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Energy

Biodiesel in the tank

Fuel produced with ethanol and vegetable oils is ready for fueling buses and trucks

Eduardo CesarTanks at the pilot plant in Ribeirão Preto, stock ethanol-based biodieselEduardo Cesar

If all turns out well, within a couple of years Brazilian vehicles powered by diesel oil trucks, buses, tractors and locomotives will be running with a percentage of biodiesel in the tank. One of the candidates for this new fuel was developed by means of the chemical reaction of vegetable oils with ethanol, the alcohol extracted from sugarcane, in the laboratories of the University of São Paulo (USP), in Ribeirão Preto. The team coordinated by Professor Miguel Dabdoub the coordinator of the Development of Clean Technologies Laboratory (Ladetel) is part of a larger group, made up of dozens of researchers, spread all over the country, who are studying and developing alternatives to petroleum diesel. In Ribeirão Preto, they arrived at an innovative process for getting biodiesel with the discovery of efficient catalysts, substances that speed up the chemical reaction and transform oils from soybeans, oil palm, corn or castor beans, for example, plus alcohol, into a new product.

With the characteristics of being totally renewable, producing less pollutants than petroleum diesel, and as there is already vast alcohol production in Brazil, the adoption of ethanol-based biodiesel facilitates the incorporation of this kind of fuel into the Brazilian energy matrix. Moreover, the results of the researches show that biodiesel is more efficient than vegetable oil in natura, because it does not cause corrosion in the engine, does not carbonize the fuel injector nozzles, and improves the starting of the vehicle, for being less dense and for flowing better in the hoses and ducts. Economic and strategic factors also make biodiesel welcome. Today, the Brazilian fleet guzzles some 37 billion liters of diesel oil a year.

In 2005, this volume will go up to 40 billion liters, according to a forecast by the National Petroleum Agency (ANP in the Portuguese acronym). The target for the Brazilian Biodiesel Technological Development Program (Probiodiesel), of the Ministry of Science and Technology (MCT) and, more recently, of the Interministerial Working Group coordinated by the Civil Office of the Presidency of the Republic, is to set up a wide-ranging plan for producing this new fuel, with an incentive for planting oleaginous species. This fuel will act as a complement to ordinary diesel oil, and in future may be used in its pure form in diesel engines, if there is sufficient supply. The idea to start with is to add 5% of biodiesel to the oil derived from petroleum a formula known as B5, in a venture similar to the one that occurs with gasoline, which is given about 25% of ethanol. The estimate is that with this measure Brazil will reduce by 33%, from a total of 6 billion liters, its imports of diesel, thus generating annual savings of US$ 350 million, besides a great number of direct and indirect jobs.

Even if the country reaches self-sufficiency in petroleum in the next few years, it will have to continue to import diesel. The problem is that the oil extracted from the maritime depths off the Brazilian coast is of an unsuitable quality for the production of diesel. In the major part of the fields, particularly those in the Campos Basin, the petroleum is of the heavy kind, characterized by not yet having completed its maturity and for suffering from a natural process of biodegradation. Producing a compound of vegetable oil and ethanol has already been known for some years, but it proved to be economically impractical, due to limitations of a technical order, such as the low rate of converting the mixture into biodiesel.

“Synthesizing by using methanol with vegetable oils in use in Europe and in the United States results in a transformation in the order of 98%, while the figure with methanol is 80%”, Dabdoub explains. Another problem to be solved was the separation of glycerin, a byproduct of the chemical reaction. “Our great challenge was to develop amethodology that overcame these two obstacles. We were successful, at the beginning of this year, in achieving a process that makes possible a transformation of over 98% and permits the spontaneous separation of the glycerin, besides reducing a lot the time of the reaction”, the researcher says.

In the biodiesel from methanol, the catalyst used is sodium hydroxide, also known as caustic soda or lye. To synthesize biodiesel from ethanol, the researcher added to the traditional catalyst another catalyzing substance, the name of which is being kept in secret, because the patent process has not been concluded. “We can say that the new catalyst is a mixed metallic hydroxide, commonly called clay”, says Dabdoub. According to him, the process of transforming vegetable oils and alcohol into biodiesel, known as transesterification, is relatively simple. The vegetable oil is mixed to the alcohol and the catalysts in a reactor and is shaken up for half an hour. For each 1,000 liters of oil, 200 liters of ethanol are used, and between 0.8% and 1% of catalyzing agents. Next, the mixture goes to a decanter, where the separation of the glycerin takes place; this is a substance with a high added value that is used by pharmaceutical, cosmetics and explosives factories. Each ton of glycerin can cost as much as US$1,300.

