TY  - MANSCPT
AU  - Ibrahim Ismail Ali Elganidi
TI  - Synthesis, and molecular  interaction study of poly (BA-co-SMA-co-MA) as pour point depressants  for improving malaysia crude oil  flowability
SN  - THE0009896 (Local)
PY  - 2024///
CY  - Kuantan Pahang
PB  - UMPSA
KW  - Faculty of Chemical and Process Engineering Technology
KW  - Dissertations
KW  - Universities and colleges
KW  - Theses
N1  - Faculty of Chemical and Process Engineering Technology; Thesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2024; Includes bibliographical references
N2  - The flow of crude oil gets impeded due to the precipitation of wax on the inner wall of  pipelines when the temperature drops below the wax appearance temperature (WAT).  Polymeric pour point depressants (PPDs) are an effective method to enhance the  flowability of waxy crude oil. In this thesis, a PPD of poly(behenyl acrylate-co-stearyl  methacrylate-co-maleic anhydride) (BA-co-SMA-co-MA) was synthesised. The novel  PPD was optimised using the OFAT technique, considering key parameters: monomer  ratio, reaction time (4–12 hours), initiator concentration (0.5–2.5 wt%), and reaction  temperature (60–120 °C). The most contributing factors were further optimized using  central composite design software (CCD) to develop a polynomial regression model for  predicting the maximum polymerisation yield. Besides, viscosity measurement, pour  point, and cold finger apparatus were employed to evaluate the efficiency of the  synthesised PPD. Lastly, molecular dynamics (MD) simulation was used to understand  the molecular level interaction between wax and PPD, analysed through radial  distribution function (RDF) values, which described the structure of PPD in wax crystals.  The chemical structure of poly(BA-co-SMA-co-MA) has been successfully identified  through FTIR and NMR. Also, from the thermal stability characterisation, the results  showed that all prepared PPDs had a slightly high degradation temperature, which  reflected excellent thermal stability and could be employed as a potential material for  PPD additives. Furthermore, GPC results concluded that the degrees of polymerisation  of the polymer are very suitable and have the optimum applicability as PPDs of crude oil.  The optimum conditions for obtaining the highest yield were an 8.1 h reaction time, 102  °C reaction temperature, 1.57 wt% initiator concentration, and a monomer ratio of 1:1:1  (BA: SMA: MA), with a yield of 93.75%. Also, the regression model analysis (ANOVA)  showed an R2 value of 0.9696, implying that the model can explain 96.96% of the data  variation. Using the optimal conditions, the highest average yield value obtained is  93.20%. Consequently, the results indicate that this model is reliable and can predict the  yield response. The rheological results show a significant viscosity reduction of crude oil  at a shear rate of 100 rpm and after the addition of 1500 ppm polymer concentration at 5  °C by 75.33%, from 33.25 mPa.s to 8.2 mPa.s. The cold finger experiment demonstrated  that after poly(BA-co-SMA-co-MA) was used as a wax inhibitor at a concentration of  1500 ppm, 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 14 °C was  observed at a concentration of 1500 ppm, which can change the growth characteristics of  wax crystals and delay the aggregation of wax and resin, thus effectively improving the  flowability of crude oil. Also, from these results can conclude that the synthesised  polymer can alter the wax crystals’ morphology, prevents agglomeration in general, and  can act as an efficient flow improver. From the MD simulation result, the RDF value in  the pure wax system (n-icosane-n-icosane) is 2.75 Å which shifted to 3.25 Å after using  (BA-co-SMA-co-MA). The RDF value shift may indicate that the dissolution of wax  molecules in wax inhibitors occurs through the breaking of H57 •••H60 bonding. As a  result, poly(BA-co-SMA-co-MA) weakens the van der Waals interaction, lowering the  interaction between wax molecules and modifying crystal morphology. As a  consequence, the presence of this wax inhibitor reduces the ability of wax molecules to  coalesce, making adherence to wax surfaces less desirable
ER  -