3, Pc = 0.3, Pd = 0.4, Pe = 0.7, Pf = 1) was used.

[Alumina Adsorbent] As alumina adsorbent, Alcoa's activated alumina F-200 (specific surface area S: 350 m ^{2 /} g, X = 0.15 × S + 50 = 103, Y = 0.02, Ta = ^2, Tb = 2, Tc = 2, Td = 1, Te = 2, Tf = 2, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 1, Pb = 0. 6, Pc = 0.3, Pd = 0.6, Pe = 1, Pf = 0.3) in powder form (hereinafter referred to as “activated alumina”) was used.

[Silica gel adsorbent] As a silica gel adsorbent, silica gel WAKOGEL-G (specific surface area S: 687 m ^{2 /} g, X = 0.15 × S + 50 = 153, Y = 0.05, Ta = ² , manufactured by Wako Pure Chemical Industries, Ltd. Tb = 8, Tc = 5, Td = 1, Te = 2, Tf = 2, Ua = 1, Ub = 1, Uc = 1, Ud = 1, Ue = 1, Uf = 1, Pa = 0.8, Pb = 0.8, Pc = 1, Pd = 0.7, Pe = 1, Pf = 0.1) in powder form (hereinafter referred to as “silica gel”) was used.

[Pretreatment of adsorbent] Copper oxide-supported alumina, zinc oxide, NaY-type zeolite, NaX-type zeolite, Na mordenite, silica gel and activated alumina for 3 hours at 400 ° C, and amorphous activated carbon and fibrous activated carbon for 3 hours at 150 ° C Dried.

[Preparation of model oil] For six types of sulfur compounds (mercaptans, chain sulfides, cyclic sulfides, thiophenes, benzothiophenes, dibenzothiophenes), n-butyl mercaptan (BM), dimethyl sulfide (DMS) ), Tetrahydrothiophene (THT), 2-methylthiophene (2MT), benzothiophene (BT), dibenzothiophene (DBT) are selected as model sulfur compounds, respectively, and decane solvent (normal decane), toluene solvent or decane and toluene. A model oil was prepared by diluting each sulfur compound concentration to 10% by mass with a mixed solvent.

[Model oil immersion test method] Each model oil (4.0 g) is immersed in 1.0 g of each adsorbent at room temperature for 24 hours or more, and the sulfur compound content in the model oil before and after immersion is analyzed by gas chromatography. Thus, the adsorption capacity of the adsorbent was measured.

[Model oil immersion test 1] Model oil diluted with decane solvent to 10% by mass (aromatic A: 0% by mass, ratio of sulfur content of mercaptans to total sulfur content: Ra: 1, total Ratio of sulfur content of chain sulfides to sulfur content: Rb: 0 Ratio of sulfur content of cyclic sulfides to total sulfur content: 0, Ratio of sulfur content of thiophene to total sulfur content: Rd: 0, total sulfur content Adsorption experiments of various adsorbents were conducted with respect to the ratio of sulfur content of benzothiophenes to Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content (Rf: 0). Table 1 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaY-type zeolite, NaX-type zeolite, and copper oxide-supported alumina having a large adsorbent selection index is large.

[Model oil immersion test-2] Model oil diluted with toluene solvent to 10% by mass of BM (aromatic content A: 90% by mass, ratio of sulfur content of mercaptans to total sulfur content Ra: 1, total Ratio of sulfur content of chain sulfides to sulfur content: Rb: 0 Ratio of sulfur content of cyclic sulfides to total sulfur content: 0, Ratio of sulfur content of thiophene to total sulfur content: Rd: 0, total sulfur content Adsorption experiments of various adsorbents were conducted with respect to the ratio of sulfur content of benzothiophenes to Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content (Rf: 0). Table 2 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacities of copper oxide-supported alumina, nickel-supported alumina, zinc oxide and NaX-type zeolite having a large adsorbent selection index are large.

[Model oil immersion type adsorption experiment-3] Model oil diluted with decane solvent to 10% by mass of DMS (aromatic A: 0% by mass, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, total The ratio Rb of the sulfur content of the chain sulfides to the sulfur content, the ratio Rc of the sulfur content of the cyclic sulfides to the total sulfur content, 0, the ratio Rd of the sulfur content of the thiophene to the total sulfur content, 0, the total sulfur content Adsorption experiments of various adsorbents were conducted with respect to the ratio of sulfur content of benzothiophenes to Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content (Rf: 0). Table 3 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaY-type zeolite and NaX-type zeolite having a large adsorbent selection index is large.

