Effect of nanocomposite pour point depressant EVAL/CNT on flow properties of waxy crude oil

The nanocomposite EVAL-CNT was produced by chemical grafting in the solution system through the esterification of ethylene-vinyl alcohol copolymer (EVAL) and carboxylated multi-walled carbon nanotubes (O-MWCNT), and its structural properties were characterized. The improvement of the rheological properties of the waxy oil system by the novel pour point depressant was investigated using macroscopic rheological measurements and microscopic observations. The results showed that EVAL-CNT nanocomposite pour point depressant (PPD) could significantly reduce the pour point and improve the low temperature fluidity of crude oil and had better performance than EVAL-GO at the same addition level. The best effect was achieved at the dosing concentration of 400 ppm, which reduced the pour point by 13 ℃ and the low-temperature viscosity by 85.4%. The nanocomposites dispersed in the oil phase influenced the precipitation and crystallization of wax molecules through heterogeneous crystallization templates, which led to the increase of wax crystal size and compact structure and changed the wax crystal morphology, which had a better effect on the rheological properties of waxy oil.

Rheological Properties of Waxy Crude at a Low Temperature in the Presence of Pour Point Depressants

Pour point depressants （PPD） are used to improve the theology of waxy crude. The affect of various factors on the theological properties, and the thermal characteristics of waxy crude treated by PPD have been investigated. The conclusions are as follows： PPD can reduce the pour point and abnormal point of waxy crude, broaden the temperature range of Newtonian fluid of waxy crude, and lower greatly the viscosity of non-Newtonian fluid of waxy crude. The influence of reheating and high-rate shear on the effect of PPD mainly depends on their temperature. When the reheating temperature is more than the abnormal point of crude by 10℃, the reheating process has little effect on the modification effect of PPD. However, when the reheating temperature is below the abnormal point of crude, the reheating process will reduce the modification effect of PPD. When temperature is above the abnormal point of crude, the high-rate shear has little effect on the modification effect of PPD. At a temperature range where a lot of wax is precipitating, high-rate shear will greatly reduce the modification effect of PPD.

Study on Application of Pour Point Depressant for Diesel Fuel

Taking into account the actual crude slate processed at the refinery, it is necessary to make reasonable combination and blending of crude oils. In order to cope with high wax content in diesel fuel it is proposed to appropriately regulate the refining process scheme and add additives to refined products. This measure after being applied in the production practice has brought about good results and has met the needs of commercial production.

Effect of nanocomposite as pour point depressant on the cold flow properties and crystallization behavior of diesel fuel

The high effective nano-hybrid pour point depressant(PPD)has attracted extensive attention for its po-tential application in improving the cold flow properties of diesel fuel.In this paper,the nano-hybrid PPD was prepared by melt-blending method using three different alkyl chain lengths(i.e.,tetradecyl,hexade-cyl,and octodecyl)of n-alkyl methacrylate-maleic anhydride copolymers(R 1 MC-MA,R 1=C_(14),C_(16),C_(18))and SiO_(2)nanoparticles.The effect of those nano-hybrid PPDs on the cold filter plugging point(CFPP)and solidifying point(SP)depressing of diesel fuel were studied.Results indicated that nano-hybrid PPD showed much better performance on diesel fuel.The diesel fuel treated with 0.2 wt%C_(14)MC-MA/SiO_(2)nano-hybrid PPD exhibited the best depression in CFPP and SP by 6℃ and 18℃,respectively,which higher than that of single C 14 MC-MA.Viscosity-temperature curves and polarized optical microscopy were conducted to explore the performance mechanism;and results presented that nano-hybrid PPD of C_(14)MC-MA/SiO_(2)could effectively lower the low-temperature viscosity,and modify the crystallization behavior and crystal morphology of diesel.Therefore,the cold flow properties of diesel were significantly improved.

Synthesis of comb bipolymers and their pour point depressing properties

A bipolymer maleic anhydride-methyl acrylate （MAMA） was synthesized from maleic anhydride and methyl acrylate based on molecular design.MAMA further reacted with oleylamine or octadecyl alcohol to generate two comb polymers called Oleamide-MAMA （NMAMA） and OctadecanolMAMA （OMAMA）,respectively.The structure of both the polymers was confirmed by their infrared spectral analysis （IR）,gel permeation chromatography analysis （GPC） and differential scanning calorimeter （DSC）.Moreover,the pour point depressing （PPD） properties of these comb polymers were examined experimentally.Experimental results showed that besides the molecular weight and concentration of the polymers,the length of side chains and the number of functional groups also had great influence on the pour point depressing performance.The π bonds and hydrogen bonds between depressants were the key factors for improving the pour point depressing properties.These results suggest that both OMAMA and NMAMA are potential pour point depressants for industry.

Relationship between the Composition of Polymer of n-Alkyl Substituted Acrylate and Vinyl Amine and Their Performance on Pour Point Depression

Polymer of n-alkyl substituted acrylate （PA） with the alkyl side chains C16- 30 were synthesized. Their crystallinity, solubility and effect on pour point depression were studied. Results showed that only carbon atoms located far away from polar groups of PAL pour point depressants participated in crystallization. When the number of carbon atoms that participated in crystallization is about three fourths of the average carbon number of wax in crude, the effect of PA is the best. The molecular weight distribution of PA pour point depressant has little influence on the effect of pour point depression, and the average molecular weight of PA in the range of （ 1.5- 2.2）× 10^4 shows the best effect. The introduction of polar groups into the molecule of PA can improve its performance. However, a too high content of polar groups in PA would cause deterioration, and even lead to loss of PA＇s performance for pour point depression.

Synthesis and Properties of Dendritic Long-Chain Esters as Crude Oil Flow Improver Additives

The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl longchain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efficiencies of dendritic long-chain esters were not only influenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efficiencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efficiencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil.

COMPATIBILITY STUDIES ON POLYMER/WAX AND POLYMER/RESIN-ASPHALTENE BY VISCOMETRY AND PHOTOMICROGRAPHY

The compatibility of mixtures of polymeric pour point depressants, i.e. poly(ethylene-co-vinylacetate) (EVA), poly(EVA-graft-octadecylacrylate) (EVA-g-POA), poly(ethylene-co-octadecylacrylate) (EOA) and poly(ethylene oxide-co-propylene oxide) (EO-co-PO) with wax or resin-asphaltene from crude oil have been studied by means of dilute-solution viscometry. It was found that each mixture pair is incompatible, but the degrees of incompatibility are quite different, which are in good agreement with the results from photomicrography.

New PAMA Technology Helps Tackle the New Challenges of China Automotive Sector

Polyalkylmethacrylate (PAMA) based viscosity index improver (VII) and pour point depressant (PPD), with the versatile chemistry and unique performance characteristics, are widely used in advanced formulations, enabling fluids to meet rheological requirement of modern specifications. This paper will be dedicated to the application of PAMA in helping China automotive lubricant formulators tackle the challenges of improving fuel economics from using lower viscosity fluids, of better protection strengthten in transmission performance and meeting new global specifications for low temperature performance.