CC BY
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Section 9. Chemistry
Phozilov Sadriddin Fayzullaevich, Ph. D., Associate Professor of Technology petrochemical industry Bukhara Engineering — Institute of Technology, Mavlanov Bobokhon Arashovich, Ph. D., assistant professor of chemistry Bukhara Engineering — Institute of Technology, Pulatova Bernora Farkhodjon kizi second-year student of the Faculty of Petroleum Chemistry, Bukhara Engineering — Institute of Technology, Uzbekistan
E-mail: sadriddinf@mail.ru
Development of technology for depressants diesel fuel from polymer wastes
Annotation: Synthesis of depressant additives on the basis of waste the Shurtan Gas Chemical Complex (SHGChC) low molecular weight polyethylene and partially hydrolyzed polyacrylonitrile. Preparation of graft copolymers of polyethylene alkylated product hydrolyzed polyacrylonitrile, improves operational properties of petroleum reduced their consumption. When introducing additives physico-chemical and technological properties of diesel fuels fully meet the state standards.
Keywords: depressant additive, fuel, low molecular weight polyethylene, pour point, the development of technology.
In the Republic of Uzbekistan refineries produced diesel fuel for summer conditions. In this regard, the diesel fuel during operation is exposed to various physical and chemical factors, which in most cases lead to deterioration of its viscosity-temperature characteristics. In addition, winter creates difficulties in the operation of equipment in the summer heat grades of diesel. To improve their low-temperature characteristics of the most efficient and cost effective manner is the use of depressants. In this regard, issues of selection and increase the range of depressant additives for diesel fuels attracted the attention of many researchers.
Development of the country fuel and energy complex is determined by growth in demand for diesel and motor fuels. For a long period of time in order to improve solidifying properties of marine and boiler fuels they were added with diesel fuels. The most economically sound method for improvement of fuels solidifying properties is the use of depressor additives. Improvement of performance and ecological properties of high-quality diesel fuels is impossible without additives of various functional purposes, such as depressor, antioxidant, anti-wear, dispersant, etc. Creation of scientific bases for development method ot production and use of diesel fuels with depressor additives is the goal of this work. For this purpose a set of practical, technological and scientific tasks was determined. [1, 2].
The main requirements to depressor additives added to diesel fuel for obtainment of high-quality fuels are availability, non-toxicity and workability. Presently the range of used low-molecular depressors do not always meet the abovementioned requirements, they have such drawbacks as volatility, migration and toxicity, resulting in environmental pollution and depression effect loss. In order to eliminate the specified drawbacks it is reasonable to use macromolecular compounds.
Depressant additives must be introduced into the diesel fuel at temperatures well above its cloud point. May be administered in the supplied form or as a solution in diesel oil. Depressant additives act as wax crystal growth modifiers. At low temperatures the co-crystallization with their normal paraffins to form fine acicular crystals to prevent the formation of large crystals in the fuel.
Use of depressor additives is one of the most efficient methods for improvement of diesel fuels solidifying properties. Polymers and copolymers are broadly used as depressor additives to diesel fuels. Introduction of depressor additives low quantities results in essential reduction of diesel fuels solidification point temperature and reduction of its viscosity at low temperatures.
Development depressants based on cheap and accessible raw materials, characterized by good viscosity-temperature properties, is an urgent task.
In this regard, the actual remains the development of effective additives, which in addition to qualitative
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Development of technology for depressants diesel fuel from polymer wastes
indicators can increase the economic efficiency of oil produced.
We have synthesized polymethacrylate depressant additives based on heterocyclic compounds such as, benzoxazolone, benztiazolon, benzoksazoltion, benz-tiazoltion.
Heterocyclic methacrylic esters were synthesized by interaction of methacrylic acids with hydroxymethyl derivatives of nitrogen-, oxygen- and sulfur-containing heterocyclic compounds in the presence of catalyst of sulfuric acid in benzene medium at temperature of 6080 °C [3].
R
CH2 = C COOH
+
R=H, CH3
HOCH2 N
( O) S=C
( O)
H
H2O
CH2 = C COOCH2
R N---
( O) S = CN
( O)
Scheme 1.