[Model oil immersion test-4] Model oil diluted with 10% by mass of DMS with toluene solvent (aromatic content A: 90% by mass, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, total The ratio Rb of the sulfur content of the chain sulfides to the sulfur content, the ratio Rc of the sulfur content of the cyclic sulfides to the total sulfur content, 0, the ratio Rd of the sulfur content of the thiophene to the total sulfur content, 0, the total sulfur content Adsorption experiments of various adsorbents were conducted with respect to the ratio of sulfur content of benzothiophenes to Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content (Rf: 0). Table 4 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaX-type zeolite, Na mordenite, K ferrierite and silica gel having a large adsorbent selectivity index is large.

[Model oil immersion test-5] Model oil diluted with decane solvent to 10% by mass of THT (aromatic content A: 0% by mass, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, total The ratio Rb of the sulfur content of the chain sulfides to the sulfur content is 0, the ratio Rc of the sulfur content of the cyclic sulfides to the total sulfur content, the ratio Rd of the sulfur content of the thiophene to the total sulfur content is 0, the total sulfur content Adsorption experiments of various adsorbents were conducted with respect to the ratio of sulfur content of benzothiophenes to Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content (Rf: 0). Table 5 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaY-type zeolite and NaX-type zeolite having a large adsorbent selection index is large.

[Model oil immersion test-6] Model oil diluted with toluene solvent to 10% by mass of THT (aromatic content A: 90% by mass, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, total The ratio Rb of the sulfur content of the chain sulfides to the sulfur content is 0, the ratio Rc of the sulfur content of the cyclic sulfides to the total sulfur content, the ratio Rd of the sulfur content of the thiophene to the total sulfur content is 0, the total sulfur content Adsorption experiments of various adsorbents were conducted with respect to the ratio of sulfur content of benzothiophenes to Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content (Rf: 0). Table 6 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaX-type zeolite, silica gel and activated carbon having a large adsorbent selectivity index is large.

[Model oil immersion test -7] Model oil diluted with decane solvent to 2 wt% 10 MT (aromatic A: 0 wt%, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, total Sulfur content ratio of chain sulfides to sulfur content Rb: 0, Sulfur content ratio of cyclic sulfides to total sulfur content Rc: 0, Sulfur content ratio of thiophene to total sulfur content Rd: 1, Total sulfur content Adsorption experiments of various adsorbents were conducted with respect to the ratio of sulfur content of benzothiophenes to Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content (Rf: 0). Table 7 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaY-type zeolite and NaX-type zeolite having a large adsorbent selection index is large.

[Model oil immersion test-8]
Model oil in which 2MT is diluted to 10% by mass with a solvent in which decane solvent and toluene solvent are mixed at 7: 3 (aromatic content A: 27% by mass, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, The ratio of the sulfur content of the chain sulfides to the total sulfur content Rb: 0, the ratio of the sulfur content of the cyclic sulfides to the total sulfur content: Rc: 0, the ratio of the sulfur content of the thiophene to the total sulfur content: Rd: 1, the total sulfur Adsorption experiments of various adsorbents were carried out with respect to the ratio of sulfur content of benzothiophenes to the minute Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content (Rf: 0). Table 8 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaX-type zeolite and activated carbon having a large adsorbent selection index is large.

[Model oil immersion experiment-9] Model oil diluted with decane solvent to 10% by mass (aromatic A: 0% by mass, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, total Ratio of sulfur content of chain sulfides to sulfur content: Rb: 0 Ratio of sulfur content of cyclic sulfides to total sulfur content: 0, Ratio of sulfur content of thiophene to total sulfur content: Rd: 0, total sulfur content Adsorption experiments of various adsorbents were conducted with respect to the ratio of the sulfur content of the benzothiophenes to Re: 1 and the ratio of the sulfur content of the dibenzothiophenes to the total sulfur content (Rf: 0). Table 9 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaY-type zeolite, NaX-type zeolite and activated carbon having a large adsorbent selection index is large.

