Analysis of Crystallization of Paraffin Wax by Using Avrami Kinetic Model and LFRA

For many years, deposition of paraffin wax in oil and gas pipelines has been the major
problems in petroleum industries that mostly related to pump, wax blockage in pipelines
and equipments failure. The objectives of this work are to study the effect of certain
parameters such as temperature differential, different wax compositions and different
type of solvents towards wax crystallization and also to understand tl1e effects against
wax properties itself such as hardness, break load, adhesiveness and viscosity that
LFRA Texture Analyzer and viscometer could produce. The kinetics and mechanism of
wax crystallization is further studied in accordance to A vrarni Theory. For the
experiment of investigating the effect of temperature differential, there will be two fixed
parameters which are fixed T min and Fixed T max· The wax compositions used is fixed
which is 17%. Firstly the Tmm is fixed to zoe while the Tmax varied from 60, 70 to 80°C.
Secondly, the Tmax is fixed to 70°C and the Tmm varied from 5, 10 to l5°C. For the
experiment the effect of wax compositions, the wax compositions is varied from 5, 10,
15 to 20% and diesel is used as the model-oil. Lastly, for the experiment the effect of
different types of solvents, four different solvents are used which are diesel, heptanes,
hexane and octane. The wax compositions used is fixed which is I 7%. The results
indicate that for temperature differential have two opposite effects on the results of wax
deposition: For fixed Tmm, wax deposition and the viscosity decreasing as tl1e
temperature difference increasing; for fixed T max, wax deposition and the viscosity are
increasing as the temperature difference increasing. For the second experiment, the wax
deposition and the viscosity are increasing with the increase of the wax composition and
this is well expected. As for the experiment of different types of solvents, the wax
deposition is highest in the diesel but for the other solvent, as tl1e carbon chain number
is increasing from hexane, heptanes to octane, the wax deposition and the viscosity is
decreasing. The growth rate, K is increasing while the A vrami exponent, n is decreasing
as the wax deposition is increasing. For the LFRA texture analysis, the hardness and tl1e
break load is increasing with the increase of the wax deposition while the adllesive force
is decreasing as the wax deposition is increasing.