DE3402264A1 - METHOD FOR THE CONTINUOUS PRODUCTION OF HYDROCARBON OILS BY SPLITTING PRESSURE HYDROGENATION - Google Patents

Description

BASF Aktiengesellschaft " O.Z. 0050/36928

Process for the continuous production of hydrocarbon oils by splitting pressure hydrogenation

In the various known processes for the production of coal oils by splitting pressure hydrogenation of coal, the extraction of the so-called grind oil from the process products plays an essential role. It is known from DE-AS 26 54 635 to rub ground coal, expediently together with finely divided catalysts, with a practically asphalt-free mixture of medium oil and heavy oil obtained in the process itself and to pass the pulp together with hydrogen under a pressure of 100 to 400 bar or to conduct several reaction spaces kept at 420 to 49O ^{0 C.} The reaction products are fed into a hot separator that is kept slightly below the reaction temperature, the bottom product (sludge) is separated into distillate oil and residue and the gases and vapors drawn off at the top of the separator, which contain the oil and components of the grinding oil, exceed the amount of liquid oil Up to 80% of the gases and vapors being drawn off, either directly or via a second hot separator, from which a small amount of high-boiling components and solids are removed, passed through one or more reaction spaces provided with fixed hydrogenation catalysts. After direct cooling to about 40 ° C, gases (circulating gas) and liquid hydrogenation products are separated in a scraper and the gasoline is removed from the part intended as the grinding oil, while the other part of the gases and vapors from the hot separator is cooled directly. The liquid product, freed from gasoline, can be used as a grinding oil for the coal. The cooled hydrogenation products are released after separation of the circulating gas and separated in distillation columns into gasoline, medium oil and heavy oil, medium oil and heavy oil are divided into oil recovery and grind oil. The non-hydrogenated mixture of medium oil and heavy oil is used for grinding oil.

It has now been found that this process for carbohydrate hydrogenation can be used industrially can be made much simpler and more economical if you use the products from the hot separators, i.e. the non-hydrogenated and cools the hydrogenated portion in separate streams in heat exchangers against the feedstock going into the coal hydrogenation in stages that accumulating condensates, consisting of heavy oil, medium oil and gasoline, collects in wipers, from these condensates a portion for the grinding oil and subtracts one share as oil gain and both shares without intermediaries Distillation is fed to the grinding of coal or the hydrogenation in the gas phase or mixed phase, while that in the non-hydrogenated Percentage of petrol collected in the scraper after the water has been separated in the

BASF Aktiengesellschaft - 2 ^ - 0-Z. 0050/36928

for the fixed bed hydrogenation is pumped in and that at the subsequent splitting hydrogenation of the middle oil and heavy oil in the oil recovery hydrogenation product obtained in stages cools down with the formation of a recycle product for the splitting hydrogenation and a light oil that is withdrawn from the hydrogenation.

In the known method, however, the direct product is from the hot separator and the hydrogenated product from the hot separator is cooled directly to room temperature, so that the resulting cooled pr oducts - but at least the ones from the hydrogenated streams - relax and in a complex pressureless distillation in the desired Must separate fractions (heavy oil, medium oil and gasoline).

In the process according to the invention, the non-hydrogenated product from the hot separator can generally be satisfied with two-stage cooling, so that on the one hand heavy oil and medium oil are obtained as a common wiper condensate for the grind oil, and on the other hand gasoline. The setting of the desired ratio of heavy oil to medium oil in the grind oil then takes place when the hydrogenated proportions of heavy oil and medium oil are mixed in. The gasoline in the stripper condensate is pumped into the inlet of the fixed bed hydrogenation without pressure relief and then hydrogenated so that no unrefined gasoline leaves the coal hydrogenation unit. In the case of fixed bed hydrogenation of the products from the hot separators, the refined hydrogenation is recommended, namely jointly for the proportion of grinding oil and oil gain. A three-stage cooling is advisable here, so that in the scrapers that are switched on, a heavy oil condensate that boils essentially above 325 ° C, a middle oil condensate that boils essentially between 180 and 325 ° C, and a gasoline condensate that essentially boils between 30 and 180 "C boils collect as condensate. Of the heavy oil and medium oil condensates, such proportions are added to the grind oil that the desired grind oil results in quantity and composition is brought into the splitting hydrogenation using the existing pressure and the remaining temperatures - i.e. without the interposition of an expensive pressureless distillation - and the hydrogenation product obtained therefrom cools in two stages, with the components boiling essentially above 180 ° C condensing on the one hand and those of about 30 to 180 * C boiling parts condense. The fractions boiling above 180 ⁹ C can be returned directly to the cleavage hydrogenation, while the fractions boiling up to 180 ° C together with the gasoline fractions from the refining hydrogenation can be returned to the catalytic aggregate

