Pour point depressants for fuels based on tall oil fatty acid esters

С целью расширения области применения жирных кислот таллового масла – побочного продукта сульфатной варки целлюлозы (которые преимущественно состоят из непредельных С18-кислот), в том числе за счет получения различных синтетических продуктов на их основе, синтезированы соответствующие этиленгликолевый и додециловый эфиры. Изучена возможность применения указанных сложных эфиров в качестве депрессорных присадок для марок универсального топливного мазута и судового экологического топлива. Жирные кислоты этерифицированы 1-додеканолом и этиленгликолем в присутствии катализатора п-толуолсульфокислоты. Температуру текучести топлив определяли ручным методом по стандарту ASTM D97. Температура текучести топлива судового экологического снизилась с +21 до 0 °С при использовании 2% додецилового эфира жирных кислот в качестве присадки. Установлено, что синтезированные эфиры жирных кислот таллового масла снижают температуру текучести остаточных топлив на уровне, сравнимом с применением промышленно производимой депрессорной присадки, что позволяет расширить сырьевую базу присадок этого типа и сократить закупки по импорту, а также более глубоко использовать жирные кислоты таллового масла в органическом синтезе. In order to expand the field of application of tall oil fatty acids, a by-product of sulfate pulping (which mainly consist of unsaturated C18 acids), including the production of various synthetic products based on them, the corresponding ethylene glycol and dodecyl esters have been synthesized. The possibility of application the esters as pour point depressants for grades of universal fuel oil and marine ecological fuel has been studied. Fatty acids were esterified with 1-dodecanol and ethylene glycol in the presence of a p-toluenesulfonic acid as catalyst. The pour point of the fuels was determined manually according to the ASTM D97 standard. The pour point of ecological marine fuel decreased from +21 to 0 °C when using 2% dodecyl ester of fatty acids as an additive. It was found that the synthesized esters of tall oil fatty acids reduce the pour point of residual fuels at a level comparable to the use of a commercially produced depressant additive, which makes it possible to expand the feedstock base of this type of additives and reduce import purchases, as well as to use more extensively tall oil fatty acids in organic synthesis.

Polyurethane Foam Composites Reinforced with Renewable Fillers for Cryogenic Insulation

Sawdust, microcellulose and nanocellulose and their silanized forms were used to reinforce rigid polyurethane (PU) foam composites. The concentration of fillers was varied in the range of 0.5–1.5%. For rigid PU foam formulations, three polyols from recycled and renewable materials were used, among other components. Polyols were obtained from rapeseed oil, tall oil fatty acids and recycled polyethylene terephthalate. As rigid PU foam composites in literature have been described as appropriate thermal insulation material, the appliance of obtained composites for cryogenic insulation was investigated by determining the various physical-mechanical properties of composites. The physical-mechanical properties, such as the modulus of elasticity, compressive and tensile strength in both 293 K and 77 K, adhesion measurements with and without cryo-shock, apparent density, thermal conductivity coefficient, and safety coefficient were measured. The results showed that the addition of fillers did not give a significant improvement of characteristics.

