The issue of high moisture content in tar
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This post was last edited by yfb777 on 2010-4-1 15:08. Recently, the moisture content in tar has suddenly increased; its density and viscosity have risen as well, along with the level of free carbon, and the amount of toluene-insoluble substances has also increased. Firstly, there are no significant changes in the types of coal used for blending or in their quality; equipment operation remains largely the same as before, and there are no substantial fluctuations in the temperature of the coke ovens. Please discuss what other factors might be contributing to the high moisture content in the tar. The problem at present is that the tar is difficult to dehydrate, as it has a high viscosity. The heating temperature in the tar tank is around 70 degrees, and the maximum time allowed for dehydration by letting it sit is 36 hours, yet the moisture content remains high. Date, Density, Moisture, Toluene-insoluble matter, Ash content, Viscosity: February 10th, 1.193, 4.2, 4.4
I want to know what’s going on too. Could some expert explain it to me?
I have seen materials on this topic. In the emulsification of tar, an demulsifier can be added to accelerate and improve the separation process between tar and ammonia water. Through demulsification, dispersion, and viscosity reduction, the emulsion layer of ammonia water and tar is thinned, thereby enhancing the efficiency of separating tar from ammonia water. This leads to a lower content of suspended particles in the ammonia water, as well as a slight reduction in the surface tension of the tar, which speeds up the separation of tar from tar residues and results in tar with lower levels of moisture and residues
3# Xue Li: Tar emulsification caused by excessively high temperature in the furnace top area. There are roughly the following reasons for this: First. The coal loading is insufficient, resulting in excessive space at the top of the furnace and a longer residence time for the gas. II. The standard temperature is too high, resulting in an excessively high temperature in the space above the furnace. Three. Poor suction coordination, with negative pressure at the flame viewing port, can also cause this situation
High phenol content is one of the reasons
This post was last edited by hao101029 on 2011-11-3 20:22. Check the level gauge with a separated interface! The most important thing is to control the interface of the ammonia water tar separator well; try lowering the upper limit of the tar separation interface.
2# xhmahailong OP, has there been any improvement regarding the issue you mentioned these past couple of days? Has your factory identified the cause? Find out the reason and discuss it in the talk; we can also learn from it.
1# yfb777 I’m sorry, I clicked by mistake; I actually wanted to address the original poster. Has the issue you mentioned, OP, improved in these past two days? Has your factory identified the cause? Find out the reason and discuss it in the talk; we can also learn from it.
The key is to maintain stable operation of the coke oven, control the temperature in the oven roof area, manage coal charging properly, and ensure that the fineness of the blending coal is not too high.
First of all, it can be determined that the tar has been emulsified. Generally speaking, the coke oven is the main cause of this issue. Based on our plant’s past experience, the operating parameters related to chemical production remain essentially unchanged. The key is to address factors such as the height at which coal is loaded, the fineness of the coal, and the flatness of the coal cakes, as well as to reduce the temperature in the space above the furnace. Things will improve over time; there’s no need to rush.
It is indeed difficult to determine the cause of the problem with tar not drying out; after all, the density is high, viscosity increases, free carbon levels are high, and toluene-insoluble substances also increase. With so many factors changing, it is certain that this must stem from coking management, especially the temperature in the furnace top space.