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Oil for biodiesel

Future increases in biofuel production will likely use several raw material alternatives



Macauba fruit and its oil at the IAC laboratory in Campinas

Macauba fruit and its oil at the IAC laboratory in Campinas

An April 2016 presidential decree increased the percentage of biodiesel blended with diesel fuel from the current 7% to 8% by 2017, with further increases to 10% by 2019.  In 2015, Brazil produced 3.9 billion liters of biodiesel  – a 15% increase over 2014, making it the second largest producer in the world, behind only the United States, and ahead of Germany and Argentina.  Demand is expected to reach seven billion liters by 2020.  In 2015, 76.5% of Brazil’s biodiesel was made using soy, 19.4% with animal fat, 2% with cotton and another 2.4% using other types of raw materials such as used cooking oil and dendê palm oil.  Production of this biofuel occurs through the chemical process of transesterification in which vegetable oils or animal fats are combined with methanol, an alcohol extracted from natural gas, and another catalyst, a chemical substance.  It takes 300 liters of methanol to obtain 1,000 liters of oil.

The increased percentage of biodiesel in diesel fuel will stimulate the demand for raw materials to produce vegetable oil.  There are a number of options. The most recent, which is a subject of study at research institutions in Brazil, is oil from the fruit of the macauba palm tree, which is found in nearly all parts of Brazil, from northern Minas Gerais State to the north of Argentina.  It is the latest promise for biodiesel production.  What is attractive about the plant is the amount of oil that a space measuring 10,000 m2 or one hectare (ha) yields without any soil improvements:  up to 4,000 liters (l).   For comparison purposes, soy yields 500 l/ha.

“Macauba palm oil will be extremely important for the future of biodiesel in a few years. It really represents Brazil because it is a native plant and is the subject of a lot of research.  It won’t take long for it to gain market share,” says Donizete Tokarski, chief executive officer of the Brazilian Biodiesel and Biojetfuel Union (UBRABIO), made up of growers. He guarantees that at current industrial capacity, the percentage of biodiesel can be gradually increased to 15% of the diesel mixture. This is possible because nearly all raw material for biodiesel comes from byproducts, such as soybean oil, animal fat and cottonseed oil.  There is also cooking oil, for example, which according to Tokarski, is a nearly untapped source.  Depending on the region, one liter can be purchased for sums ranging from R$0.40/l to R$1.80/l.

Macauba palm trees and seedlings for developing a plant variety

Macauba palm trees…

The future also includes oil from another palm tree – the dendê – that can yield 4,000 l/ha. This crop has not yet achieved the required volume for biofuel production and it certainly will have a more favorable cost in Brazil’s Northern region, where it is grown and is best suited.  Estimates with regard to the macauba are that within four years, producers will have seedlings for cultivation and in over six years, oil for sale.

The macauba plant (Acrocomia aculeata) is an oil-bearing native palm found in the Cerrado savannah of the Central-West region, the Pantanal wetland, and even in southwestern portions of the Amazon region.   “Never in Brazil’s history has a native plant attracted the attention of so many researchers in such a short period of time,” says agricultural engineer Carlos Augusto Colombo, a researcher at the Campinas Institute of Agronomy (IAC). “There are more than 100 researchers in Brazil engaged in studying the genetic improvement of macauba and the chemical characteristics of its oil.”   Work at IAC began in 2006, when the National Council for Scientific and Technological Development (CNPq) and other funding agencies started issuing requests for proposals to promote research into using oleaginous plants for the production of biodiesel.  Colombo’s project, funded by FAPESP, involved surveying and identifying macauba plants in various locations in the state of São Paulo. “We collected seeds from its fruit so that we could study the genetic variation in the population and use crossing techniques among them for future development of plant cultivars.” After 10 years, Colombo says that within four years, IAC could introduce a variety of oil-producing plants in the agricultural market.

Memories of physic nuts
“Macauba oil is very stable and contains lauric acid, an important ingredient in the cosmetic industry.  In nature, the plant generates about 3,000-4,000 liters of oil per hectare each year. By using our improvements, we could increase the yield to 8,000-9,000 l/ha,” Colombo says. Among projects he takes part in is one sponsored by the World Bank together with Leuphana University of Germany that  funds the cultivation of macauba on 2,000 ha in Patos de Minas (in the Brazilian state of Minas Gerais) with support from the IAC and that operates in conjunction with livestock farming. This type of association is contributing to the recovery of pasturelands.

...and seedlings for developing a plant variety

…and seedlings for developing a plant variety

Colombo says that all steps are being taken to keep the macauba from suffering the same fate as that of the physic nut (Jathopha curcas) a few years earlier: overly optimistic forecasts among biodiesel producers before research had been completed and agricultural data had been obtained about the crop.  “The physic nut does not produce small plants, which makes harvesting difficult. It has both large and small fruit that ripens at different times on different plants sown at the same time,” he recalls. To avoid this situation, the researchers are trying to identify the best macauba plants, which are small in size, yield more fruit and have a higher oil content.  Macauba can bear fruit for more than 20 years.