[Model oil immersion experiment-10] Model oil diluted with decane solvent and toluene solvent in a ratio of 7: 3 to 10% by mass of BT (aromatic content A: 27% by mass, based on total sulfur content) Mercaptan sulfur fraction Ra: 0, chain sulfide sulfur ratio relative to total sulfur content Rb: 0, cyclic sulfide sulfur ratio relative to total sulfur content Rc: 0, thiophenes relative to total sulfur content The ratio of sulfur content of Rd is 0, the ratio of sulfur content of benzothiophenes to the total sulfur content is Re: 1, and the ratio of sulfur content of dibenzothiophenes to the total sulfur content is Rf: 0). Carried out. Table 10 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of NaX-type zeolite and activated carbon having a large adsorbent selection index is large.

[Model oil immersion test 11] Model oil diluted with 10% by mass of DBT with toluene solvent (aromatic content A: 90% by mass, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, total Ratio of sulfur content of chain sulfides to sulfur content: Rb: 0 Ratio of sulfur content of cyclic sulfides to total sulfur content: 0, Ratio of sulfur content of thiophene to total sulfur content: Rd: 0, total sulfur content Adsorption experiments of various adsorbents were carried out with respect to the ratio of the sulfur content of benzothiophenes Re: 0 and the ratio of sulfur content of dibenzothiophenes to the total sulfur content Rf: 1). Table 11 shows the adsorbent selection index and the adsorption capacity. It can be seen that the adsorption capacity of the activated carbon having a large adsorbent selection index is large.

[Immersion-type adsorption experiment 1 of fuel oil] For NaY-type zeolite, NaX-type zeolite and fibrous activated carbon A, the adsorptive desulfurization performance of the gasoline base material was evaluated. Fluid catalytic cracking (FCC) gasoline base (aromatic content A: 21% by mass, total sulfur content: 62 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0.02, chain sulfides based on total sulfur content Rb: 0.15, the sulfur content of cyclic sulfides relative to the total sulfur content Rc: 0.03, the sulfur content of thiophenes relative to the total sulfur content Rd: 0.19, relative to the total sulfur content Ratio of sulfur content of benzothiophenes Re: 0.58, ratio of sulfur content of dibenzothiophenes to total sulfur content: Rf = 0, density (15 ° C.) 0.7115 g / ml, nitrogen content 23 ppm, boiling range 25.5 (212.5 ° C.), the adsorbent was immersed at a ratio of fuel oil: adsorbent = 20 g: 3 g for 24 hours or more at room temperature, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 12 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that the concentration of sulfur is reduced in the case of activated carbon and NaX type zeolite having a large adsorbent selection index.

[Fuel oil immersion adsorption experiment-2] NaY-type zeolite, NaX-type zeolite, fibrous activated carbon C, NaY-type zeolite and fibrous activated carbon C mixed at a ratio of 50% by mass to 50% by mass, and NaX-type zeolite And the adsorbing desulfurization performance of gasoline was evaluated for the mixture of the fibrous activated carbon C and the fibrous activated carbon C at a ratio of 50% by mass to 50% by mass. FCC gasoline base material (aromatic content A: 21% by mass, total sulfur content: 31 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0.03, ratio of sulfur content of chain sulfides to total sulfur content Rb: 0.39, ratio of sulfur content of cyclic sulfides to total sulfur content Rc: 0.03, ratio of sulfur content of thiophenes to total sulfur content Rd: 0.32, sulfur of benzothiophenes relative to total sulfur content Proportion of minute Re: 0.23, ratio of sulfur content of dibenzothiophene to total sulfur content Rf: 0, density (15 ° C.) 0.7283 g / ml, nitrogen content 10 ppm, boiling point range 33.5-212.0 ° C. ), The adsorbent was immersed for 24 hours or more at 10 ° C. at a ratio of FCC gasoline base material: adsorbent = 20 g: 2 g, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 13 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that the sulfur concentration is lowered in the case of 50 mass% NaX zeolite + 50 mass% fibrous activated carbon C, 100 mass% NaX zeolite, and 100 mass% fibrous activated carbon C having a large adsorbent selection index.