One of the advantages of the new fuel is the possibility of producing it from the oil of various plants. They are oleaginous plants with different levels of productivity and adaptation to the regional mosaic of the country. Accordingly, soybeans produce 400 liters (l) of oil per hectare (ha), sunflowers, 800 l/ha, castor beans, 1,200 l/ha, babassu, 1,600 l/ha, oil palm (dendê), 5,950 l/ha, pequi seeds, 3,100 l/ha, corn, 160 l/ha, cotton 280 l/ha and the macauba palm 4,000 l/ha. “According to the Brazilian Agricultural Research corporation (Embrapa), peanut forage from the BR-1 and BRS-151 L-7 cultivars is resistant to drought and suitable for planting in the semi-arid, and without any irrigation it yields 750 l/ha of oil, or almost 2,100 l/ha in irrigated planting”, the professor says.

“We used in our experiments 11 varieties of vegetable oils, besides the cooking oils already used. Our preference was for soybean oil, though, because it is the most abundant, and Brazil is the second largest producer in the world of this product, with an annual total of 54 million tons.” But the planting of other oleaginous plants may be encouraged, increasing the demand for these and promoting development at various points of the country. “In two regions of the state of São Paulo, in the Ribeira valley and in Pontal do Paranapanema, macauba palms could be used, while in the Jequitinhonha valley, in Minas Gerais, for example, biodiesel could be produced from pequi seeds. For the regions of the North and Northeast, this can be done with oil from babassu, peanuts and oil palm.”

Today, a great discussion is going on in the federal level about the production of biodiesel with castor bean oil. Chiefly for the semi-arid region of the Northeast. Dabdoub thinks that this is possible, but there also has to be a good dose of precaution and many tests. “The transesterification reaction comes out very well with castor bean oil. Producing biodiesel this way is no problem. Although we need conclusive researches about the effects caused by the prolonged use of biodiesel from castor beans in engines”, he says. This is necessary because there is a chemical grouping equivalent to an alcohol in the molecule of castor bean oil, making the physicochemical characteristics of the biodiesel produced with this plant very different from those observed for esters (compounds of carbon, hydrogen and oxygen that characterize biodiesel), methylic or ethylic, derived from any other oil. This grouping may become a serious technical restriction that only the practical and concrete results of the researchescaneliminate.

Regardless of the oil to be used, the process for producing biodiesel developed by Ladetel has other advantages that make it superior in the manufacture of methanol biodiesel as well. “We have succeeded in making the reaction in 30 minutes, while the traditional process takes six hours. This means that we are 12 times more productive”, Dabdoub says. These new characteristics, coupled with the chemical transformation that occurs cold, at room temperature, made the process for producing biodiesel technically viable, reducing energy consumption and the operational costs. In spite of the efficiency of the conversion process and of making good use of the glycerin, Brazilian biodiesel is still more expensive than common diesel. The percentage depends on the price of the oil employed in production. But the difference, says Dabdoub, can easily be annulled, if the government frees the product from taxes in the initial stage of the program, before reaching large-scale production. The researcher adds that the newfuel does not require any modifications in the engine for it to work normally, even if the use of ethylic biodiesel is adopted without the presence of petroleum diesel.

Exclusive use brings countless advantages, starting with the fact that it is a totally Brazilian fuel and 100% renewable. There are also environmental gains, such as the reduction in the emission of pollutant gases. The use of biodiesel in its pure form reduces the emission of carbon dioxide by 46% and of particulate matter by 68%. If the B5 mixture is used, the reduction of black smoke comes to 13%. According to Dabdoub, pure biodiesel is exempt from sulfur, a component of diesel oil and a generator of acid rain. “The great advantage of ethylic biodiesel is that provides for much cleaner combustion”, says José Domingos Fontana, the coordinator of the Brazilian Reference Center in Biofuels (Cerbio) and the technical director of the Paraná Technology Institute (Tecpar).

To prove the efficiency of the ethanol biodiesel, Dabdoub made agreements with companies, entities and research institutions to carry out tests of performance, consumption and power. These partnerships, which include alcohol mills from the Ribeirão Preto region, were the source of a major part of the financial resources that Ladetel used in the studies. One of the main tests was carried out by the São Paulo State University (Unesp), at the Jaboticabal campus, which was responsible for checking the efficiency of the product in agricultural tractors. In charge of the tests was agricultural engineer Afonso Lopes, a professor from the Rural Engineering Department of the School of Agrarian and Veterinarian Sciences (FCAV). Besides the financial support from FAPESP, the researcher received a tractor, as a result of a partnership with Valtra do Brasil and the São Paulo Coffee and Citrus Growers Cooperative (Coopercitrus). Lopes tested the fuel in the tractor, a BM100 model, with an engine of 100 horsepower, equipment with a fuel measurement system developed at Unesp.

