RU2331466C1 - Method of obtaining adsorbent of aluminosilicate for cleaning hydrocarbons - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of obtaining the adsorbent for cleaning oils consists of granulation and modification of synthetic aluminium silicate, of the type Y containing zeolite in cation-decationated form with the content of rare-earth elements. Granulation is carried out on the devices with impact load.

EFFECT: opening of the additional strong centres of adsorption and improvement of the quality of adsorbent.

2 cl, 3 tbl

Description

Deep purification of hydrocarbons from impurities of sulfur, nitrogen, tarry and other undesirable compounds is carried out by adsorption of impurities by a solid absorber - adsorbent [General course of processes and apparatuses of chemical technology, ed. V.G. Einstein, M .: Logos, 2002, book 2, p.1157]. Adsorbents are highly porous solids in the form of grains ranging in size from fractions of a millimeter to several millimeters. Due to the developed porosity, adsorbents can absorb adsorbate in amounts commensurate with their own mass. As raw materials for the production of adsorbents, aluminosilicates of natural origin — clays — are widely used [R.V. Alekseeva, M.M. Kuvaeva, L.K. Kharitonova “Adsorbents based on natural clays for hydrocarbon purification”, Review TsNIITEneftekhim, 1978]. This includes bentonites of various origin (deposits), palygorskites, bauxites, montmorillonites, all kinds of their variants and combinations. Natural raw materials are attractive due to their accessibility, however, they are obviously heterogeneous; it requires an enrichment stage and, as a rule, chemical modification by treatment with solutions of acids (sulfuric) or salts (for example, aluminum sulfate) to secure adsorption properties at the required level [A.V. Minibaev, PPZagidullin “Adsorbent based on clay, activated aluminum sulfate from the installation VZhS ". Oil refining and petrochemistry, scientific and technological achievements and best practices, M. 1993, No. 3, p.10-13]. The ability to control the properties of the adsorbent from natural raw materials is very limited.

Granulation of clays to obtain the required particle size distribution of the adsorbent using spray drying is cost-effective only with a capacity of thousands of tons.

With the development of catalytic processes on a synthetic aluminosilicate catalyst (molded and / or powdered), attempts have been made to use production wastes (crumbs) as raw materials for the production of adsorbent [A.D. Goncharenko, A.S. Leontyev, A.N. Pereverzev, etc. "The current state of the processes of purification of paraffins", topics. Review TsNIITEneftekhim, 1978, p. 42]. The desired adsorbent fraction is obtained by dropping out of crumbs. The need for this adsorbent significantly exceeds its resource.

A special production of fine-spherical aluminosilicate adsorbent was organized in joint production with a zeolite-containing cracking catalyst [Technological regulations of VPO Soyuznefteorgsintez, 1981]. However, the performance of this adsorbent is low.

Obtaining an adsorbent by mixing crystalline aluminosilicates with a binder containing at least 80 wt.% Zeolitized clay, and molding followed by drying and calcination [application RU 2001125937/12 of 2000.02.16] or alumina in γ-form [application RU No. 97104027 / 04 from 1995.06.07] allowed to expand the range of properties of adsorbents. However, the production methods of adsorbents for these technical solutions are complex and cumbersome; they are profitable only with very large volumes of production.

The closest in technical essence and the achieved effect to the proposed technical solution is a method for producing an adsorbent containing molecular sieves by extruding a mixture of molecular sieves with a binder, which is selected from clays, silicas, silicates, zirconium oxides, titanium oxides and aluminum phosphates, the binder being up to 50 wt.% by weight of the composition [application RU 2005133484/15 of 03.03.2004].

The disadvantages of adsorbents for this technical solution are their low adsorption ability when refining petroleum oils due to the low acidity of the molecular sieves used and the low stability of the bleaching ability of petroleum oils, as well as the low mechanical stability of the granules, which complicates the process of separating the purified oil from the adsorbent residues.

A disadvantage of the known method for producing an adsorbent is also the use of a substantially different nature as a binder, as well as the need to introduce molecular sieves up to 50 wt.%, Which leads to low mechanical stability of the granules.

The aim of the proposed technical solution is to obtain an adsorbent with high adsorption ability when refining petroleum oils, high stability of its bleaching ability and high mechanical stability of the granules.

This goal is achieved by the method of producing aluminosilicate adsorbent for the purification of hydrocarbons by granulation and modification of aluminosilicates, characterized in that synthetic aluminosilicate is used as a raw material, including a component with a frame structure — preferably type Y zeolite in a cation-decationized form, granulation is preferably carried out on percussion apparatuses -abrasive load, and the modification is carried out preferably before granulation.

