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Biodiesel by-product can be used to suppress dust in vehicles used in mines

DrümSince 2008, trucks and buses in Brazil have run on a percentage of biodiesel from vegetable oils or animal fat added to the traditional petroleum-based diesel. At first, biodiesel accounted for 2% of the fuel; since 2010, this renewable and less polluting fuel has accounted for 5%. However, production has increased and this poses a problem: what should be done with the remaining glycerol, which is left over at a proportion of 100 kilos to each one thousand kilos of biodiesel produced? The solution, as shown by various research studies conducted in the country, is to transform the glycerol into a product with added value, as shown in an award-winning study produced by the Federal University of Minas Gerais (UFMG). This resulted in a liquid dust suppressor made from glycerol. The liquid is sprayed onto the wagons loaded with iron ore, as they travel from the mines to the processing facilities or to the ports from where the iron ore is exported. Spraying the glycerol liquid prevents dust particles – that cause economic losses, environmental damage, and hazards to the health of the communities that surround the railway tracks – from being released by wind or rain into the atmosphere.

“Fragdust, the suppressor our group created, is more efficient than the other commercially available suppressors produced from oil by-products. Fragdust forms a malleable resistant layer under the iron ore, even in the case of very low concentrations, which is not the case of the other suppressors on the market. In addition, it costs 60% of the price of similar products,” says chemist Miguel Araújo Medeiros, a professor at the Federal University of Tocantins (UFT). The innovative suppressor, developed through a partnership with the Environmental Technologies Group from the Federal University of Minas Gerais (UFMG), coordinated by professor Rochel Lago, was licensed for manufacturing to the Verti Ecotecnologias company in Belo Horizonte. The firm is studying the possibility of producing the material on an industrial scale. Development of Fragdust has already led to major recognition of the Brazilian researchers. For example, they were ranked first at the Global Startup Workshop 2012, organized by the Massachusetts Institute of Technology (MIT) in Istanbul, Turkey, and at the Idea to Product Global 2011, held in Stockholm, Sweden. Both competitions focus on new technologies and entrepreneurship.

058-063_Glicerina_196-2The progress of the national biodiesel program – last year 2.6 billion liters of biofuel were produced and estimated production for 2020 is 14.3 billion liters – means that enormous volumes of glycerol will be produced, which is far more than current demand. Last year, production as a by-product of biodiesel alone reached approximately 260 thousand tons, which is eight times higher than current demand, estimated at some 40 thousand tons. The traditional markets for this material, commonly referred to as glycerin – a word for the commercial form of the product, with over 95% purity – are the cosmetic, medical drug, food, and chemical industries.

Until 1949, all glycerol produced in the world was a by-product of the soap industry. Synthetic glycerin obtained from petroleum came later on. In the middle of the last decade, the production and supply of glycerol increased significantly, due to the high volumes of biodiesel produced in various countries. Currently, it is estimated that 1.5 million tons of the substance come from the biodiesel plants installed around the world. Argentina, which produces 3.3 billion liters, ranked as the world’s biggest producer in 2011. The United States (3.1 billion liters) is followed by Brazil, and Germany (2.4 billion liters), according to information from the Association of Biodiesel Producers in Brazil (Aprobio), an entity that accounts for 60% to 70% of the country’s biodiesel installed capacity.

Most of the glycerin from the biodiesel plants in Brazil is used in ovens and boilers to generate energy at industrial facilities, such as biofuel production plants, brick making kilns, steel mills, etc. “This is an environment-friendly activity, because the glycerol can replace wood and fossil fuels, such as oil and coal,” says Expedito José de Sá Parente Júnior, a member of the technical committee of Aprobio. He adds that the leading biodiesel producers, such as Oleoplan, from the State of Rio Grande do Sul, also export their glycerin surplus to other countries, where it is used as raw material in traditional markets. “Biodiesel glycerol is mostly used to generate heat and in exports to China,” says Parente Júnior. Without going into detail, he says that the glycerol produced in Argentina and Germany is also exported to China, which uses a great deal of it yet does not produce biodiesel.

Light yellow biodiesel sample and glycerol, which is denser, in the lower part

Eduardo CesarLight yellow biodiesel sample and glycerol, which is denser, in the lower partEduardo Cesar

Parente says that the high volumes of the substance should be viewed as an opportunity rather than a problem. “New technologies are needed to add value to the product,” he states. “The general consensus is that glycerin is an abundant low-cost raw material, with chemical potential for the development of new products and processes with higher added value. But it’s pointless to create alternatives where the demand is not equivalent to the supply of glycerin, because without large-scale applications we’ll continue burning and exporting glycerol.”

Green propylene
The transformation of glycerol into a dust suppressor is merely one of the many efforts to provide an appropriate use for the residue. Some initiatives result from partnerships between universities and the private sector, such as the project that involved Quattor, a petrochemical company acquired two years ago by Braskem, and the Federal University of Rio de Janeiro (UFRJ). “The company contacted us in 2006, as it was interested in converting glycerol into propylene,” recalls professor Cláudio Mota, from the Chemistry Institute of the UFRJ. Propylene, a resin obtained from oil by-products, is one of the major raw materials of the petrochemical industry. It is used in the manufacturing of polypropylene, widely employed in automobile parts, home appliances and packaging for food and housecleaning products. According to Mota, his group developed a catalyst for the transformation of glycerol into propylene through an efficient process, even though there were no references in this respect in scientific literature at the time. This generated a patent for the university and for Quattor.