[Fuel oil immersion type adsorption experiment-3] Adsorption desulfurization performance of light oil was evaluated for NaY zeolite, NaX zeolite, fibrous activated carbon A and fibrous activated carbon B. Ultra-deep desulfurized gas oil A (aromatic content A: 18% by mass, total sulfur content: 38 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, ratio of sulfur content of chain sulfides to total sulfur content Rb : 0, ratio of sulfur content of cyclic sulfides to total sulfur content Rc: 0, ratio of sulfur content of thiophenes to total sulfur content Rd: 0, ratio of sulfur content of benzothiophenes to total sulfur content Re: 0. 03, ratio of sulfur content of dibenzothiophenes to total sulfur content Rf: 0.97, density (15 ° C) 0.8377 g / ml, nitrogen content 1 ppm, boiling range 206.0-367.0 ° C) : Adsorbent = 20 g: 3 g of the adsorbent was immersed for at least 24 hours at room temperature, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 14 shows the adsorbent selection index and the sulfur concentration after soaking. It can be seen that the sulfur concentration is lowered in the case of fibrous activated carbon having a large adsorbent selection index.

[Fuel oil immersion adsorption experiment-4] The adsorption desulfurization performance of light oil was evaluated for NaY zeolite, NaX zeolite, fibrous activated carbon A and fibrous activated carbon B. Ultra-deep desulfurized gas oil B (aromatic content A: 20% by mass, total sulfur content: 31 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, ratio of sulfur content of chain sulfides to total sulfur content Rb : 0, ratio of sulfur content of cyclic sulfides to total sulfur content Rc: 0, ratio of sulfur content of thiophenes to total sulfur content Rd: 0, ratio of sulfur content of benzothiophenes to total sulfur content Re: 0. 03, the ratio of sulfur content of dibenzothiophenes to the total sulfur content Rf: 0.97, density (15 ° C) 0.8377 g / ml, nitrogen content 2 ppm, boiling range 171.5 to 374.0 ° C) : Adsorbent = 20 g: 3 g of the adsorbent was immersed for at least 24 hours at room temperature, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 15 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that the sulfur concentration is lowered in the case of fibrous activated carbon having a large adsorbent selection index.

[Immersion-type adsorption experiment of fuel oil-5] The adsorption desulfurization performance of a gasoline base material was evaluated for NaY-type zeolite, NaX-type zeolite, copper oxide-supported alumina, nickel oxide-supported alumina, and zinc oxide. Catalytic cracking (FCC) gasoline base (aromatic content A: 30% by mass, total sulfur content: 77 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0.19, of chain sulfides based on total sulfur content Sulfur content ratio Rb: 0.02, Cyclosulfide sulfur content ratio relative to total sulfur content Rc: 0.04, Thiophene sulfur content ratio relative to total sulfur content Rd: 0.41, Benzo content based on total sulfur content Ratio of sulfur content of thiophenes Re: 0.33, ratio of sulfur content of dibenzothiophenes to total sulfur content: Rf = 0, density (15 ° C.) 0.7406 g / ml, nitrogen content 30 ppm, boiling range 36.5 203.0 ° C.), the adsorbent was immersed at room temperature for 24 hours or more at a ratio of fuel oil: adsorbent = 6 g: 1 g, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 16 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that the sulfur concentration is decreased in the case of NaX type zeolite having a large adsorbent selectivity index.

[Fuel oil immersion adsorption experiment-6] The adsorption desulfurization performance of a gasoline base material was evaluated for NaY zeolite, NaX zeolite, KL zeolite, Na mordenite, and K ferrierite. Catalytic cracking (FCC) gasoline base (aromatic content A: 27 mass%, total sulfur content: 39 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0.52, chain sulfides based on total sulfur content Sulfur content ratio Rb: 0.01, Sulfur content ratio of cyclic sulfides relative to total sulfur content Rc: 0.04, Sulfur content ratio of thiophene relative to total sulfur content Rd: 0.25, benzo content relative to total sulfur content Ratio of sulfur content of thiophenes Re: 0.19, ratio of sulfur content of dibenzothiophenes to total sulfur content: Rf = 0, density (15 ° C.) 0.7276 g / ml, nitrogen content 21 ppm, boiling point range 26.0 At 215.0 ° C., the adsorbent was immersed in a ratio of fuel oil: adsorbent = 9 g: 2 g for 24 hours or more at room temperature, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 17 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that the sulfur concentration is decreased in the case of NaX type zeolite having a large adsorbent selectivity index.

