Abstract:
The rising of fuel prices and the contribution of fossil fuels towards global warming have
been major global concerns during past few decades. Interest in renewable fuels has increased
due to the above mentioned problems. Green Diesel (GD) has emerged as a promising
solution to these issues. The objective of this research is to derive hydrocarbons from rubber
seed oil. Rubber seeds are considered as a waste in our country. Therefore, oil of rubber seeds
is a potential fatty acid source for GD production.
Rubber seed oil was extracted using soxhelet method. Only a part of the exracted oil was
hydrolyzed. Decarboxylation of both hydrolyzed, and non hydrolyzed oil were carried out in
a especially designed glass apparatus with sodalime and alumina mixtures.The proportions of
sodalime and alumina were varied in the catalyst mixture. Five non-hydrolyzed and three
hydrolyzed samples were decarboxylated. The products were analyzed by GC-MS.
The hydrocarbons in the range of C-11 to C-16 carbon chain length have been produced
during the decarboxylation process. However, unsaturated hydrocarbons were observed, as
rubber seed oil mainly consist of unsaturated fatty acids such as linoleic acid. Percentage
peak area can be taken as an indicator to quantitatively compare the hydrocarbons.The
highest percentage peak are of 57.61% was shown by 6-Dodecene, which was present in the
non- hydrolyzed sample where 25% alumina was added. Apart from that, 5-Undecene
(19.90% peak area) and Tridecane(12.03% peak area) showed their presence in the nonhydrolyzed
decarboxylated samples.
Hydrolyzed oil samples showed the presence of Tetradecane (4.46%), 2-Tetradecene
(6.48%), 1-Hexadecene (0.41%),5-Tetradecene(2.39%), Pentadecane (7.90%) and 6-
Tetradecyne(0.30%) which were not present in non-hydrolyzed samples.
It can be seen that with the addition of alumina to the catalyst system, that there is an increase
in the percentage peak area. These experiments indicate that decarboxylation of rubber seed
oil in the presence of sodalime and alumina can be employed to produce hydrocarbons in the
diesel range which is of C-10 to C-28 chain length. Future studies will be conducted to
optimize pressure and temperature conditions based on these findings.
