Carbon recycling a money-making chance

Carbon dioxide (CO2) continues to dominate the media, not only because of its greenhouse gas effects, but also as an emission gas attracting carbon taxes.

Governments are increasingly desperate to find an answer to our increasing CO2 problem. Ironically, the more than 27 billion metric tons of CO2 produced each year may actually represent an excellent business opportunity.

Energy-related waste carbon dioxide emissions are projected to reach 43 billion metric tons a year by 2030, an increase of 60 per cent.

A new report by the International Energy Agency (IEA) estimates that growing energy demands from emerging giants like China and India, coupled with a lack of cost-effective alternatives to fossil fuels, means that 77 per cent of the world's power will still be derived from fossil fuels by 2050.

"We will require immediate policy action and a technological transition on an unprecedented scale," IEA executive director, Nobuo Tanaka said.

Thinking imaginatively shows us that carbon recycling for profit could offer an exciting and viable alternative to carbon capture and storage programmes.

Many scientists are looking at what appear to be risky, unworkable and expensive technologies to capture and store carbon dioxide, so as to remove it from the environment and from polluting industries.

However, recycling carbon provides another and more potentially attractive solution.

Carbon recycling may be destined to be at the forefront of research for many years to come.

The huge technological challenge lies in the "reduction" of carbon dioxide, the chemical term used to denote the removal of oxygen from carbon compounds, a process that plants and forests do easily every day.

Sadly, these natural processes occur too slowly to balance the effects of increasing industrialisation and growth of China and others in the developing world.

Extractive metallurgists are able to reduce any oxide compound to its elemental form. Examples of this are found in the manufacture of iron from iron oxides, aluminum from aluminum oxides, and hydrogen from hydrogen oxide (or water). Carbon dioxide is similar to any other oxide and can be reduced to its respective elements by applying energy, a process that could minimise the amount of CO2 released into the air and, thus, result in improved fuel self sufficiency.

As with other oxide compounds, "reductions" require the input of some form of energy to overcome the tendency of carbon to form compound oxides.

Such reductions into fuels would be better environmentally than simply capturing CO2 and pushing it back into the ground, but they cost both money and energy.

An added difficulty is that unlike most other solid oxide compounds metallurgists work with, CO2 is a gas, which adds to the complexity and cost of its collection and capture.

Carbon recycling options being developed globally, vary considerably. The range includes the biochemical conversion of CO2 into algal biofuel, the thermochemical conversion into methanol, and the biocatalytic or solar photocatalytic conversion of CO2 to fuel.

Each has its own set of advantages and disadvantages and some are more feasible than others. A new technology, named the electro-reduction of carbon dioxide (ERC), aims to take CO2 directly from industrial waste gases and convert it to formate salts and/or formic acid, both of which are used in a variety of industrial applications.

Formic acid also has the potential to play a leading role in fuel cell development.

We are living in an era with an exciting range of projects calling out for solutions from economists, politicians, scientists and engineers. David Shillington is head of the School of Applied Health Sciences at UCOL.

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