RU2282609C1 - Method for naphthalene production - Google Patents

Abstract

FIELD: petroleum chemistry.

SUBSTANCE: claimed method includes purification of naphthalene-containing cuts from unsaturated compounds by catalytic polymerization followed by isolation of high purity naphthalene. Polymerization is carried out in presence of aluminum-cobalt-molybdenum catalyst, containing (mass %): cobalt oxide (CoO) 2.0-6.0 and molybdenum trioxide (MoO₃) on carrier: Y-Al₂O₃ under pressure up to 0.6 MPa, at temperature of 180-200°C for 1-10 hours.

EFFECT: increased naphthalene yield.

2 tbl, 5 ex

Description

The invention relates to the field of petrochemistry, and in particular to a method for producing naphthalene from naphthalene-containing fractions of liquid pyrolysis products of hydrocarbon feedstocks.

A known method of producing naphthalene from naphthalene-containing fractions of liquid pyrolysis products by hydrogenation purification from unsaturated hydrocarbons in the presence of aluminum-palladium-sulfide catalyst (1. A.D. Berents, A. B. Vol-Einstein, T. N. Mukhina, G. A. Avrech. Liquid processing pyrolysis products. - M .: Chemistry, 1985. S.128-130).

Hydrogenation is carried out according to a single-threaded two-stage scheme at a pressure of 5 MPa, a hydrogen flow rate of 0.6 m ³ per 1 kg of naphthalene-containing raw materials.

Naphthalene, isolated by crystallization and pressing from the purified fraction in the amount of 86% of its potential content, has a crystallization temperature of 79.8 ° C, iodine number 0.2 g of iodine / 100 g, sulfur content 0.04%, color with sulfuric acid - less 9.

The disadvantages of this method of producing naphthalene, adopted as a prototype, are high pressure, a two-stage processing scheme, a significant consumption of hydrogen for the hydrogenation of unsaturated compounds, which increase energy and resource costs.

A less expensive way to obtain naphthalene from naphthalene-containing fractions of liquid pyrolysis products is the purification of unsaturated hydrocarbons by a known method of their polymerization in the presence of alumina-cobalt-molybdenum catalyst (2. Papiyan TG, Kushchev NF. Method for producing a dark petroleum resin. RF patent No. 2231530, bull. . No. 8, 2004). According to method (2), the process of polymerization of unsaturated hydrocarbons is carried out at a temperature of 150-210 ° C, pressure up to 0.1 MPa, for 0.5-2 hours.

The main disadvantage of this method is the low degree of purification of naphthalene-containing raw materials from unsaturated hydrocarbons, which does not allow to obtain naphthalene of high purity.

The aim of the invention is to obtain high purity naphthalene from naphthalene-containing fractions of liquid pyrolysis products with the lowest energy and resource costs.

This goal is achieved by processing naphthalene-containing fractions of the liquid pyrolysis products in the presence of a stationary cobalt-molybdenum alumina catalyst containing cobalt oxide (CoO) 2.0-6.0 wt.% And molybdenum trioxide (MoO ₃ ) 10-18.0 wt.% the carrier Y - Al ₂ O ₃ , at a pressure of up to 0.6 MPa, a temperature of 180-280 ° C, for 1-10 hours.

At the same time, naphthalene isolated from the products of processing has a crystallization temperature of 76-79.8 ° C, iodine number 0.2-0.5 g of iodine / 100 g, color with sulfuric acid 5-7. The yield of naphthalene from its potential content in raw materials is 90-92%.

To implement examples of specific performance, a naphthalene-containing fraction of 190-250 ° C was used, isolated from liquid pyrolysis products obtained at the ethylene plant of OOO Stavrolen (Budennovsk), with the following characteristics:

Density at 20 ° С, kg / m ³ - 982 Boiling point, ° С - 190 Boiling point temperature, ° С - 250 Iodine number - 15.2 Mass fraction,%: Naphthalene - 32.3 Sulfur - 0.05

Example 1. The processing of naphthalene-containing raw materials was carried out in a reactor with a volume of 20 liters. The reactor was heated by built-in electroten. The reactor was loaded with 3 liters of aluminum-cobalt-molybdenum catalyst and 10 liters of the above fraction of 190-250 ° C. The chemical and granulometric compositions of the catalyst are shown in table 1.

Modes of the process of polymerization of unsaturated hydrocarbons of raw materials are given in table 2.

After completion of the polymerization process, a narrow naphthalene fraction of 216-218.5 ° C was isolated from the reaction products by rectification on a laboratory column of periodic action (40 plates). Subsequently, naphthalene was separated from low-boiling liquid hydrocarbons by crystallization and pressing on a vacuum filter press.

The output of naphthalene and its main characteristics are shown in table 2.

Examples 2-5 were carried out analogously to example 1.

The characteristics of the catalysts are shown in table 1. Modes of the polymerization process are shown in table 2.

The selection of naphthalene from the reaction products was carried out analogously to example 1. The output of naphthalene and its characteristics are shown in table 2.

The results of examples 1-4 show that the stated conditions for the polymerization process on an alumina-cobalt-molybdenum catalyst provide a sufficient degree of purification of naphthalene-containing raw materials from unsaturated compounds and allow high purity naphthalene to be isolated.

The results of example 5 show that the processing of the naphthalene-containing fraction under the conditions regulated by the method (2) does not allow to obtain high-purity naphthalene.

Thus, the proposed method for producing naphthalene from naphthalene-containing fractions of liquid pyrolysis products allows to achieve quality indicators of naphthalene obtained by the method (1) with lower energy and resource costs, and, in addition, is characterized by a higher yield of naphthalene (by 4-6%) in comparison with the method (1).

Table 1
Characterization of alumina-cobalt-molybdenum catalysts Example # Composition, wt.% Sizes of granules, mm Soo MoO ₃ Y-Al ₂ O ₃ diameter length one 6 eighteen 76 2-2.5 5-7 2 5 16 79 2-2.5 5-7 3 5 16 79 2-2.5 5-7 four 2 10 88 2-2.5 5-7 5 5 16 79 2-2.5 5-7 table 2
Polymerization process mode, yield and properties of naphthalene Indicators example one 2 3 four 5 one 2 3 four 5 6 1. Polymerization process mode: - temperature in the reactor, ° C 180 210 250 280 210 - pressure, MPa 0.05 0.1 0.3 0.6 0.1 - duration, hour 10 6 3 one 2 2. The output of naphthalene from its potential content,% 92 91 90 91 93 3. Properties of naphthalene: - crystallization temperature, ° С 76 77.5 79.8 78.3 69.8 - iodine number, g-iodine / 100 g 0.5 0.4 0.2 0.3 1.7 - staining with sulfuric acid 7 6 four 5 More than 8 - sulfur content, wt.% 0.01 0.01 0.01 0.01 0.01

Claims (1)

A method of producing naphthalene from naphthalene-containing fractions of liquid pyrolysis products by purification from unsaturated hydrocarbons, characterized in that the purification is carried out by polymerization in the presence of an aluminum-cobalt-molybdenum catalyst containing cobalt oxide (CoO) 2.0-6.0 wt.% And molybdenum trioxide (MoO ₃ ) 10-18.0 wt.% On the carrier Y - Al ₂ About ₃ at a pressure of up to 0.6 MPa, at a temperature of 180-280 ° C for 1-10 hours