Kinetics of Acidity Removal of Naphthenic Acid Model Compound Using Sub-Critical Methanol

This paper studies on the reaction kinetics of naphthenic acids model
compounds upon reacting with subcritical methanol. Naphthenic acids are the
primary contributor to the total acid number of the oil and it can be expressed in
terms of total acid number (TAN). Crude oil containing these acids which are
corrosive can cause many problems such as equipment failures, high maintenance
cost, reduces product quality and environmental disposal problems. The model
compounds of naphthenic acid; 2,6 – naphthalene dicarboxylic acid (C12H8O4) was
tested with subcritical methanol under temperature range from 180 to 220 with a
temperature interval of 20 in an autoclave reactor. The reaction time for the
mixture was from 0 min to 60 min. This experiment reveals that the highest TAN
reduction was achieved at 220 and 60 minutes where the reduction was about
48.80%. The TAN reduction followed second order kinetics; with Arrhenius
parameters of activation energy 7.472 kcal/mol and a pre-exponential factor of 0.877
fraction-1s-1.The result show that methanol is capable to reduce TAN in sub-critical
condition with absence of catalyst