DE1470471B - Process for reducing the sulfur content of hydrocarbons - Google Patents

Description

1 2

The invention relates to the reduction of sweating, in particular with oxygen-containing gases

oil content of hydrocarbons, for example, can be used.

Hydrocarbons derived from petroleum, in particular the invention relates to a method for

their petroleum fractions of high molecular weight. Reduction of the sulfur content of hydrocarbon

The presence of sulfur or sulfur-containing materials by an oxidizing 5 Raffinationsbehand compounds in petroleum crude oils, distillates and rear lung, wherein the hydrocarbons for ^l / ₂ to 20 Stunständen is usually highly undesirable. Many of the oxidizing agents will be selectively oxidized at 80 to 180 ⁰ C with such an amount of the valuable properties of these materials that 1 to 6 active oxygen atoms are impaired by the presence of sulfur compounds, so that their commercial value decreases. that is characterized by

So far, numerous processes have been used, it is noted that a petroleum fraction with at least

the undesired sulfur compounds contain 1 percent by weight sulfur and at least one

neither to remove them nor to form them in harmless forms. Share of hydrocarbons boiling ^{above 250 ° C.}

to convert. In one of these processes, one is subjected to oxidative refining treatment

Extraction with a liquid solvent such as 15 and that the oxidized material subsequently

Sulfuric acid, sulfur dioxide, furfural and the like, before at a temperature of over 250 ⁰ C thermally

taken. Another type of process is decomposition, with the sulfur being the sulfur-containing one

the sulfur compounds are removed by adsorption on gas.

suitable substances, e.g. B. activated bauxite, activated charcoal As input materials boiling over 250 ° C

or activated sound, removed. With a further 20 shares, in particular, raw oils and return ».

Processes are the undesirable forms of the atmospheric distillation and the

Sulfur compounds, ζ. B. Mercaptans, by vacuum distillation, contain sulfur in an amount of

various chemical treatments, e.g. B. containing plumbit, 1 percent by weight and more, used.

Hypochlorite and copper chloride, in less harmful ones, it is relatively easy to find the sulphurous ones

Forms such as disulfides and polysulfides. 25 gases to be eliminated. The energy requirements for the oxidative

The above processes are special and thermal treatment is relatively low

used for the treatment of gasoline fractions. For selective oxidation, a number of

det. Oxidizing agents are used, for example

In the case of feedstocks of high molecular organic and inorganic peroxides, hydroper weight, a large part of the material is in the form of oxides, organic and inorganic peracids, oxides of molecules containing at least one sulfur atom of nitrogen, ozone, molecular oxygen or contain, and especially in the case of selective separation processes, air. Molecular dignity is preferred as the oxidizing agent 'This portion is removed, so that the product is more oxygen or air because of its low cost. yield would be low. Molecular oxygen or air can get through

In a further type of process which are activated as suitable materials, e.g. B. by particularly advantageous for the treatment of medium metals of group Va and group III des distillate fractions, such as gas oils, are shown in the periodic table or their salts or oxides, Material usually with hydrogen under pressure especially platinum, palladium, nickel and vanadium. and at elevated temperature above a suitable These activators can be based on a suitable material, Catalyst passed, the sulfur atoms from 4 ° z. B. aluminum oxide, soda lime or activated carbon, the sulfur-containing compounds be applied in the form of. In cases where the carrier is hydrogen sulfide removed. This process material has acidic properties and thus column characteristics aims to dissolve the carbon-sulfur shafts, such as ζ. Β. Aluminum oxide, can Bonds in the sulfur-containing compounds, these by treatment with an alkali metal, ins-removal -des sulfur in the form of sulfur- 45 special sodium, or with an ammonium hydrogen and simultaneous hydrogenation of the compound being modified. Using this As a result of the desulfurization reaction remaining carbon activators improves the selective oxidation and hydrogen fragments. Such methods are also increased the rate of reaction, so that e.g. in U.S. Patents 2,450,724 and the process completed in less time or at lower 2 801 208. 5 ° lower temperature can be carried out.

However, it has been found that to achieve a The reaction conditions for the oxidation stage

substantial reduction in the sulfur content of high- depend both on the material to be treated

molecular material, for example from residue as well as from the oxidizing agent used.

heating oils, severe conditions for treatment. A temperature in the range from 80 to 180 ⁰ C is used

with hydrogen are required. Also, 55 becomes active with an oxidant amount ranging from 1 to 6

the life of the catalyst is determined by the formation of oxygen atoms per sulfur atom in use.

shortened by deposits. speaks, applied for a time from V ₂ to 20 hours.

Processes in which sulfur compounds are produced by using molecular oxygen or

Selective oxidation are removed, temperatures are already in the air as the oxidizing agent

known. 60 range from 130 to 180 ⁰ C and treatment times

For example, US Pat. No. 1972,102 can be used as an auxiliary from 2 to 20 hours.

play for an oxidation with hydrogen peroxide, the thermal decomposition takes place at temperatures

the USA. Patent 1954488 as an example for one above 250 ⁰ C, in particular in the range of

Oxidation with a salt of a peracid, the USA - 300 to 400 ⁰ C, carried out for a long enough time.

