Journal of Environmental Treatment Techniques
2020, Volume 8, Issue 3, Pages: 1140-1143
J. Environ. Treat. Tech.
ISSN: 2309-1185
Journal web link: http://www.jett.dormaj.com
Structural Information from Ratio Bands in the
FTIR Spectra of Long Chain and Branched
Alkanes in Petrodiesel Samples
Flora Ferati 1*
Department of Technology, University of Mitrovica “Isa Boletini” Ukshin Kovaqica, Mitrovica, 40000, Kosovo
Received: 15/06/2020
Accepted: 14/07/2020
Published: 20/09/2020
Abstract
FTIR is a widely used equipment for determining the chemical structure of organic materials. Vibrational analysis was
employed to characterize hydrocarbon structure from which depends their quality and environmental effect. The results showed
that the FTIR spectrum of petrodiesel allowed structural information about degree of branched or aliphatic chain hydrocarbons.
2 3
The ratios of aliphatic carbons especially CH /CH (A2920/A2950) and A1376/(A1376+A1460) appeared to be suitable indicators for
identifying type of alkanes present in petrodiesel samples.
Keywords: FTIR, Petrodiesel, Hydrocarbon structure
Introduction1
others applied NIR-Spectroscopy (4, 15), or NMR (5, 16).
Most of them use a lot of toxic chemicals also need a lot of
time for sample preparation and cost analysis are very
expensive.
1
Most of air contaminants have origin from diesel
petroleum which is urgent problem in most world countries
and simplicity of determination of fuel quality is still
challenge. Today all European countries have strong quality
control of quality diesel fuel, but all these quality parameters
do not involve petroleum hydrocarbons (PHCs) which can
contain a lot of contaminants, or can initiate formation of
other air contaminants which can be chemical product in
engine combustion of diesel petroleum. Nakakita et al.
reports about diesel fuel which contain branched and ring
hydrocarbon compounds under engine combustion produced
high level of PM precursors, such as benzene and toluene
which are in high level produced from branched paraffins
compare with n-paraffins where their formation are in low
level (1, 13). Their funding’s suggest branched
hydrocarbons to be in low level in diesel fuel because of
possibility to increase PM emissions in air also particle
matter of are in strong correlation with composition and
physico-chemical parameters (1, 14). Anyway, high level of
n-paraffins or long chain aliphatic hydrocarbons have lower
impact in PM emissions compared with branched paraffins;
but also has other negative effect which originates from their
higher boiling point and under engine incomplete
combustion some of them can be exhaust gases or can be
condensed droplets from unburned fuel (2). From this point
of view it is very important to know what type of
hydrocarbons contain diesel fuel branched or long chain
hydrocarbons. Cetane number and molecular composition of
petrodiesel properties was done by gas chromatography (3),
Other important parameter used in fuel quality is cetane
number which depends from organic structure of molecules
and can be in correlation with molecular structure of
hydrocarbons but from cetane number is not possible to
know more details about type of hydrocarbons. Most of
methods used in cetane number determination are expensive
and time consuming but using this cetane number is possible
to know molecular structure of fuel hydrocarbons (6).
Cetane Number has minimum legislative limit, but not the
maximum, based on European Commission legislation.
Cetane number, combustion level and PM emissions are in
strong correlation between and as a conclusion high cetane
number provide complete and faster combustions and lower
PM emissions (7, 17). Our research group proposed FTIR-
spectroscopy application which has a lot of benefits
compared with other methods for the reason that it does not
need any sample preparation, it does not use any hazardous
chemicals, the cost analysis is cheaper and FTIR-
Spectroscopy known as green but also as fast and sensitive
method of analysis. FTIR spectroscopy was applied in order
to estimate structural information of hydrocarbon molecules
present in coal using single wavenumber and using ratio of
frequencies from asymmetric stretching vibrations of
2 3
CH /CH ratio (8, 18). Cetane number is one fuel parameter
which corresponds with ignition delay, but in general this
depends on the type of hydrocarbons content in fuel. Similar
application in coal sample characterization was reported
Corresponding author: Flora Ferati, Department of Technology, University of Mitrovica “Isa Boletini” Ukshin Kovaqica,
Mitrovica, 40000, Kosovo. E-mail: flora.ferati@umib.net.
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