CS224795B1 - Manufacturing process of generator gas by partial oxidation - Google Patents

Description

The present invention relates to a process for the production of generator gas by partial oxidation. Gasification of petroleum residues is usually carried out in the pressure range of 2.5 to 6 MPa with oxygen and steam. The main product is generator gas which, after pre-treatment, is the starting material for the production of synthesis gases, eg for the production of methanol, for the oxonation of olefins and for the production of hydrogen. The pretreated generator gas can also be used in metallurgy to reduce ore as a so-called reducing gas. The by-product of partial oxidation is soot, which is washed out of the produced gas by pressurized water and is discharged from the gasification section as so-called soot water. From this soot water, the soot contained is separated by pelletizing with petroleum fractions such as gasoline or by means of atm, oil residue, and re-injected with the fresh feed into the generator. Installed partial oxidation units are equipped for gasification of atmospheric or vacuum petroleum residue and for recirculation of soot.

It has now been found that generator gas can also be produced by partial oxidation of other hydrocarbon feedstocks on equipment designed for gasification of atmospheric or vacuum petroleum residues.

The process for the production of generator gas by partial oxidation of carbonaceous raw materials with oxygen and steam at temperatures of 1250 to 1500 ° C and a pressure of 3 to 6 MPa consists in that the partial oxidation is subjected to a low temperature tar or a distillation residue thereof.

224 79S alone or in admixture with distillation residues of carbonaceous raw materials. Thus, the low temperature tar or the distillation residue thereof may be subjected to partial oxidation in admixture with 5 to 80%, preferably 50% petroleum residue, in admixture with the distillation residues from the ethylbenzene production, the distillation residue from the phenosolvan extract or the distillation residue from the oxoalcohol production. This can be replaced by water or steam condensate in the amount of 5 to 150 kg / t of feedstock. The feedstock may be all of the low-temperature tar produced by the pressure or atmospheric gasification of coal, or the atmospheric tar residue remaining after the distillation of the tar gasoline and optionally other fractions. petroleum distillation residues. The low-temperature tar usually contains the fractions obtained in the purification of petroleum and tar water as a separated hydrocarbon layer. These proportions are often referred to as oils.

Gasification of tar feedstocks or mixtures thereof with carbonaceous distillation residues can be more economical than gasification of petroleum feedstocks alone. Oak has been found, the conditions for the gasification of the tar raw material can be adjusted so that the total production of generator gas is maintained at a similar level. The specific consumption of tar raw material will increase insignificantly. It was assessed that 350 kg of tar raw material had to be gasified to produce 1,000 desulphurized generator gas, while gasification of atmospheric oil residue required 330 kg to produce 1,000 m ^{3 of} desulphurized generator gas. The lower specific yield of the generator gas from the partial oxidation of the tar raw material is due to the fact that the low-temperature tar contains a higher level of oxygen species, in particular phenols, which in part gasify water or water vapor.

Low-temperature tar can be gasified entirely as it is obtained in the production of municipal gas in pressurized gas plants or in the production of fuel gas at generator stations. If the interest in obtaining phenols, cresols, xylenols and aromatics contained in tar gasoline can be distilled from the low-temperature tar naphtha, for example, boiling in the range of 50 to 220 ° C and subjected to a partial oxidation to a tar residue boiling above 220 ° C, to the entire low-temperature tar

- 3 224 795 and / or the tar residue can be added to the tar and phenosolvan extract extract as well as to the petrochemical product. It has been verified that the following substances can be added to the tar raw material:

distillation residue of phenosolvan extract after distillation!

phenol - cresol fractions distillation residue from ethylbenzene production distillation residue from oxonacs propylene light and heavy fractions from distillation of 2-ethylhexanol light and heavy fractions from distillation of n-butanol and i-butanol

Such proportions may, for example, have the following composition:

Distillation residue from propylene oxonation (i.e., heavy fractions) density at 20 ° C 0.867 water content 0.5% wt org. nitrogen 0.46 wt

