Treatment measures for residue water content
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The feed for coking units is required to have a moisture content of no more than 0.1%. However, the moisture level often exceeds this limit upon arrival at the plant, which causes significant problems in unloading, storage, and use. Does anyone know of a quick method for removing moisture?
As far as I know, residue dehydration is generally carried out through thermal sedimentation. Due to the high viscosity of the residue and its presence of water, it is possible to heat the residue in the tank to around 130°C in order to remove the water – I wonder if this can be achieved
Thank you! However, the heat sinking method consumes a large amount of steam and takes too much time. I’ve heard of a technology that uses heat transfer oil for heating along with forced air; does anyone have experience in this area?
Our unit previously stocked nearly 10,000 cubic meters of residue oil containing water; after more than 2 months of heating, sedimentation, and dehydration, the results were very unsatisfactory: a water layer formed, and the moisture content, as determined through sampling analyses, ranged from 1.8% to 0.5%. To this day, it still cannot be sent to the coking unit for processing. Preparing to send common pressing devices back for reprocessing will result in huge losses; it’s frustrating! I would appreciate it if some experts could help come up with some ideas. Thank you!
By adding a demulsifier, was something else introduced along with the water last year?
Home-made demulsifiers are theoretically feasible, but (1) it is very difficult to achieve uniform mixing of the demulsifier with the residue oil in 10,000 cubic meters of tank volume. (2) The oil extraction specific gravity is 0.99–1.05, which is almost the same as that of water; is sedimentation separation feasible?
Agree with the view from floor 7: The basic principle behind static dehydration is the existence of a difference in density between oil and water. If there is no such difference in density, then it’s impossible to remove even water in an emulsified state; even free water cannot be removed in this case. The best approach is to add 10%–30% light oil to alter the density difference between oil and water, and then heat the mixture or use demulsifiers to facilitate sedimentation and dehydration
The views of those upstairs are worth considering, but costs and facilities need to be taken into account; we are currently blending it with crude oil. I heard that using heat transfer oil for heating along with air blowing for dehydration yields good results. Does anyone have experience in this area?
The dehydration temperature must not exceed 100 degrees, otherwise the water will vaporize and cause the container to overflow
In fact, when the density of heavy oil is above 1.0, sedimentation combined with heating for dehydration is not very effective, and this approach results in high energy consumption in the atmospheric and vacuum distillation units. Demulsifiers can be used as a solution, but the density difference is too small; I wonder if there are any other good solutions? Our plant used to flash the crude oil in a vacuum distillation tower for dehydration, and it was required that the vacuum distillation unit handle the residue on a dedicated basis.
Reply to Floor 11: The atmospheric and vacuum distillation process is used for the centralized treatment of aqueous residue oil – can your unit handle that? Let’s talk about experience! We use two-thirds crude oil for blending; only after it has been mixed do we dare to feed it into the processing equipment, as we are concerned about the pumps being overloaded or the trays and pipelines getting clogged.
Running it through electrical desalination with atmospheric and vacuum pressure should, I think, achieve the goal you mentioned! (Our factory adopts this measure for reference.)