BASF Aktiengesellschaft -J ^ - OZ 0050/36928

Feed reformers. With the method of operation according to the invention, the otherwise usual, complex, pressureless distillation.

A highly refined hydrogenation can also be used instead of the splitting hydrogenation Use hydrogenation and then get hydrogen-rich hydrocarbons in the heavy oil, medium oil and gasoline sectors, which are suitable, for example, for pyrolysis to form olefins. If here, for example, the end product If three steps are desired, the hydrogenation product leaving the reactor is cooled in three stages with between the heat exchangers arranged scrapers.

example

117 tpd (t / day) hard coal with 10% water in raw coal and 5% ash in dry coal, corresponding to 100 tpd pure coal (water- and ash-free (waf)), are produced with 1.2 tpd FeSO ₄ . 7 H ₂ O and 2 tpd Bayer mass offset is supplied to a mill drying and mixed with a distillate oil mixture of 60 tpd middle oil (bp. 180 to 325'C) and 110 tpd heavy oil (bp. 325-450 ⁰ C) to form a slurry, the 0 , 3 tato sodium sulfide are added. Using a pulp press, the pulp is brought to the operating pressure of. 225 bar and then mixed with 20 tpd of sludge (return sludge), which is fed from the sump of the hot separator without pressure relief and without lowering the temperature. The coal pulp is fed together with 15,000 Nmr * / h of cycle gas with 80% by volume of hydrogen via a heat exchanger

a preheater and heated to 43o ° C and introduced into a reactor of 7.5 m ^ volume, where the hydrogenation takes place at 465 ⁰ C. The reactants leave the reactor in a hot separator, where at 43O ^e C the separation takes place into a bottom product (sludge) on the one hand and the gases and vapors withdrawn from the upper part on the other. 37.4% of these gases and vapors (stream I) go directly to the cooling path, where they give off part of their latent heat to the incoming mixture of coal pulp, cycle gas and fresh hydrogen in two heat exchangers connected in series. In the first heat exchanger, the gases and vapors are cooled to around 350 ° C., 42.07 tpd heavy oil condensing, which is taken up in a first scraper. In the second heat exchanger, the cooling to about 225 ⁰ C, whereby 29.23 tpd middle oil condensate, which are incorporated in a second wiper. In the final cooling, the temperature at 40 ⁰ C is lowered, whereby 4.07 tpd gasoline condense, to be included in a third wiper. The 62.6% (stream II) remaining after the removal of stream I is passed through a hydrocyclone at 420.degree. C., 9 tpd heavy oil being separated out, which return to the preheater without pressure relief and cooling. The product leaving the hydrocyclone will

BASF Aktiengesellschaft - A ^ OZ 0050/36928

passed at 400 ^° C. over a Ni-Mo-alumina catalyst and then fed to cooling in heat exchangers, 65.69 tpd heavy oil, 50.05 tpd medium oil and 9.38 tpd gasoline condensing from the hydrogenation product and being taken up in strippers. The gasoline condensate obtained during direct cooling and water separation, 4.07 tpd, is pumped back into the stream behind the hydrocyclone and thus also passed through the refining hydrogenation, whereby the gasoline quantity is reduced to 3.99 tpd. Of the heavy oil / medium oil products obtained from the refining hydrogenation, 48.63 tpd heavy oil and 30.77 tpd medium oil are added to the grind oil; for further processing, the oil yield from the refining hydrogenation is 17.06 tpd heavy oil, 19.28 tpd medium oil and 13% .37 tpd of gasoline available. Together that is 49.71 tpd. In addition, there are 20 tpd of Cj to C ^ hydrocarbons. The hydrogen bound is 6.2 tpd.