[Immersion-type adsorption experiment of fuel oil-7] The adsorption desulfurization performance of a gasoline base material was evaluated for NaY zeolite, NaX zeolite, copper oxide-supported alumina, nickel oxide-supported alumina, and zinc oxide. Catalytic cracking (FCC) gasoline base (aromatic content A: 2 mass%, total sulfur content: 19 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0.60, of chain sulfides based on total sulfur content Sulfur content ratio Rb: 0.01, Sulfur content ratio of cyclic sulfides to total sulfur content Rc: 0.01, Sulfur content ratio of thiophene to total sulfur content Rd: 0.38, benzo to total sulfur content Ratio of sulfur content of thiophenes Re: 0, ratio of sulfur content of dibenzothiophenes to total sulfur content: Rf: 0, density (15 ° C.) 0.6634 g / ml, nitrogen content <1 ppm, boiling range 32.0-105 (5 ° C.), the adsorbent was immersed at room temperature for 24 hours or more at a ratio of fuel oil: adsorbent = 6 g: 1 g, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 18 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that in the case of NaX type zeolite and NaY type zeolite having a large adsorbent selection index, the sulfur concentration is lowered.

[Fuel oil immersion type adsorption experiment-8] The adsorption desulfurization performance of a gasoline base material was evaluated for NaY type zeolite, NaX type zeolite, KL type zeolite, Na mordenite, K ferrierite and copper oxide supported alumina. Catalytic cracking (FCC) gasoline base (aromatic content A: 1% by mass, total sulfur content: 3 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0.24, chain sulfides based on total sulfur content Sulfur content ratio Rb: 0.10, Sulfur content ratio of cyclic sulfides relative to total sulfur content Rc: 0, Sulfur content ratio of thiophenes relative to total sulfur content Rd: 0.66, benzothiophenes relative to total sulfur content Sulfur content ratio Re: 0, Sulfur content ratio of dibenzothiophene to total sulfur content Rf: 0, density (15 ° C.) 0.6568 g / ml, nitrogen content <1 ppm, boiling range 31.0-88.5 (° C.), the adsorbent was immersed for 24 hours or more at room temperature in a ratio of fuel oil: adsorbent = 9 g: 2 g, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 19 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that the sulfur concentration is lowered in the case of NaY type zeolite, NaX type zeolite, and KL type zeolite having a large adsorbent selection index.

[Submerged adsorption experiment of fuel oil-9] The adsorption desulfurization performance of a gasoline base material was evaluated for NaY zeolite, NaX zeolite, KL zeolite, Na mordenite, K ferrierite, and copper oxide supported alumina. Catalytic cracking (FCC) gasoline base (aromatic content A: 2 mass%, total sulfur content: 17 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, sulfur content of chain sulfides based on total sulfur content Rb: 0.55, ratio of sulfur content of cyclic sulfides to total sulfur content: Rc: 0.01, ratio of sulfur content of thiophenes to total sulfur content: Rd: 0.43, benzothiophenes relative to total sulfur content Sulfur content ratio Re: 0, Sulfur content ratio of dibenzothiophene to total sulfur content Rf: 0, density (15 ° C.) 0.6667 g / ml, nitrogen content 4 ppm, boiling range 32.5-114.0 ° C. ), The adsorbent was immersed for 24 hours or more at room temperature in a ratio of fuel oil: adsorbent = 9 g: 2 g, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 20 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that the sulfur concentration is lowered in the case of NaY type zeolite, NaX type zeolite, and KL type zeolite having a large adsorbent selection index.

