It is said that using large-scale steam injection in delayed coking yields good results in saturating the water (question)
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It is said that replacing large-scale steam injection in delayed coking with saturated water can save energy; I wonder what the effects are? What impact does it have on the quality of coke, and are there any changes in the oil content?
The purpose of performing large-scale and small-scale purging in coking units is to remove the residual oil and gas remaining in the old towers. Superheated steam is generally used for this purpose, as it has a high temperature and fast flow rate. If saturated water is used, the temperature drops, resulting in a poorer effect in removing oil and gas; moreover, more water is required, which increases the load on the subsequent oil-water separation process. Therefore, I believe that steam should still be used for this purpose.
I am working on related projects, studying *studying*
Personal opinion: Steam is more effective than saturated water; after all, superheated steam under pressure has a greater capacity to carry oil than water.
The use of saturated water is primarily driven by energy-saving considerations. The biggest risk associated with using saturated water is that its temperature is lower than that of steam, which affects the temperature variation curve during coke cooling in the coke tower and can easily cause damage to the tower structure
We use high-pressure saturated water, which flashes into steam as soon as the pressure is reduced; there isn’t much difference.
A certain proportion of deoxygenated water can be added during the middle to later stages of large-scale steam injection; this proportion can be increased gradually from the middle to the later stages, which prevents localized cooling. On the other hand, during low-level water injection, it reduces the temperature difference when switching between steam injection and water injection. It works well and also helps to save steam consumption. Steam costs 300 yuan per ton, while deoxygenated water costs 7 yuan per ton. Calculate it yourself!
Switching to deoxygenated water in the middle and later stages can save only a limited amount of steam, and it increases the complexity of operations as well as the associated risks; therefore its practicality is low. In recent years, several companies such as CNPC’s Dagang facility tried this approach, but as far as I know, they have all stopped using it now
Please pay close attention to this issue and engage in active discussions. This energy-saving measure.
The speed of cooling the coke has increased, and 1.0 MPa of steam has been saved as well. However, if the operation is incorrect, it can easily lead to blockages in the cold coke channel.
I’m also working on this project right now. Are there any other units that have already implemented it? I really need some help
We are working on this project, and it will be put into use in a few months. It has already been implemented in Tahe, using Youhua’s intelligent atomization technology that replaces steam with water.
I don’t think it’s very good; this topic focuses mainly on energy conservation, with the aim of reducing the temperature of coke. It overlooks the purpose of blowing air in and out, whether there are any changes in the volatile matter content of the coke, and whether this has an impact on the operation; remember, this is putting the cart before the horse. Energy conservation should be achieved without compromising the results.
How is the optimized technology in Shanghai? How much to invest?
We use saturated water as well to save steam; that’s how we proceed here. First, blow steam for a while, then introduce saturated water; reducing the amount of steam has no effect on the quality of the coke. The pressure of saturated water is relatively high, so it vaporizes once it enters the tower