WO2012082010A1

WO2012082010A1 - Sorbent for purification of air-gas mixtures, groundwater and waste water from oil and fuel hydrocarbons and method of its preparation

Info

Publication number: WO2012082010A1
Application number: PCT/RU2011/000564
Authority: WO
Inventors: Vladimir Andreevich Breus; Sergey Alexandrovich Neklyudov; Irina Petrovna Breus; Andrey Vladimirovich Savin
Original assignee: Federalnoe Gosudarstvennoe Avtonomnoe Obrazovatelnoe Uchrezhdenie Vysshego Professionalnogo Obrazovaniya "Kazansky (Privolzhsky) Federalny Universitet"
Priority date: 2010-12-15
Filing date: 2011-07-26
Publication date: 2012-06-21
Also published as: RU2462302C2; RU2010151615A

Abstract

The invention relates to environmental protection, in particular, to purification of air-gas and aqueous environs from oil and fuel hydrocarbons with help of organo-mineral sorbents prepared by modification of a mineral matrix by organic polymers. The sorbent is the product of modification of a mineral carrier by plasticized polymer modifiers which composition includes natural and synthetic silicates and/or aluminum silicates - as mineral carriers, synthetic polymers - as polymeric modifiers, ethylene oligomers or aliphatic and aromatic esters of two- and tribasic acids - as plasticizers at the following relationship of ingredients, parties by mass: mineral carrier - 100, polymer - (5-30), plasticizer - (1-20). Natural or synthetic silicate or aluminum silicate is treated by a solution or a latex containing polymer and plasticizer at the temperature of 15-30 °C, or by a viscous- plastic mixture of polymer and plasticizer at the temperature of 100-180 °C under agitating.

Description

Sorbent for purification of air-gas mixtures, groundwater and waste water from oil and fuel hydrocarbons and method of its preparation

The invention relates to environmental protection, in particular, to purification of air-gas and aqueous environs from oil and fuel hydrocarbons with help of organo-mineral sorbents prepared by modification of a mineral matrix by organic polymers.

The method of preparation of organo-mineral sorbents on the basis of preliminarily thermo-treated zeolites by their modification by natural high-molecular substances is known (RU Pat. Ns 2184607, publ. 7/10/2002); hereby as natural high-molecular substances, polysaccharides - alginates or chitosan in the quantities providing their content in a sorbent of 4,5-40,5 and 3-9 mass. % accordingly are used. The modification of zeolites by the specified polysaccharides is carried out by their interaction during mechano-chemical synthesis in a oscillatory mill reactor or in aqueous medium. The obtained organo-mineral sorbents possess high sorption capacity towards cations of metals and organic dyes of various origin, however they practically do not sorb hydrocarbons. The last property is connected with some structural features of natural polysaccharide modifiers, which are characterized (unlike synthetic polymers) by very low sorptive capacity in respect to low- and non-polar organic compounds.

The method of preparation of an organo-mineral sorbent on the basis of clinoptilolite zeolite and an organic polymer is also known, which includes the sequential three-stage processing of zeolite: by 33%-water solution of polyhexamethyleneguanidine, by anhydrous epichlorohydrin, and by 30%-water solution of caustic soda at the last stage (RU Pat. N°2050971 , publ. 12/27/1995). The duration of each stage makes from 8 hours to one day, and the constant or periodic agitating of suspension is required. The disadvantages of this method are high losses of polyhexamethyleneguanidine owing to the use during the synthesis of concentrated solutions of polymer as well the toxicity of the used structure- forming agent (epichlorohydrin) which belongs to the UN Hazard Class 6.1 (risk phrases R10 R23 R24 R25 R34 R43 R45).

The most close to the proposed method is two-stage method of preperation of organo-mineral sorbents on the basis of clinoptilolite, polyhexamethyleneguanidine (or polyethyleneimine) and epichlorohydrin (RU Pat. N°2161066, publ. 12/27/2000), which is characterised by smaller expenses and comparatively simple implementation in comparison with the above described method (RU Pat. N°2050971 ). According to the method, clinoptilolite is being impregnated with the water solution (10-16%) of mixture of an organic polymer and epichlorohydrin at their molar relationship (1 -10): 1 , followed by removing excess of impregnating solution by filtration up to obtaining the moist sorbent, washing out by 10-15% of alkaline solution and then by water with desiccation by hot air in the end. As an organic polymer, along with polyhexamethyleneguanidine or polyethyleneimine their copolymers with the composition of (4: 1 ) and (1 :4) are also used. Despite of decreasing the concentration of toxic structure-forming agent (epichlorohydrin) in the impregnating solution, the processes of modification of the mineral, of washing and drying the product are dangerous for health of the servicers, and also demand some complementary measures on prevention of harmful effects of such dangerous production on the environment.