Increasing the efficiency of phosphate ore processing using flotation method

The paper presents flotation of two phosphate ore samples of different origin. Statistical analysis was used to study the effect of operating parameters on flotation efficiency. The paper proposes to increase the efficiency of flotation processing of magmatic phosphate ore with a low grade of the valuable component (P2O5 = 10.88 %), containing nepheline and feldspars, by means of direct anionic flotation. Authors present an optimization of anionic flotation using tall oil fatty acids mixed with anionic phospholane as an anionic collector. The effect of adding soda ash to compensate for the influence of calcium cations on technological parameters of P2O5 flotation was examined. The results of studying the flotation of nepheline ore (flotation tailings of magmatic phosphate ore) showed that replacement of phospholane with oxyethylated isotridecanol allowed to obtain a high-quality concentrate. It was estimated that with the addition of Na2CO3 in the amount of 2,000 g/t, a concentrate was obtained with the grade and recovery of phosphorus pentoxide equal to 39.15 and 94.19 %, respectively. The paper proposes to increase the efficiency of flotation processing of sedimentary phosphate ore with a low grade of the valuable component (P2O5 = 22.5 %), containing gypsum and quartz, by means of desliming followed by anionic or cationic reverse flotation. Tall oil fatty acid with anionic phospholane was used as a collector in anionic reverse flotation, and amine was used in cationic reverse flotation. Sodium tripolyphosphate was used as a P2O5 depressant. It was found to be an effective depressant in both anionic and cationic flotation. When analyzing the statistical plan, it was estimated that the maximum grade of the valuable component in the concentrate (P2O5 = 31.23 %) and the recovery to concentrate of 95.22 % were obtained in the chamber product at amine consumption of 950.88 g/t and sodium tripolyphosphate consumption of 500 g/t.

Synthesis of Biodiesel from Tall Oil Fatty Acids by Homogeneous and Heterogeneous Catalysis

This study compared the yield of biodiesel produced from tall oil fatty acids (TOFA) via (i) homogeneous catalyst (sulfuric acid) and (ii) a heterogeneous catalyst (Amberlyst® BD20, together with Ambersep BD 19 (Midcontinental Chemical Co., Olathe, KS, USA)® using a batch reactor. The effect of operation conditions including temperature, catalyst concentration, methanol: oil ratio and reaction time on esterification yield were investigated. Gas chromatographic data showed that the major fatty acids present in the TOFA are oleic acid (C18:1n9) and linoleic acid (C18:2n6). Homogenous catalysis yielded 96.76% biodiesel compared to 90.24% for heterogeneous catalysis. Optimized conditions for homogenous catalysis were at a catalyst concentration of 0.5 w/w%, 15:1 methanol: oil mass ratio at 55 °C for 60 min. FTIR results also showed that the homogeneous catalyst yielded a more complete reaction toward biodiesel production in a shorter time (60 min) compared to the heterogeneous catalyst (4.7 h). For heterogeneous catalysis, the highest yield and the lowest acid value were achieved after a second recycling because the reactants were not fully in contact with the catalyst during the first recycling. The catalyst did not show a reduction in catalytic activity even after the fourth recycling. However, the acid value was higher than that for ASTM standards for biodiesel.

Impact of Different Epoxidation Approaches of Tall Oil Fatty Acids on Rigid Polyurethane Foam Thermal Insulation

A second-generation bio-based feedstock—tall oil fatty acids—was epoxidised via two pathways. Oxirane rings were introduced into the fatty acid carbon backbone using a heterogeneous epoxidation catalyst-ion exchange resin Amberlite IR-120 H or enzyme catalyst Candida antarctica lipase B under the trade name Novozym® 435. High functionality bio-polyols were synthesised from the obtained epoxidated tall oil fatty acids by oxirane ring-opening and subsequent esterification reactions with different polyfunctional alcohols: trimethylolpropane and triethanolamine. The synthesised epoxidised tall oil fatty acids (ETOFA) were studied by proton nuclear magnetic resonance. The chemical structure of obtained polyols was studied by Fourier-transform infrared spectroscopy and size exclusion chromatography. Average molecular weight and polydispersity of polyols were determined from size exclusion chromatography data. The obtained polyols were used to develop rigid polyurethane (PU) foam thermal insulation material with an approximate density of 40 kg/m3. Thermal conductivity, apparent density and compression strength of the rigid PU foams were determined. The rigid PU foams obtained from polyols synthesised using Novozym® 435 catalyst had superior properties in comparison to rigid PU foams obtained from polyols synthesised using Amberlite IR-120 H. The developed rigid PU foams had an excellent thermal conductivity of 21.2–25.9 mW/(m·K).

