SU719510A3 - Method of coal liquation products purification - Google Patents

Description

(54) METHOD FOR CLEANING COIL LIQUID PRODUCT

I2

The method relates to methods for purifying products obtained from coal liquefaction, and can be used in the chemical industry.

A known method of purification of the products of coal liquefaction obtained by hydrogenation from solid particles by mechanical separation 1.

However, the suspended ash particles are very small, some of them have submicron sizes, and therefore they are very difficult to remove from liquid products.

Closest to the invention is the cleaning of coal liquefaction products from solid particles by mechanically separating the latter 2. As a result, the liquid hydrogenation products are divided into target products and a stream containing a concentrate of solid particles.

However, the degree of purification of products is insufficient.

The aim of the invention is to increase the degree of purification of the products.

This goal is achieved by the described method of cleaning coal liquefaction products by mechanically separating solid particles from the raw material to produce a stream containing a concentrate of solid particles, to which aliphatic alcohol, Cr-Xu, is added to the “similar raw material” in the CU | 0.05- 15 wt. %

A distinctive feature of the process is the addition of aliphatic alcohol in the amount indicated in the feedstock.

When adding alcohol, the temperature of the feedstock is maintained at 38-370 ° C, preferably or

204-288 ° C. After the addition of alcohol, the mixture is stirred to form a homogeneous composition. Before separating the solid particles, the mixture is kept at a stirring temperature for 0.5-180 minutes,

preferably 60 or 2-30 minutes.

In case the alcohol is added to a hot, unfiltered suspension of dissolved coal, the mixture is stirred and aged. The mixture is then passed through a filter to which a precoat of diatomaceous earth is first applied. The filtrate containing alcohol is distilled by a scientific research institute for alcohol recovery. Alcohol is recycled, and mixed with the feed; they are filtered onto the filter along with the required amount of a fresh batch of alcohol.

with the following filtration equation:

l - -KW - C.

where T is the filtration time, min.

W is the weight of the filtrate collected during time G, min / g;

K - Resistance Coefficient

filter cake;

C — coefficient of precoating resistance, min / g;

- ----- (speed), g / min.

In the filtering experiments below, the amount of the extracted filterate V7 is recorded automatically as a function of time T. W and T are the basic data obtained in these experiments.

Data on the dependence of W on T is processed in accordance with the specified mathematical model.

When performing filtration experiments, use a 90 mesh sieve located in the filter element, the sieve is pre-coated with diatomaceous earth. The thickness of the layer is 1.27 cm. The filter element has an internal diameter of 9 cm, a height of 2.5 cm and a surface area of 2.84 cm. The strainer rests against a solid frame. The application of the preliminary coating is carried out by pressing 5 wt. % suspension of dicalite material in light oil on a sieve using nitrogen under a pressure of 2.8 kg / cm. The application of precoating is carried out at a temperature close to that of the subsequent filtration operation. The resulting porous layer of pre-coating material weighs –1.2 g. After applying the pre-coating material, nitrogen is purged under a pressure of 0.35 kg / cm for 1-2 seconds to remove traces of light oil.

Then, a sample of a coal liquefaction product - 750 g unfiltered oil (NOM) is introduced into a separate autoclave operating as a reservoir. The temperature of the product is maintained at 38-54 ° C. The product is continuously displaced. The transfer is carried out using two turbines. The shaft speed is 2000 rpm. Filtration begins when the nitrogen pressure in the autoclave is 2.8-5.6 kg / cm. The oil flowing out of the autoclave is passed through a preheating coil, the residence time in which is controlled by means of valves. The spiral is equipped with thermocouples at the inlet and outlet, so that

The temperature of the oil entering the filter is kept constant. The oil coming out of the preheater is fed to the filter. The filter element and filter holder are also connected to thermocouples. The weight of the filtrate is automatically recorded every 5 s.

To determine the effectiveness of additives, comparative tests are carried out using the same batch of raw oil.

In the experiments, a coal liquefaction product (mass) is used, having the following characteristic:

Specific weight at 15.6 ° C

1.15 Kinematic viscosity

at 98.9 ° C, eat

24.1 lot at 15.6 ° С 1,092 Ash, weight. % 4.49 Insoluble Pyridine, wt. %

6.34

Distillation data

Temperature, °

Percent

C, at 1 atm 270

ykipani 285

10,297

20

30,317 341

40 368

50 409

60 487

70

71 (all retrieved 496

distilled substances)

The drawing shows a graph of the results of the experiments given in the examples.

The horizontal axis represents the value of W, while the vertical axis shows the values of T / W, which are reverse filtration rates. The slope of each curve is K, and the intersection of each curve with the vertical axis corresponds to C.

In the first experiment, isopropanol was not added to the raw materials. This experience illustrates the curve. In experiments 2, 3 4, the feedstock contains 2 wt. % alcohol. In these cases, the dwell times are 2, 4, and 6 minutes, respectively. These experiments illustrate curves 2, 3, and 4.