A distinctive feature of the proposed technical solution is the use of synthetic aluminosilicate as a raw material, including a crystalline component with a frame structure - preferably type Y zeolite in cation-decationized form; granulation is carried out on devices with shock-abrasive load, and the modification is carried out before granulation.

The qualitative and quantitative composition of the raw materials, the set and sequence of methods for preparing the adsorbent according to the proposed technical solution make it possible to obtain an adsorbent for the purification of hydrocarbons with enhanced characteristics: toluene adsorption ability, oil bleaching ability, decolorizing stability, and mechanical stability. Thus, the proposed technical solution has the sign of "significant differences".

The use of the totality of the proposed methods for producing an adsorbent is not known, i.e. the proposed technical solution has the sign of "novelty."

The proposed method for producing aluminosilicate adsorbent for the purification of hydrocarbons is implemented as follows.

The raw material is synthetic aluminosilicate, including a crystalline component with a skeleton structure, obtained in accordance with technical solutions according to US Pat. RF No. 2229932, 2221644, 2221645, 2229933, 2233309, 2285562, 2287370.

The characteristics of the raw materials are presented in table 1.

Table 1 Component Units rev. Value Al ₂ O ₃ wt.% 8-20 SiO ₂ wt.% 80-92 Na ₂ O wt.% 0.3-0.5 Rare Earth Oxides (REE) wt.% 1.8-2.1 Zezholit type zeolite molar - silicate module M = SiO ₂ / Al ₂ O ₃ the attitude 4,5-10,0 Bulk density kg / dm ³ 0.6-0.9 Particle size mm up to 7.0

Aluminosilicate synthetic raw materials with a particle size of up to 7.0 mm and a bulk density of 0.6 to 0.9 kg / dm ³ , containing a faujasite type zeolite with a silicate module SiO ₂ / Al ₂ O ₃ from 4.5 to 10.0, having a residual content of Na ₂ O from 0.3 to 0.5 wt.% and a content of oxides of rare earth elements from 1.8 to 2.1 wt.%, preliminary screened into fractions: less than 0.3 mm (waste); 0.3 mm - 1.5 mm (first target fraction); 1.5 mm - 3.0 mm (second target fraction); 3.0 mm - 5.0 mm (third target fraction); above 5.0 mm (residue). The set of fractions during preliminary screening depends on the requirements of the customer.

Depending on the material balance of the sieving process and the customer’s requirements for the size of the adsorbent particles, the desired target fraction (or fractions) is separated, and the residue is treated with a modifier and sent to granulation on a percussion-disk mill or other apparatus where material is crushed under the influence of loads, preferably, of impact type . The crushed material is sieved with the allocation of the target fractions; a residue with a particle size greater than the particle size of the target fraction is returned to grinding.

Below are examples of the implementation of the proposed technical solution, with which it is illustrated, but not exhausted.

Example 1

1000 g of synthetic aluminosilicate containing 10 wt.% Faujasite type zeolite with a silicate module SiO ₂ / Al ₂ O ₃ = 8.9, with a bulk density of 0.81 kg / dm ³ , with a content of 0.43 wt.% Na ₂ O and 1.8 wt.% REE oxides, scattered into fractions:

less than 0.3 mm - waste 32 g 0.3 mm ÷ 1.5 mm - fraction No. 1 155 g 1.5 mm ÷ 3.0 mm - fraction No. 2 265 g 3.0 mm ÷ 5.0 mm - fraction No. 3 500 g more than 5.0 mm - the remainder 48 g

The presence of faujasite-type zeolite with a frame structure in the feedstock creates in the adsorbent a set of strong adsorption centers available for hydrocarbons with a high molecular weight, characteristic of petroleum oils. The grinding of raw materials on apparatuses with a load on the material, preferably of shock type, makes it possible to increase the availability of zeolite adsorption centers without covering them with grinding products by attrition. The raw materials before grinding are treated with water or an aqueous solution of a surfactant to increase the efficiency of the grinding process.

As target fractions, fraction No. 1 and fraction No. 3 were separated, as well as waste (less than 0.3 mm).

The remaining material (a fraction of 1.5-3.0 mm and more than 5.0 mm) was treated with water (pH 6.0) and passed through a device such as a disintegrator, where grinding under the influence of shock type loads occurred. The crushed material was dispersed into fractions, as described above. Received

less than 0.3 mm - waste 16 g 0.3 mm ÷ 1.5 mm - fraction No. 1 181 g 1.5 mm ÷ 3.0 mm - fraction No. 2 93 g 3.0 mm ÷ 5.0 mm - fraction No. 3 23 g more than 5.0 mm - the remainder no

The target fractions after preliminary screening and after grinding are analyzed separately, then after mixing in terms of:

- adsorption capacity (static) in toluene;

- bleaching ability oily in a stationary layer;

- thermal stability.