Phenol-cresol mixture distillation residue after distilling the phenol-cresol mixture density at 20 ° C 1.18 vacuum residue 320 ° C / 12 mm kg 19% by weight asphalts 16% by weight pyrocatechins 61 - 66.5% by weight

That the gas from the partial oxidation of the tar feedstock contains H? + CO in the highest proportion, it is desirable to modify the gasification conditions in contrast to the working conditions of the partial oxidation of the oil residues, and it is desirable to increase the amount of gasification oxygen and to reduce the amount of gasification steam. In addition, it may be appropriate to spray the condensate with the tar material.

The supplied low-temperature tars contain fluctuating emulsified water content and for further treatment of the tar raw material it is desirable that the obtained mixture has a reduced and in particular a constant emulsified water content, e.g. 1 to 5%. This amount of water in the coal tar feedstock does not have to be removed for subsequent partial oxidation.

224 795

It is important that the water content of the tar raw material does not fluctuate. The gasification reaction conditions are adjusted according to the water content. In order to avoid a sudden increase in the water content of the tar mixture, precautions are required. Usually it is sufficient to drain the tank into which the individual deliveries are bottled. It may be advantageous to incorporate a centrifuge in which the water content can be reduced to values below 1% by weight, even when hardening emulsions are formed. Also, the incorporation of a rotary evaporator to which the emulsified water is distilled off at atmospheric pressure makes it possible to maintain the water content of the gasification feedstock at the desired value. However, the use of emulsifiers is not always fully reliable.

Dewatered tar, usually containing 0.2 to 5% water, or its distillation tar residue, can be subjected to partial oxidation in admixture with petroleum residues, ie with oil or vacuum oil residue, □ if verified, the vacuum oil residue can be mixed with tar material, without excretion of asphaltenes and resins or other deposits. The mixing of both these raw materials proved to be useful only before entering the pressure generator of the partial oxidation.

The water contained in the tar mixture in an amount of 0.2 to 5% θθ when mixed with the vacuum residue has no adverse effect. The advantage of mixing the vacuum residue with the tar feedstock is that, in addition to the flexibility in gasification of these feedstocks, the viscosity of the inlet vacuum residue is reduced and that the vacuum residue prior to gasification does not need to be heated to more than about 240-250 ° C.

Similarly, the distillation residue from the production of ethylbenzene, the distillation residue from the detection of fensolvan extract, and the distillation residues from the production of oxoalcohols in admixture with petroleum residues, in particular petroleum.

The results obtained in the gasification of the tar feedstock as well as the suitable working conditions are given in the following examples.

- 5 Example 1

224 785

It feeds to the generator ee 9.9 tonnes per hour of tar residue, obtained from low-temperature tar after distillation of tar gasoline 50 to 220 ° C containing t, zv, dirty oil from sewage treatment, with the following parameters:

density at 20 ° C viscosity at 100 ° C flash point freezing point sulfur content solids content, coal dust ash content calorific value

1,077

5.3 mm / sec 137 ° C 0.7 in particular

0.2 wt% 0.05 wt% 37.37 MO / kg

Gasification takes place at a pressure of 3.5 MPa and a temperature of 1350 [deg.] C. 0.785 m < 3 > of oxygen and 0.52 kg of steam are metered into 1 kg of tar raw material.

Instead of 0.52 kg of steam, the addition of 0.45 kg of steam and 0.07 kg of condensate was also verified.

The obtained generator gas after washing the carbon black has the following composition:

H ₂ 43% v / v

CO 48,5% vol CO ₂ 5,5% vol H ₂ S + COS 0,3% vol CH ₄ , N _o + A 0,7% vol CO

350 kg of tar raw material are gasified to produce 1,000 m 2 of desulfurized generator gas. Carbon black isolated from soot water contains

0.3% by weight of ash without vanadium and nickel compounds.