The vehicle was assessed under conditions for preparing the soil with a plow attachment with five kinds of biodiesel-petroleum diesel mixture: B100 (just biodiesel), B25 (25% biodiesel and 75% diesel), B50 (half biodiesel and half oil), B75 (75% biodiesel and 25% oil) and B0 (only diesel). “The tractor worked normally with all the mixtures. We found that up to the limit of 50% of biodiesel there were no significant alterations to be noted in consumption. When the tractor worked with 100% biodiesel,consumption increased 11% on average”, Lopes says. Accordingto the researcher, this happened because, compared with diesel, biodiesel has lower calorific power from 3% to 4% and for this reason consumption is higher when the mixture is higher than 50%. The next stage of the study will be to assess the emission of pollutants.

The product developed at Ladetel was also tested in cars, locomotives, engines and electricity generators. In the last case, a partnership was formed with Branco, a company from the state of Paraná, in April this year. “The results have been highly satisfactory”, says Dabdoub. “We observed a reduction in the emission of pollutants, and we are now carrying out tests of durability using pure biodiesel (B100).” The tests with locomotives are being carried out by América Latina Logística (ALL), a railroad concessionaire that works in Rio Grande do Sul, Santa Catarina, Paraná, São Paulo and Argentina. At the first moment, laboratory tests were successfully carried out to measure consumption, power and emissions. The second stage will involve the use of the fuel in its B25 form in locomotives that will run over the Ourinhos-Apucarana and Curitiba-Apucarana stretches during one year.

“In the light of the results, ALL will assess the possibility of using biodiesel in its entire fleet”, Dabdoub says. Finally, biodiesel is also being tested in B20, B30 and B100 mixtures in passenger cars with diesel engines produced for export, as in the cases of the automobiles from the French manufacturers Peugeot and Citroën. The studies by USP are concentrating on analyzing fuel consumption, durability and emission of pollutants (carbon monoxide and dioxide, sulfur dioxide, unburned hydrocarbonates, nitrogen gases and particulate matter). The durability tests are carried out with the car covering at least 80,000 km, and an analysis of the variation in the emission of pollutant gases is done every 20,000 km. “We are also doing tests with engines handed over by these manufacturers, in a collaboration with Professors Antônio Moreira and Josmar Pagliuso, from the Mechanical Engineering School of USP in São Carlos. These same tests are in parallel at the PSA Peugeot-Citroën headquarters in France”, says Dabdoub.

Besides USP in Ribeirão Preto, there is in Brazil an extensive network that involves universities, research institutes, trade associations, regulatory and development agencies, companies, cooperatives and nongovernmental organizations (NGOs) interested in the development and implementation of biodiesel. Important work is being done by Tecpar, one of the pioneers in research into the mixture of ethylic alcohol and petroleum diesel as a fuel. Since 1998, several buses of companies associated to Curitiba Urbanization (Urbs) are circulating in the city with a mixture of diesel oil (89.4%), ethanol (8%) and a soybean-based additive (2.6%), which was baptized as Mixture of Alcohol with Diesel (MAD-8), a fuel that is sometimes wrongly called biodiesel. It so happens that, according to international standards, a simple mixture does not characterize the product. The additive used is manufactured and supplied by Ecomat, a company from Mato Grosso. In another research by Tecpar, buses circulated in Curitiba with methylic biodiesel imported from the United States and fossil diesel, in a 20-80 proportion.

In Rio de Janeiro, an experiment carried out by the Alberto Luiz de Coimbra Engineering Postgraduate and Research Institute (Coppe), of the Federal University of Rio de Janeiro (UFRJ), in a partnership with the government of the state, tested successfully a bus driven by biodiesel made with recycled oil donated by the McDonald’s chain of fast food restaurants. This kind of leftover oil used in Rio is also the object of study at Ladetel, which is running a subproject that ispart of the Biodiesel Brazil Project, the name of the studycoordinated by Dabdoub. The group is using material donated by USP’s university canteens in the capital and in the interior, as well as from what is donated by McDonald’s. Among companies, Petrobras is carrying on with its biodiesel program, which was kicked of two years ago. This public sector company intends to put into activity, at the end of 2004, a pilot plant for the production of biodiesel made with castor bean oil and ethylic alcohol. The unit will be set up in Mossoró, in Rio Grande do Norte, and will have an initial production estimated at 5,000 liters of biodiesel a day. The fuel will be tested on the company’s own fleet of vehicles. The program has a strong social bent, because it provides for buying the oil from small farmers, who will be able to use the water from the wells drilled by Petrobras, where oil was not found, to irrigate the plantations.

