SYNTHESIS, CHARACTERIZATION AND EVALUATION OF SURFACTANTS DERIVED FROM NATURAL OILS FOR EOR APPLICATIONS

Enhanced oil recovery methods are directed towards the recovery of residual oil
from a reservoir. Surfactants have been gaining prominence as a main chemical for
EOR methods. Natural oils, owing to their naturally long hydrocarbon chains, possess
remarkable potential to be used as raw materials for the development of surfactants.
The oleic acid methyl esters obtained from Jatropha oil and high oleic acid methyl
esters were modified by the attachment of nine different alkoxy groups (derived from
alcohols) and these were successfully converted to 18 types of sulfate and sulfonate
based anionic surfactants. The high FFA value of Jatropha oil was suppressed to as
low as I % by employing an indigenously developed silica based catalyst. The
synthesized methyl esters were epoxidized by optimizing the epoxidation process by
using the RSM technique utilizing a central composite rotatable design. The DOE
successfully optimized the yield and dramatically shortened the reaction time. The
obtained oxirane ring was then opened up using nine different alcohols thereby
attaching them as alkoxy chains on the oleic acid methyl ester parent chain. Sulfation
of the -OH groups located trans to the alkoxy groups yielded nine sulfate type
surfactants. For the synthesis of sulfonate surfactants, the -OH group was protected by
the acetylation reaction before sulfonation by an S03-air mixture in a falling film
reactor, hence producing nine sulfonate based surfactants. The sulfate and sulfonate
surfactants were obtained in high yields. All end products and precursors were
characterized by GC-FID, GC-MS, FT -IR and NMR techniques.