Cloud of Uncertainty Hangs over Carbon Capture Technology

According to figures from the UN, the world's icecaps would be in danger of melting if the average global temperature rose as little as 1.9 degrees centigrade above pre-industrial levels. This could mean a rise in sea level of around seven metres.

Carbon capture is one technique scientists in China and beyond are hoping may reverse this trend; but, as CRI's Dominic Swire finds out, there is still a cloud of uncertainty hanging over this technology.

Carbon capture is a technique that involves collecting carbon dioxide, or CO2, as it's produced in power stations and then storing it underground. It's a key component of many country's plans to reduce carbon emissions, especially China, which generates about 70% of its energy from coal power stations. However, there are still a number of questions about the safety and feasibility of the technology.

Professor Haroun Mahgerefteh is an expert in chemical engineering at University College London. He is collaborating with experts from China's Dalian University on a project examining the safety of carbon capture.

"The problem with CO2 is that it displaces oxygen, so you suffocate if you breath it. It's not explosive. If, for example, there is a CO2 pipeline that will pass near house, what you want to know is what is the risk to me."

The scenario of a major leak is not unprecedented. In 1986 a huge amount of carbon dioxide that was stored naturally under

Lake Nyos in Cameroon escaped killing 1,700 people within 25 kilometres. One of the key questions Professor Mahgerefteh and his Chinese team are working on is, in the event of a major catastrophe, what distance from the leak can be considered safe?

"The problem is that at the moment nobody knows–certainly, if you're very close to the pipeline and there is accidental rupture of the CO2 pipeline, they you are exposed to serious risk, fatality, if you happen to be very close. The question is how far you need to be to be safe."

The potential for carbon capture is huge, especially in China, the world's largest coal user. However, Zhang Dong Xiao,

Associate Dean of Beijing University's College of Engineering, says there are even more hurdles that need to be overcome in China.

"I think the potential is large. China should be able to sequest or store away a large amount of CO2, the problem is who is going to pay? The consumer, the power generator, or the government? Once we figure out who's going to pay for what, then it may be implemented."

Hopefully such questions can be answered before long, meaning that predictions about the benefits of carbon capture can be considered more than just hot air.

For CRI, I'm Dominic Swire.