Patent specification 1803 964 as an example of an Oxy-65 that the release of all gaseous decomposition products

dation with ozone and the USA patents is ensured. This time can be in the range of

1 971 172 and 1 862 952 and the Swiss patent V2 up to 5 hours and is preferably

font 53 965 as an example of oxidations with oxy-V ₂ to 2 hours. Under these conditions we will.

the oxidized sulfur compounds decompose and the sulfur is mainly released as SO ₂ , but at higher temperatures in the range of 350 ^° C. and above, increasing _{amounts of H 2} S are also released. The thermal decomposition can also be carried out in the presence of suitable activators. Porous solids with acidic or basic properties are suitable for this, eg ferric oxide on aluminum oxide, bauxite, thorium oxide on pumice stone, silica-aluminum oxide, soda-lime and acid sodium phosphate on carbon. A small amount of an inert carrier gas, for example nitrogen, is preferably passed through the reaction mixture during the thermal decomposition in order to avoid local overheating and, furthermore, to remove the gaseous decomposition products.

example 1

An originating from Kuwait Petroleum atmospheric residue with a sulfur content of 4 weight percent, an initial boiling point of 370 ⁰ C and a viscosity at 50 ⁰ C of 405 cSt was first oxidized with various oxidizing agents and subsequently for 1 hour of thermal decomposition by rapid heating to 37O ⁰ C subjected. During the thermal

To decompose, a small amount of an inert carrier gas (nitrogen) was passed through the material, to remove the gaseous decomposition products and avoid local overheating. To the For comparison, the unoxidized residue was also subjected to decomposition. The results are listed in Table 1 below.

Table 1

Oxidizing agent Mole of reagent Oxidation ^:
temperature
⁰ C time
hours Sulfur content
in the product
Weight percent product
yield
% Cumene hydroperoxide
Tertiary butyl hydroperoxide
Nitrogen peroxide / air
Hydrogen peroxide / acetic acid
Molecular Oxygen
Barium peroxide gAtom S 110
85
30th
98
180
90 1
15th
<2
0.5
4th
0.5 3.9
3.6
2.9
3.7
3.5
3.7
3.6 99
95.8
95
99 2
7th
1
6th
0.6
6.0

Example 2

The residue from the atmospheric distillation mentioned in Example 1 was with molecular Oxygen is oxidized, which is applied in one case alone and then in the presence of various activators would. With the exception of the first catalyst, the amount of catalysts used was in Table 2 (nickel bromide on activated carbon) 12 percent by weight, based on the amount of the starting material. The oxidized material was then thermally decomposed as in Example 1 at 370 ° C. for 1 hour. The results are shown in Table 2 below.

Table 2 Modified by temperature
° C Absorbed
oxygen
1/100 g length of time
hours ■ Oxidizing agent Nickel bromide on activated carbon ...
Platinum on aluminum oxide
Sodium and platinum
Aluminum oxide
Ammonium and platinum
Aluminum oxide
Palladium on aluminum oxide.
Palladium on aluminum oxide.
Vanadium pentoxide
Aluminum oxide
Vanadium pentoxide
Activated carbon
Vanadium pentoxide
Soda lime
Sodium + vanadium pentoxide
on aluminum oxide 180
135
160
200
180
180
160
160
160
160
160 2.1
2.7
5.6
5.7
8.5
8.2
8.3
8.9
4.5
6.2
8.5 3.0
21
6.5
5.5
11.5
6.0
13.5
5.0
3.5
14.5
4.5 Sulfur content
in the product
Weight percent More molecular
Oxygen.... 3.9
3.2
3.3
3.5
3.4
3.5
3.5
3.5
3.5
3.1
3.5

Example 3

The residue of the atmospheric distillation mentioned in Example 1 was in the presence of Hydrogen peroxide and acetic acid are oxidized under the following oxidation conditions:

Residue 2 parts by weight

Toluene 1 part by weight

Glacial acetic acid, 1 part by weight

30% hydrogen peroxide .. amount containing 6 active oxygen atoms per
Sulfur atom corresponded

Temperature, 98 ° C

Response time 25 minutes

Stripping time 25 minutes

Decomposition activator Sulfur in the product
Weight percent No activator used
Fe ₂ O ₃ on aluminum oxide
Bauxite (rich in iron)
Thorium oxide on pumice stone
Soda lime "
Silica-alumina .... 3.0
2.9
2.9
2.7
2.8
2.8

Decomposition activator Sulfur in the product
Weight percent Sodium acid phosphate
money 2.8

IO

20th

The oxidized residue then underwent thermal decomposition for 1 hour as in Example 1 subjected at 370 ° C, first in the absence of activators and then in the presence of various activators. The amount of catalyst used was 12 percent by weight based on the amount of starting material. The results are shown in Table 3 below.

Table 3

35

40

Claims (4)

Patent claims: 1. Process for reducing the sulfur ■ content of hydrocarbons by an oxidizing refining treatment, the hydrocarbons being _{selectively oxidized for V 2} to 20 hours at 80 to 180 ° C with such an amount of the oxidizing agent that 1 to 6 active oxygen atoms are one sulfur atom of the starting material correspond, characterized in that a petroleum fraction comprising at least 1 weight percent sulfur and at least a proportion of about 250 ⁰ C boiling '"hydrocarbons of the oxidative refining treatment is subjected and in that the oxidising material is then thermally decomposed at a temperature of about 250 ° C , whereby the sulfur is removed as a sulfur-containing gas. 2. The method according to claim 1, characterized in that crude oil as the starting material, a residue from atmospheric distillation or vacuum distillation is used. 3. Process according to Claims 1 and 2, characterized in that the thermal decomposition is carried out at 300 to 400 ° C. 4. Process according to Claims 1 to 3, characterized in that the thermal decomposition carried out in the presence of a porous solid with acidic or basic properties the following auxiliaries are used in particular: ferric oxide on aluminum oxide, Bauxite, thorium oxide on pumice stone, silica-aluminum oxide, soda-lime or acid Sodium phosphate on charcoal.