JPS6010069B2 - Method for separating fine powder from gas cleaning liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing powder particles mixed in gas produced when coal or coal/heavy oil slurry is gasified, and a gas cleaning liquid particularly suitable for removing powder particles. The present invention relates to a method for separating powder from powder.

The gas produced when coal or coal/vehicle oil slurry is gasified contains a large amount of coal and fine particles.

In order to remove these tars and fine particles, the generated gas discharged from the gasifier is guided to a fluidized bed quencher to remove the tar, and the fine particles are collected in a cyclone. However, very small particles of powder and tar cannot be collected and are entrained in the gas, so they are removed by introducing them into a scrubber and washing them with water. The cleaning method is to send water from the cleaning liquid tank to the scrubber to wash away the powdery tar.
A circulation system is adopted in which the water is returned to the cleaning liquid tank together with the water.

Therefore, tar condensed on the surface of the powder is discharged from the scrubber at the same time as the cleaning solution. Therefore, when the gasifier is operated for a long period of time, the amount of powder particles in the cleaning liquid gradually increases and accumulates in the scrubber and in the cleaning liquid circulation pipe, thereby clogging the cleaning liquid flow path. For this reason, it is necessary to remove the powdery particles from the cleaning liquid discharged from the scrubber, and it has been considered to pass it through a filter. However, the powder mixed in the cleaning solution is so small that it is visible to the filter, making it difficult to separate the powder. In order to improve these drawbacks, a surfactant is added to water to create a cleaning solution, and this cleaning solution is used to wash away the particles from the generated gas.
Air is blown into the cleaning liquid containing these fine powders to foam them, and the fine powders suspended in the liquid are adsorbed to the surface of the foam, thereby separating the fine powders along with the foam, and the cleaning liquid from which the fine powders have been separated. The technology to recycle and use
It is shown in the publication No. However, blowing air into the cleaning liquid as in this technique has the disadvantage of requiring an air source such as an air pump. The present invention was made to improve this drawback, and its purpose is to:
The purpose is to foam a used cleaning liquid without using any equipment.

For this reason, a cleaning liquid made by adding a surfactant to water is supplied to the scrubber, and after cleaning, the cleaning liquid containing the powder is discharged to a cleaning liquid tank whose pressure is lower than that of the scrubber. It releases the absorbed gas and causes foaming.

In other words, the surface tension of the cleaning liquid that is mixed with the powder discharged from the scrubber is lower than that when the cleaning liquid is water due to the addition of a surfactant, and the cleaning liquid is more likely to foam inside the scrubber. It absorbs carbon dioxide gas, which is part of the generated gas. For this reason, the powder is collected and foamed in the cleaning liquid tank, which has a lower pressure than the scrubber, and the foam moves to the surface of the cleaning liquid tank and floats, so the foam is continuously removed using an electric impeller, etc. As a result, powdery particles are removed, and a cleaning solution with a small amount of powdery particles can be constantly circulated and supplied. The present invention uses water with a surfactant added as the cleaning liquid, and maintains the cleaning liquid tank at a lower pressure than the scrubber and releases the absorbed gas to produce an effect. 0.0% neutral detergent.
The cleaning liquid containing 5 wt% was used, and the scrubber pressure was 3.
．． 0k9/person in charge, coal/vehicle oil slurry supply amount 17k9/
h, steam supply amount 34k9/h, oxygen supply amount 10kg
The cleaning liquid tank was kept at normal pressure and the gasifier was operated for 6 hours to examine its effectiveness.

The drawing shows a comparison of the changes over time in the concentration of fine powder mixed in the circulating cleaning solution with the conventional method by suspending and continuously removing fine powder under the above-mentioned conditions of the present invention.

When water is used as the cleaning liquid, the powder concentration 1 in the cleaning liquid increases with the elapsed time after the start of gasification, and reaches approximately 1% after 6 feeding hours.

On the other hand, according to the present invention, when 0.5M of a neutral detergent is added to water, the powder concentration 2 in the cleaning solution increases slowly until about 3 field hours after the start of gasification, and increases to about 1. It becomes a fine t%, and there is almost no change after that, at 2.0 to 2. t%, and can constantly circulate and supply cleaning water with little powdery appearance. As described above, the present invention shows that the effect of floating and separating the powder particles mixed in the cleaning liquid in a state where they can be removed is extremely large.
According to the present invention, the powder particles that have entered the cleaning liquid can be made to adhere to the foam and suspended without using equipment such as an air pump, and the powder particles can be easily removed.

[Brief explanation of the drawing]

The drawing is a graph comparing the effects of the present invention with the results of the conventional method.

Claims (1)

[Claims] 1. A method in which coal and coal/heavy oil slurry are gasified and fine powder contained in the gasified gas is washed and removed with a cleaning solution made by adding a surfactant to water, in which the cleaning solution of the cleaning agent is applied at a pressure higher than that of a scrubber. A method for separating fine powder from a gas cleaning liquid, which is characterized by discharging the gas into a liquid layer with a low temperature, causing the gas absorbed by the cleaning liquid to be released and foaming due to a pressure difference, and floating and separating the fine powder from the cleaning liquid.