DE550687C - Process and device for the distillation of mineral oils - Google Patents

Description

Method and device for the distillation of mineral oils The subject of the invention forms a process for the production of clean smelling marketable distillation products from foul-smelling, especially high-sulfur raw materials directly by means of Vacuum distillation.

The new vacuum distillation process is characterized by that, while the majority of the vapors distilling off in a known manner condensed in a cooler and discharged as condensate by the shortest route, another, smaller part of the vapors distilling off, which in one Pre-cooler 16 prevailing, the condensation of the main part causing temperature, which is higher than otherwise under the same conditions with simple air cooling would be possible to remain uncondensed, together with the lower-boiling malodorous ones Components from the contact area of the hot condensates, as long as they are are still at a temperature close to their boiling point, derived and is condensed separately from the main part.

The most expedient process to achieve this is to that one = the condensate formed first of the fractional distillation is not can be cooled down to one significantly below the temperature at which it is formed Points its way to the cooling devices where it is no longer in contact with the aforementioned foul-smelling gases and vapors.

Here, the temperature of the causing the partial condensation Scheider regulated in such a way that the hot condensate with a just below the the respective boiling point is separated from the oil vapor flow.

The condensate thus separated from the oil vapor flow, which mostly more than 20 ° / o, with the heavy oil fractions more than 99% of the respective amount of the oil vapor flow is detrimental to the color, smell and taste influencing substances almost or completely free, while those from the separator In addition, portions of the oil vapor flow removed in vapor form after their liquefaction a substantial amount of pure oil practically the predominant or total amount the offensive smelling, tasting and discoloring components of the oil vapor stream contain. Just a few drops of this foul-smelling (hereinafter referred to as olfactory distillate designated) product are sufficient to z. B. 5 liters of the pure, odorless and tasteless To give condensates a bad color cast and bad odor. at recommends raw materials that are particularly contaminated by sulfur and acid components it is, before the distillation with basic substances, such as alkali lye and the like., to stir in agitators in a manner known per se and only then the Subject to distillation.

To achieve the best results, it is also useful to through additional measures to prevent any possibility of oxidation of the hot Vapors, especially through welding of the seams and connection points of the distillation bladder, the partial condenser and the lines carrying the hot vapors and condensates to ensure the most careful exclusion of oxygen.

It is also advisable to use the line from the separator in vaporous form In the state of suction, the lighter proportions are about 0.5 to 4 mm lower in absolute terms Maintain pressure than in the cooler and storage tank of the heavy pure Condensate, which makes the heavy condensate odorless with increased security is guaranteed.

A system suitable for carrying out the new process is shown in Fig. i shown in side view and Fig. 2 in plan.

Fig. 3 shows a system for distillation with the aid of Steam.

The horizontal still, suitably provided with internal stiffeners = o is provided with several equally spaced oil vapor extraction pipes 12, which are inclined downwards as close as possible to the apex of the boiler, around the reflux in the boiler as much as possible. The old steam exhaust pipes i2 are with each connected to a cooling coil 13 which open into the common collecting pipe 15. Each steam pipe 12 is connected to a separator in connection with the illustrated Embodiment is designed as a riser pipe 16. The tops of the risers open into the common horizontal manifold 17, which is U-shaped by means of five guided lines 18 and = g with the corresponding ones opening into the collecting tube 22 Cooling coils 2o and 21 is connected.

For a short time, the one from the riser tubes 16 and conduit tubes 18, = g, 2o and 22 existing part of the system hereinafter referred to as the separation group. Likewise, lines i2 and 16 should be referred to as VQrkühlzone.

The top of the boiler and the oil steam line 12 are provided with thermal protection 23 provided in order to guide the vapors as far as possible without condensation to a point, from where the condensate can no longer flow back into the bladder.

The riser pipes 16, the collector 17 and optionally the riser pipes the lines z8, = g are also insulated; the clothing of these parts can - Weather and operating conditions or the respective desired degree of Condensation can be changed accordingly.

From the collector 15, the line 24 leads the heavy condensate into the Container 25, 26, 27 or 28. In the vertical part of the line 24 there is one Screw gun 29.

The collector 22 receiving the olfactory distillate is with the container 31 connected by the line 3o, in which the screw socket 32 is switched on.

The vacuum pump 37, which keeps the system under the desired low pressure, is connected directly to the odor distillate container 31 by means of the main vacuum line 39, 40. From the main vacuum line 39, 40 branch lines 41, 42, provided with valves. 43, 44 to the individual heavy condensate containers 25, 26, 27, 28.

All seams and connections of the system are functional Welding combined completely airtight. This is especially the case with all of them Parts of the system that contain hot vapors or liquids are essential.

The embodiment of the system shown in Figure 3 is with the steam line s for introducing steam into the still, furthermore with the powerful condenser 14 'fitted in the separation group. The container 31 'of the olfactory distillates is expedient also cooled, e.g. B. through the cooling coil c.

