Logos Química, Barueri, in the metropolitan region of São Paulo, established a target, in 1997, that some international technological centers are still pursuing – to develop an alternative to the use of diethylenetriamine pentaascetic acid (DTPA). At the time, this product was the only chemical substance (chelate) used to eliminate unwanted metallic compounds in the process of bleaching eucalyptus pulp that had the official seal of “clean technology”.
With the support of FAPESP, through the Small Business Innovation Research (PIPE), Logos achieved its goals. In 1999, the company launched the Logosperse family of multi-functional chelates, which combine three molecule based on phosphonates synthesized in its laboratory. This product, which does not harm the environment, replaces the DTPA with advantage because it can be used in an alkaline and an acid medium, lowering production costs and reducing corrosion of the stainless steel equipment and components used in the pulp and paper industry.
The new product has already won a 36% share of the Brazilian market, and is establishing itself as the leading product in the chelate for bleaching pulp segment in Brazil. One detail: in this area, Logos, which has customers such as Aracruz Celulose, Cenibra and Jafel, competes with the giants of the international chemical industry, such as Dow, Basf and Monsanto. The commercial outlook for the product is also pointing to exports.
“We are testing the application of Logosperse chelates for a Portuguese manufacturer of pulp and paper”, says the company’s commercial director, Valério Gabrielli. In his opinion the export prospects for the product are good.”This is not just the replacement of a traditional product, but real technological progress”, comments the engineer Hugo Antonio Vilca Meléndez, who coordinates the project from the Chemical Engineering Electrochemical and Corrosion Laboratory of the Polytechnic School of the University of São Paulo (USP), with the help of professor Idalina Vieira Aoki, in charge of the laboratory. “Logosperse chelates lower the use of hydrogen peroxide, the popular oxygenated water, in bleaching pulp, and other inputs, which leads to a lowering of costs of around 50%”, explains Gabrielli.
It is no accident, therefore, that in 2000 the product accounted for 5% of Logos’s sales of R$ 15 million. According to José Paulo Bonsonaro, the administrative director, the company should reach R$ 20 million by the end of this year. The company produces chemical products for the manufacture of paints, plastics, water treatment, sugar and alcohol and, of course pulp and paper.
Cleansing process
The manufacture of pulp essentially consists of converting wood into fibrous material – the paste or pulp. After the laborious process including cooking and eliminating impurities, the resultant material still contains organic compounds that retain the natural color of the pulp, namely, brown. It is at this stage that material is bleached and then, by fresh cleaning.
“The need to use a chelate in bleaching arose when, at the beginning of the 90’s, part of industry began using processes that were less harmful on the environment, partially replacing chlorine with hydrogen peroxide”, says professor Francides Gomes da Silva Júnior, of the Forestry Sciences Department of the Luiz de Queiroz Agricultural College (Esalq), at the University of São Paulo (USP). The role of the chelate is to “abduct” the metal ions, such as the iron, copper, and the manganese, in the brown pulp paste, which, otherwise, would react with the hydrogen peroxide, degrading it and impairing the degree of whiteness of the product.
The introduction of the DTPA into the process, which was already used for chelating in the paint and pharmaceutical sectors, demanded, however, that a new stage in bleaching be established. As the compound cannot be used in an alkaline medium, a new process had to be included to lower the pH of the paste. “By using Logos’s products this stage became unnecessary; the products work in either an alkaline or acid medium”, comments Silva.
Choice of molecules
“The option for the phosphonate family was based on references to the properties of chelates in scientific publications chiefly from Russia”, relates Ademir de Azevedo Marques, Logos’s research and development director. “An additional advantage of these compounds is that they are anticorrosive.” Logos synthesized four molecules initially, to later choose two that produced the best results.
The commercial feasibility of the molecules that resulted in the Logosperse line depended, however, on carrying out trials to assess their efficiency as chelates in the bleaching process and their corrosive effects on the equipment used in the company. “Turning to the PIPE, we carried out tests with the latest technology”, says Bonsonaro. The trials of the chelate action of the molecules synthesized by Logos were the responsibility of the Esalq. “We worked with the sequence used in the industry, whereby the pulp is treated with chlorine dioxide and then with hydrogen peroxide”, recalls Silva. The performance of the Logos products was then compared with that of the DTPA. In all the trials, the results were very positive for the Logos products.
For the corrosion analysis, 304 stainless steel was used, the same material used in the pulp industry. These tests were carried out at the Chemical Engineering Department of USP’s Polytechnic School. Once again, the multi-functional chelates proved to have the advantage over the DTPA. For the Poli’s Electrochemical and CorrosionLaboratory, FAPESP’s support for the Logos project also brought good news. With it, it was possible to purchase various items of equipment. “They are instruments enabling the laboratory to carry out tests considered state-of-the-art in Brazil and internationally”, observes Meléndez.
Advanced products
From Logos’s side, the project was important in reaffirming its research potential. Established ten years ago, company’s policy is to invest 3% to 5% of its revenues in research and development. “For us, ensuring that at least 30% of the company’s sales come from products launched in the last three years of a point of honor”, says Bonsonaro. As well as its own laboratory, Logos hires services from universities, like USP’s Poli and Esalq, and the Federal University of Viçosa (UFV).
“We are undertaking around 30 projects in our laboratory”, says Bonsonaro. “Besides this, we are expanding our production capacity, leaping from 650 tons a month of chemical products to 3,500 tons a month this year, with a new production plant in the town of Leme, between Campinas and Rio Claro”. This expansion will broaden our ability to produce and supply industrial chemical products in this country.
The Project
Development and Assessment of Pseudo-chelates in Bleaching Pulp Paste with H2O2 and inhibiting the Corrosion of Equipment (nº 97/07395-6); Type Small Company Technological Innovation Program (PIPE); Coordinator Hugo Antonio Vilca Meléndez – Logos; Investment R$ 175,806.80 and US$ 85,940.80
