JPS6166794A - Cleaning of parts clotted with sulfur in desulfurization unit for coke oven gas - Google Patents

Abstract

PURPOSE:The clogging substance containing sulfur is dessolved off by circulating a solution containing a specific amount of tar acids for washing to enable complete removal of the clogging substance without dismantling the installation and to obtain low-viscosity cleaning oil. CONSTITUTION:The clogging substance containing sulfur depositing in the installation, in where hydroge sulfide in the code furnace gas is removed by bringing the gas into contact with an absorbing solution containing alkali, is washed by circulating a solution containing tar acids in an mount of more than half of the cloggings, preferably more than equal volume. The resultant cleaning solution is mixed with tar and can be treated with a usual tar distillation plant. Thus, tar acid can be recovered as a distilate and high-polymer such as sulfur gum is used as a pitch polymerization catalyst to improve the binding effect of the pitch.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for cleaning sulfur-adhered blockages in coke oven gas desulfurization equipment.

(Prior Art) Conventionally, a redox reaction type wet desulfurization method for removing hydrogen sulfide from coke oven gas involves a step of bringing an absorption liquid containing a catalyst into contact with gas to absorb hydrogen sulfide into the absorption liquid; The process consists of bringing an oxygen-containing gas (e.g. empty %) into contact with the absorption liquid that has absorbed the hydrogen sulfide, oxidizing the hydrogen sulfide to elemental sulfur, and at the same time regenerating the alkali in the absorption liquid and the catalyst.

(Problem to be solved by the invention, 昺) However, in the process in which the absorbing liquid and gas come into contact, trace amounts of oil and unsaturated hydrocarbons contained in the gas may form a viscous mixture or mucilage with elemental sulfur. It formed and adhered firmly to the packed bed of the desulfurization tower, heat exchanger, etc., causing rI4 blockage, and eventually making the blasting equipment unable to operate.

Conventionally, as a countermeasure for this, the operation of the equipment is temporarily stopped, and if the closed hammer is a packed bed, the closed packed bed is taken out and cleaned with high-pressure noet, hot water, or hot ammonium water, and then restored to its original condition. The method was to put it in the equipment, assemble it, and restart operation, which required a lot of effort including disassembly, cleaning, and reassembly. In addition to the need for additional equipment, there were many other problems during this period, including the installation of spare equipment, a drop in desulfurization efficiency, and environmental issues related to cleaning.

In order to wash such ff
As disclosed in No. 07, cleaning with a mixture of ammonium water and 7-ethanol, a mixture of ammonium water and tar acid, or an aqueous tar acid solution is an extremely effective means. However, although this method has a cleaning effect, it has the following problems.

■If the tar acid concentration is 70% or more, there is a cleaning effect, but cleaning with a mixed solution containing a large amount of water is safer and the dispersibility of the mixed solution during cleaning is better.

■To burn the liquid after cleaning, tar a concentration is 20%.
The above is necessary.

(Means for Solving the Problems) The present invention further improves the cleaning method in order to solve these 1121 problems. In other words, by washing at room temperature or low temperature without heating with a solution containing tar acid of a degree (1/2 or more by weight to the blockage), the sulfur-attached blockages are completely dissolved and removed by the solution. This method takes advantage of the fact that a cleaning and dissolving oil with a low viscosity can be obtained at the same time, and instead of the absorption liquid of the coke oven sulfurization equipment, tar acid is added at a weight ratio of 1/2 or more to the clogging material, preferably 1 i It is possible to completely clean the equipment without disassembling the equipment by simply circulating a solution containing one or more of the above.

(Function) According to this cleaning method using tar acid solution, blockages are almost completely dissolved.
) is also effective in preventing the phenomenon in which occlusions peeled off from the occlusive filling layer (tA1 Fig. 2) adhere and make cleaning even more difficult.

If the weight ratio of tar acid to blockages is lower than 1/2, the effect of dissolving blockages will decrease, and the amount of undissolved substances will increase after cleaning, so it will take a lot of effort to remove the blockages from the tank. A new problem arises in that it is costly.