The 48.4 tpd sludge that is also obtained is -Vacuum distillation separated into 19.3 tpd distillate heavy oil as grind-61 component and 29.1 tpd topped blowdown for gasification to synthesis gas.

The oil production products are under pressure from the plant. The temperatures for the heavy oil about 35O ⁰ C, for the medium oil is about 225 "C and for petrol about 40 ° C. Heavy oil and middle oil are sold under the given pressure at 300 ^e C over noble metal-zeolite catalyst in its own gas circuit with about 85% hydrogen splitting, hydrogenated and cooled first to about 200'C, the parts boiling above 180 "C essentially condensing, then to 40 ° C, the parts boiling from 30 to 180" C condensing. The parts boiling above 180 "C condense units are returned directly to the cleaved hydrogenation, which up to 180 ⁰ C boiling fractions are introduced together with the gasoline fractions from the refining hydrogenation after depressurization to atmospheric pressure in the initial distillation of the catalytic reformer, where they are fractionated into 3 parts: 1) 30 to 70 "C, 2) from 70 to 170 ° C as a reformer feed and 3) 170 to 180 ^e C (fraction

1) and 3) can be used as gasoline components) and residue above 180 "C for return to the splitting hydrogenation. From the oil recovery After the refined hydrogenation of 49.71 tpd, after the splitting hydrogenation without reforming, 46.23 tpd of gasoline with a boiling range of up to Maintained 180 ° C, the chemical hydrogen bond is 2.5%, of which one a substantial part is recovered from the exhaust gas of the reformer.

Claims (1)

BASF Aktiengesellschaft OZ 0050/36928 A. Claim Process for the continuous production of hydrocarbons from coal by splitting pressure hydrogenation, in which ground coal, advantageously together with finely divided catalysts with a practically asphalt-free mixture of medium oil and heavy oil obtained in the process itself, is driven and the pulp is driven together with hydrogen under a pressure of 100 to 400 bar and passes through one or more ^{reaction chambers kept at 420 to 49O e} C, the reaction products in a slightly below the reaction temperature kept hot separator, the bottom product (sludge) separates into a distillate oil for grinding the coal and a residue for gasification of the gases and vapors drawn off at the top of the separator up to 80%, but more than the liquid oil gain, which contain the oil gain and components of the grinding oil, directly or via a second hot separator through one or more reaction provided with fixed hydrogenation catalysts The other part of the gases and vapors from the heating separator when dealing with the fixed bed hydrogenation leads, characterized in that the unhydrogenated and the hydrogenated portion are cooled in separate streams in heat exchangers against the feedstock going into the coal hydrogenation in stages, the accruing Collects condensates, consisting of heavy oil, medium oil and gasoline, in wipers, deducts a portion for the grinding oil and a portion as oil gain from these condensates and supplies both portions to the grinding of coal or the hydrogenation in the gas phase or mixed phase without intervening distillation, thereby the gasoline collected in the non-hydrogenated portion in the scraper is pumped into the stream provided for the fixed-bed hydrogenation after the water has been separated off and the hydrogenation product obtained in the oil recovery during the splitting or highly refining hydrogenation of the medium oil and heavy oil is cooled in stages, in the case of the splitting hydrogenation under A. In the case of a recycle product for the splitting hydrogenation and a light oil that is withdrawn from the hydrogenation, in the case of the highly refined hydrogenation, heavy oil, medium oil and gasoline are produced from the Eliminate hydrogenation.
35 503/83 gr / ro 23.01.1984