JPS60137803A - Production of synthesis gas - Google Patents

Abstract

PURPOSE:An appropriate amount of ammonia is added to the furnace or after the furnace process in which liquid hydrocarbon is partially oxidized in the presence of molecular oxygen and steam to produce synthesis gas without erosion of the installation. CONSTITUTION:In the production of synthesis gas where liquid hydrocarbon such as naphtha-cracked oil is partially oxidized in the presence of molecular oxygen such as air or oxygen gas and steam in a furnace such as a shell furnace, 0.6- 3kg, per 1t of the hydrocarbon, of ammonia is introduced into the furnace or the scrubber thereafter, whereby the pH of water-slurry in the gas scrubbing is kept higher than 7, preferably 8 or higher to prevent the installation from being eroded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing synthesis gas by subjecting liquid hydrocarbons to a partial oxidation reaction in the presence of molecular oxygen and water vapor in a furnace.

According to the method of the present invention, synthesis gas can be produced while suppressing corrosion of the synthesis gas generator η.

BACKGROUND ART Conventionally, methods for producing synthesis gas using hydrocarbons as raw materials include the Shell method, the Texaco method, and the like, which apply partial oxidation reactions. The feature of these partial oxidation methods is that the raw material hydrocarbon is subjected to a partial oxidation reaction with molecular oxygen in the presence of water vapor to gasify it. In the produced crude synthesis gas, impurities contained in the raw material hydrocarbons, namely sulfur and nitrogen, are converted to hydrogen sulfide and ammonia as hydrides under the synthesis gas production conditions, and the crude It is included as an impurity component in synthesis gas. At the same time, in addition to the by-product carbon that has reached equilibrium, carbon dioxide gas, unreacted water vapor, etc. are also entrained as impurities in the crude synthesis gas.

This crude synthesis gas is washed using cooled drained water and separated into slurry water containing the above-mentioned accompanying impurities and synthesis gas. Slurry water contains plundered carbon powder, but some of the gases such as ammonia, hydrogen sulfide, and carbon dioxide are dissolved in the slurry water, and the final result depends on the partial pressure of impure gas components at that time. This will affect the pH of the slurry water.

On the other hand, since the carbon produced as a by-product in the production of synthesis gas as described above has particularly excellent conductivity, research is being conducted to improve the quality of carbon by-product in conjunction with the production of synthesis gas. When carbon atoms determined by elemental analysis are used as a raw material instead of C'' oil, which has superior quality to this by-product carbon, the electric content contained in the raw material is lower than that of, for example, C heavy oil. The content is extremely low.For this reason, the partial pressure ratio between ammonia gas, which is a by-product in the synthesis gas, and carbon dioxide gas and hydrogen sulfide gas becomes large, and the pH value in the slurry water is extremely low, at 5 or less. The PH of slurry water causes acid corrosion to equipment in the parts of the equipment where slurry water is present.
In order to solve the problem of equipment corrosion due to low oxidation rate, we have conducted intensive studies to develop a method for producing synthesis gas by performing a partial oxidation reaction in the presence of oxygen and water vapor. 0.6 to 1 ton of the hydrocarbon
The present invention provides a method for producing synthesis gas, characterized in that the operation is carried out by supplying ammonia of 3.

Partial oxidation furnaces to which the method of the present invention is applied include shell furnaces and Texaco furnaces, but shell furnaces are particularly preferred for oxidizing natural gas, crude oil, naphtha, kerosene, C heavy oil, etc., which generally contain a large amount of methane. In addition to heavy oils, asphalt, etc., carbon oil (liquid hydrocarbon in which carbon is mixed with aromatic liquid hydrocarbon), aromatic type There are mixed oils in which liquid hydrocarbons are mixed with C heavy oil, etc., and the raw materials for which the method of the present invention is particularly suitable include naphtha pyrolysis oil (ethylene heavy end) with a carbon atom/hydrogen atom weight ratio of 12 or more; A mixture of carbon and ethylene heavy end is subjected to partial oxidation reaction in the presence of molecular oxygen and water vapor. In the partial oxidation reaction, the temperature range in the furnace is 1200 to 1500 °C and the pressure in the furnace is 10 to 8 °C.
0~/cd, the amount of steam supplied into the furnace is 200~800 odors per ton of raw material hydrocarbon, and the partial oxidation reaction system or the process after the furnace, e.g. reaction product gas 0.6 to 3 V per ton of hydrocarbon in water washing process, etc.
4. Preferably, it is necessary to supply 0.75 to IKg of ammonia to carry out the reaction. As the ammonia source to be supplied, ammonia gas, aqueous ammonia, etc. can be used.

By carrying out the partial oxidation reaction under such conditions, the P of the slurry water can be reduced even if a feedstock hydrocarbon with a low nitrogen content is used.
The H value can be maintained at 7 or more, preferably 8 or more, and the problem of corrosion in the synthesis gas production equipment is solved.

Experimental Examples 1 to 6 The properties of the raw material hydrocarbons are as follows: Initial distillation temperature: 180-190°C 10% distillation temperature: 205-215°C 50% distillation temperature: 250-260°C 979I+distillation temperature: 320-340°C Viscosity (80°C)
) About 1. Ocst Carbon carbon atom/water atomic weight ratio) 1:2.5 sulfur content o
, oswt% nitrogen content 0. ．． Ethylene heavy end with a very low nitrogen and sulfur content of 0.01 wt was used in the furnace of the shell gasification process.

Inside the furnace: 25 thiammonia water is emulsionized and mixed with the feedstock hydrocarbon in the amount shown in Table 1, and the amount shown in Table 1 is mixed and supplied.
Kg/ca -G and the reaction was carried out with the dimensions shown in Table 1.

(The following is a blank space) The obtained crude synthesis gas was introduced into a water washing tower, and the water was washed 12 times by countercurrent flow at a water supply amount of 2.5 tons/1 ton of raw material hydrocarbon, and synthesis gas and slurry water were obtained. The pH of the slurry water at this time is as shown in the table below.
It was as shown in 1. In addition, the composition of the synthesis gas obtained in Experiment 1@6 was -53.7 volumes of carbon oxide, 42 volumes of hydrogen.
．． 0 volume, carbon dioxide gas, 3.4 volume, and other 0.6 volume, and the amount of by-product carbon collected from slurry water is i65/1 ton of raw material hydrocarbon, and its DBP oil absorption CJIS- 6221, and the amount of dibutyl phthalate (DBP) absorbed by the carbon of sample 9f (m/) was converted to the carbon amount of 1001 [also the value] was 365 m1/Loof.

Patent applicant Mitsubishi Yuka Co., Ltd. Agent: Patent Attorney Hidetoshi Furukawa Agent: Patent Attorney Masahisa Nagatani

Claims (1)

[Claims] (1) In a method for producing synthesis gas by subjecting a raw material liquid hydrocarbon to a partial oxidation reaction in the presence of molecular oxygen and water vapor in a furnace, the hydrocarbon 1 A method for producing synthesis gas, characterized in that operation is performed by supplying 0.6 to 3 kg of ammonia per ton.