The toluene adsorption capacity is expressed in% relative to the ability of the standard, which is taken as a sample of adsorbent fractional composition of 0.25-0.50 mm with a bulk density of 0.58-0.65 kg / DM ³ and a fixed adsorption capacity for toluene.

The decolorizing ability of the adsorbent by oil in a stationary layer is determined by the oil yield with a refractive index of 1.4870-1.4875 and a color of not more than 1.

The thermal stability of the adsorbent is evaluated by its ability to maintain a decolorizing ability after calcining the fresh adsorbent at a temperature of 825 ° C for 6 hours and is expressed as a percentage relative to the standard.

The mechanical stability of the adsorbent was evaluated by the presence of particles (turbidity) in a bleached oil: + (turbidity) and - (no turbidity).

According to the results of the analysis of the volume and quality of the target fractions obtained (see table 1):

Fraction The total yield, wt.% Toluene adsorption capacity,% Decolorizing ability by oil,% Thermal stability,% rel. Mechanical stability 0.3 mm ÷ 1.5 mm 33.6 282/267/270 * 182/170/173 95.1 - 3.0 m ÷ 5.0 mm 52.3 248/230/241 *  161/153/157 95.2 - ^{* the} value of the indicator after grinding / after preliminary sieving / after mixing

The composition of the raw materials and the set of target fractions are given in table.2.

Characteristics of raw materials.

table 2 Example No. Raw materials Bulk
density,
kg / dm ³ Fractional composition, wt.% Al ₂ O ₃ ,
wt.% SiO ₂ ,
wt.% Na ₂ O,
wt.% REE,
wt.% Zeolite
Module The size
particles mm 0.3 mm 0.3-1.5 mm 1.5-3.0 mm 3.0-5.0 mm > 5 mm one 9.2 rest 0.43 1.80 type Y 8.9 0.71 <7.0 3.2 15,5 26.5 50,0 4.8 2 14,4 rest 0.38 1.88 type Y 9.3 0.82 <7.0 4.1 23,4 10.0 60.5 2.0 3 8.0 rest 0.49 1.83 type Y 5.0 0.60 <6.5 4.7 20.8 14.3 56.3 3.9 four 17,2 rest 0.3 1.94 type Y 7.8 0.81 <6.5 2,3 13.7 10.7 70.1 3.2 5 20,0 rest 0.5 2.1 type Y 10.0 0.90 <6.5 3.0 9.6 18.2 64.0 5.2 6 7.9 rest 0.51 1.76 type X 4.0 0.58 <7.0 2,3 13.3 31.7 48.1 3.6 7 6.8 rest 0.53 1.74 type Y 4.9 0.56 <7.0 0.3 5.9 12.6 75.3 5.9 8 7.4 rest 0.38 1,69 type Y 11.0 0.95 <7.0 6.3 14.9 20.7 53.8 4.3 9 7.0 rest 0.40 2.2 type Y 5.6 0.55 <6.5 3,7 10,2 21.7 58.0 6.4 prototype 20.1 rest 0.49 1,2 Type X 3.8 0.65 <7.0

The conditions of preparation and the quality of the adsorbent are shown in table 3.

An analysis of the materials of Table 3 showed that the conditions for producing an adsorbent in accordance with the proposed technical solution, including raw materials, granulation conditions and modifications, allow one to obtain an adsorbent (examples 1-5) with an adsorption capacity for toluene in the range of 236–281%, a decolorizing ability for oil in the range of 156 ÷ 173% and thermal stability of 95.1-96.3%, which significantly exceeds the characteristics of the adsorbent of the prototype.

Going beyond the scope of the claimed technical solution (examples 6-9) leads to an undesirable decrease in the quantitative characteristics of the adsorbent.

Thus, the proposed technical solution meets the criterion of "industrial applicability".

Claims (2)

1. A method of producing an adsorbent for the purification of oils by modification and granulation of synthetic aluminosilicate, characterized in that they use raw materials containing 10% of type Y zeolite in cation-decation form with a content of rare earth oxides of 1.8-2.1 wt.% , and with a silicate module SiO ₂ / Al ₂ O ₃ equal to 5.0-10.0. 2. The method according to claim 1, characterized in that the modification is carried out by treating the raw material with a surfactant, after which grinding is carried out on percussion apparatuses.