Synthesis, characterisation and pre-evaluation of a novel terpolymer as pour point depressants to improve the Malaysian crude oil flowability

Wax deposition is considered one of the most serious operational issues in the crude oil pipelines. This issue occurs when the crude oil temperature decreases below the temperature of wax appearance and paraffin wax starts to precipitate on the pipelines’ inner walls. As a result, the crude oil flow is impeded because of the precipitated wax. The use of polymeric pour point depressants has obtained significant interest among researchers as an approach of wax control for enhancing the flowability of the waxy crude oil. PPD of poly(behenyl acrylate -co-stearyl methacrylate-co- maleic anhydride) (BA-co-SMA-co-MA) was facilely synthesised by the use of free radical polymerisation. The variation of the PPD structure was studied by choosing several essential parameters like monomers ratio, reaction time, initiator concentration, and reaction temperature. Furthermore, viscosity measurement, pour point, and cold finger apparatus have been employed to evaluate the efficiency of the synthesised Polymer. The chemical structure of poly(BA-co-SMA-co-MA) has been identified through the use of Fourier transform infrared as well as nuclear magnetic resonance. The experimental findings demonstrated that the ideal conditions for obtaining the highest yield were 1.5% initiator concentration, reaction time and temperature of 8 h and 100 °C, respectively, and monomer ratio of 1:1:1 (BA:SMA:MA). Under these ideal conditions, the prepared terpolymer reduced the crude oil viscosity at 30 °C and 1500 ppm from 7.2 to 3.2 mPa.s. The cold finger experiment demonstrated that after poly(BA-co-SMA-co-MA) was used as a wax inhibitor, the maximum efficiency of paraffin inhibition of 45.6% was achieved at 200 rpm and 5 °C. Besides, the best performance in depressing the pour point by ΔPP 14 ℃ observed at the concentration of 1500 ppm, which can change the growth characteristics of wax crystals and delay the aggregation of asphaltene and resin, thus effectively improving the flowability of crude oil.

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.

A REVIEW OF VARIOUS POUR POINT DEPRESSANTS USED FOR FLOW ASSURANCE IN OIL INDUSTRIES

Crude oil needs to be transported from oil wells to refinery and storage facilities in one form or another to ultimately become end use products. After the successful extraction of oil from the ground it is mostly transported through pipelines where the crude oil experiences various changes in its physical and chemical properties. These rheological changes may cause numerous flow assurance problems such as wax and paraffin deposition which ultimately restricts the flow of oil. Chemical additives such as Pour Point depressants (PPDs) are used in this case for the efficient transportation of crude oil by lowering the Wax Deposition Temperature (WAT). Hence, in order to enhance the knowledge about PPDs, the mechanism of various types of Pour Point Depressant for aiding the flow of crude oil while transportation were discussed in this paper.