Let's analyze each curve. Parameter C is primarily a precoat characteristic, since it is the reciprocal of the filtration rate at the beginning of the experiment, before a significant amount of the filtered substance is deposited on the surface of the precoat. On the other hand, the slope of K is a parameter of the filter cake deposited on the precoat. It controls filtering by itself, without precoating. The relatively low slope of K (low K value) is characterized by a rather low resistance of the precipitate on the filtration filter. From the examination of the figure, it is clear that the upper curve itself has the largest slope (the highest K value), while the lowest curve itself has the smallest slope (the smallest K value). This graph shows that after a minute of filtration, a lower amount of filtrate forms on the upper curve than on the lower curve. On the other hand, although each curve shows a lower one (filtration rate (i.e., higher value (speed)) at the end compared to the beginning of the experiment, a low slope of the curve indicates that the filtration rate does not sharply decrease during the experiment. It should be noted that each filtration experiment is carried out without washing the solvent 1 of the filter cake. Since washing the solvent is associated with a change in the nature of the filter cake, it will also change the value of K. Most industrial filters are considered rotary. continuous filters, in which the filters of the walkie-talkie filter for no more than a minute are continuously replaced by washing cycles, in which the washing solvent is sprayed through the precipitate on the washable absorbed liquid carbon filter. during the first Minute of filtration. The values noted in the experimental data along each parametric curve (numbers 0.25; 0.5; 0.75; 3.0; 1.5; 2.0) represent the time B minutes elapsed from the start of the filtration experiment. I.e., the moment when these experimental data were obtained. As shown in the graph, the use of pzopropanol reduces filtration resistance in all cases. A gradual increase in the temperature between the addition of isopropanol and the beginning of the filtration experiment leads to a gradual decrease in the resistance of φ, ΔltracI1. Example 1. In order to illustrate the effect of filtering the addition of various alcohols and phenol to the carbon liquefaction product, a series of experiments was carried out. The experiments were carried out at a temperature of 260 ° C and a pressure on the filter of 2.8. The results of the experiments are given in table. one.

The filtration resistance coefficient K is the best indicator of the effect of an additive on filtration, since this coefficient excludes all effects on filtration from the side of the filter system and pre-coating. The value of. Illustrates. filtering and precoating action regardless of the effect of alcohol or phenol additives. The above data shows that the filtration resistance factor K when alcohol is added decreases to varying degrees, with secondary butyl alcohol having the greatest effect on reducing the resistance coefficient. In contrast, pheno, n increases the resistance coefficient, showing that it is a dispersed medium, not an agglomerate. Therefore, the presence of phenol shows the opposite effect on the filtration of coal liquids. Since phenol and cresols are present in coal liquids and since phenol boils at about 181 ° C, recirculation of the oil fractions from the process having the indicated boiling point to the filter is avoided during filtration. Measurement 2. To illustrate the effect of the introduction of methyl and ethyl alcohol, we conducted additional experiments on filtration at 210 ° C and a pressure on the filter of 5.6 kg / cm. The results of these experiments are given in table. 2

 SPECIFICALLY FROM the above data table. 2, methyl alcohol increases the filtration resistance coefficient K, as ethyl alcohol reduces it.

PRI me R 3. Conducted experiments on fi.-1tritsii to determine the effect of orgD. Addition (2 all.%)

 can be seen from the data table. 3, additions of 1e butyl aldehyde, methyl ethyl ketoia and acetic acid are not very useful; The introduction of acetone isescitelio uvelpchzast coefficient. In industry

Table 2

L lsh / g

 KIS.LOT, aldehydes and on g-rocees filtering.

The results of experiments pr | ivedeya tab,). 3. Filtration is carried out, iri 260 ° C and dazleiin 5.6 kg / sl1.

Table 3

: Speed.

Deprivolanle acids are undesirable because of the zl ;; x a1Arr ative nature.

Test 4. Experiments were carried out to determine the effect of pa filtration of the additive pzopyranol. The experiments were carried out at 260 ° C and a dazleneI of 5.6 kg / cm.

The results of the experiments are given in table. four.

t a b l 1 c a 4

0.0192i -5.6

0.01197.3

0.0065.S.6

0.0086 9.2

Grivedenpy data table. 4 shows}) t a gradual decrease in the C0111 coefficient of the K growth as the amount of isopanol increases. Then the coefficient is pressed.

11 RI mep 5. To illustrate the effect; - the dwell time applied to

f. the raw material containing the additive is carried out ;; one experiments on the use of butyl) and 3 as an additive; and a holding temperature of 49 ° C. Filtration according to the filter is carried out at 260 ° C and 5.6 kg / sg and npiJ exposure 2 minutes at 260 ° WITH.

The results of the experiments are given in table. five.

T a bl II c a 5

The data table. 5 show that the dwell time between the introduction of the secondary butyl acid to the filter feed and the filtration operation has an effect on the filtration resistance coefficient K. Thus, for 80 minutes after the addition of the secondary butyl spirits, the effect of alcohol increases and then decreases. A similar phenomenon occurs with the addition of tertiary butyl alcohol.

The data table. Figure 6 shows the positive effect on the resistivity factor when filtering K, the achievable increase (m times the lead time between the addition of isopropanol and the start of filtration. These data illustrate the phenomenon of the interaction of alcohol and the feedstock.

Example 7 To illustrate the effect of holding time between the introduction of isopropanol into the feedstock and the start of filtration, four experiments were carried out. The experiments were carried out at a temperature of 260 ° C, a pressure of 5.6 kg1 cm.

Claims (2)

1. The method of purification of coal liquefaction products from solid particles by mechanical example 6. A series of experiments using isopropanol was carried out to illustrate the effect of the exposure time between the addition of isopropanol to the raw materials and the start of filtration. The experiments were carried out at 260 ° C and a pressure of 5.6 kg / cm. The results of experiments on two samples of the starting products are given in table. 6 Table 6 the separation of solid particles from the raw material to obtain a stream containing a concentrate of solid particles, characterized in that, to increase the degree of purification, the aliphatic alcohol Co-Xu is added in the amount of 0.05-15 wt. % 2. A method according to claim 1, characterized in that isopropyl, G1erv | ary, secondary, tertiary butyl alcohol is used as an aliphatic alcohol. Sources of information taken into account in the examination: 1. US patent number 3852183, cl. 208-10, published. 1974. 2. US patent number 3892654, cl. 208-8, published. 1975 (prototype). GM g / min03o, r0, 1 Cr Sz WITH;, 7 77 ; /.