3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
V a c u u m D i s t i l l a t i o n o f T O M E
Data on amounts of obtained distillates (D1, D2), residues
(Z1, Z2) and weight losses (WL) from 1 st and 2 nd distillation
stage are listed in Table V and VI.
Table V
Vacuum Distillation material balance: 1 st stage
TOME D1 Z1 WL
[g] [g] [wt. %] [g] [wt. %] [wt. %]
2362 845 35.8 1419 60.0 4.2
Table VI
Vacuum distillation material balance: 2 nd stage
TOME D2 Z2 WL
[g] [g] [wt. %] [g] [wt. %] [wt. %]
845.3 712 84.2 101.4 12.0 3.8
The prepared amount of TOME was heated and then let
settle. Formed water and unreacted methanol were removed
with a vacuum (molecular) evaporator.
Then 2.5 dm 3 TOME was withdrawn from 3 dm 3 volume
of TOME and distillated at the folowing conditions: pressure
10–50 Pa and temperature 135–140 °C. 955 ml (~ 845 g) of
distillate (D1) was obtained which represented ~ 38 % vol.
(~ 36 % wt.). During this distillation D1 was polluted
by RA.
Destillate D1 955 ml (~ 845 g) was consequently distillated
at pressure 2–20 Pa and temperature 130–135 °C.
Under these conditions, we obtained 835 ml (711.8 g) of distillate
D2, i.e. ~ 87 % vol. from D1, (84 % wt.)
The total yield of these processes: from 2,500 ml TOME
(2,363 g) we obtained 835 ml (711.8 g) which represented
33.4 % vol. (30.1 % wt.).
Acid number parameter of D2 (19.610 mg KOH g –1 ) did
not comply with European standard En 14214 for biodiesel
(stipulating less than 0.5 mg KOH g –1 ), D2 had to undergo
further treatment. D2 included some RA. They were neutralised
and precipitated and D2 (tall oil fatty acids methyl esthers
– TOFAME) after this treatment had acid number 0.3 mg
KOH g –1 . This value fully meets En 14214. However, total
volume of the final product decreased from 835 to 630 ml
(566.6 g) which represented – when comparing to the TOME
amount – 25.2 % vol., (~ 24 % wt.).
The final product prepared in such a mode was subjected
to analyses in laboratory of VÚRUP, which was accredited
for analyses of biofuels. Results are assembled in Table VII.
R e s u l t s O b t a i n e d b y F o u r i e r
T r a n s f o r m I n f r a r e d S p e c t r o m e t r y
( F T I R )
FTIR spectra of our product and a sample of soybean
oil methylesters (SOME) were scanned and were found to
s554
comply with En 14214. We observed very good similarity
in absorption peaks of our product and SOME sample. Both
spectra are almost identical. This may mean that both speci-
Fig. 1. Comparison of FTIR spectra: TOFAME and SOME
mens have similar physical and chemical properties.
T e s t R e s u l t s f o r B i o d i e s e l f r o m
Table VII
Values of prepared biodiesel compared with En14214 standard
values
Properties Units Determined En 14214 Uncertainty
value value
Density at
kg m –3 15 °C
Carbon residue
899.3 875–900 0.1 %
(10% distillation wt. %
residue)
Kinematic
< 0.010 max. 0.3 10 %
mm2 s –1 viscosity
at 40 °C
3.932 3.5–5 1.5 %
Cold filter
plugging point
°C –12
0 to –13
–13 to –20
(winter)
3 °C
Ester content wt. % 95.7 min. 96.5 2.5
Linolenic acid
methyl ester
wt. % 0.7 max. 12 –
Sulphur
mg kg –1 content
1208 max. 10 2 %
A c c r e d i t e d L a b o r a t o r y
Conclusions
Prepared tall oil was esterified by methanol at optimal
conditions in the presence of acid catalyst. Tall oil fatty acids
methyl esters were isolated from TOME mixture by vacuum
distillation.
Total yield of these processes: from 2,500 ml TOME
(2,363 g), 630 ml (566.6 g) resulted which represents