• Multiple Feedstock
(Liquid Oil - Palm - Palm Olein - Used Fried Oil)
• Continuous Trans - Esterification process
with a very low soap formation
• Separation by gravity
• Final Washing by Centrifugal Separator
• High Conversion Yield
• Low Methanol Consumption
• Low Catalyst Consumption
• High grade Pharmaceutical Glycerine
• Zero effluent since plant is coupled with
Glycerine concentration
• High Quality Biodiesel in compliance with
All the international Standard
• Low Utilities consumption
• Accurate Computer Control System
• Soap Removal (Acidulation) without presence
of methanol
• No use of Sulphuric Acid
Our Company, together with one of the most important
producers operating in the field of Biodiesel, has
developed a very efficient industrial plant (already in
operation) capable to process not only standard refined
vegetable oils but also 100% Used Fried Oils.
The target has been achieved thanks to a proven
technology already applied in the field of Oils Refinery and
Oleochemical Plants.
Low quality oils, such as Used Fried Oil, containing a high
FFA (up to 10%), need to be treated and neutralised in a
very special distillation plant (Pack Tower).
The obtained crude glycerine has to be treated as well,
concentrated and refined in similar units already used in
oleochemical plants but with relevant modifications.
The experience of C.M. BERNARDINI also in Plants where
solvent is used, particularly into the distillation section,
has allowed us to develop a very efficient alcohol recovery
distillation and rectification system which conforms to all
the Safety Standards.
Thanks to special arrangements in our process steps, the
whole system has also the great advantage of having
almost zero effluent water.
Compared to other processes, our system is also one of the
few where the produced crude glycerine can be easily
processed up to 99.8% purity, respecting all the
International Parameters.
The refined oils are not suitable to be used exactly as they
are in a diesel motor because of their high viscosity (70-80
cSt at 20°C against 4-7 cTs of diesel oil) and because of the
unexpected environment emission. A very high
improvement of this characteristic can be achieved through
the process of Transesterification (or Esterification), and it
can have, as the most evident result, the breaking of
triglyceride molecule into three smaller and therefore less
viscous molecules.
It's easy to see that, chemically speaking, the reaction of
Esterification is very simple.
To obtain an ester, it is necessary to treat the refined oil
with alcohol (methyl alcohol in most of the cases, but also
ethyl alcohol can be used) and with the right catalysts
(normally potassium hydroxide, sodium hydroxide or
sodium methylated), which increase the speed and
efficiency of the reaction which may occur at low
temperature and pressure.
For crude oils with acidity level higher than 0,1%, the use of
alkaline catalysts can lead to the formation of soaps.
It is therefore an imperative to use neutral or better refined
oils.
The final product has a lower viscosity than the crude oil
(about 6-7 cSt at 20°C - of the same size order of the gasoil
one); the characteristics at cold are such to make it
suitable for almost every kind of climate and the cetane
number increases of 12-15 units; therefore it is possible to
add a mineral fuel at any requested ratio.
It is necessary to eliminate phospholipides and mucilage
and to keep the lowest oil acidity level in order to obtain an
high conversion rate in methyl ester.
Two proceedings may be used to speed up the process:
adding the exceeding methanol/ethanol;
eliminating the produced Glycerine.
Methanol is not totally soluble in oil at room temperature,
it is therefore necessary to heat and stir the mixture.
Reaction temperature is variable and it must be
individuated considering also the reaction time.
After about one hour there are no significant differences of
yield with temperature of about 60°C.
1. In case of crude oil an oil-refining the pre-treatment is
suitable to improve the yields and to increase the efficiency
of the subsequent steps. It is suitable to remove the
impurities and free fatty acids in order to avoid any side
reactions;
2. Mixing alcohol, oil and catalyst in a controlled and safe
reactor under nitrogen blancketing. It normally works with
excess of alcohol. The use of methanol requires suitable
safety precautions, as provided by the law.
The mixture reacts at 70°C for about two hours.
The reaction environment is corrosive, so all the equipment
has to be in stainless steel;
3. Special continuous gravity settling apparatus in order to
separate the methylester and glycerine phases;
4 Recovery of the exceeding alcohol through a vacuum
evaporation process (stripping). This operation is carried
out both on the produced methylester and on the aqueous
phase containing glycerol;
5. Methylester washing through a water solution so as to
remove the residual glycerine. A special centrifugal
separator is used in this step;
6. Crude Glycerine Acidulation so as to split the relevant
soap produced during the reaction. In the CM Bernardini’s
system this reaction is performed without alcohol and with
HCl. The obtained so called Acid Oil can be then esterified
using glycerine produced by the Biodiesel Plant and the
obtained neutral oil can be mixed with the relevant
feedstock for Biodiesel Production. Fatty acids coming
from Crude Oil Refining can also be esterified in order to
increase the overall yield. This kind of Esterification
reaction avoids the use of sulphuric acid normally used in
the others’ processes, with no formation of sulphide,
difficult to remove and harmful for the subsequent
Glycerine Refining steps. The non – use of H2SO4 also
avoids the utilization of special stainless steel materials,
which are used to prevent the corrosion, whereas the HCl
permits the use of plastic materials with lower costs;
7. Alcohol Rectification in a rectification column in order to
obtain a concentration of alcohol at 99,9 %.
Optional Production Steps
• Final distillation of methylester (optional plant) when
using 100% Used fried Oils or low quality raw materials (to
lower total contamination value).
• Refining of the obtained crude glycerine for the
production of pharmaceutical grade (99,8% purity).
Glycerine is the main by-product and it is obtained at
80-85% concentration.
Since most of the soap formed during Methylester reaction
and all the relevant impurities are concentrated in the
Glycerine, a proper treatment is needed.
There are processes treating the concentrate glycerine with
HCL in order to split the soap and to recover the so called
Acid Oil; this reaction takes place normally with glycerine
having still the presence of methanol, which is negative for
a good treatment and also requires a special stainless steel
material, since the reaction is very corrosive.
C.M. Bernardini has already installed several units where
the relevant treatment with HCL is performed only after
Methanol removal from the crude Glycerine in order to
treat it properly.
Besides using U.F.O., if Glycerine is not properly purified
and if further treatment is not used to remove salt
formation and other undesirable components in the final
Glycerine Distillation, a poor quality Glycerine is obtained
with also high losses (polymerization).
The advantage given by our route is that all the processed
water coming from Methylester Unit is mixed with crude
glycerine and then distilled in order to obtain zero effluent
from the Transesterification process.
There is also the advantage of diluting the glycerine, since
it cannot be deeply purified if the concentration is 80-85%;
the best conditions are at 60-65% concentration.
Once the treatment has been properly made, the further
Glycerine Distillation Plant will produce a high quality
product which follows all pharmaceutical grade parameters
(99.8% min).
The obtained pitch is also discharged in solid form (easy to
handle).
Biodiesel is a methyl ester of fatty acids from vegetable
and/or animal oils.
It is a bio-fuel produced through a reaction of
Transesterification, a process in which a vegetable oil
reacts with methyl alcohol, in the presence of an alkaline
catalyst. The final product is a mixture of different methyl ester chains which does not contain sulphur and aromatic compounds.
It has an high oxygen content (not less than 10%) and can be used as fuel for road-traction and heating, either mixed with gasoline or not.
Biodiesel is usually commercialized in the field of heating, while as a fuel for road-traction, it is mainly used by public transport Companies.
The by-product obtained is glycerol (commonly known as glycerine), which is sold to pharmaceutical and cosmetic Industries after being refined.