875 m / g according to BET. For the recovery of the soot, the soot from the tar raw material is more suitable than the soot obtained from the gasification of petroleum residues.

Example 2

224 795

To the tar residue of Example 1 was added a detection residue from the production of ethylbenzene by alkylation of benzene with ethylene with AlCl ₃ as a catalyst.

density at 20 ° C flash point (closed cup) start of boiling point freezing point below combustion heat viscosity at 20 ° C

0.938 ° C 188 ° C

43.6 MO / kg 4.7 cSt

The distillation residue from ethylbenzene production was 5 to 6 tonnes per day at the time of the test. This amount was added in batches in an amount of 2 to 10% of tar material. This addition did not affect the gasification process. The obtained generator gas had a composition similar to that of Example 1.

Example 3

A mixture of low-temperature tar, obtained by mixing the supplies from pressurized gas and generator stations, and containing t. Dirty oil from a sewage treatment plant is drained in the tank, possibly by centrifugation, and exhibits the following characteristics:

density at 20 ° C 1,037 water content 1,2% wt sulfur content 0,66% wt solids content (mainly coal dust) 0,15% wt ash content 0,04% wt flash point (closed crucible) 46 ° C

This mixture is gasified at a pressure of 3.5 MPa, a temperature of 1 390 ° C 3 and 9.80 t / h of tar, 7 900 m _{n of} oxygen are metered into the generator,

- 7,224,788

5.1 t / h of steam, 800 kg / h of steam condensate, i.e. per kg of tar, 0.805 m @ 2 of oxygen, 1.520 kg of steam and 0.082 kg of steam condensate were dosed. After the desulfurization, the recovered gas produced had the following composition:

^H 2

WHAT WHAT,

H ₂ S

CH.

N ₉ +

Ar

41,5% vol 49,78% vol,

6.8% vol., 02% vol., 0.20% vol. * 1.5% Vol.

The amount of carbon black formed was 1.4 wt% per feedstock.

Example 4

A mixture of vacuum oil residue and tar residue, characterized in Example 1 in a ratio of 70 parts vacuum residue and 30 parts tar residue, obtained by mixing in the pipeline upstream of the generator is subjected to partial oxidation. In this case, the resulting gas is of conventional composition, the COg content is

5, i% vol. Even after 1150 hours of the experiment, no problems were found that would cause excretions, the operation of the generator was as smooth as the gasification of individual unmixed raw materials »The vacuum oil residue used in mixing has the following characteristics:

density at 90 ° C 962

130 ° C 936 sulfur content 3,27%

Conradáon test 18,10% ash content 0,06% viscosity inc

100 ° C frame ² / sec 426

200 ° C 24.5

mp 28.0 ° C

Claims (6)

SUBJECT OF THE INVENTION 224 795 Process for producing a generator gas by partial oxidation of carbonaceous feedstocks with oxygen and water vapor at temperatures of up to 150 ° C to 1500 ° C and a pressure of 3 to 6 MPa, characterized in that the partial oxidation is subjected to low temperature tar or its distillation residue alone or mixed with distillation residues of carbonaceous raw materials. Method according to claim 1, characterized in that the low-temperature tar or its distillation residue is subjected to partial oxidation in a mixture with 5 to 80% of the petroleum residue, preferably with 50% of the petroleum residue. 3. The process of claim 1 wherein the low temperature tar or distillation residue thereof is subjected to partial oxidation in admixture with distillation residues from the production of ethylbenzene. 4. The process of claim 1 wherein the low temperature tar or dest. the residue is subjected to partial oxidation in admixture with the distillation residue from the phenosolvan extract. 5. The process of claim 1 wherein the low temperature tar or distillation residue thereof is subjected to partial oxidation in admixture with an oxidation residue from the production of oxoalcohols. 6. Process according to claim 1, characterized in that the vaporising steam is replaced by water or steam condensate in an amount of 5 to 150 kg / t of feedstock.