SU979489A1 - Process for purifying light liquid paraffin cuts - Google Patents

Description

The invention relates to methods of adsorption purification of liquid paraffins and can be used in the refining industry.

Sulfuric acid (oleum) purification methods 1L are widely used in refining npoNOJii for purifying liquid paraffins from accompanying impurities.

When cleaning liquid paraffins with sulfuric acid (oleum), a large amount of non-utilizable acid tar is formed and the equipment and pipelines are corroded. The known method of purification of liquid paraffins by the adsorbent in periodically operating systems is characterized by the inefficient use of equipment, while cleaning there is a low yield of the target product.

Methods are known for continuous adsorption purification of liquid paraffins with a moving adsorbent, for example, a method for adsorptive purification of petroleum hydrocarbons, including liquid paraffins, carried out in a liquid phase in countercurrent with a moving fine-grained adsorbent, while the descending stream

the adsorbent is in contact with the upward flow of the solution of the raw material being cleaned. According to the method, the purified product is removed from the top of the adsorber, and the spent adsorbent enters the dec (in which the countercurrent is contacted with a hot solvent to extract the adsorbed aromatic compounds.

The adhesive is a adsorbent with strongly adsorbed 1В0 "and resinous organic compounds (resins), dried and then fed to oxidative regeneration to restore

5 of the initial (equilibrium) adsorption capacity, after which the contact with the raw material f 2 is again reversed.

.1 This method cleans a wide,

 fraction of liquid paraffins, for example, 240-360 С, separated with carbamide, or narrow fractions: light N.K. The average is 275-320 ° C and the corresponding 320-360 ° C obtained by distilling a broad fraction. When cleaning the light fraction of liquid paraffin (N.K.-275С), the raw material for a number of petrochemical industries is the production of sulfonol, as an extraction liquid for the extraction of metals, and, in particular, graphite @ nn @ ether and others. "N @ in @ take out trebuchema depth © t Aremaciche uglyy ugvederoeyesh (n @ yo 1.3%), they @@ n @ zyvky output of the purified product, it is necessary to introduce significant amounts of heat into the regeneration stage of the adsorbent ( liquid fuel). ; This is due to the practical absence in light fractions of liquid paraffins of resinous organic compounds (resins), medium and heavy aromatic hydrocarbons, which is associated with a small amount of organic residue on the adsorbent. Entering and burning a significant amount of fuel in the regenerator leads to cracking and melting of the adsorbent grains, reducing its porosity and its activity. The purpose of the invention is to increase the degree of purification of the light fraction of liquid paraffins and increase the yield. This goal is achieved by the fact that according to the method of cleaning the light fraction of liquid paraffins by contact with the adsorbent, desorption and regeneration of the adsorbent, 20-100 wt.% Of the heavy fraction of liquid paraffins are added to the stage of contact with the adsorbent. From above the boiling point of the refined light fraction, followed by the subsequent separation of the purified paraffins by distillation into fractions. The amount of the introduced fraction at the stage of adsorption is determined by the content of aromatic hydrocarbons and resins in it. With an increase in their content, its quantity decreases, and vice versa, the injected fraction provides the content of organic residue on the adsorbent and its pereiepa-r. The purification method according to the invention is carried out as follows. With countercurrent contacting, a light fraction of liquid paraffins is mixed with a 20-100% liquid paraffin fraction with a boiling point 30-50 ° C above the end of the raw material being cleaned, for example a fraction 200-275 ° C with a fraction 320-370 ° C (conditional fraction). The mixture is cooled to 30-40 ° C and fed to the bottom of the adsorber. The adsorbent is introduced into the adsorber through special metering (soaking. E.) Device, which is simultaneously a device for evenly distributing the adsorbent inlet stream over the cross section of the adsorber, the adsorbent moistened with liquid particles settle in the solution, not emerging in the ascending fluid stream. To eliminate the ablation of the raw material with the adsorbent, a solvent is fed into the lower part of the adsorber. RastaFa echeen emeen fractions of paraffin paraffin more than e of the centacth edeenterenerm südyd e to the top of the adeberbe and sent for regeneration to the solvent. After the regeneration, the solvent was regenerated in a process, and the mixture was heated to 220-280 ° C and sent to the distillation. The distillation is carried out in a vacuum column with separation into initial fractions, for example 200275 C and 320-370 ° C, which, after using heat, is removed from the process. The spent adsorbent is fed to a stripper, in which it is contacted in countercurrent with a hot solvent to recover adsorbed aromatics. The washed adsorbent with strongly adsorbed resinous organic compounds is dried in a dryer and fed to oxidative regeneration to restore the original (equilibrium adsorption capacity, after which it is cooled and returned to contact with the raw material. Other known methods of adsorbent regeneration are possible. P and I P 1 A light fraction of liquid paraffins, which boils in the range of 202-259 ° С and contains 7.6% of aromatic hydrocarbons, is subjected to purification. 20% by weight of a paraffin fraction boiling within 289-ЗБО С is added (the temperature difference between the beginning and the end of the boiling point is 30 ° C. The content of aromatic hydrocarbons and resins is 3.05%. The mixture is diluted with a solvent the de-aromatized fraction 80-120 ° C, solvent consumption is 15 wt. per raw material. Processing the mixture to be cleaned is carried out at 40 s and the adsorbent: raw material ratio is 0.5: 1. The solvent consumption in the washing zone and for desorption is maintained: 1: 1 is used per adsorbent for each operation. Desorption temperature. The spent adsorbent is dried in a stepwise counter-current dryer with a boiling bed of the adsorbent at 175 ° C. The fluidized bed is steam generated. Pounded adsorbent from the dryer is fed to the regenerator. The regeneration of the adsorbent is carried out in a fluidized bed. In two stages, pyrogenation and burning of coke, the temperature in the stages of 300 ° C and 580 ° C. After regeneration, the adsorbent is cooled and fed to the adsorption stage. The solvent is distilled off from the solutions of the purified fractions and the desorbed product by heating to a temperature in the range of 120-160 ° C. The solvent is condensed, cooled and returned to the process. The purified fraction of liquid paraffins after distillation of the solvent is heated in an oven and sent to a vacuum column. Column mode: temperature

SBtpsyr nelenny -, shnishu, rfr whose -, ravnvd gvr chvy vtrui - ill on iarpyaku @ l @ nnY | Vacuum - 720 NM pf.eXi С with gakumy of the column aaode F of fraction 202-2§9 С and 289 and, determine their yield and quality.