The closest to the proposed composition is the sorbent consisting of a mixture of propylene stereopolymers with the content of the atactic polypropylene of 5 to 50 mass. % (RU Pat. Ns2182849, publ. 5/27/2002). The presence in the sorbent composition of two structurally different polypropylenes (isotactic and atactic ones) reduce the crystallinity of their mixture and thus, positively affect the sorptive capacity of the sorbent towards hydrocarbons. The disadvantages of this composition are: the high cost of the sorbent (since it consists only from synthetic polymers and does not contain more low-cost components, mineral additives for example), the technological complexities (at finishing the size of sorbent particles to the specified dispersity, which is necessary for creation of the required permeability of a sorption layer), as well the reinforcement of cohesion of polymer particles during the process of its saturation by a hydrocarbon as a result of absorption.

The purpose of the proposed invention is the creation of an organo-mineral sorbent possessing high sorptive capacity towards hydrocarbons in both dry and wet conditions and capable to refine air-gas and aque]ous environs contaminated by oil and petroleum products. Hereby the method of sorbent preparation should be technologically simple, provide a uniform distribution of a layer of modifier on the mineral surface, use ecologically safety components, and does not demand any expensive and special equipment.

For the purpose of achievement of the technical result, the organo-mineral sorbent for the purification of air-gas and aqueous mediums from oil and fuel hydrocarbons is offered. The sorbent is the product of modification of the mineral carrier by plasticized polymeric modifiers which composition includes natural and synthetic silicates and/or aluminum silicates, a polymeric modifier (synthetic polymer), as well a plasticizer: oligomers of ethylene or aliphatic and aromatic esters of two- and tri-basic acids; which have the mass-based relationship of mineral basis : polymer : plasticizer equal to 100 : 5-30 : 1 -20; and which possess high sorption activity in relation to hydrocarbons both in the vapour phase (sorption capacity towards hexane and benzene forms up to 300 mkl/g) and in the aqueous phase (sorption coefficients towards benzene form K_d - 14-16). As a mineral carrier, sand, zeolites, zeolite-containing minerals, montmorillonites, bentonites, silica gel, and diatomite; as a polymeric modifier, low-molecular polyethylene, natural and synthetic rubbers (isoprene, chloroprene, divinyl, butadiene-styrene, butadiene-methylstyrene, butadiene-chlorbutadiene, butyl rubber, brombutyl rubber, chlorbutyl rubber); and as a plasticizer, ethylene oligomers, dialkyl phthalates, alkylaryl phthalates, triaryl phosphates, dialkyladipinates, and dialkylsebacates are used.

The method of preparation of the organo-mineral sorbent by treatment of natural or synthetic silicate or aluminum silicate by the mixture of polymer and plasticizer in the ratio of 5-30: 1 -20 is offered. This mixture is being used as a latex or a solution in an organic solvent at the temperature of 15-30 °C, or as a viscous- plastic mixture of polymer and plasticizer in the ratio of 5-30: 1 -20 at the temperature of 100-180 °C. The sorbent is being made by intermixing of the mineral carrier, polymer and plasticizer under the relationship of 100: 5-30: 1-20 mass units respectively. In case of treatment of the mineral by a solution or a latex, the obtained organo-mineral sorbent is being filtered off and dried at the temperature of 90-1 10 °C. In case of modification by latexes, the mineral carrier preliminarily is being processed by coagulants (salts of polyvalent metals). The offered method provides a uniform distribution of all components in the organo- mineral sorbent. It is attained by simultaneous introduction of both modifier and plasticizer in the form of a liquid mixture (latex, solution or melt) into the reactor filled with mineral matrix. The offered method creates the homogeneous plasticized polymeric covering thus providing high sorptive capacity of the obtained sorbent towards hydrocarbons as well reproducibility of its consumer and processing properties. Besides, the offered method simplifies and makes cheaper the technology of sorbent production.

The matter of the invention consists in the following:

The synthetic polymers, which molecules have carbon-chain structure, absorb hydrocarbons by binding them within the volume of a polymeric phase. According to the mechanism of absorption the degree of binding of a hydrocarbon sorbate is governed by the rate and depth of its diffusion into the polymer phase. The diffusion process is essentially controlled by the structure of the polymeric phase, and first of all of its density as the major index that directly depends on the energy of interaction of polymer molecules with each other. As a result, the more is the energy of intermolecular interaction in the polymer, the more its its density and thus, the less is absorption of a hydrocarbon sorbate. For the purpose of attenuation of intermolecular binding between polymer chains, into the offered composition organic plasticizers are being introduced, that sharply raise its sorption activity towards hydrocarbons both in the vapour phase (sorption capacity towards hexane and benzene forms up to 300 mkl/g) and in the aqueous phase (sorption coefficients towards benzene form Kd - 14-16).

For reduction of the price of the obtained sorbent and enhancement of its filtering characteristics, cheap minerals as a mineral matrix in its composition are used. The use of the minerals does not result in decreasing sorption ability of the offered composition because the polymer is uniformly distributed on the mineral surface in the form of a film that is almost completely accessible to hydrocarbon diffusion. Together with effect of an organic plasticizer, the polymer film allow increasing the sorption capacity because of the lack of diffusion difficulties during the sorbent - hydrocarbon interactions. The uniform distribution of the modifying layer on the surface of mineral particles is attained by simultaneous introduction of both modifier and plasticizer in the form of a liquid mixture (latex, solution or melt) into the reactor filled with mineral matrix. The thickness of the organic layer is controlled by a ratio of the mineral and the modifying composition introduced into the reactor. It was established experimentally that by variation of the content of the mineral, modifiers and plasticizers in the offered composition, the sorbents with optimum sorption and filtration characteristics are generally produced at the content of the mineral basis - of 66,67-94,34 mass. %, of the polymer - of 4,72- 20,00 mass. %, and of the plasticizer - of 0,94-13,33 mass. %.