[Fuel oil immersion adsorption experiment-10] The adsorption desulfurization performance of a gasoline base material was evaluated for NaY zeolite, NaX zeolite, KL zeolite, Na mordenite, K ferrierite, and copper oxide supported alumina. Catalytic cracking (FCC) gasoline base (aromatic content A: 2% by mass, total sulfur content: 26 ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, sulfur content of chain sulfides based on total sulfur content Ratio Rb: 0.49, ratio of sulfur content of cyclic sulfides to total sulfur content: 0.02, ratio of sulfur content of thiophenes to total sulfur content: Rd: 0.49, benzothiophenes relative to total sulfur content Sulfur content ratio Re: 0, dibenzothiophene sulfur content ratio to total sulfur content Rf: 0, density (15 ° C.) 0.6704 g / ml, nitrogen content 5 ppm, boiling point range 32.5-121.0 ° C. ), The adsorbent was immersed for 24 hours or more at room temperature in a ratio of fuel oil: adsorbent = 9 g: 2 g, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 21 shows the adsorbent selection index and the sulfur concentration after soaking. It can be seen that the sulfur concentration is lowered in the case of NaY type zeolite, NaX type zeolite, and KL type zeolite having a large adsorbent selection index.

[Fuel oil immersion type adsorption experiment-11] The adsorption desulfurization performance of a gasoline base material was evaluated for NaY zeolite, NaX zeolite, KL zeolite, Na mordenite and K ferrierite. Catalytic cracking (FCC) gasoline base (aromatic content A: 2% by mass, total sulfur content: 24 ppm, ratio of mercaptan sulfur content to total sulfur content Ra: 0.54, chain sulfide content to total sulfur content Ratio of sulfur content Rb: 0.02, ratio of sulfur content of cyclic sulfides to total sulfur content: Rc: 0.02, ratio of sulfur content of thiophenes to total sulfur content: Rd: 0.42, benzo to total sulfur content Ratio of sulfur content of thiophenes Re: 0, ratio of sulfur content of dibenzothiophenes to total sulfur content: Rf: 0, density (15 ° C.) 0.6704 g / ml, nitrogen content 3 ppm, boiling range 33.5 to 102. 5 ° C.), the adsorbent was immersed at room temperature for 24 hours or more at a ratio of fuel oil: adsorbent = 9 g: 2 g, and the sulfur concentration of the fuel oil before and after the immersion was measured. Table 22 shows the adsorbent selection index and the sulfur concentration after immersion. It can be seen that the sulfur concentration is lowered in the case of NaY type zeolite, NaX type zeolite, and KL type zeolite having a large adsorbent selection index.

[Fuel oil immersion type adsorption experiment-12] The repeated adsorption desulfurization performance of a gasoline base material was evaluated for a NaY-type zeolite molded product (binder: alumina 20 wt%, pellet diameter: 1.5 mmφ). 79Yg of NaY-type zeolite molded product, catalytic cracking (FCC) gasoline base (aromatic content A: 2% by mass, total sulfur content: 26ppm, ratio of sulfur content of mercaptans to total sulfur content Ra: 0, total sulfur content Rb: 0.49 of the sulfur content of the chain sulfides with respect to the total sulfur content Rc: 0.02 of the sulfur content of the cyclic sulfides with respect to the total sulfur content, Rd: 0.49 with respect to the total sulfur content , The ratio of sulfur content of benzothiophenes to the total sulfur content Re: 0, the ratio of sulfur content of dibenzothiophenes to the total sulfur content: Rf: 0, density (15 ° C.) 0.6704 g / ml, nitrogen content 5 ppm, boiling range 32.5 to 121.0 ° C) was poured until the adsorbent was completely immersed, and after 15 to 60 minutes, the operation of separating the FCC gasoline base material from the adsorbent was repeated. Table 23 shows the FCC gasoline base material injection amount and the sulfur concentration at each time. It can be seen that the sulfur content is 1 ppm or less until the seventh time.

Claims (2)

In a desulfurization method for removing an organic sulfur compound contained in a liquid hydrocarbon by bringing the liquid hydrocarbon into contact with an adsorbent, the organic sulfur compound is mainly composed of chain sulfides, and the liquid hydrocarbon has a nitrogen compound content of 10 ppm. NaX-type zeolite or NaY having a gasoline fraction with an aromatic content of less than 20% by mass and an adsorbent having a specific surface area of 400 m ² / g or more and a SiO ₂ / Al ₂ O ₃ molar ratio of 10 mol / mol or less. A method for desulfurization of liquid hydrocarbons containing 30 wt% or more of type zeolite and having an adsorption treatment temperature of 0 to 100 ° C. The method for desulfurizing a liquid hydrocarbon according to claim 1, wherein the chain sulfides are 0.3 or more in terms of the sulfur content of the chain sulfides with respect to the total sulfur content.