In order to perform etherification and balanced reaction off set towards formation of compound ester, water was removed by reaction medium boiling with addition of water-moisturing benzene agent. Due to high activity of forming heterocyclic methacrylic esters, etherification process is followed by polymerization thus reducing output of end product. Monomeric product output may be increased by 15-20% by addition of 1.0% hydroqui-none to reaction medium.
All the synthesized monomers identified by liquid chromatography are colorless crystalline matters very soluble in many organic solvents.
Composition and structure of heterocyclic meth-acrylic esters are determined by elemental analysis data and by methods of UV-, IR-, NMR- and EPR-spectroscopy and mass-spectrometry. In heterocyclic methacrylic esters IR spectrum observed are absorption bands at 1745-1800 cm-1 referred to vibrations of carbonyl group of benzoxazolynon and methacrylic radicals; in <irea of 1640 cm 1 corresponding to characteristic frequency of absorption of bond C=C;
1600-1620 cm 1— corresponding to stretching vibrations of double bonds C=C ofbenzene ring; 12501300 cm 1 — corresponding to stretching vibrations of bond -N-C-; 1350-1450 cm 1 — corresponding to deformation vibrations of bond C-H, at sp3 — to hybridization.
The IR spectra of the ester group of absorption is observed in the 1000-1200 cm-1, which corresponds to a deformation and stretching vibrations of C-O. Deformation vibrations of the C-H-unsaturated group in the 950-1000 cm -1; characteristic oscillations fused ring benzoxazolinone — in the 680-860 cm -1.
Heterocyclic methacrylic esters UV-spectra are characterized by maximum absorption in area of273-275 nm. In heterocyclic methacrylic esters NMR-spectra observed are signals under 7.20-7.50 parts by weight of corresponding protons of aromatic ring; 5.71 and 6.12 parts by weight of corresponding methylene group double bond; 6.00 parts by weight ofprotons of-N-CH2-O- group; and at methacrylic derivatives there are signals under 1.91 parts by weight related to protons of CH3-group.
F ig. 1. IR spectra of absorption, benzoxazoitionilmethylethylen acrylic ester (1) and benzoxazoitionilmethylethylen methacrylic ester (2)
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Section 9. Chemistry
Synthesized heterocyclic methacrylic esters were polymerized by free radical mechanism in medium ofpolar organic solvents. Composition and structure of obtained homopolymers is substantiated by element analysis data and UV, IR, NMR spectra.
Manufacturing process polymethacrylate additive consists of two main stages: an etherification of methacrylic acid with hydroxymethyl derivatives of heterocyclic compounds. As used gidroksimetilbenzoksazolona hydroxymethyl derivatives, hydroxymethyl benzoksazolt-iona hydroxymethyl benztiazolona, gidroksimetilmben-ztiazoltiona, methacrylic acid, the solvent, sulfuric acid (as catalyst), aqueous ammonia, benzoyl peroxides (initiator), a oil-dilutant. Polymethacrylates production procedure is performed as follows: heterocyclic compounds hydroxymethyl derivatives, metacrylicacid, solvent, sulfuric acid are supplied in portions to etherifier device 1. Etherification process is performed under atmospheric pressure, heating and continuous mixing. Water vapors forming during reaction are removed from the device 1 together with solvent vapors and are supplied through cooler 2 to water separator 3. Degree of feedstock conversion to methacrylic ester is 95-97%. This process flow diagram is presented in Figure 2.
The product containing a mixture of methacrylices-ters, feedstock unreacted components, a catalyst and a solvent are continuously supplied to neutral-izer 4 for
aqueous ammonia neutralizing. A mixture of neutral product and scouring water is supplied by gravity to filter separator 5 for separation from scouring water, extra scouring of monomer. Purified product is accumulated in drying machine 7, and scouring water is supplied to tank 6 for subsequent disposal. Neutral methacrylic esters serve as feedstock for the second primary stage of synthesis — polymerization.
Methacrylic esters polymerization reaction is performed continuously in device 11 in the presence of initiator — bensoperoxide and a solvent. Forming polymer is supplied to non-solvent 18 from reaction mixture using isopropanol, then it is filtered in filterer 19 and is subjected to drying till its weight is constant. Then obtained depressor additive flows continuously to mixer 12, where diesel fuel is supplied in quantity providing production of 60-70% polymer concentrates in fuel — commercial additives.