In the field and in the city Castor bean oil is also the main ingredient in the studies carried out at Embrapa. In partnership with the Chemistry Institute of the University of Brasilia (UnB), developed equipment capable of transforming vegetable oil into vegetable diesel oil, with physicochemical characteristics different from those of biodiesel. “It is a very simple process. We do not use transesterification, but a technique using thermal catalytic cracking (breaking down the chains of carbon molecules). The vegetable is put into a stainless steel cracker and is submitted to a temperature of 360ºC. Each 100 liters of vegetable oil produces 60 liters vegetable diesel oil, 20 liters of gasoline and kerosene, 10 liters of gas and 10 liters of water”, explains a researcher from Embrapa, José Roberto Rodrigues Peres, one of those responsible for the innovation. According to Peres, the technique will be directed towards isolated rural communities, allowing small producers to have the capacity for generating their own fuel.

In Ceará, a project that is developing biodiesel is led by Bioenergetic Technologies (Tecbio), a company incubated in the Technological Park of the Industrial Technology Nucleus Foundation (Nutec). Starting in 2004, the fleet of buses of Guanabara, a company from Fortaleza, should begin to be supplied with castor bean based biodiesel produced by Tecbio. To do so, 10,000 hectares of this plant are being sown in the state. The expectation of the researchers involved in the project is that one job will be created for every 2 hectares planted, generating a yield of R$ 500.00 per hectare. With all these experiments, it becomes easy to imagine a promising future for biodiesel in the country, in a very short time, bringing great social, economic and environmental benefits.

Diesel used vegetable oil

It was after the invention of the diesel engine, by the French engineer of German origin, Rudolph Christian Carl Diesel (1858-1913), at the end of the 19th century, that the possibility of using vegetable oils as fuel was glimpsed for the first time. It was only in the first decade of last century that diesel oil came to be produced from petroleum. The first patent for biodiesel made with peanut oil and methanol was deposited in Japan in the 1940s, followed by another three American patents in the 1950s. In Brazil, the researches started in the 1980s with the creation of the Vegetable Oil Program (Oveg). The pioneer spirit was shown by, amongst others, the Federal University of Ceará (UFC), responsible for the first Brazilian patent for a biodiesel process. Researchers from Ceará produced this fuel by mixing several vegetable oils with methanol and ethanol.

“The Brazilian program did not prosper at that time for economic reasons. There was a lack of a long-term strategic vision to make it possible to overcome the technological shortcomings in the way that was done with the program for alcohol (Proálcool)”, says Professor Miguel Dabdoub. In the 1990s, countries from Europe began to implant programs for using biodiesel. Nowadays, 2 million vehicles are running on the continent with this fuel. In Germany and in Austria, pure biodiesel is used, while in the other countries it is mixed with diesel in a proportion of 5% to 20%. In 2005, 2% of all the fuel consumed in Europe should come from renewable sources. In 2010, this percentage goes up to 5.75%.

The projects
1.
Biodiesel Brazil; Coordinator Miguel Dabdoub (USP); Investment
R$ 1,087,000.00 – partnerships with companies
2. Test of Agricultural Tractor with Biodiesel (nº 01/09972-8); Modality Regular Line of Research Grants from FAPESP; Coordinator Afonso Lopes (Unesp); Investment R$ 43,331.93 and US$ 4,117.59
3. Bus Driven by Biodiesel; Coordinator Luciano Bastos (Alberto Luiz de Coimbra Engineering Postgraduate and Research Institute of the Federal University of Rio de Janeiro – Coppe/UFRJ); Investment R$ 700,000.00 – divided between Coppe, Financier of Studies and Projects (Finep), State of Rio de Janeiro Research Support Foundation (Faperj) and Petrobras
4. Castor Bean Oil Biodiesel; Coordinator Carlos Nagib Khalil (Petrobras); Investment R$ 5,000,000.00 – company
5. Vegetable Diesel Oil; Coordinator José Roberto Rodrigues Peres (Embrapa); Investment R$ 50,000.00 – Embrapa
6. Castor Bean Biodiesel for Buses; Coordinator Expedito Parente (Bioenergetic Technologies – Tecbio); Investment R$ 1.2 million – R$ 775,000 from the Ceará Scientific and Technological Development Support Foundation (Funcap) and Ministry of Science and Technology (MCT), R$ 300,000 from the Industrial Technology Nucleus Foundation (Nutec) and R$ 125,000 from Tecbio

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