RU2090258C1 - Method of preparing sorbent for cleaning water to remove petroleum and petroleum derivatives - Google Patents

Abstract

FIELD: water treatment. SUBSTANCE: method consists in treating aluminosilicate hollow microspheres (fly-ash waste from heat power stations) with crude oil followed by burning it off by way of kindling it in access of air and maintaining process until burning is completed. Adsorption capacity of adsorbent is 800 mg/g (470 mg/cu.cm). EFFECT: volume purification degree with regard to water- emulsion and dissolved petroleum and petroleum derivatives is at least 98%. 1 tbl

Description

 The invention relates to methods for the preparation of adsorbents designed to purify water from oil and oil products located on its surface, as well as in solution and water-emulsion phase in the entire volume of a natural or technical reservoir.

 A known method of preparing an adsorbent for removing oil and oil products by applying it to floating oil [1] consisting in the fact that aluminosilicate hollow microspheres isolated from fly ash of thermal power plants are used as adsorbent.

 However, the microspheres have a relatively low adsorption capacity (445 mg / g), as a result of which the method requires a large consumption of adsorbent.

 Known methods for producing sorbents for water purification from oil, including applying a hydrophobic carbon-containing layer to the surface of an aluminosilicate carrier. So, for example, in the method [2], kaolin is treated with cyclopentadiene in the gas phase at a vapor pressure of 220-320 mm RT. Art.

 There is also known a method of producing a carbon-containing sorbent for wastewater treatment from oil [3] comprising applying to the surface of the expanded clay carrier hydrocarbons or their halogen derivatives by treatment with ionizing radiation.

 However, the sorbents obtained by the method have a comparatively lower sorption ability (maximum 180 mg / g), and therefore require a greater consumption of sorbent. In addition, the method involves the use of ionizing radiation sources and, therefore, costly measures to protect personnel. Finally, the method is intended to increase the capacity of the sorbent only for water-soluble fractions of oil.

 The technical result of the proposed method is to increase the sorption ability of the sorbent, the ability to remove both floating and soluble oil products, i.e. increasing the efficiency of the sorbent.

 The technical result is achieved by the fact that in the method including processing the aluminosilicate with a hydrocarbon-containing liquid, the difference is that as the aluminosilicate, hollow aluminosilicate microspheres are extracted from the ash of coal-fired thermal power plants, and the treatment is carried out with oil, followed by its burning with free access to air until the combustion ceases to burn .

 As a result, a film of products of incomplete oil combustion (petroleum coke, soot) is formed on the surface of microspheres, which increases the capacity of the sorbent in relation to oil and oil products by 1.8 (relative to [1]) and 4.4 (relative to [2] ) times.

 The following is an example implementation of the method.

Hollow aluminosilicate microspheres were isolated from fly ash of Novocherkasskaya State District Power Plant (Rostov Region, Russian Federation) by reagent-free flotation. They are gray non-caking powder, consisting of regular, spherical, hollow particles with a diameter of 20 to 200 microns (an average of 120 microns), resulting from the melting of the mineral components of coal during its combustion at thermal power plants. The wall thickness of the microspheres is from 2 to 15 microns. Mineralogical composition: glass (prevails), mullite, silymanite. Chemical composition: SiO ₂ 51.3-56.3, TiO ₂ 0.85-1.0, Al ₂ O ₃ 29.1-32.9, Fe ₂ O ₃ 3.8-8.15, MgO 0, 6-1.6, CaO 0.8-1.0, K ₂ O 0.4-6.2, Na ₂ O 1.0-4.85, SO ₃ 0.01-0.04.

The content of microspheres in fly ash of Novoscheskaskaya GRES is 0.07% (wt.) 0.12% (vol.). During the year, 1050 tons (1800 m ³ ) of microspheres enter the ash dump.

Some physical characteristics of microspheres: density 580 kg / m ³ , bulk density 380 kg / m ³ , volume filling factor 0.67, thermal conductivity 0.125 W / (mK), melting point 1350 ^o C, hydraulic compression strength 8-15 MPa .

 Example 1. Evaluation of the sorption ability of the sorbent obtained by the proposed method, when cleaning the surface of the water from oil.

 The microspheres were mixed with crude oil. After a short time (1-2 min), the microspheres floated to the surface of the oil (the density of the microspheres is about 1.5 times lower than the density of the oil), from where they, together with the oil sorbed by them, were removed and ignited. As a result of the combustion of sorbed oil on the surface of the microspheres, an incomplete combustion film (carbon black, petroleum coke) with a thickness of a fraction of microns was formed. The resulting sorbent was applied to the surface of water contaminated with oil. After 15 minutes, the sorbent with sorbed oil was removed mechanically, after which the sorbent-oil ratio was established.

 The table shows the comparative characteristics of the sorbents used in the known (1, 2) and the proposed methods.

 From the data of the table it can be seen that according to the proposed method, the sorbent has a higher (1.8-4.4 times) sorption ability in relation to oil and oil products in comparison with the known [1, 2] Thus, the proposed method allows to purify water from oil and oil products with a lower consumption of sorbent.

 Example 2. Evaluation of the sorption ability of the sorbent obtained by the proposed method, when cleaning the entire volume of water contaminated with oil.

 Prepared in the same way as in example 1, the sorbent was immersed in the depth of oil-contaminated water in order to extract dissolved and water-emulsion oil and oil products from the entire volume of contaminated water. As a result, the content of oil and oil products decreased from 40 mg / L to 0.02-0.04 mg / L, i.e., it became lower than the MPC for household and drinking water (0.3 mg / L) and fishery (0 , 05 mg / l) purpose (Guidelines on the principles of organizing a system for observing and monitoring the quality of water in water bodies and streams on the Goskomhydrotem network within the OGSNK. L. Gidrometeoizdat. 1984, 39 pp. Directory "Nature Protection" M. Agropromizdat. 1987 , p. 74). Thus, the sorbent obtained by the proposed method is effective in bulk water purification from oil and oil products.

 The method involves the following preparation and use of the sorbent: the separation of microspheres by reagent-free flotation from the water of a pond in the settling pond of the GRES ash dump, the mixing of microspheres with oil and burning in any device that purifies flue gases from pollutants (see, for example, "Environmental Protection Technique". M. Chemistry. 1981. Thermooxidative methods of liquid waste neutralization. Fire method), mixing of sorbent (microspheres coated with a film of products of incomplete oil combustion) with water contaminated with oil products, removal of waste bent with oil from the surface of the water in any mechanical way. Thus, the method is industrially applicable.

Claims (1)

 A method of producing a sorbent for purifying water from oil and oil products, comprising treating aluminosilicate with a hydrocarbon-containing liquid, characterized in that hollow microspheres extracted from the ash of coal-fired thermal power plants are used as aluminosilicate, and the treatment is carried out with oil, followed by its burning with free access to air until the cessation of combustion .

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