The results were encouraging and the company began to plan the construction of a pilot glycerol processing plant. “Unfortunately, after Quattor was acquired by Braskem, the project was aborted, because the company had detected logistical problems linked to transporting the raw material. The plant was to be built in São Paulo, but the leading biodiesel manufacturers are in the Midwest. In addition, Braskem already had other routes for the manufacturing of propylene from renewable materials,” Mota adds. “Still, we will continue our research studies and we are looking for a new partner.”

058-063_Glicerina_196-3Braskem is also involved in another project, in partnership with professors from the chemical engineering department at the Polytechnic School of the University of São Paulo (USP). The objective of the project is to convert the glycerol found in 3-hydroxypropionaldehyde (3-HPA) and 1,3 propanediol (1,3 PD) compounds into chemical substances with high added value. These substances are used in food preservation and in the production of polymers. They are also the precursors of important chemical compounds for the petrochemical chain. With the support of the Program for the Support of Partnered Research for Technological Innovation (Pite) and of the FAPESP Program for Research on Bioenergy (Bioen), the project aims at converting glycerol through biotechnology, using genetically modified micro organisms, including the Caulobacter crescentus bacteria.

During the research study, which began in 2010, the researchers established a biotechnological route. However, they were challenged by the high cost of the culture medium of the microorganisms, which made the process more expensive. This obstacle was overcome four months ago, when the research team replaced the traditional culture medium with vinasse, a by-product of the sugar and ethanol industry. “This will make the biotechnological project we developed economically feasible,” says Cláudio Oller, one of the members of the research team headed by professor Carlos Frederico Menck, from the Biomedical Sciences Institute (ICB) of USP.

Ethanol and hydrogen
At the Federal University of Rio Grande do Sul (UFRGS), a group of scientists is working on a line of research similar to that of USP. In addition to 1,3 propanediol, they plan to produce ethanol and hydrogen from biodiesel-based glycerol by biotechnological means. “Our research is divided into several steps. The first, which has already been concluded, was to identify biological agents capable of metabolizing residual glycerol. The second, conducted on the lab bench, is under way, and covers the in-depth study of the physiology of the Klebsiella pneumoniae bacteria. 
 The next step entails the optimization and operation of bioreactors through the cultivation of microorganisms. We designed and built bioreactor prototypes and they have already been submitted for preliminary trials,” says chemical engineer Marco Antônio Ayub, a professor at the Institute of Food Science and Technology at UFRGS.

058-063_Glicerina_196-1Illustrations: DrümThe researcher points out that the process has proven to be technically feasible; the bacteria strains convert the glycerol with no pre-treatment to remove impurities being necessary. The production rates are good. “This indicates that the process is economically feasible. However, the economic feasibility issue has not been totally explored by our group. We still have to calculate the costs,” says Ayub. He adds that at least three companies have already expressed interest in the product. “One of these companies wants to manufacture equipment associated with the technology, while the others are interested in producing ethanol using this process. For reasons of non-disclosure, I cannot reveal the names of the interested firms,” he says. The research project is being funded by the Agency for the Funding of Studies and Projects (Finep) and by the Research Foundation of the State of Rio Grande do Sul (Fapergs).

Electric power generation
At the State University of Campinas (Unicamp), chemical engineer Juliana Albarelli conducted a feasibility study on using glycerol as fuel to produce power and steam in a co-generation system. The researcher’s objective is to use the energy generated in the production of biodiesel to reduce manufacturing costs and to enable the company to enjoy the financial benefits. “We used software for programming and for energy and economic analyses. We observed that only 50% of the generated power would be necessary to supply the biodiesel production process. The 50% surplus could be sold to the local community or to the electric power supplier in the region, thus generating an extra source of income for the company,” says Juliana. The results of her study showed that the initial investment in a co-generation unit would yield returns in four years. However, several obstacles must still be overcome, such as developing a system to perform this conversion. “We don’t know of any industrial technology that is being developed to do this,” says Juliana.

The group headed by professor Carlos Mota, from the Chemical Institute of the Federal University of Rio de Janeiro, is working on the production of bio-additives from glycerol. “One of the additives we developed helps to improve the fluidity of the biodiesel, especially the additive made from tallow. This kind of biodiesel starts to freeze at temperatures lower than 15 degrees Celsius, which occur in many cities in the South of Brazil,” says Mota. His team has also developed a bioadditive with anti-oxidizing properties. This has a potential for use in several industrial applications. “It can be used for food preservation or mixed into soybean biodiesel, which needs an anti-oxidizing agent to avoid chemical degradation when it comes into contact with air,” explains the researcher from the UFRJ. Many oxidants are imported and therefore expensive. Producing bio-additives from a renewable source, such as biodiesel glycerol, is environmentally friendly and can result in major economic gains for the country.

The Project
Developing strategies for the transformation of glycerol via chemical and biotechnological routes (nº 2008/03620-1); Modality FAPESP Program for Bioenergy Research (Bioen); Coordinator Carlos Frederico Martins Menck – USP; Investment R$ 255,050.11 and US$ 211,297.51 (FAPESP)

Scientific articles
ROSSI DM et al. Bioconversion of residual glycerol from biodiesel synthesis into 1,3-propanediol and ethanol by isolated bacteria from environmental consortia. Renewable Energy. v. 39, n. 1, p. 223-27. Mar. 2012.
MEDEIROS, MA et al. Use of glycerol by-product of biodiesel to produce an efficient dust suppressant. Chemical Engineering Journal. v. 180, p. 364-69. Jan. 2012.
ALBARELLI, JQ et al. Energetic and economic evaluation of waste glycerol cogeneration in Brazil. Brazilian Journal of Chemical Engineering. v. 28, n. 4, p. 691-98. 2011.