Coal is an irreplaceable energy source in my country, not only in large reserves but also in high quality.
The state vigorously advocates the development of coal-to-gas technology, which uses a gas generator to carry out a series of redox reactions on coal to turn coal from solid into gas as fuel.
The sewage in the gas production process mainly has two parts: one is the washing sewage, which not only contains a large amount of cod, but also a large amount of cracked tar and harmful chemicals.
The second is gas condensate. This kind of sewage has less cod, but this kind of sewage contains phenol and other harmful substances, which is highly toxic and highly corrosive, causing great damage to the environment. Absolutely no escaping is allowed.
The two kinds of water were mixed and recycled in the past, but after reaching a certain concentration, they were forced to be discharged or treated by incineration. The incineration method uses coal gas and the by-product tar and light oil in the production process as fuel, and the harmful substance phenol is cracked in the high temperature state, and the decomposition produces co2 and h2o.
This consumes a lot of gas and increases the cost of enterprises, and most enterprises do not use it.
Over the years, some companies have also tried many water treatment methods, such as: sedimentation method, air flotation method, chemical method, etc., but the effect is not satisfactory.
In recent years, due to the problem of sewage treatment in the gas station, the development of the coal-to-gas industry has brought a lot of challenges. In order to solve this problem, many domestic manufacturers have changed the original direct contact cooling in the gas purification process to indirect cooling. Cool, that’s a big improvement.
Each generating station of this kind of condensed sewage can produce 5 tons/day, which is not a small amount. How to make full use of water resources is a difficult problem, especially this kind of sewage is highly toxic and must not be discharged outside.
Therefore, we propose to vaporize this sewage as a gasification agent in the process of coal-to-gas, so that it can be fully utilized.
However, it was found to be highly corrosive during use. In the two-stage boiler gas station, a lot of experiments and researches have been carried out on the gas condensate.
In the indirect cooling process, when 1 ton of coal is gasified, about 80-150 kilograms of condensed water is precipitated, and ph=7-8.5.
The main chemical substances contained in it are: Phenol ≥ 8000 mg/L, Oxide: 20 mg/L, Sulfide: 200-300 mg/L, Sulfate and Bisulfate: 8000 mg/L The content of cod is 30000ppm.
The carburetor generally needs to be repaired once every 2-4 months, which not only affects the production, but also costs a lot of maintenance, which is not worth the loss.
In view of the above-mentioned deficiencies in the prior art, the present invention provides a gas condensed water treatment method that reduces environmental pollution, increases the added value of products, and prolongs the service life of equipment.
The technical scheme adopted by the present invention is:
A gas condensed water treatment method, the gas condensed water enters a phenol water tank through a pipeline for precipitation, then passes through a filter device to filter the gas condensed water, and the filtered gas condensed water is discharged through a pipeline.
- It includes the following steps: the gas condensate water flowing out of the phenol water tank is separated from oil and water in the oil-water separation device.
- The oxidant is added to the gas condensed water after oil-water separation, and the secondary precipitation is in the phenol water tank.
- The gas condensed water after the secondary precipitation is filtered by the filter device, and then preservatives are added.
- The preservative-added gas condensate is mixed in the mixer and discharged through the pipeline.
- The oil-water separation device is composed of a machine base, a transmission device, a rotary drum screen, a liquid collecting pan, and a liquid inlet.
- The oil and gas condensate is injected into the high-speed rotating drum from the bottom liquid inlet, and the drum drives the blades to rotate the oil-water mixture to form a strong centrifugal force.
- The oil and water are separated due to the existence of density difference under the action of centrifugal force, and the separated water enters the water collecting tray through the drum channel and is discharged from the water collecting tray.
- The separated oil enters the oil collecting pan through the drum channel and is discharged from the oil collecting pan. A few large particles sink to the lower part of the drum wall and are discharged from the sewage outlet.
- The rotating speed of the drum of the oil-water separation device is 8000-10000 rpm.
- The height of the blades in the drum of the oil-water separation device is 600 mm.
- The diameter of the liquid inlet hole of the oil-water separation device is 3 mm to 4 mm in diameter.
- The mixer consists of a cylinder body, legs, a sewage tank, a cylinder body, a water inlet, a water outlet and a mixing device.
- The gas condensate enters the channel between the mixing device and the cylinder from the water inlet of the mixing cylinder, and the liquid is rotated through this channel, and the gas condensate flows in the channel with changing cross-section.
- The mixed liquid part is discharged into the next process through the water outlet of the mixer.
The beneficial effects of the present invention relative to the prior art:
The added value of the product is increased, the service life of the product is prolonged, the pollution is reduced, and the environment is protected.