Impact of synthesized depressor additives nature on Dts 989:20 01 diesel fuel solidification temperature was investigated. The results are as follows: PBOO (in Russian) reduces diesel fuel solidification temperature by 14 °C, РВОТ (in Russian) — by 16 °C, PBTO (in Russian) — by 1 7 °C, PBTT (in Russian) — by V) °C correspondingly. Heterocyclic methacrylic esters depressor activity estimation proved that it increases with enlargement of polar groups in heterocyclic compound [4].
Fig. 2. Process flow diagram of getting depressant-graft copolymers based on low molecular weight polyethylene. 1-treator, 2-filter, 3-pump, 4-agitator, 5-reactor, 6-etherifier, 7-mixer, 8-drying filter, 9-container
Note: ГПГС (in Russian) -hydroxymethyl derivatives heterocyclic compounds, НМПЭ (in Russian) -low molecular weight polyethylene.
To investigate the properties of the synthesized depressor heterocyclic polymethacrylic acid esters (GEPMAK) studied the physical and mechanical properties of diesel fuel.
Physico-chemical and mechanical properties of diesel fuels fully meet the requirements of the standard and have improved low temperature properties such as pour point and cloud point [5].
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Development of technology for depressants diesel fuel from polymer wastes
Thus, polymethacrylate depressant additives, which when administered in small amounts (0.1-1.0%) significantly reduces the pour point and improve the fluidity at low temperatures.
And also we have obtained an additive based on waste polyethylene polymethacrylate heterocyclic compounds
such as benzoxazolone, benzoksazoltion, benztiazolon, benztiazoltion. Heterocyclic esters of methacrylic acid (GE-MAK) obtained by reacting an alkali metal salt of meth-acrylic acid with halomethyl derivatives of nitrogen, oxygen, halogen and sulfur-containing heterocyclic compounds in benzene at a temperature of60-80 °C to the scheme 2:
/
R
R- CH2 -X + CH2 = C-
R =
(O)S
N
C
O
O
C — OMe-----.-CHg
N
N
N
R
:C
O
.C
C
O
O
-C -OCHgR +MeX
Me = Na; Sf. X =CI; Br. R =HlCHs •
Scheme 2
The composition and structure poluchennyhget-erotsiklicheskih esters of methacrylic acid (GEMAK) established by elemental analysis and by UV, IR, NMR, EPR spectroscopy and mass spectrometry. In the IR spectrum GEMAK has absorption bands at 17451800 cm 1 related to the vibrations of the carbonyl group and methacrylic benzoksazolinonovyh radicals; in the
7,5 6,0 5,5 2,0 1,5 м.д
,r
7,0 6,0 5,0 2,0 1,0 М.Д.
1640 cm-1 corresponding to the characteristic absorption frequency of the C = C bond; 1600-1620 cm 1 — stretching vibrations of the double C = C bonds of the benzene ring; 1250-1300 cm 1 — stretching vibrations of -NC-; 1350-1450 cm 1 — deformation vibrations of C-H bonds in the sp3 — hybridization.
Fig. 3. EPR-spectra benzoxazolonylmethylene methacrylic acid esters (a) and 6-chlorbenzoksazolonylmethylene methacrylic acid ester (b). 6-brombenzoksazolonylmethylene methacrylic acid ester (a) and benzoksazoltionyl methylene methacrylic acid ester (g)
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Section 9. Chemistry
Deformation and stretching vibrations of the C-O ester group absorbing in the 1000-1200 cm -1, the deformation vibration of C-H unsaturated group — region 950-1000 cm-1; characteristic oscillations fused ring benzoxazolinone — in the 680-860 cm -L
UV spectra GEMAK characterized by an absorption maximum in the region 273-275 nm. In the PMR spectrum ETMC observed signals at 7.20-7.50 ppm corresponding protons of the aromatic ring; 5.71 and 6.12 ppm — Double bond of the methylene group; 6.00 ppm — Protons -N - CH2- O - group; and methacrylic derivatives, there are signals at 1.91 ppm, related to the protons of CH3 group (Figure 1) [3].
Obtained composite polymers with depressant properties when added to diesel fuel to improve their physical-chemical and mechanical properties and meet the requirements of the standard, have improved low temperature properties such as pour point and cloud point. Also, the structure of diesel fuels with and without composite depressant examined under a microscope, apparently (shown), it is a continuous grid of fine needles imbedded in her large conglomerates crystal size of 0.05-0.10 microns.