In the following, the processing of an Aikansas crude oil is described as an exemplary embodiment of a specific gravity of o.972 with a sulfur content of 30/0 and above described. This crude oil contains neither gasoline nor light oil; the first distillate is a gas oil with a specific gravity of approximately 0.88o. If the crude oil contains more than 1/2% moisture, drainage must be carried out before processing be done in a known manner.

The bladder = o is filled with the crude oil to 80% of the capacity and heated to a temperature which is only a few degrees lower than the previously determined initial boiling point of the crude oil at 5 mm Hg pressure (abs.). In the present case this temperature is approximately x94 °. The system is now evacuated, with valves 251, 261, 271, 28i, 30i and 401 open, valves 441, 411, 421 and 431 closed; as soon as the manometer 1o0 in the bladder has a pressure of = 0 mm abs. indicates, the gas oil begins to distill. The valves 261, 271, 9, 81 are now closed so that the gas oil condensate is fed into the container 25. In this container the pressure is slightly higher than in the boiler = 0 and in the light condensate container 31. It is advisable to keep this pressure difference at a level of 4 or 5 mm during the first half of the gas oil distillation and the bubble is heated vigorously in order to dissipate considerable amounts of hot oil vapor into the To drive separation group and to be able to warm them up accordingly. In the later course of the gas oil distillation, the pressure difference decreases and at the end of the gas oil distillation it drops to 1 mm. During the gas oil distillation, a distillate with extremely bad smells and a strongly phosphorescent blue cast collects in the odor distillate container 31. Even very small amounts of this olfactory distillate can make considerable amounts of pure oil unstable and discolored. This olfactory distillate consists predominantly of gas oil, but contains a very considerable proportion of the harmful substances contained in the crude oil, the purpose of which is to excrete them. These harmful substances have a lower boiling point than the proportions of the crude oil evaporated at the same time in the bladder, so that they do not condense in the separator 16, in the collector 17 and in the rising parts of the tubes 18 and 19, but are sucked off in vapor form, but at the same time, some of the oil vapors in the form of steam or condensate are entrained. This proportion is relatively large during the first part of the gas oil distillation, but is continuously decreasing. The olfactory distillate secreted during the gas oil distillation amounts to a total of 5 to 6% of the bubble filling. In normal operation, the rising parts of the separation group are so hot that the condensate is cooled only just below the boiling point, so that not only the condensation, but also the adsorption of the harmful low-boiling components is avoided as much as possible.

It should be noted that with correct management of the company, so if the pressure in the bladder and in the separation group is lower than in the respective one used collecting container 25, 26, 27, 28, in the Schaubüchse 32 of the light distillate line 2o a fog is visible, however, the Schaubüchse 29 of the Schiver condensate line 24 is fog-free. The desired pressure difference can be adjusted accordingly the valves of the vacuum lines can be achieved.

As soon as a sample of the pure distillate taken by the sampler 241 the desired limit of the flash point, e.g. B. 16o ', the current of the now accumulating lubricant oil in one of the following collecting tanks 26, 27, 28 deflected. Since during the gas oil distillation the predominant part of the harmful Components from the crude oil has already been driven out, the pressure difference can now between the collecting container on the one hand and the separation group on the other hand from 4 to 5 mm on z. B. be lowered 1 mm. For this purpose the corresponding Valve 411, 421 or 431 of the vacuum line is more or less open.

The lubricating oil condensate can either be collected undivided in the collecting container 26 or divided into fractions in the individual collecting containers. The pressure is expediently continuously reduced, e.g. B. from the pressure prevailing at the beginning of the lubricating oil distillation of 4 to 6 mm to 3 to 1.5 mm towards the end of the distillation. The amount of olfactory distillate separated by the separating group during the lubricating oil distillation is mostly small and is usually 0.5 to 1% / a of the crude oil filled into the bladder. This olfactory distillate is less malodorous than that collected during the gas oil fraction, so that it can be collected separately from this.

In the first section of the lubricating oil distillation, they show intermittently samples taken a rise in the flash point; as soon as that bladder temperature is reached at which a Krakken sets in, the flash point remains constant for a while, to sink after a while. The distillate from the previous one is most appropriate now collected separately, e.g. B. in the collecting container 28, since now the cracking is strong begins. The vacuum valve 441 is now fully opened, so that the suction effect is fully deployed directly through the container 28 and the wide tube 24; here only almost exclusively non-condensable gases become due to the separation group escape.

The distillation can be continued until one is still marketable Product is achieved. At most, the last part of the condensate is due to the Cracked products less pure than the previous lubricating oil fractions.

The bladder residue is hard or harder, depending on the degree of expulsion soft asphalt or flux oil. All of these products are easily recyclable.

The gas oil obtained in the collecting container 25 as the first fraction is as Finished product can be sold immediately.

The lubricating oil fractions collected in tanks 26 and 27 are Although they can also be used immediately, they still contain a small amount of organic material Acids, which are expediently removed if the oils are perfectly stable, smelling good and must be pure. Contains the heaviest fraction collected in container 28 also organic acids and also a not inconsiderable one lot Cracked products. These must also be removed in order to keep the oil completely pure.