PRI mme R 2. Purification of a light liquid paraffin boiling that boils within 210-276 s and containing 5.2% of aromatic carbohydrates 50% by weight of the paraffin fraction boiling away within 315-360C is added to the liquid paraffin fraction being cleaned. (temperature difference at the beginning and end of the boiling point is 39 ° C). The content of aromatic hydrocarbons and resinous substances 1.23%. The mixture is fed to the adsorption stage, the mixture is processed at 38-40 s and the adsorbent: 0.65: 1 feedstock. The consumption of solvent in the washing eonu and on desorption is supported 1: 1 and the adsorbent for each operation. Desorption temperature. The spent adsorbent is dried in a step-countercurrent dryer with boiling wood of the adsorbent at. The fluid bed is created by steam.

Pounded adsorbent from the dryer is fed to the regenerator. The regeneration of the adsorbent is carried out in a fluidized bed in two stages - pyrogenation and burning of coke. The temperature in stages and, respectively. After regeneration, the adsorbent is cooled and fed to the adsorption stage. Solvents are distilled off from solutions of purified fractions and desorbed product to a temperature of 120-160 ° C, the solvent is condensed, cooled and returned to the process, the desorbed product is removed from the process.

The purified liquid paraffin fraction after distillation of the solvent is heated in an oven and sent to a vacuum. the column. Column mode - temperature -. It is above, below - 217 ° C, the hot stream is 1, the flow rate of the hot stream is 1: 1 per column load, and the vacuum is 720 mm Hg. Fractions 216-276 ° C and 315-360 ° are determined from the vacuum column to determine their yield and quality.

Froze Cleaning is subjected to a light fraction of liquid paraffins.

1s: 1uchuyuS limits 200-2IS e to the carrying out §, 191 aromatic coal vzdvvdvEI To the cleaned fraction of liquid vapor $ indv enter 100 web. | fraction of paraffin I boiling xx9ft in the range of 305-370 ° С (temperature difference between aacha, la and boiling point). The content of aromatic hydrocarbons and resinous substances is 0.62%.

The mixture is diluted with a solvent (dearomatised fraction 80120 ° C), the consumption of solvent is 50% by weight per mixture. Processing the diluted mixture with the adsorbent is carried out at 38-40 ° C; the adsorbent is used as raw material: 0.65: 1. The consumption of solvent in the washing zone and the desorption rate is 1: 1 per adsorbent for each operation. Desorption temperature 80 ° C.

The spent adsorbent is dried in a step-countercurrent fluidized bed dryer with adsorbent at. The fluidized bed is created by water pars l.

Pounded adsorbent from the dryer is fed to the regenerator. The regeneration of the adsorbent is carried out in a reflux furnace in two stages — pyrogenation and coke burnout, the temperature of the stage is 300580 ° C. After regeneration, the adsorbent is cooled and fed to the adsorption stage.

The solvent is distilled off from the solutions of the purified fractions and desorbed product by heating to a temperature of steps within 120160 ° C, the solvent is condensed, cooled and returned to the process, desorbed (the 1st product is removed from the process.

The purified fraction of liquid paraffins after distillation of the solvent is heated in an oven and sent to a vacuum column.

The mode of the column: top temperature - 92 ° C, at the bottom - 220 ° C, combustible jet - 230 ° C, consumption of hot jets 1: 1 to load the column, vacuum 720 mm Hg. Fractions 200-255s and 305370 s are removed from the vacuum column, their output and quality are determined.

Test data on the proposed and known methods are given in the table. Adsorbent: raw materials ratio 0.5: 1 0.65 Solvent consumption: raw material dilution,% for raw materials in the washing zone,% for adsor100100 100 bent for desorption,% for 100 100 adsorbent Entering the heavy fraction of paraffin for the adsorption stage,% by raw material temperature, C; 40 38-4 adsorption 175 175 drying the regeneration adsorbent ad300-580 solvent regeneration sorbent Vacuum distillation of the mixture of purified fractions: temperature, ° C at the top of the column at the bottom of the hot stream vacuum column, mm Hg. The yield of purified 72.2 80.3 light fraction,% Paraffin quality before purification light fraction 202 210 beginning of boiling point, С 259 276 end of boiling point, ° С, content of aromatic 7.6 5.2 hydrocarbons,% 1205: 1 0.5: 1 0.65: 1 0,65: 1 50 15 00 100 100 100 100 100 100 100 50 100 8-40 38-40 38-40 38-40 75 175 175 175 300-580 120-160 0 202 210 200 5 5 259 276,255 5.2 5.69 69 7.6

Table continuation

Claims (1)

Claim The method of purification of the light fraction of liquid paraffins by contact with the adsorbent followed by desorption and regeneration of the adsorbent is about ~, characterized in that, in order to increase the degree of purification and exit the target product, the stage of contact with the adsorbent reaches 20-100 wt.% 45 of the heavy fraction of liquid paraffins with a boiling point of 30-50 ° C above the end of boiling of the light fraction to be purified, followed by separation of the purified paraffins by distillation into a fraction of 50, are added.