A great influence on the pour point of fuel has cooling rate, namely, increases with increasing final temperature of freezing due to the formation of a large number of nucleation sites uniformly distributed throughout the volume and promote a more solid structure. Adding produce composite depressant additives necessary at a temperature above the cloud point, it is optimum, the temperature is not lower than 10 °C. Compliance with this condition will allow to achieve the best results [4-7].
Thus, when administered in the diesel fuel composition based on polyethylene and a polymethacrylate pour point depressant additives in small amounts (0.05-0.50%), leads to a significant reduction in the pour point and improve the fluidity at low temperatures
The study of the process of obtaining a partially hydrolyzed polyacrylonitrile (HIPAN) seems relevant not only from the scientific point of view, but it has practical significance, since lets you create a unique polymer additives on the basis of local secondary raw materials of chemical industry. In this regard, the study of the process of obtaining depressant additives based on low molecular weight polyethylene and Hydrolyzed polyacrylonitrile is scientific and practical interest [8-10].
Objects and methods of research. The object of the study is one of the waste products of polyethylene and
polyacrylonitrile, which is carried out at the Shurtan Gas Chemical Complex and OJSC “Navoiazot”, respectively.
The main departure is the production ofpolyethylene, ethylene-containing gas mixture, paraffin hydrocarbons, cyclohexane containing the low molecular weight polyethylene product oil and the oil drain alkaline column, the so-called yellow oil.
Hydrolyzed polyacrylonitrile etherification is performed as follows: water-soluble product (pH = 14) was neutralized to a neutral medium (pH = 7) by reacting sulfuric acid. Dedicated lumpy product in ethanol medium in the presence of H2SO4 provided the product containing ester groups (a copolymer of ethyl acrylate, acrylamide, acrylonitrile ratio (95: 3.5: 1.5)).
Get partially hydrolyzed polyacrylonitrile performed as described [7], as well as TU 6.1-0020384953 HIPAN. IR—spectra are removed on the device IR— Furespektrometre System 2000 FT-IR.
The results and discussion. The IR — spectrum HIPAN appears the absorption band of stretching vibrations of CN group region 2,957 cm -1, which has a weakly pronounced maximum. The stretching vibrations of carbonyl groups appear mediumintensive peak at 1667 cm-1. The stretching vibrations of NH2, and he showed an intense broad band absorption in the 3250-3500 cm -1, and deformation vibrations of NH shown in the 1563 cm -1, 1451, 1408 cm 1 are -CH2-CO-groups, 1326 cm-1 are -CN- connection, 680 cm-1 to C-strain oscillations of H bonds, 2120 cm 1 asymmetric stretching vibrations -C=N groups.
The IR — spectrum polyethylene manifests stretching vibrations CH2 group in 2931, 2855 cm -1, 11321378 cm 1 are (-CH2-) n group, 720 cm-1 pendulum oscillations CH2 groups ((-CH2-), n > 4), 993 cm 1 belongs to the non-planar deformation vibrations of CH2 — groups.
In the IR spectrum of the graft copolymer of low molecular weight polyethylene and leaded HIPAN appears wide intensive band 3400 cm-1 for the NH2 group and the absorption band at 2162 sm -1-CN groups, 1659 cm 1 absorption band of deformation vibrations of -NH2 groups in 1407, 1454 cm -1, bending vibrations of CH2 — groups, 1353-1325, 712 cm-1 a little intense absorption band of stretching vibrations are — CH bond.
The low molecular weight polyethylene or dissolved CCl4 decalin and benzoyl peroxide initiator was added (0.1% of the reaction mass), the mixture was heated to reflux (80-1200S) efirizat HIPAN added, stirred for 3 hours at a temperature 800S. Image of the product was precipitated with ethanol, purified starting material is a
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Development of technology for depressants diesel fuel from polymer wastes
three-time dissolving octane and ethanol precipitation. Similarly synthesized by graft copolymers NMPE + MMA + PMMA NMPE, NMPE + MMA + GIPAN (in Russian).
Application depressants is one of the most promising ways to improve the low temperature properties of diesel fuels and expand their resources. Since the polymers and copolymers of acrylates and methacrylates are widely used as depressants for fuels and oils.
