Enhancement of oil recovery under active water flooding using modified lignin extracted from coconut coir
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Date
2021-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Dar es Salaam
Abstract
The aim of this study was to investigate on the use of modified lignin extracted from
coconut coir for active water flooding in Enhanced Oil Recovery (EOR). Three steps of
processing coconut coir into sodium lignosulfonate (SLS) werefollowed, which were
separation of coir from the outer layer of the coconut fruit, extraction of lignin and
sulfonation of lignin to form SLS. Extracted lignin and SLS were characterized by FT-
IR and porosimeter analyzer. The TGA was also used to characterize modified lignin
while coconut coir was only characterized by FT-IR. SLS was then tested for its use in
active water flooding for oil recovery process through simulated geological reservoir.
The extraction of lignin wasachieved through acid precipitation method while the
modification of lignin was done by sulfonation reaction. In this study, 80.0884 g of
coconut coir produced 17.4608 g of lignin. Lignin (8.1112 g) produced 3.4132 g of
SLS, which is 42.08% yield by weight. The porosimeter results indicated that modified
lignin exhibits large surface area (947.915in2/g) than unmodified lignin (554.864 m2/g).
The FT-IR results for coconut coir showed peaks at 2250 cm
and 1019 cm'
1464 cm'
which were not observed in spectrum of the extracted lignin. SLS
indicated peaks al 1450 cm'
cm
1595 cm
for—SO3, 1037 cm'
for S-O, 1118 cm'
forS=O and 623
for C-Sas an indicator for successful sulfonation of lignin. Modified lignin
showed thermal stability at temperature up to about 200 °C, pertinent to enhanced oil
recovery (EOR) processes. Also, during chemical flooding, SLS surfactant solution
indicated maximum concentration of 4461.2 ppm and IFT of -3.9096xI0'5 Nm'’which
accounted for the maximum oil recovery of 36% during active water flooding.
Description
M.Sc. (Chemistry) Dissertation
Keywords
Oil recovery, Active water flooding, Modified lignin extracted, Coconut coir