- Production capacity increases due to continue pressing process. - Saves time because the production process does not require pretreatment, i.e.size
reduction and cookingheating. - Increase yield
8. Biodiesel Production Stage
Methyl ester biodiesel from jatropha oil can be produced through a process of transesterification. In the production of biodiesel, the common used
catalyst is sodium ethylate, NaOH or KOH. To drive the reaction to move right to produce methyl ester biodiesel it is necessary to use alcohol in excess amount or
one of the resulting products must be separated. The main factors affecting the ester yield under transesterification reaction are molar ratio between triglycerides
and alcohol, the type of used catalyst, the reaction temperature, reaction time, water content, and free fatty acid content in the raw material which may inhibit
the expected reaction. Others factors affecting the ester content of biodiesel are the content of glycerol, the type of alcohol used in the transesterification reaction,
the amount of residual catalyst and soap content.
Figure 3.38 shows the production process stages of biodiesel using CJCO. This scheme shows common production process which is generally carried out by
milling industry i.e. esterification process followed by transesterification stage 1 and stage 2. Esterification reaction with acidic catalysts is performed due to FFA
value of CJCO is greater than 5.
Figure 3.38 CJCO process under catalytic method in PT Adaro esterification and 2 stages transesterification
Detail process of biodiesel production from CJCO is similar with crude palm oil CPO. The difference is that esterification process should be performed
in CJCO process. Flow chart of mass and energy balance at each sub process of esterification is as follows:
Sub Unit of Esterification Reactor
separation of glycerol-
I
purification
Washing and Dehydration
Biodiesel
Transesterification Stage I
Transesterification Stage II
Alkali catalyst + Methanol
separation of glycerol
II
pinch methanol
pinch
Glycerol
Crude of glycerin Salt fertilizer
Esterificatin Reaction
Alkali catalyst + Methanol
acid catalyst
methanol
CJCO
This sub unit is used to react free fatty acid and methanol in the presence of sulfuric acid catalyst Figure 3.39.
Figure 3.39 Sub unit of esterification reactor The input on line number 7 is: methanol, sulfuric acid, and water. The
input on line number 4 is: FFA, triglycerides, water, and dirt. While the output on line number 8 is: methyl esters, FFA, triglycerides, methanol, sulfuric acid, water,
and dirt.
The results of biodiesel milling plant survey which implemented in PT.Adaro are as follows:
- Biodiesel plant capacity is 1.1 tons per day - Raw material used in the process is still obtained from the outer city. Based on
the results found in the field, CJCO is purchased from Jakarta and West Nusa Tenggara.
- FFA value of CJCO is higher than 5 i.e. 7 to 11. Thus, esterification process should be followed by transesterification.
- FFA value of CPO is less than 5. Thus it only needs transesterification process.
- Biodiesel plant in PT.Adaro is developed by BPPT Serpong, Indonesia. In general, the existing system of machine equipment consists of : crude oil tank,
degumming tank, degummed oil tank, FFA tank, FFA separator, FFA recovery tank, vacuum evaporator FFA tank, FFA free oil tank, vacuum oil
evaporator tank, salt water tank, alkaline tank, mixing alkaline catalyst tank, mixing acid catalyst tank, washing tank, reactor tank 4 units, vacuum
evaporator biodiesel, esterification reactor 1 unit, transesterification reactor 3 units, QC tank, biodiesel tank 4 units, and pump equipment at each stage.
Conclusion
The conclusions that can be drawn in this chapter are as follows: 1. Palm oil consumes higher input material and energy than Jatropha curcas.
2. Jatropha curcas starts to produce at 4 months the first year, while palm oil starts to produce at 30 months the third year.
3. Intensive application of agro-chemical input fertilizers, herbicides, pesticides, etc. on oil palm and Jatropha curcas occurs during the 1-5 years unstable
production. Stable application occurs when the plants have reached 6-25 years stable production.
4. The life cycle of oil palm is 25 years, while Jatropha curcas can reach up to 50 years, but the effective life cycle is only up to 25 years.
3
OH
2
SO
4
FFA Triglyceride
water dirt
CH
3
OH H
2
SO
4
7 4
8 methyl ester
Triglyceride water
dirt CH
H water
FFA
