CS255706B1 - A method for producing a gas generator by gasifying an oil residue - Google Patents

Abstract

A method for producing a generator gas by gasification of a petroleum residue from primary and / or secondary oil treatment by partial oxidation with oxygen and water vapor at a pressure of 3 to 6 MPa with the addition of carbon dioxide as a gasification medium in which waste gases from acetaldehyde production are added to carbon dioxide or / and and, dispersing liquid portions into the liquid feedstock in an amount of 8 to 10 t / h, eliminating the distillation of the crude acetaldehyde in an amount and scrubbing off the scrubbing effluent from the production of acetaldehyde in an amount of 15 to 25 kg / h.

Description

The invention relates to the production of producer gas by partial oxidation of oil residues from primary or secondary oil processing. In the petrochemical and oil industries, a significant portion of hydrogen and synthesis gases intended for the production of ammonia, methanol, oxonation of olefins, etc., are produced by partial oxidation of oil and tar residues. In this gasification using oxygen and steam carried out at elevated pressure, usually in the range of 3 to 5 MPa, atmospheric oil residue, vacuum residue and distillation residues from secondary oil processing, such as from visbreaking, can be gasified.

Other fractions for which there is no effective use can also be subjected to gasification by partial oxidation, such as pyrolysis oil, waste in pyrolysis units producing ethylene and propylene, waste oils from wastewater treatment, and others.

In the interest of saving crude oil, there is interest in gasifying other wastes and intermediate products from various petrochemical productions. It is essential that after adding these wastes and intermediate products to the basic crude oil, there are no problems either during the gasification itself or during the subsequent processing of the producer gas and in the purification of waste water. One of the wastes generated in petrochemical productions is liquid and gaseous wastes from the production of acetaldehyde, obtained by catalytic oxidation of ethylene. These substances are characterized by the fact that they contain small amounts of organic chlorine compounds. When they were burned in a field burner, as was customary until now, the flue gases emitted also contained hydrogen chloride.

255,708

However, increasingly stringent requirements for air purity require that the amount of undesirable substances released, including hydrogen chloride, be minimal or that its release be prevented altogether. Although separating hydrogen chloride from flue gases is technically feasible, it is costly in terms of investment and operation.

Data on the quantity and analytical data on waste from acetaldehyde production with a production capacity of approximately 10 t/h are given in the following tables:

Off-gases from acetaldehyde production: reaction off-gas gas from distillation quantity m^/h approx. 300 50 composition: e ty len % vol . 65 to 70 10 to 20 acetaldehyde % vol. - 20 oxygen % vol. about 7 - carbon dioxide % vol. 15 to 20 25 inertness % vol. 8 to 10 30 to 40 ethane + methane % vol. 2 to 1 - chlorinated hydrocarbons % vol. (CH ₃ C1, ch ₃ ch ₂ ci) 1 5 water saturated - amount of chlorinated organic substances m^/h 3 2.5

In total, 5.5 m^/h of chlorinated organic substances with a chlorine content of approximately 9 kg are produced.

Oh

255,706

Liquid fractions (crude crotonaldehyde fraction from crude acetaldehyde distillation) about 20 kg/h composition in wt.%

crotonaldehyde acetaldehyde water other organic substances chlorine content max. kg/h up to 60 up to 10 5 up to 10 up to 40 1

The use of the reaction off-gas as a raw material for partial oxidation is made more difficult by the fact that it contains around 7% by volume of oxygen. If it is to be gasified, it must be available at a pressure of around 3.5 MPa. Compression of this reaction off-gas, even in a mixture with distillation off-gas, cannot be recommended for safety reasons.

It has now been found that gaseous and liquid waste products from the production of acetaldehyde by catalytic oxidation of ethylene can be utilized in the production of producer gas by gasification of petroleum residues. The method for producing producer gas by gasification of petroleum residue from primary or/and secondary processing of crude oil by partial oxidation with oxygen and steam at a pressure of 3 to 6 MPe. with the addition of carbon dioxide GOg as a gasification medium according to the invention consists in adding waste gases from the production of acetaldehyde to carbon dioxide in a volume ratio of waste gases: COg of 0.7 to 1.5, preferably 1, or/and adding liquid fractions from the distillation of crude acetaldehyde and washed fractions from the washing of the waste gas from the production of acetaldehyde in an amount of 15 to 25 kg/h to 8 to 10 t/h of liquid raw material.

The added waste materials from acetaldehyde production are converted into the usual components of producer gas. The organic chlorinated compounds contained are converted into hydrogen chloride during gasification, which passes into the soot water during soot washing and is converted into sodium and ammonium chloride by the ammonia and alkali contained. The main amount of organic chlorine compounds, especially methyl chloride and ethyl chloride, is in the gaseous fractions. The amount of gaseous and liquid waste fractions from acetaldehyde production in

255 70B ratio to the oil residues fed to the gasification process is small and its addition does not affect the composition of the resulting producer gas. Also, the amount of hydrogen chloride formed is neutralized (with a large reserve) to chlorides during the technological process of producer gas production by water washing of soot, without the need for additional measures.

