Rhodia, Brazil pioneer in reboiling

Adriana Tardin, chemical engineer, designs projects to implement improvements at the Rhodia plant near Paulínia in Brazil.

DATE 2023-11-28 AUTHOR Jonathan Wheatley

It's a typically Brazilian setting for a thoroughly multinational company. The Rhodia factory near Paulínia, deep in the interior of São Paulo state, occupies the site of an old coffee fazenda (plantation). The colonial-style ranch house, resplendent in blue and white behind a double row of royal palms, still stands guard over the driveway that leads from the main gates to the factory proper.

Factories, like fazendas, need water, and this driveway also takes visitors over the Rio das Pedras (River of Stones), which winds its way through the property, its dark brown waters a reminder of the rich soil that has put this region at the center of the agricultural heartland of Brazil.

This is one of seven Rhodia factories in Brazil, in addition to the company's South American headquarters in São Paulo. The company has been operating in Brazil since 1919. But it's a young organization, too: Rhodia became an independent company in 1999 when its former controller, Rhône-Poulenc, sold its remaining interests. The newly reorganized Rhodia sells its products in 150 different countries. It has 110 factories, and employs 29,500 people. Its business is specialty chemicals, with products designed for the automotive, health care, fragrance, apparel, electronics, personal care and environmental protection industries.

Rhodia gets its raw materials for Paulínia from Petrobrás, the Brazilian public sector, full-service oil group with activities running from deep-sea exploration and production of crude oil to refining and distribution through its own chain of gasoline stations. The Petrobrás refinery at Paulínia is one of the group's biggest, and the area around the town is dotted with multinational and local petrochemical companies that rely on it for naphtha and other basic inputs.

Continuous evolution and improvements

Adriana Tardin, a 25-year-old chemical engineer, is one of a team of 15 process engineers at the Paulínia factory. Although originally from the port city of Vitória in the state of Espírito Santo (just up the coast from Rio de Janeiro), Adriana took her degree at nearby Unicamp, one of a handful of world-class Brazilian universities and another reason why so many companies like to set up in the region. She is in charge of overseeing three production units at the factory: one produces ammonium bicarbonate, a chemical yeast used in making biscuits; the others produce solvents, used in non-toxic inks.

Her job is to make sure that the plants under her control are functioning as efficiently as possible and at maximum capacity. That involves constantly monitoring many processes in many different stages. "I have to identify potential improvements, and design projects to implement them," she says.

Her work approaches an art form. In a typical unit at the Paulínia factory, a collection of vertical, polished steel columns – in which distillation or other processes are used to separate liquids and/or gases from each other – are interconnected with a lot of piping. These pipes pass in and out of heat exchangers, condensers, renoilers, decanters and other equipment apparently crammed together in a girder-built structure the size of a small apartment block.

And it's not just their appearance that is strangely organic. These structures are in a state of ongoing evolution, constantly modified to improve this or that stage of the process. Adding or changing a piece of equipment is almost like surgery: sometimes there's a lot of cutting and joining up to be done, sometimes it's a straight, simple operation.

The world's first Compabloc reboiler

The Paulínia factory is the first plant in the world to use Alfa Laval's Compabloc compact, fully welded plate heat exchanger as a reboiler. It's installed at the base of a distillation tower separating alcohol from water. Rhodia bought it in 2000, soon after Alfa Laval acquired the Compabloc's previous manufacturer and realized that it could easily be used as a reboiler. In this case, the Compabloc won not only on efficiency and space – it's a fraction of the size of the alternative: an old-style shell and tube exchanger – but also on cost. "With the modifications that would have been needed for a shell and tube exchanger, the Compabloc worked out cheaper," Tardin explains.

Recently, Tardin discovered that a pair of condensers in the middle of the production process was holding back the capacity of her solvent. She calculated that adding an extra condenser would increase the unit's capacity by at least 5 percent. But there was a problem: the condensers were bolted onto a girder up on the second floor of the structure, and there was neither the space nor the resistance in the girder to take another shell and tube exchanger. The only alternative was to use a compact solution to do the same job. That would save both space and weight. The question was which condenser to use.

Ricardo Chade, manager at Alfa Laval's process industry segment in São Paulo, offered two solutions: a fully welded Compabloc condenser, or a semi-welded plate condenser. Both could be installed with minimum modifications in the plant. Tardin chose the semi-welded version on cost grounds. Chade agreed that, in this case, the semi-welded exchanger would do the job just as well.

Working together in Brazil

Rhodia Paulínia's and Alfa Laval's relationship began in the early 1970s.That's before Alfa Laval manager Ricardo Chade was born, but you can tell he takes pride in his part in keeping the relationship going.

"Every single variety of heat exchange technology produced by Alfa Laval for the petrochemical industry is at work here in Paulínia," he says. He regards himself as a personal consultant to Rhodia's Adriana Tardin and the other process engineers at the plant. Tardin feels the same way. "Our relationship is like this," she explains. "I send him a lot of technical data. He sends me solutions."

Convincing solutions

Those solutions have to be convincing. A Compabloc or other Alfa Laval exchanger has to do the job better than a traditional shell and tube heat exchanger. For example, the Compabloc as a reboiler installed on Tardin’s unit has been working perfectly, 24 hours a day, since May 2001.

The Compabloc in Paulínia is being used as a reboiler in a solvent production unit. Rhodia chose the Compabloc for this application because it required much less space – and much less modification to the production unit – than the shell and tube design. It’s also more efficient, and was cheaper to install.