Example 1

The 100 mass parties of dry sand were placed into the metal vessel and then 10 mass parties of low-molecular polyethylene with melting point of 85 °C were added. As a modifier, the ethylene oligomers contained in low-molecular polyethylene were acting. The vessel was placed in a furnace at 100-120 °C for 30 minutes, then mixture was carefully intermixed and was kept at the specified temperature for 30 minutes. The mixture was cooled and mixed to a friable conditions.

Example 2

The 100 mass parties of silica gel with particle size of 0,2-1 ,0 mm were placed into the vessel at 25 °C and then the 20 mass parties of low-molecular polyethylene with melting point 85 °C as solution in 300 mass parties of hexane or petroleum ether under agitating were added. The ethylene oligomers contained in low-molecular polyethylene acted as modifier. A solvent was evaporated on the water bath under agitating before thickening, and then the sorbent was placed in the furnace at 100-120 °C for one hour for removal of solvent residue. The mixture was cooled and mixed to a granular conditions.

Example 3

The 100 mass parties of dry sand were placed into the vessel at 25 °C and then solution of 20 mass parties of brombutyl rubber and 10 mass parties of dinonylphthalate in 500 mass parties of carbon tetrachloride under agitating was added. The mixture was intermixed during 30 minutes and then was filtered off. The obtained sorbent was placed in the furnace at 100-120 °C for 1 -2 hours for removal of solvent residue. The mixture was cooled and mixed to a granular conditions. Example 4

The 100 mass parties of dry sand were placed into the vessel at 25 °C and then solution of 30 mass parties of chlorbutyl rubber and 20 mass parties of tricresyl phosphate in 500 mass parties of carbon tetrachloride under agitating was added. The mixture was intermixed during 30 minutes and then was filtered off. A sorbent was placed in a furnace at 100-120 °C during (1 -2) hours for removal of solvent residue. The mixture was cooled and mixed to a granular conditions. Example 5

The 100 mass parties of silica gel with particle size of 0,2-1 ,0 mm were placed into the vessel at 25 °C. The silica gel was preliminarily treated with 5% water solution of aluminium sulphate and then exsiccated. Then the mixture of 30 mass parties of butadiene-chlorbutadiene latex DVCB-70 and 10 mass parties of tricresyl phosphate under agitating was added. The mixture was agitated during 30 mines and then was filtered off. The sorbent was placed in a furnace at 100-120 °C for (1 -2) hours for drying. The mixture was cooled and mixed to a granular conditions.

Claims

What is claimed is:

1. The organo-mineral sorbent for purification of air-gas and water mixtures from oil and fuel hydrocarbons on the basis of natural and synthetic polymers, different in that it contains a plasticizer and a mineral carrier at the following relationship of ingredients, parties by mass: the mineral carrier - 100, polymer - (5- 30), plasticizer - (1-20).

2. The sorbent as is claimed in claim 1 wherein as the polymer, low-molecular polyethylene and polypropylene, natural and synthetic rubbers (isoprene, chloroprene, divinyl, butadiene-styrene, butadiene-methylstyrene, butadiene- chlorbutadiene, butyl rubber, brombutyl rubber, chlorbutyl rubber) are used.

3. The sorbent as is claimed in claim 2 wherein as the plasticizer, ethylene oligomers, aliphatic and aromatic esters of two- and tribasic acids (dialkyl phthalates, alkyl aryl phthalates, triaryl phosphates, dialkyl adipinates, dialkyl sebacates) are used.

4. The sorbent as is claimed in claim 3 wherein as the mineral carrier, sand, zeolites, zeolite-containing minerals, montmorillonite, bentonite, silica gel, and diatomite are used.

5. The method of the preparation of the sorbent by treatment (modification) of a mineral carrier by organic polymers wherein mineral carrier is treated by a mixture of polymer and plasticizer.

6. The method as is claimed in claim 5 wherein the mixture of polymer and plasticizer in the form of solution on the mineral carrier at the temperature of 15-30 °C under agitating is applied.

7. The method as is claimed in claim 5 wherein the mixture of polymer and plasticizer in the form of latex on the mineral carrier treated by a coagulant at the temperature of 15-30 °C under agitating is applied.

8. The method as is claimed in claim 6 or 7 wherein the organo-mineral sorbent after treatment is filtered off and dried up at the temperature of 90-110 °C.

9. The method as is claimed in claim 5 wherein the viscous-plastic mixture of polymer and plasticizer on the mineral carrier at the temperature of 100-180 °C under agitating is applied.