US1000646A - Treatment of acid tar. - Google Patents

Description

UNITED STATES PATENT a ms WILHELM 0. TH. TIENEN, OF EOTTERDAM, NETHERLANDS, ASSIGNOR TO DE BATAAFSOHE PETROLEUM MAATSCHAPPIJ, OF THE HAGUE, NETHERLANDS, A.

CORPORATION OF THE NETHERLANDS.

TREATMENT OF ACID TAB.

No Drawing.

Specification of Letters Patent.

Application filed October 21, 1910. Serial No. 588,303.

Patented Aug. 15, 1911'.

To all whom it may concern:

Be it known that I, \VILHELM O'r'ro THAARUP VAN TIENEN, a subject of the the like, nearly the whole of the acid used for the treatment being recovered at the same time.

In the various methods for purifying if mineral oils and distillates therefrom, con-' centrated sulfuric acid is mixed with the crude oil and this mixture continuously stirred and, under some conditions, heated. If now the mass is left to itself, two layers are formed of which the upper layer consists of purified oil (illuminating oil) and 'the other of a mixture of sulfonic acids formed by the action of the sulfuric acid on aromatic and unsaturated hydrocarbons, which mixture constitutes the so called acid tar. In the reaction of aromatic and unsaturated hydrocarbons with sulfuric acid to form sulfonic acids, water is liberated. Since this reaction is reversible, it has been attempted, by introducing steam, to re-convert' the sulfonic acids into heavy hydrocarbons and sulfuric acid. This has not led to an economical result; since the yield of recovered hydrocarbons is too small. It is true that the steam carries along with it the greater part of the hydrocarbons, but the consumption of steam is too costly. Moreover the sulfuric acid liberated is impure and cannot be concentrated without fundamental regeneration. I have discovered that the reversal of the said reaction yields commercial products if instead of steam, a certain proportion of water is added to the sulfonic acids and the mixture is heated under pressure. In this manner the sulfuric acid is obtained sufiiciently'diluted and clean, and

can be very well-concentrated without previous regeneration, while the heavy hydro carbons also separate in a pure state According to the invention a certain pro- -hour to two hours.

7 portion of water, previously determined in relation to the kind of sulfoni'c acids to be treated, the excess of sulfuric acid mixed with the acid tar and the degree of dilution thereof, is added to the acid tar. This mixture of water and 'acidtaris then heated in.

duration of the heating depends on the kind of acid-tar, and ranges from a quarter of an In practicing the invention, therefore,a

predetermined quantity of wateris added ,to

the sulfonic acids and then the mixture'is heated in a closed vessel to about 140165 C and at a pressure of about seven atmospheres. The hydrocarbons and; sulfuric acid are only regenerated from the mixture if, the other conditions (temperature ,and

pressure) being favorable, the sulfuric acid present or formed, diluted by the quantityof water added, has a certain concentration. The acid tar is therefore heated withv a quantity of water which brings the sulfuric acid present and formed, to the desired degree of concentration. The sulfonic acids are then split up, if the temperature and pressure conditions. are right, into the original aromatic hydrocarbons and sulfuric acid. Three layers are formed, of which the uppermost consists. of pure hydrocarbons, which can be used directly, after washing with water, as motor oils and for other purposes, the lowest layer consists of pure d1- luted sulfuric acid capable of direct concentration, which can be used again for purifying mineral oils or their distillates, while between these two layers there is formed a very thin layer, which contains small residues of acid and resinified tar. Owing to this Stratification the various products can easily be separated. a I

The proportion of 'water to be added to the acid tar as mentioned above, depends on the kind of hydrocarbons present in the tar as sulfonic acids, because these hydrocarbons determine each byits composition the pro ortion of sulfuric acld combined 1n the "sul onic acid and also the proportion of free (reckoned as acid of 1,692 specific gravity equal to '59? Baum) are ascertained and the quantity of water necessa for suflicient dilution is then calculate The excess of free acid remaining from the acid of 66 Baum specific gravity originally used has been diluted to 59?,Baum specific gravity by the water liberated during the sulfonation. For the reaction which is to occur in the pressure vessel, the quantity of water added mustbe such as to dilute this excess of acid'and that liberated by the water from the sulfonicadids, to 52 Baum specific gravity. An acid of the specific gravity last named cannot re-sulfonate the oils. The quantity of water is therefore so reckoned that the, acid present after the action has a specific gravity of 1,565 specific gravity equal to 52 Baum only to insure that the acid shall not have a sulfonating action. It is not advisable to add a larger proportion ofwater, since this would dilute the acid unnecessarily and increase the cost of subsequent concentration.

The following example illustrates the inve11tion:--An acid tar which contains for each 100 parts by wei ht 43 parts by weight of combined acid 0 66 Baum speclfic gravity and 14 parts by weight free acid of 59 Baum specific gravity, must be heated for two hours at 165 C. and 7 atmospheres pressure with 233 parts by weight of water.

The liquid separates into two layers, of which the-one consists of the regenerated oils and the other'of sulfuric acid of about, at the most, 52 .Baum specific gravity. These twolayers can be separated in any knownmanner and the acid concentrated to 66 Baum specific gravity. In this man- 'the free acid existing in the acid tar, to a specific gravity of not more than 52 Baum and heating themixture at a pressure of about 7 atmospheres and at a temperature of about 140165 C. y

In testimony whereof I have hereunto set my hand in presence of two subscribing wit- :Witnesses:

- ANTONIO ELBERTS DoYER,

.THOMAS U. VERHAVE.