Every year, some 160 thousand tons of long-life packaging is produced in Brazil, to hold milk, fruit juices, tomato paste, and even coconut water. Of this total, only 25% is recycled, in a process that makes use only of the paper and sends to the sanitary landfills the other two components of these small cartons, the plastic and the aluminum. A scenario that began to change after May this year, with the inauguration in Piracicaba, in the state of São Paulo, of a factory for the total processing of these materials. The factory is endowed with a technological process without precedent in the world, capable of carrying out the total separation of the aluminum and the plastic that are part of the walls of long-life packaging, also called cartons. The development of the new technique was possible with the union of four companies: Alcoa, which produces aluminum, TSL, an environmental engineering company, Klabin, a paper producer, and Tetra Pak, the manufacturer of the packaging. They expect that the recycling percentage will increase, to start with, to 65% of the total produced in the country.
“There were seven years of research and development for us to arrive at this new process”, says Nelson Findeiss, Tetra Pak’s president. For it to be ready, the new Piracicaba factory consumed investments of R$ 12 million, split between the four companies of the partnership. TSL, which built and operates the 2.2 thousand square-meter unit, has four years to return the money invested by the other three companies. It is responsible for the processing of the material and for the sale of the resulting products, such as aluminum ingots, paper, and paraffin obtained from the plastic. The factory is capable of producing 8 thousand tons of plastic and aluminum a year, equivalent to 32 million tons of long-life packaging. According to Fernando von Zuben, Tetra Pak’s environment director, with the start of the plant’s operation, it will be possible to increase the volume of this kind of recycling, increasing the chain that participates in this kind of activity, with the generation of employment and income. “With the implantation of total recycling, we believe that the value of the long-life packaging gathered by the pickers, today around R$ 250 a ton, will increase 30%”, Von Zuben says. The recycling unit in Piracicaba will be supplied with material collected by cooperatives of pickers, small junk dealers, and by municipal programs for selective garbage collection.
Plasma in the matter
Based on sustainable development, the technology created by TSL as the main agent for the recycling. Plasma is a gas produced at a high temperature, partly ionized, with the loss of electrons and molecular and atomic modifications. They are characteristics that leave it different from the other existing solid, liquid and gaseous states, A fourth stage of matter, therefore. The gas that induces the plasma, in this case, is argon. Also known as chemical or industrial plasma, it acts at high temperatures of about 15,000°C, generated by the use of electricity in the so-called plasma torches, present in a reactor.
To understand how the process of recycling with plasma works, one needs to know that long-life packaging, made up of paper (75%), plastic of the polyethylene kind (5%) and aluminum (20%), are initially processed in a piece of equipment known as a hydrapulper, which does the separation of the paper. After being separated, the paper fibers are recycled and used in the manufacture of cardboard. This first stage of the recycling is done by one of Klabin’s factories, located alongside the plasma recycling unit. The company has the capacity to produce 400 thousand tons of recycled paper a year.
In the second stage of the process, the aluminum and the plastic resulting from the separation are forwarded to TSL Ambiental’s thermal plasma reactor. The plastic compounds are broken down into smaller chains and volatilized, leaving the reactor in the form of vapors. Afterwards, these hydrocarbon vapors generated in the plasma process are condensed, generating a paraffin compound, which can be sold to the petrochemical industry, where it is used as an additive for lubricants, amongst other uses. The aluminum present in the material, made up of films of a thickness of 6 microns (1 micron corresponds to a thousandth part of a millimeter), is melted down and recovered in the form of high purity ingots. It is sold to Alcoa, which reuses it in the production of aluminum foil for new long-life packaging.
After carrying out total recycling, with undeniable environmental, social and economic gains, the plasma technology has another advantage: the process is clean, because there is no emission of any kind of pollutant. This happens because the processing of the plastic and aluminum in the reactor is done without the use of oxygen and of any kind of burning. Any liquid effluents resulting from the processing, in turn, are treated to remove impurities, and the water can be reused at the same factory. The energy efficiency of the process, almost 90%, is another attraction of the technology. “The transfer of heat from the plasma flame to the products that are being recycled (plastic and aluminum) is 90%. To get an idea of how high this transfer is, all you need to know is that when we heat water on the stove, the energy efficiency is only 30%”, Fernando von Zuben explains.
According to engineer Roberto Szente, from the Technological Research Institute of the State of São Paulo (IPT), contracted to evaluate the new technology, the plasma recycling process is a variant of the process for treating petroleum sludge and soil contaminated with hydrocarbons, developed five years ago by TSL Ambiental. Its adaptation to treat plastic material and aluminum was analyzed and proven by the IPT’s Plasma Group. “After the use of technology for processing the plastic and aluminum in the cartons proved to be technically and economically viable, the partnership between the four companies was entered into, for the construction and installation of the recycling unit in the interior of São Paulo”, Szente explains. TSL owns the patent for the process in the United States and has already entered an identical request in several European countries.
The success of the technology has already awakened interest abroad, and, by the end of the year, the first industrial plant outside Brazil should be inaugurated. TSL is building a unit in Valencia, in Spain, in partnership with a paper manufacturer, Nessa, which carries out the recycling of the paper from long-life packaging. Furthermore, missions from several countries, such as Sweden, China and India, have now visited the Piracicaba industrial unit and the pilot plant of TSL Ambiental in Osasco, in Greater São Paulo, showing interest in associating themselves with the company to build new recycling units in their respective countries.
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