The main departure is polyethylene ethylene-containing gas mixture, paraffin hydrocarbons, cyclohexane containing the low molecular weight polyethylene and oil product — Oil Stock alkaline columns, so-called yellow oil [10].
When administered depressant additives in small amounts in the diesel fuel is achieved a substantial
reduction of the pour point and viscosity reduction at low temperatures, which is the most efficient and cost-effective to improve low temperature properties of fuels.
It is known that as a depressant additives to oil and oil products are used a lot of polymer compounds. Current trends produce multifunctional composite polymer additives, leading to a reduction in the number of additives in the composition and the additional costs to its individual species.
Development of modified polymer depressants based on cheap and accessible raw materials and have better viscosity-temperature properties, is an urgent task.
To study depressant properties obtained polymer products were tested diesel Bukhara refinery.
Table 1. - The dependence of the pour point of the diesel fuel additive content
Sample name Additive concentration Concentration % Pour point °С Effect Cloud point temperature °C Effect
DF without additive Without additive -13 - -2 -
DF+ HIPAN+MMA 750 ррm 0,075 -12 +1 -1 + 1
1000 рm 0,01 -18 -5 -3 -1
1250 рm 0,125 -21 -8 -3 -1
DF+HIPAN + PММА 750 ррm 0,075 -19 -6 -4 -2
1000 pm 0,01 -19 -6 -4 -2
1250ppm 0,125 -21 -8 -5 -3
DF+PE+HIPAN 750 ррm 0,075 -19 -6 0 +2
1000ppm 0,01 -23 -10 -3 -1
1250ppm 0,125 -25 -12 -4 -2
DF+PE+HIPAN 750 ррm 0,075 -21 -8 -5 -3
1000ppm 0,01 -26 -13 -4 -2
1250ppm 0,125 -29 -16 -6 -4
DF+PE+PMMA 750 ррm 0,075 -22 -9 -5 -3
1000ppm 0,01 -27 -14 -3 -1
1250ppm 0,125 -29 -16 -4 -2
Table 1 shows that the properties of diesel fuels fully meet the requirements of the standard and have improved low temperature properties such as pour point and cloud point.
The study of the process of obtaining a partially hydrolyzed polyacrylonitrile (HIPAN) seems relevant not only in terms of research of another type of polymer analogous transformations, but also provides an opportunity based on local secondary raw materials of the chemical industry, to create the unique composite polymeric additives for petrochemical products.
In this regard, the study of the process of obtaining modified depressant additives based on low molecular
weight polyethylene and HIPAN are scientific and practical interest [11].
HIPAN is a product ofwaste fiber nitrone produced by JSC «Navoiazot» th, and low molecular weight polyethylene — waste gas and chemical complex «Shurtangas.»
Secondary-nitrone fiber material which consists of elementary units of acrylonitrile, methylacrylate and ita-conic acid in a ratio of monomer units of 92.2: 6.3: 1.5 respectively.
To obtain a polymer product having a depressant properties of low molecular weight polyethylene (waste Shurtan Gas Chemical Complex) and HIPAN, we offer set forth above flowsheet.
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Section 9. Chemistry
Summary. To investigate the properties of the depressor graft copolymers (NMPE-EGIPAN) were added to a dimethylformamide solution of varying concentration of 0.001-0.1% (wt.) In the diesel fuel. It is shown that the addition of diesel fuel graft copolymers (NMPE-EGIPAN) giving influence on the viscosity of diesel fuel as a concentration of 0.001 (wt.)% Pour
point -130S, 0.01% (wt.) -180S 0.1% (wt.) -160S, respectively [12].
Thus, the polymers possess depressant properties, based on a low molecular weight polyethylene and partially hydrolyzed polyacrylonitrile and ethyl ether graft copolymer lowers the pour point of the diesel fuel is
1.8 times (-18).
References:
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12. Phozilov S.F, Mavlonov B.A, Adizova N.Z, Abdulov R.Z study of multi-depressant properties ofpolymers based on low molecular weight polyethylene and partially hydrolyzed polyacrylonitrile. Magazine of scientific publications and doctoral students graduate in 2014 № 2 (92). Kursk - 2014 S.301-303.
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