Production of Biodiesel from Vegetable Oils or Tallow

By Dr. Hans Valerius
October 2005

The Author is Director at Enigma Process Technologies Corp in Muntinlupa, Philippines. His company provides engineered solutions for laundry waste, hospital waste, animal blood, animal waste, palm oil mill waste etc. → See also:

Biodiesel Technology

Biodiesel

Advantages and Emissions

From the point of view of ecology the Biodiesel has many advantages in comparison with the diesel fuel oil as it causes lower emissions when burned in diesel engines:

Carbon Monoxide emissions:
Carbon monoxide (CO) is emitted, during the combustion of biodiesel in diesel engines, in lower quantity (less than 50% of the same engine fuelled with normal diesel fuel oil). Toxicity of carbon monoxide is well known, especially in crowded towns.
Sulphur Dioxide emissions:
There is no emission of sulphur dioxide (SO2) because the biodiesel is a sulphur free compound (no damaging due to sulphur dioxide to monuments and to vegetation besides to the human health).
Carbon particulate emissions:
The so called "carbon particulate" (smoke) emission is by 65 % lower than the one emitted by normal diesel fuel oil (reduced effect on health, smog and damaging to buildings).
Aromatic organic product emissions:
Biodiesel does not contain any aromatic product (benzene derivatives compounds) that have been demonstrated to be very hazardous for human health.
Carbon Dioxide Balance:
Carbon dioxide (CO2) emitted during biodiesel combustion has a zero balance towards the environment because it is re-absorbed by future crops growth or by the growth of the animal fats.

Biodiesel can be considered a "renewable" fuel for its living matter origin (90%). Biodiesel is not harmful to human health, to vegetation, to monuments and to buildings. It is hence preferable to normal diesel fuel oil especially for public transportation and crowded towns traffic.

Application

Energy balance
The energy balance of biodiesel (the difference between the energy produced during the combustion of one kg of biodiesel against the amount of energy spent for its production) is positive for at least 30%. Then the production of biodiesel does not ”deplete” the natural environment from an energetic point of view.

Immediate use in existing engines
Biodiesel, to get a perfect combustion, does not require any modification to endothermic diesel existing engines and then the engines can be fuelled both with normal diesel or biodiesel and even with mixed fuels.

Economic importance of by-produced raw glycerol
From the production of biodiesel raw glycerol as by-product is obtained. Every 1000 tons of biodiesel about 100 tons of raw glycerol are obtained. If the biodiesel plant is integrated with a glycerol distillation unit, the revenues from the sale of USP grade glycerol cover most part of the direct transformation cost of the oil into biodiesel. The market for pure glycerol is huge, more than 1500 different end uses have been identified. Glycerol can be exported world-wide.

Savings of hard currency and reduction of low skilled unemployed local manpower
Those Countries that are import dependant for oil and that have high level of unemployment for local man power may find in a nation-wide biodiesel program important social and economic benefits with only minor investment cost:

Material Flow Diagram

Material Flow Diagram

Process Description

The proposed Biodiesel production process is named C.J.R. technology (Continuous Jet Reactor). It reduces by more than 30% the overall investment costs in comparison to competition as this process does not require the costly agitated vessels that are necessary for a batch production. With this process it is also possible to utilise directly the raw oil (unrefined oil) or animal fats (tallow and grease) with an additional saving in the raw material cost.

The process starts with tallow preliminary treatment. The oil is treated with solvent by filtration to remove solids impurities. Proteic residues, together with filtration residues, can be sold as animal feed or sent to composting. The treated oil is sent to the biodiesel production plant.
Two reactions in series are provided in the process (the first one is used to remove free fatty acids and the second is meant for the transesterification to biodiesel). Oil and methanol are continuously fed, together with the catalyst, into reaction units.
Methanol (which is fed in excess) and produced glycerol are separated from biodiesel excess methanol is recycled into reaction units.
The production of USP grade glycerol from crude glycerol requires a specific know-how as the distillation of crude glycerol is not an easy task especially when the crude glycerol contains inorganic salts that may cause the glycerol to become jelly.
The process has been successfully implemented in Italy to treat crude glycerol from biodiesel (that is the worst case to handle) and from other more traditional sources.
The biodiesel and glycerol processes are not polluting and are provided with the necessary devices for environmental protection and safety. For the two reaction units special proprietary designed reactors are used. The reactors have no moving parts and specific productivity is high with low investment and maintenance costs as there is very little wearing.

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