Effect of washing oil components on benzene absorption
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Let’s analyze the impact of the components in tar washing oil on benzene absorption. I have here a mass spectrum analysis report for this cleaning oil; let’s take a look and see how this oil is Name Content Name Content Name Content Naphthalene 1.54 Quinoline 1.37 Methylnaphthalene 17.48 Ethynaphthalene 1.92 Dimethylnaphthalene 19.44 Anthracene 0.28 Benzene 21.34 Oxofluorene (A) 0.46 Fluorene 3.34 Trimethylnaphthalene 4.71 Vinylnaphthalene 6.87 Methylquinoline 0.4 Oxofluorene 14.25 Methylbiphenyl 2.57 Dimethylbiphenyl 0.42 Tri**aldehyde 0.58
Absorption capacity: highest for methylnaphthalene, lowest for acenaphthene
Generally, coking plants only test the distillation range of the washed oil, with a total naphthalene content not exceeding 15% being used as the control parameter. Alpha-methylnaphthalene and beta-methylnaphthalene are the main components of the benzene-washing process; their concentrations determine to a certain extent the distillation range and intrinsic quality of the washed oil, thereby affecting the efficiency of benzene removal from it. Reference: http://bbs.hcbbs.com/viewthread.php?tid=359211&highlight=%CF%B4%D3%CD%D6%CA%C1%BF%B6%D4%CF%B4%D3%CD%D0%A7%B9%FB%B5%C4%D3%B0%CF%EC This post was last edited by vvvvvbbbbb on 2009-4-1 at 19:34
The methylnaphthalene content should not be too high nor too low; generally, 5–15 is a good range
Typical coking plants require that the flow rate of the washed oil at 270 degrees be greater than 70%, with a naphthalene content of less than 10%; importantly, methylnaphthalene has a relatively strong absorption capacity for benzene
In tar deep-processing projects, if benzene and oil extracts are to be obtained, it is advisable to subject the oil extract to a second round of refining. If a qualified-quality oil extract is obtained directly through the distillation of industrial naphthalene, the consequence is a significant reduction in the yield of such oil extract. Compared to the period when oil extracts could be sold readily for use in diesel production, it is not economical to do so now.
Please take another look at the mass spectrum analysis sheet attached at the top, and examine this kind of washing oil. In actual use, this oil is very poor quality; in winter it turns completely solid at low temperatures. Let’s analyze the main components of solid substances Another copy is attached; this oil is fine. Name, Content: Name, Content, Name, Content. naphthalene: 1.83; quinoline (type A): methylnaphthalene: 9.87; ethynaphthalene: 9.98; dimethylnaphthalene: 20.62; phenanthrene: 0.34; benzene: 26.30; oxofluorene (type A): 17.06; fluorene: 5.88; trimethylnaphthalene: 4.18; anthracene: 1.13.
1. **The standard requires that the total amount of naphthalene not exceed 15%; currently, it is possible to reduce this level to below 5%, and with proper control, it can be brought down to around 2%.**； 2. α-Methylnaphthalene and β-methylnaphthalene have good absorption effects on benzene ； 3. The flow rate before 270 degrees is the useful component for benzene washing; it is generally desirable that this value be greater than 70%. The greater the flow rate before 300 degrees, the better.
Why can’t the methylnaphthalene level be too high?
What is the basic requirement for the ratio of α-methylnaphthalene to β-methylnaphthalene?
What is the color of the washing oil? Are there blended washing oils available on the market now? Can the 270-degree process for tar processing and oil washing now achieve a value of over 70?
It is mainly naphthylmethane that affects the benzene washing efficiency; the higher the level of naphthylmethane, the better. From my experience, it’s best to use as little washing oil as possible in joint-venture tar processing plants; since naphthalene is removed, the fuel consumption is high. Refined oil brought in through intermediaries is generally not effective.
As mentioned on floor 13, the higher the amount of methylnaphthalene, the better the benzene removal effect; then why is there a limit set on the methylnaphthalene content at 15%?
The levels of oxofluorene and acenaphthene are too high, causing the polymers to crystallize and precipitate at lower temperatures
Methylnaphthalene is favorable, while higher molecular weight components (270 degrees) are unfavorable; compounds that tend to crystallize easily (such as acenaphthene) are also unfavorable.