FURANIUM COMPOSITE MATERIAL BASED ON TALL OIL AND ITS FATTY ACIDS

A new polymer composite material based on furfural-acetone monomer, crude tall oil and its fatty acids, which are waste from the pulp and paper industry, was obtained. In this paper, the effect of crude tall oil and its fatty acids on furfural-acetone monomer binder in a composite material is considered. The composition for the composite material, consisting of FA monomer, filler and catalyst p-toluenesulfonic acid, was modified with crude tall oil additives or tall oil fatty acids. It was shown that the compressive strength of composite samples after 30-day exposure at room temperature, obtained with a reduced amount of furfural-acetone monomer and the introduction of 100% fatty acids of tall oil from the furfural-acetone monomer content, increases by 37%, with the introduction of 150% fatty acids of tall oil, the strength increases slightly - by 1.5%, but the density increases significantly and water absorption decreases with respect to the standard sample. Additives of crude tall oil (up to 150% of furfural-acetone monomer) lead to an increase in density, a decrease in water absorption - by 84%, but reduce the compressive strength of samples by 12%. The improvement in the physicochemical properties of the composite material was explained by the alleged chemical interaction of tall oil fatty acids with mono- and difurfurilideneneacetone (furfural-acetone monomer), which takes place with the formation of new polymers. This is confirmed by DTA data, chromatograms of the furfural-acetone monomer - fatty acids of tall oil (TLC) mixture, and IR spectra. The use of fatty acids of tall oil or crude tall oil, non-expensive, non-toxic products of natural origin in the composite material, can reduce the consumption rates of furfural-acetone monomer and improve the quality of the polymer.

APPLICATION OF IMIDAZOLINES BASED ON TALL OIL FATTY ACIDS AND THEIR QUATERNARY SALTS FOR THE SEPARATION OF THE BINARY NON-AQUEOUS AZEOTROPE SYSTEMS

Методом экстрактивной (в том числе солевой) ректификации с использованием имидазолинов и четвертичных солей на их основе разделены на компоненты неводные двойные азеотропные системы. В качестве разделяющих агентов выбраны: промышленный продукт 1-гидроксиэтил-2-алкенил-2-имидазолин на основе жирных кислот таллового масла, а также его четвертичные соли - хлорид и тетрафторборат 1-гидроксиэтил-2-алкенил-3-бензил-2-имидазолиния. Для разделения были использованы неводные азеотропные системы: ацетон-метанол, метилацетат-метанол, этилацетат-этанол и хлороформ-метанол. Равновесие жидкость-пар в соответствующих тройных системах исследовано в модифицированном приборе Отмера при 101,3 кПа, состав жидкой и паровой фаз определен газохроматографическим методом анализа. Минимальные концентрации (в мольных долях) имидазолина и имидазолиниевых солей для разрушения азеотропов составили 0,156-0,264. Для корреляции экспериментальных данных о парожидкостном равновесии в системах, содержащих имидазолиниевые соли использована электролитная модель NRTL. Средние абсолютные отклонения расчетных данных от экспериментальных значений мольного содержания растворителей в паровой фазе и температуры в системах составили 0,007-0,008 и 0,25-0,35 К, соответственно. The non-aqueous binary azeotrope systems have been separated into components by the method of extractive rectification (and salt rectification) using imidazolines and their quaternary salts. The following were selected as separating agents: industrial product 1-hydroxyethyl-2-alkenyl-2-imidazoline based on tall oil fatty acids, as well as its quaternary salts - chloride and tetrafluoroborate 1-hydroxyethyl-2-alkenyl-3-benzyl-2-imidazolinium. Non-aqueous azeotrope acetone - methanol, methyl acetate - methanol, ethyl acetate - ethanol, and chloroform - methanol systems were used for separation. The vapor-liquid equilibrium in the corresponding ternary systems was investigated in a modified Othmer still at 101.3 kPa, the composition of the liquid and vapor phases was determined by gas chromatographic analysis. The minimum concentrations (in molar fractions) of imidazoline and imidazolinium salts for the azeotrope breaking were 0.156-0.264. The mean absolute deviations between experimental and calculated data for the solvent mole fraction in the vapor phase and temperature in the imidazolinium salt containing systems were 0,007-0,008 and 0,25-0,35 К respectively.