However, in the method of the present invention, which uses a solution in which the weight ratio of tar acid to the blockages is 1/2 or more, all the blockages are dissolved at room temperature or low temperature, and after cleaning, the solution is pumped through the blow line using a pump or the like. By simply extracting it, it has the effect that it can be processed economically after cleaning.

Incidentally, the energy of the solution after washing is recovered by incineration, or the tar acid is recovered by distillation, and the residue can be effectively used as a pitch modifier.

When a solution in which the weight ratio of tar acid to the blocked substance is 1 or more is used, the effect of the present invention becomes extremely noticeable.

In particular, the cleaning liquid that dissolves sulfur-adhered blockages generated during cleaning processing is a liquid with low viscosity at room temperature, and water can be separated by IF separation, and the dissolved cleaning liquid from which water has been separated can be incinerated. .

In addition, this cleaning solution can be mixed with tar etc. and processed in a normal tar distillation plant, and the tar acid of the cleaning agent is recovered as a distillate, and at the same time, the sulfur molecule components such as sulfur are removed by polymerization of pitch. It was found that t40R is effective as a catalyst and in improving the pineapple characteristics of tuna.

Next, the present invention will be explained in detail based on the drawings.

In Fig. 1, 1 is a desulfurization tower in which the coke oven gamma gas and the absorption liquid are in countercurrent contact, and 2 is a packed bed containing plastic packing, which is blocked by sulfur-adhered blockages. 3 is also a packed bed with a plastic filler in it, but I11 is not blocked, and 4 is a tank in which tar acid for carrying out the method of the present invention is contained in a weight ratio of 1 to the blockage. .5 (tar acid concentration 30%), this solution flows down from the top of the desulfurization tower via circulation line G by pump 5, returns to tank 4, and is recirculated. 7 is a blow line at the bottom of the tank.

The blockages adhering to the packing in the packed bed 2 are dissolved by the tar acid solution and flowed down with the solution, and the blockages in each stage are almost completely dissolved and removed by circulating cleaning, and the blockages are removed from the bottom of the desulfurization tower. Collects at the bottom of tank 4.

(Example) Next, Table 11 shows an analysis example of the sulfur-containing coating of the desulfurization tower and an analysis example of the cleaning cloth in which the clogging material was washed and dissolved by the method of the present invention. An example of analysis is shown in Table 2.

Furthermore, use the above tar acid to remove sulfur-adhered blockages by 7f! Table 3 shows the properties of the oil obtained by distilling and recovering the washed solution.

Also, the above cleaning treatment on tar? Table 4 shows the modification effect of the residual pitch in the case of addition distillation of &3%.

Table 1 Table 2 Example of analysis of the tar acid cleaning solution used , coal tar-based absorption oil, creosote oil, etc., at room temperature to super-temperature!!, the complete dissolution effect as in the method of the present invention could not be obtained.

(Effects of the Invention) As described above, according to the method of the present invention, it is possible to completely clean a 1 fl liter of sulfur-adhered offerings from coke oven gas desulfurization equipment with a homemade tar acid solution without dismantling the equipment. This provides significant AI benefits in reducing processing costs, such as shortening cleaning time, reducing equipment dismantling costs, reducing heating costs for cleaning fluids, and reusing clogged slag after cleaning is completed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a desulfurization tower for carrying out the method of the present invention. 1... Desulfurization tower, 2... Packed bed, 3... Packing j-,
4...Tank, 5...Pump, 6...Circulation line, 7...Blow line.

Claims (1)

[Claims] (1) Cleaning sulfur-adhered blockages in equipment that removes hydrogen sulfide from coke oven gas by contacting coke oven gas with an absorption liquid containing alkali using a solution containing tar acid at a weight ratio of 1/2 or more to blockages. A method for cleaning sulfur-adhered blockages in coke oven gas desulfurization equipment.