Production of environmentally adapted lubricant basestock from jatropha curcas specie seed oil
Int J Ind Chem (2017) 8:133–144
DOI 10.1007/s40090-017-0116-1
RESEARCH
Production of environmentally adapted lubricant basestock
from jatropha curcas specie seed oil
Matthew C. Menkiti1,2 • Ocholi Ocheje2 • Chinedu M. Agu2
Received: 30 June 2015 / Accepted: 17 March 2017 / Published online: 3 April 2017
Ó The Author(s) 2017. This article is an open access publication
Abstract Jatropha curcas seed oil was studied for the
synthesis of trimethylolpropane based biolube basestock via chemical transesterification of Jatropha methyl
ester with trimethylolpropane (TMP) using calcium
hydroxide catalyst. Reactions temperatures ranged
between 80 and 160 °C and methyl esters to TMP mole
ratios ranged between 3:1 and 7:1. Product analysis,
ester groups and physio-chemical properties were
obtained by gas chromatography, Fourier transform
infrared spectroscopy and American Society for testing
and material standard methods, respectively. Gibbs free
energy indicated that the reaction was spontaneous
with a second order rate constant of 1.00E-01 (%wt/
wt min C)-1 and kinetic energy of 13.57 kJ/mol. Jatropha biolubricant (JBL) had the following properties:
viscosity of 39.45 and 8.51 cSt at 40 and 100 °C,
respectively; viscosity index of 204, pour point of
-12 °C and flash point of 178 °C. Temperature and
mole ratio were the main factors that influenced the
reaction. JBL properties complied with ISO VG 32
standard and could be applied as lube basestock with
minor modifications.
Keywords Jatropha curcas Biolubricant
Transesterification Trimethylolpropane
Abbreviations
ASTM
American Society for testing and material
CJO
Crude jatropha oil
DE
Diesters
FAME
Fatty acid methyl ester
FTIR
Fourier transform infrared
GC
Gas chromatography
ISO
International Standard Organisation
JBL
Jatropha biolubricant
JME
Jatropha methyl ester
JTE
Jatropha triester
JTMPE Jatropha trimethylolpropane esters
ME
Monoester
PE
Polyol ester
PUFA
Polyunsaturated fatty acid
TE
Triesters
TER
Transesterification
TMP
Trimethylolpropane
VG
Viscosity grade
VI
Viscosity index
Introduction
Electronic supplementary material The online version of this
article (doi:10.1007/s40090-017-0116-1) contains supplementary
material, which is available to authorized users.
& Matthew C. Menkiti
;
1
Civil, Environmental and Construction Engineering
Department, Texas Tech University, Lubbock, TX, USA
2
Chemical Engineering Department, Nnamdi Azikiwe
University, Awka, Nigeria
Strong environmental concerns and growing regulations
on contamination and pollution of the environment by
petroleum based lubricants have increased the need for
renewable and biodegradable lubricants [1]. There have
been lots of active research and development in this
area due to increasing pressure from public demand,
industrial concern and government agencies.
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The oleochemical esters are a growing interest with
respect to the base lubricants industry. Their advantages
compared to mineral base oil include low toxicity,
higher biodegradability, renewability, high flash point,
low volatility, high additive solvency power, high added
value, good lubricity (due to molecule polarity), high
viscosity index due to the double bonds and molecular
linearity. However, the main disadvantages of these
organic compounds are oxidative instability, hydrolytic
instability, low temperature properties. These disadvantages can be minimized by additives, but the
biodegradability, toxicity and the price can be endangered. Thus, the chemical synthesis of these compounds
seems to be a veritable choice towards eco-friendly
basestocks. The additives that could be used include
anti-oxidant, anti-wear, anti-corrosion, etc., which are
associated with low biodegradability. However, the
additives industry is working hard to develop
biodegradable additives [2].
Development works reported by many studies on
novel high performance biodegradable lubricants focus
on reducing the market price, ecological compatibility,
processes as well as technical performances [3]. Several
studies focus on improving the performance of vegetable oils through modification of structures to improve
their properties [4–9]. Due to its structure, unmodified
vegetable oil suffers from inadequate oxidative stability,
poor corrosion protection, poor hydrolytic stability and
poor low temperature performance. One of the techniques that could improve the properties of the vegetable oil is to change the structure of the oil by
converting it to a new type of ester called polyol ester
(PE). This process eliminates the hydrogen atom on the
b-carbon of the vegetable oil structure, thus providing
the esters with high degree of thermal stability, seldom
found in vegetable oil [10].
The transesterification (TER) process for biolubricant synthesis can be catalysed chemically or enzymatically. Equations (1) and (2) illustrate a two-stage
base catalysed transesterification for biolubricant
synthesis.
Stage one
H2C – OCOR1
|
+
H C – OCOR2
3CH3OH
|
H2C – OCOR3
Triglyceride
Methanol
CH2 – OH
R1COOCH3
|
Catalyst
CH – OH
+
R2COOCH3
|
CH2 – OH
R3COOCH3
Glycerol
Methyl esters
ð1Þ
Stage two
HO
R1COOCH3
+
HO
R2COOCH3
OH
R3COOCH3
Trimethylolpropane
Methyl esters
RO
+
RO
3CH3OH
OR
Trimethylolpropane
ester
Methanol
ð2Þ
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Int J Ind Chem (2017) 8:133–144
The objective of this work is to investigate the use of
Nigerian Jatropha oil as a feedstock for the production of
biolubricants in a two-step base catalysed reaction of Jatropha oil methyl ester (JME) with trimethylolpropane
(TMP). JME was first synthesized from crude Jatropha oil
(CJO) by transesterification, after which JME was then
washed and purified before used in the synthesis of Jatropha biolubricant (JBL) [11]. Process parameters that
were systematically investigated include the reaction temperature, reaction time and the molar ratio of methyl ester
to trimethylolpropane. Furthermore, the kinetics of the
reaction was also discussed. Jatropha curcas is a shrub
belonging to the family of Euphorbiaceae. It is a plant with
many attributes, multiple uses and great potential. It is a
native of tropical America, but now thrives in many parts
of the tropics and sub-tropics in Africa and Asia. Jatropha
curcas has the potential to become one of the world’s key
energy crops. At present, it is globally taking the centre
stage as the oil seed of choice in biolubricant production
[12–18].
The composition of Jatropha curcas oil from two different locations in Nigeria consists of main fatty acids,
such as palmitic acid (14.69–14.68%), stearic acid
(0–5.23%), oleic acid (0–6.06%) and linoleic acid
(79.08–80.07%) [19], in addition to high percentage of
unsaturated fatty acid.
This makes the oil suitable for biolubricant production
because the presence of double bond will lower the melting
point, which would enhance the low temperature performance of the biolubricants. Also after chemical modification, drawbacks such as inst (...truncated)
