• by Fabiana Frayssinet* - Tierramérica (belo horizonte, brazil)
• Tuesday, November 10, 2009
• Inter Press Service
• Tierramérica

Scientists in Brazil are developing a technique for absorbing industry-produced carbon dioxide before it ever reaches the atmosphere. The secret lies in half-centimetre ceramic spheres.

The low-cost approach is the brainchild of a chemistry department team at the Federal University of Minas Gerais (UFMG) in south-eastern Brazil.

The inventors told Tierramérica that they believe this method is far better than the existing techniques for sequestering carbon in gas form, as CO2, the leading greenhouse gas. The ceramic balls neutralise the gas before it dissipates into the air while also transforming it into an input for other industrial uses.

Made to be placed in factory smokestacks, the small spheres are made from a porous, white ceramic that is specially designed to absorb the CO2 produced in industrial processes, preventing climate changing emissions, UFMG chemistry professor Geraldo Magela Lima, one of the inventors, told Tierramérica.

The technology could be applied in steel mills, cement factories or power plants, and even in smaller industries, like bakeries, that are run on fossil fuels.

A chemical process is used to absorb the gas. When the CO2 interacts with the material of which the spheres are made of, a high-temperature reaction takes place, said fellow researcher Jadson Belchior.

'The absorption isn't instantaneous. It occurs as a function of time and temperature. They are the two major variables we can control: a more rapid emission process at higher temperatures, or slower emission at lower temperatures,' he added.

Belchior underscored that unlike other techniques for capturing greenhouse-effect gases, the ceramic balls absorb CO2 before it is released.

'In our case, we are preventing emissions. In the case of the technology developed for capturing the gas that is already in the atmosphere, it is a correction, because the gas was already released' and the pollution has already occurred, he added.

The better-known processes for sequestering climate changing gases are largely based on the premise that a polluting activity can be offset at least partially at a later stage and even at any other location on the planet.

That is why this approach is unique - it prevents the pollution from occurring in the first place, and therefore engages the factories from the beginning of their productive activity.

Another advantage, and 'the main point of the proposal,' according to Lima, is that when each sphere becomes saturated with CO2, it is reused for other purposes, for example, as a raw material in the chemical, plastic or textile industries.

'The resulting residue is carbon dioxide in its gaseous form, which can be packed in cylinders, or its molecules used to make a different molecule through chemical reactions,' Lima said.

'Here we have a double environmental function. Other techniques don't have a way to dispose of the CO2, they just store it,' he said.

The new technique is much cheaper than other systems used today to capture and store carbon, such as underground storage of CO2, which is utilised in the undersea oil wells and is also a bid to offset emissions from the oil industry's other activities.

Preliminary tests show that the ceramic material can be reused up to 10 times to capture CO2.

That is why the UFMG researchers believe that, in addition to creating a new option in the international carbon credit market, the technology could generate profits 10 times greater than the value invested in manufacturing the ceramic balls.

Although the formula looks simple, the chemists point out that they had to take a bold stand in opposition to what they call 'the myths of the scientific literature.'

'All of the records indicated that the material we were using, subjected to a certain temperature, would not be effective in absorbing carbon dioxide,' said Lima.

But with the latest and most sophisticated equipment, they were able to refine the results, verifying and correcting data, which allowed them to improve the composition of the ceramic material and its resistance to high temperatures.

The formula, which is currently in the process of being patented, remains a secret. The chemists only revealed that they chose the sphere as the most efficient shape for the ceramic because it is best for transportation and handling.

They also said the ceramic material they developed has a CO2 absorption capacity of 40 percent of the gas that enters into contact with the balls, which they are working to boost to at least 60 percent, according to Lima.

That goal is far from the ideal of 100 percent, but the scientists consider it progress compared to estimates for other methods of capturing CO2, which range from 12 to 20 percent.

But that progress has not been merely relegated to the experimental realm.

Other studies financed by UFMG and the Minas Gerais state government will determine the number of the tiny ceramic spheres necessary for each industry and the best way of installing them in factory smokestacks, facilitating the application of the technique.

Belchior and Lima say it depends on the volume of gas emissions at each factory. But experiments conducted by researcher Geison Voga Pereira found that each kilogram of the special ceramic can absorb up to 500 grams of CO2.

The study was promoted by entrepreneur André Santos de Rosa, with the Amatech company, which financed the first phase of the project. He is interested in investing in technologies that mitigate climate change.

Brazil is considered one of the leading emitters of greenhouse gases.

According to the Ministry of Environment, of the two billion tonnes of greenhouse gases Brazil produces each year, about three-quarters come from deforestation of the Amazon. But the remaining 25 percent comes from industry and energy production.

(*This story was originally published by Latin American newspapers that are part of the Tierramérica network. Tierramérica is a specialised news service produced by IPS with the backing of the United Nations Development Programme, United Nations Environment Programme and the World Bank.)

© Inter Press Service (2009) — All Rights Reserved. Original source: Inter Press Service

Where next?

Advertisement