Another line of research and the potential production of macauba plant varieties is taking place at the Federal University of Viçosa (UFV), in Minas Gerais, where agronomist Sergio Motoike has been heading up a project funded by Petrobras and the Minas Gerais Research Foundation (FAPEMIG) since 2005. The group began studying dendê palm oil (Elaeis guineenses) and has discovered a system of micropropagation (multiplication), which received funding from CNPq and the Agropalma company. “We were able to obtain 20 clones from the best plant and they are now being tested.” Dendê palm oil is still little used in producing biodiesel. What oil is produced in Brazil goes to the food and cosmetic industries.  The same is true for castor beans, although the oil of this plant has a high viscosity content that complicates the process of obtaining biodiesel. “With regard to dendê palm oil, crop area in the state of Pará is being increased so that when there is a surplus of oil, a few years from now, it can be used for biodiesel production,” Motoike says.

“Prospects are good for biodiesel production using macauba, not only because of the high yield per hectare, but also due to the physical-chemical properties that result in a high-quality biodiesel product,” explains food engineer Aldara da Silva César, a professor and coordinator of the Agroindustrial Systems Analysis Group at the  Universidade Federal Fluminense (UFF), in Volta Redonda (RJ). Yet she thinks the oil produced could be targeted mainly to the pharmaceutical and cosmetic industries.  “Right now, financial returns to this sector are better than if they were used to make biodiesel.  Although, extractive harvesting in regions where the macauba plant is native could lead to social inclusion which is also the focus of the National Program for the Production and Use of Biodiesel (PNPB),” César suggests.

At IAC, oil analysis is important for selecting the best fruit

At IAC, oil analysis is important for selecting the best fruit

“We are now selecting the best specimens of macauba in an effort to find a definitive and high-yield variety,” Motoike explains. This is carried out through traditional crossing among the best and highest-yielding plants. One of the Viçosa studies concerns the breakdown in dormancy of the macauba seeds, an important step in establishing crop cultivation of this palm tree. “That was in 2007.  Seed germination had been 3% and using our method, which resulted in a patent, we were able to achieve 80%,”  he says. The technique uses a hormone in the seed that triggers pre-germination.

Preserving the fruit
One factor that could adversely affect the macauba oil is rapid acidification of the fruit.  “Processing time is two days.  After that, it begins to acidify,” explains microbiologist Elisa Costa Cavalcanti, a graduate student at the Chemistry Institute of the Federal University of Rio de Janeiro (UFRJ). Cavalcanti says that the group led by Professor Denise Freire has conducted several experiments to try to preserve the fruit for more days.  “The most appropriate method appears to be in an autoclave, using a process that heats the fruit, which is then dried in an oven.  It can then be stored for 180 days,” she says.

Learning how to preserve the fruit is also important for competing with soy, a grain that can be stored for up to six months with no special handling and that has a large domestic and international market. “Its main product is bran, a protein used in the food industry as well as in animal feed.  In order to obtain bran, the grains have to be crushed; the oil is a byproduct of this process, which is increasingly being used in cooking,” explains agricultural engineer Décio Gazzoni, a researcher at Embrapa Soja, in Londrina, Paraná State.

Biodiesel_245Ten years ago, it was algae that represented biodiesel production’s greatest hope.  At that time, there were experiments demonstrating that the mass of fats extracted from growing algae could reach 50,000 l/ha. But that endeavor came to a screeching halt on the economics side.  In 2007 and 2008, several companies were established, mainly in the United States, and the expectation was that the cost involved in biodiesel production would fall.  There were some cost reductions, but not enough to make the process competitive.

“Biofuels from algae ended up not being viable,” says Sergio Goldemberg, a partner in Algae, a São Paulo company that developed technology for the production of fats using microalgae cultivated in vinasse, a byproduct of sugarcane ethanol production  (see Pesquisa FAPESP Issue nº 186) Goldemberg is now looking for other uses for the microalgae that feed off vinasse, as animal feed and additives for cosmetics.

Until macauba and dendê become viable alternatives, biodiesel will likely continue to be produced as an agricultural and industrial byproduct. Experts say that Brazil needs to take better advantage of the potential involved in used cooking oil from homes, restaurants and industry. What is not used is poured down drains and into sewers or even into bodies of water. “Cooking oil collection is a challenge because sites are scattered among small units throughout any city,” says Aldara da Silva César.

1. Development of SSR loci enriched libraries and characterization of the genetic population structure of macauba (Acrocomia aculeata) (nº 2005/56931-6); Grant Mechanism Regular Research Grant; Principal Investigator Carlos Augusto Colombo (IAC); Investment R$77,126.93.
2. Genetic diversity and selection of higher plant with progeny testing of macaw for biodiesel production (nº 2011/13182-4); Grant Mechanism Regular Research Grant – Program for Research on Bioenergy (BIOEN); Principal Investigator Carlos Augusto Colombo (IAC); Investment R$236,494.57.
3. Selection of donor macauba trees aiming at biodiesel for forming garden seed and commercial seedling production preserving genetic variability (nº 2014/23591-7); Grant Mechanism Thematic Project; Principal Investigator Carlos Augusto Colombo (IAC); Investment R$555,424.25 and $40,078.03.

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