To this end, the contents of containers 26, 27 and 28 are either combined or separately subjected to a new distillation. The separate Distillation of the individual fractions is generally preferred.

The previous examples were for the production of the noble lubricating oils two vacuum distillations from the very inferior raw material. necessary. In In many cases, however, it is possible to apply the neutralizing agent directly to this add the raw material to be processed and distill it immediately and only once. In the case described, this working method was not recommended because the N neutralizing agent would have impaired the quality of the remaining asphalt. On the other hand, immediate neutralization is probably feasible with oils and their distillation residues z. B. should only be used as heating oil.

In the previous example it was assumed that a bubble fill in itself is processed separately. The process is also suitable for continuous operation suitable, in which case the feedstock is sequentially a series of stills flows through, in each of which one of the desired fractions is driven off.

Of course, you can use any other one instead of stills Evaporators, e.g. B. tubular boiler and the like., Use.

The procedure is not just for processing crude oils, but also suitable for residues and semi-finished products of any origin. Even off Sales goods originating from other companies can be significantly increased with the aid of the procedure be refined.

It is noteworthy that in the example described above, the the lubricating oil fractions produced in the first distillation after the gas oil has been driven off completely odorless and tasteless are like the best so-called medicinal ones Mineral oils, although they have not been subjected to any special cleaning and are not water-white, but are honey yellow. Previously, tasteless mineral oils could only be repeated by repeating them Achieve cumbersome acid treatment, these well-known medicinal oils at the distillation always result in decomposition products. Light yellow tasteless mineral oils, which contain practically no decomposition products at all were previously completely unknown.

In general, therefore, the invention enables the production of high quality Oil products by a simple vacuum distillation.

It differs from the known distillations with fractional condensation The new method is in principle that, while with the new method, how mentioned above, the simultaneously formed heavy and light fraction almost the same qualitative composition and only insignificantly different boiling points have, but the heavier fraction smelling clean, the lighter fraction The fractions formed at the same time in the known processes are very malodorous very significant differences both qualitatively and with regard to their boiling points have, since the purpose of the previous method is to separate the oil components on sales products with different boiling points and other properties was. While the previous distillations with fractional condensation the respective oil vapors emerging from the bladder are converted into a large number of different ones Sales products was divorced, in the present process the one from the Bladder, the amount of oil that escapes is always separated into two parts, of which one the lighter, smaller part has an extremely bad smell and is therefore not a sales product is.

However, the new process differs from the previous vacuum distillation with partial condensation in that the heavy condensate in the new process condenses almost at the temperature of its boiling point and is removed from the area of the foul-smelling vapors and gases, so that these foul-smelling parts are absorbed the condensate is avoided as far as possible. In contrast to this, in the usual fractional condensation, the steam mixture z. B. introduced at the temperature of 300 ° into the partial condenser and cooled in the same below?, 8o 'in order to condense the fraction boiling between 28o and 300'. Those shares of this fraction that z. B. boil at 299 ', so are cooled in the condenser to less than 28o', that is, substantially below their boiling point, a and are now in this relatively strongly cooled state in a position to absorb the foul-smelling vaporous compounds. It should also be noted that in practice of the previous fractionated condensation, the fraction limits and, accordingly, the cooling are much more extreme than in the example assumed above.

Claims (6)

PATENT CLAIMS: e.g. Process for the distillation of mineral oils for the purpose Production of lubricating oils under reduced pressure, preferably in a high vacuum, where lighter fractions that are not desired in the end product are eliminated, characterized in that, during the vast majority of the distilling off Vapors condensed in a known manner in a cooler and as condensate on the shortest Ways is discharged, another, smaller part of the vapors distilling off, which in the case of the one prevailing in a pre-cooler (i6), the condensation of the main part effecting temperature, which is higher than this under otherwise identical conditions with simple air cooling would be possible, remains uncondensed, along with the lower boiling malodorous components from the contact area of the hot condensates, as long as these are still at a temperature close to their boiling point, is derived and condensed separately from the main part. 2. Procedure according to Claim r, characterized in that when the gas oil fractions are distilled off more than 90%, when distilling off the lubricating oil fractions more than 99% as the main part be condensed. 3. The method according to claims r and 2, characterized in that that in the line for the main part of the condensates a mercury pressure of 0.5 to 4 mm higher absolute pressure is maintained than in the line for the easier boiling parts. 4. Device for carrying out the method according to claims z to 3 with a still and this subsequent pre-cooler with separate Leiturigen for the condensate and for the non-condensed portion of the oil vapor flow, characterized in that the pre-cooler (z6) connected to a vacuum line is thermally insulated. 5. Device according to claim 4, characterized in that the vacuum device and the vacuum lines in such a way with pressure regulating devices are equipped that you have a lower one in the tanks for the heavier distillates Vacuum can be maintained than in those of the lighter distillates. 6. Establishment according to claims 4 and 5, characterized in that a part of the pre-cooler as is designed strongly constricted, uninsulated riser cooler.