Essesment of IM-50 and TOFA Adsorbed Layer on Cassiterite in Flotation of Tin Sulfide Wastes

The paper presents the results of experimental study of the adsorption characteristic of theIM-50 and tall oil fatty acids (TOFA) collector reagents on cassiterite. UV-spectrophotometric method, scanning electron and lasermicroscopy were applied to analyze the adsorption of the reagents. SHIMADZU UV 1800 was used to obtain the UV spectra of aqueous solutions of IM-50 reagents and saponified TOFA at varied concentrations. IM-50 has not got characteristic adsorption maximain ultraviolet and visible spectrum. TOFA has a weakly pronounced maximum absorption in the range of 233-244 nm. Microscopicphotographs of cassiterite sections were obtained with LEO 1420VP INCA equipped OXFORD ENERGY 350 analyzer. Reagent IM-50and TOFA collector reagent, Newly formed organic matter phases of IM-50 and TOFA were detected. X-ray spectra characterized theincreased carbon content indicating adsorption on the surface of cassiterite IM-5- and TOFA.By measuring the surface relief parameters of polished cassiterite, using KEYENCE VK-9700 scanning laser microscopy and VK-Analyzer software, a qualitative and quantitative assessment of the IM-50 and TOFA reagent layer on the cassiterite surface was performed. Measurements were performed in the several fields of view and showed the degree of IM-50 coating varied from 40.5 to 42.6%of the surface area, and TOFA average coating was 38.5%. Subsequent washing with water does not remove the reagents from thesurface of the mineral and indicates a strong fixation of IM-50 and TOFA on cassiterite, which can have a positive effect on flotationextraction of sludge tin fractions.Qualitative and quantitative results of the reagent adsorption helped to make a forecast of their floatability by the studied collectors.This study is supported by the Russian Science Foundation (project No. 17-17-01292).

Efficient hydrothermal deoxygenation of tall oil fatty acids into n-paraffinic hydrocarbons and alcohols in the presence of aqueous formic acid

Hydrothermal deoxygenation of tall oil fatty acids (TOFA) was investigated in the presence of aqueous formic acid (0.5–7.5 wt%) as a H2 donor in the presence of subcritical H2O pressure (569–599 K). Pd and Ru nanoparticles supported on carbon (5% Pd/CSigma, 5% Ru/CSigma, 10% Pd/CO850_DP, and 5% Ru/COPcomm_DP) were found to be efficient catalysts for deoxygenation of TOFA. The reaction pathway was mainly influenced by the concentration of formic acid and the catalyst. In case of Pd catalysts, in the presence of 0–2.5 wt% formic acid, decarboxylation was the dominant pathway producing n-paraffinic hydrocarbons with one less carbon atom (heptadecane yield up to 94 wt%), while with 5–7.5% formic acid, a hydrodeoxygenation/hydrogenation mechanism was favored producing C18 deoxygenation products octadecanol and octadecane as the main products (yields up to 70 wt%). In contrast, Ru catalysts produced a mixture of C5-C20 (n-and iso-paraffinic) hydrocarbons via decarboxylation, cracking and isomerization (up to 58 wt% C17 yield and total hydrocarbon yield up to 95 wt%) irrespective of formic acid concentration. Kinetic studies showed that the rates of deoxygenation displayed Arrhenius type behavior with apparent activation energies of 134.44 ± 31.36 kJ/mol and 148.92 ± 3.66 kJ/mol, for the 5% Pd/CSigma and 5% Ru/CSigma catalyst, respectively. Furthermore, the experiments with glycerol tristearate, rapeseed oil, sunflower oil, rapeseed biodiesel, and hydrolyzed rapeseed oil produced identical products confirming the versatility of the aforementioned catalytic systems for deoxygenation of C18 feedstocks.