More details are provided in the following examples.

Example 1

8.83 t/h of oil residue from vacuum distillation and 350 m^/h of off-gases from acetaldehyde production, of the above composition, are dosed into the pressure generator. The off-gases are dosed together with 500 m^/h of carbon dioxide after compression to 3.8 MPa.

Partial oxidation takes place at a pressure of 3.5 MPa and at

at a temperature of 1,350 to 1,380°C. For one kg of input 3 it doses 0.76 oxygen and 0.49 kg steam. raw materials Obtained generator gas has soot after washing this composition: _CO2 6.22% vol · WHAT 45.50 ' ^H 2 46.20 .. ch ₄ 0.31 N ₂ + A 1.44 H ₂ 3 0.33 Soot was created 2.1% by weight, counted on entry raw material.

Example 2

The liquid fractions, which are lost during the distillation of raw acetaldehyde, are stored in a special tank in the partial oxidation plant, from which they are dosed under a pressure of 3.6 MPa into the pressure generator. 9,374 kg/h of atmospheric residue and 20 kg/h of raw crotonaldehyde fraction of the following composition are dosed into the pressure generator:

255,706

crotonaldehyde 53.4% by weight acetaldehyde 5.5 water 6.2 chlorine .4.8 other organic substances 30.1 Gasification is carried out at a pressure of 3.5 MPa

37O°C. oxygen and

0.535 θζ 0.57 kg of steam.

The obtained producer gas has the following composition after washing out the soot:

_CO2 4.97 WHAT 45.80 ^H 2 47.26 ck ₄ 0.27 N ₂ + A 1.37 h ₂ s + COS 0.33 created 1.98 % by weight

% vol.

M tl n

« , calculated on mixed raw material.

The addition of the crude crotonaldehyde fraction was not evident.

Under the conditions of producer gas production, the organic compounds were converted to CO?, H^O and HC1. The composition of the producer gas produced was similar to that without the addition of the crude crotonaldehyde fraction. The contact time of the gasified petroleum residue and the added liquid waste from acetaldehyde production is short, about 13.5 seconds. No problems were observed in the preheater, nozzle or generator.

Example 3

9,421 kg of petroleum vacuum residue, 350 m^ of off-gases from acetaldehyde production and 20 kg of crude crotonaldehyde are dosed into the pressure generator per hour. The off-gases are dosed together with 350 m^/h of carbon dioxide after compression to 3.8 t. The gasification was carried out at 3.5 MPa and a temperature of 1,380°C.

Per 1 kg of input raw material, 0.768 m^ of oxygen and 0.490 kg of steam were dosed.

255,708

The obtained producer gas had, after washing out the soot, the following composition:

cc ₂ 5.70 what 45.96 h ₉ 46.46 ch ₄ 0.22 _No + A 1.36 _H23 + COS 0.30

% vol.

In the

tt w

n

Soot was 1% by weight, calculated on the input raw material.

Example 4

The amount of hydrogen chloride produced during the production of the producer gas according to the invention under the conditions given in the previous examples is around 10 kg per hour. Most of the hydrogen chloride comes from the gaseous fractions left over from the production of acetaldehyde.

In the wastewater from partial oxidation, the HCl content increases by about 100 mg/l. Since the gasified oil residue also contains residual chlorides, e.g. 8 mg/l as NaCl, the total HCl content in the wastewater is about 135 mg/l.

The obtained soot water had the following compositions during the tests:

pH 9.2 content

c ₍ g/1 9 until 11 HUNTING mg/1 70 until 150 h ₂ s mg/1 180 until 250 no ₃ mg/1 550 until 1100 WHAT. g/1 2.5 until 3.5 Cl* mg/1 135 until 140 Fe mg/1 7 None mg/1 24 In mg/1 40 On mg/1 1,270 About mg/1 3

There is enough Spavk in the wastewater to neutralize the extra hydrogen chloride that has formed.

Claims (1)

Process for producing a generator gas by gasifying a petroleum residue from a primary and / or secondary oil treatment by partial oxidation with oxygen and water vapor at a pressure of 3 to 6 MPa with the addition of carbon dioxide CC ₂ as a gasification medium. Addition of gases from acetaldehyde production in the volume ratio of off-gases: CO ₉ 0.7 to 1.5, preferably 1 or / and to 8 to 10 t / h of liquid raw material liquid fractions leaving during distillation of crude acetaldehyde and scrubbed fractions from scrubbing off from the production of acetaldehyde in an amount of 15 to 25 kg / h.