CS234796B1 - A method for producing a generator gas - Google Patents

Abstract

The invention relates to a method for producing producer gas by partial oxidation of petroleum or/and tar raw materials boiling in the range of atmospheric and vacuum distillation residue boiling points, in which the feedstock is partially oxidized by adding oxygen in an amount of 0.76 to 0.95 mn3, steam in an amount of 0.3 to 0.6 kg and carbon dioxide in an amount of 0.001 to 1 mn3 per 1 kg of feedstock. In this case, the production of soot is reduced from 2.75 to 3.5 % to a value lower than 2.6 percent.

Description

The invention relates to the production of producer gas by partial oxidation of petroleum and tar raw materials boiling in the range of the boiling point of atmospheric and vacuum distillation residue with reduced consumption of input distillation residue and reduced soot production.

During the partial oxidation of petroleum and tar raw materials, producer gas is obtained, which is the starting material for the production of technical hydrogen and synthesis gases for methanol production, oxonation and other syntheses.

In the gasification of petroleum raw materials, the usual raw material is atmospheric and vacuum residue from primary or secondary processing of crude oil. A by-product of partial oxidation is soot, which is washed from the produced producer gas with pressurized water. This results in soot water, which usually contains 11 to 20 g of soot per liter. The soot is separated from the soot water by so-called pelletization, in which the soot contained is converted into the form of easily separable balls, so-called pellets, using gasoline, kerosene, fuel oil or other petroleum fractions.

During the gasification of atmospheric petroleum residue, so-called fuel oil, 2.75 to 3.5% of soot is produced per input raw material.

The high selling price of crude oil and petroleum products and the expected decrease in the amount of crude oil offered in the future have resulted in work being done on methods to increase the yield of produced producer gas and reduce the specific consumption of the input raw material.

Of the raw materials for partial oxidation, the input distillation residue is the most highly valued and its savings are therefore most evident in the economic evaluation. The higher oxygen consumption is only reflected in the economic evaluation to a lesser extent, especially where oxygen is produced using coal-based electricity. The situation is similar with steam: the entire amount of steam required for gasification is obtained as the steam that is simultaneously lost.

It has now been found that the consumption of the incoming distillation residue can be reduced by adjusting the operating mode of the partial oxidation, without major modifications to the already installed generators.

The correction of the operating mode of partial oxidation of oil and tar raw materials according to the invention consists in that the raw material is partially oxidized by adding oxygen in an amount of 0.76 to 0.95 m _n ³ of oxygen per kg of input raw material, and that a mixture of water vapor and carbon dioxide is used instead of steam alone. 0.3 to 0.6 kg of water vapor and 0.001 to 1 m _n ³ of carbon dioxide are dosed per kg of input raw material.

Higher oxygen addition will allow the gasification temperature to be increased from the usual 1300 to 1320 °C to a value higher than 1340 °C.

The reaction temperature range depends on the quality of the lining used; for alumina-based linings, the gasification temperature can be up to 1420 °C, and for higher quality linings, the temperature can be even higher, for example 1500 degrees Celsius.

Under adjusted gasification conditions, the added carbon dioxide participates in the ongoing partial oxidation reactions and the majority of the carbon dioxide is converted to carbon monoxide.

The added carbon dioxide, which is converted to carbon monoxide, is then part of the produced producer gas: this proportion of carbon monoxide, transferred to the H2 + CO mixture, represents a saving of input raw material. As has been verified, carbon dioxide can be added both to water vapor and to the oxygen stream or to the oxygen-steam mixture.

Under modified partial oxidation operating conditions, the amount of soot produced is reduced; even with the addition of 0.001 to 1 m _n ³ carbon dioxide per kg of input raw material, the amount of soot was lower than 2.5%, usually below 2%, while under previously usual gasification conditions, 2.75 to 3.5% soot was produced, calculated on the gasified raw material (atmospheric oil residue).

Reduction of soot production can also be achieved by recirculating soot separated from soot water in the form of pellets; it was common to recirculate soot in an amount of, for example, 25 to 50%. The addition of potassium and sodium salts to the gasified raw material also has a beneficial effect on suppressing soot formation.

Savings in input raw material, achieved by adjusting the reaction conditions with the addition of carbon dioxide, arise during the gasification of petroleum or tar raw material boiling in the distillation range of atmospheric or vacuum distillation residue and also during the gasification of a mixture of both raw materials.

Example

The following table shows the course of partial oxidation of atmospheric petroleum residue (fuel oil) under usual conditions and the results achieved under modified partial oxidation conditions according to the invention.

One generator produced 24,000 to 30,000 _m3 /h ^of producer gas; its composition varied depending on the amount of carbon dioxide added.

For example, the composition of the produced producer gas was in this range:

CO2 (!% by volume) 4.5 to 7.5

H2O + CO (% volume) 90 to 94.5

CH4 (°/o by volume) 0.17 to 0.3

N2 + A (θ/o volume) 1.2 to 1.8

H2S + COS (% by volume) 0.25 to 0.5

Table

Production of generator gas, r

Amounts dosed into the generator

Quantity Recycle Temperature in Pressure in the ge- Quantity per kilogram of input material fuel oil to soot generator nerator soot to- generator (%) (°C) (MPa) soot oxygen couples oxygen (t/h) water (m _n ³ ) (kg) carbon dioxide (kg/-h) í (m _n ³ )

Partial oxidation under normal conditions

9,412 without recycling 1320 3.6 259 0.775 0.531 — Partial oxidation according to invention 9.5-65 50 1375 3.6 -197 0.78 0.45 0.04 9,616 50 1400 3.6 185 0.785 0.35 0.07 9,700 50 1390 3.6 170 0.79 0.4 0.06 8,900 — 1400 3.6 170 0.785 0.35 0.083 10.5-23 50 1390 3.6 170 0.810 0.54 0.057 9,450 — 1390 3.6 145 0.870 0.54 0.076

Claims (1)

PSEDMET of the invention Process for producing a generator gas by partial oxidation of petroleum and / or tar feedstocks boiling in the boiling range of atmospheric and vacuum distillation residue, wherein carbon dioxide is added to the generator in addition to oxygen and water vapor, characterized in that the feedstock is partially oxidized oxygen in an amount of from 0.76 to 0.95 m ³ _n, the steam-the amount of from 0.3 to 0.6 kg and carbon dioxide in an amount of 0.001 to 1 m ³ _n per 1 kg of feedstock.