Can carbon capture and storage solve climate change?

Ronan Dubois investigates carbon capture and its potential to revolutionise the fuel industry

The 2016 Paris climate accord fixed a threshold of 450 ppm (parts per million) for the atmospheric CO2 concentration to limit the global temperature rise to 2°C by the end of the century. The International Energy Agency (IEA) has forecasted that reaching these targets will be 140% more expensive without carbon capture and storage (CCS). So, what exactly are they talking about?

CCS was first used in American oil rigs in the 1970s. In short, it involves extracting carbon dioxide gas at polluting power plants or industries, transporting it to a storage facility and injecting it deep underground in a special geological formation. Today, 17 large-scale projects operate around the world, storing 40 million tonnes of CO2 underground annually.

CCS has two main purposes; enhanced oil recovery (EOR), whereby CO2 gas is injected into an oil well to increase the reservoir pressure to extract more petroleum; and the permanent sequestration of CO2 in deep saline formations. It is estimated that these represent 95% of the global CO2 storage resource, which could amount to several centuries of global present-day emissions. Why, then, has CCS not yet been massively implemented? The answer is that the practical obstacles to its wide-scale implementation have, so far, proved more substantial than its reported benefits.

One of the major challenges is reducing costs - the largest projects amounting to billions of dollars in investments and operation. This is compounded by the efficiency-penalty suffered by power plants equipped with CCS, which are often too significant to justify it without financial incentives. In addition, population acceptance has shown to be a crucial factor in the success or failure of CCS pilot projects. Concerns have been expressed over the environmental impact of CO2 injection and the risks associated with induced seismic activity and leaks. Some may remember the 1986 ‘Lake Nyos disaster’ of Cameroon, in which the sudden discharge of a natural carbon dioxide cloud caused thousands to suffocate. Furthermore, there are ongoing legislation disputes in Europe to have CO2 reclassified as a commodity rather than a pollutant in order to enable its transport across borders.

In spite of this, recent developments seem to signal a renewed momentum for CCS. The governments of India and Scotland have pledged to fund it, with others set to follow their lead. Three projects entered the operational phase this year; one being Australia’s Gorgon project, the world’s largest to date; China, whose power generation sector is largely reliant on coal, is leading the way in a new wave of projects and began the construction of its first plant in 2017; meanwhile Norway plans to turn CCS into a new pan-European industry within the next 5 years by collecting and storing European emissions below the North Sea.

The challenge humanity now faces is to store 4 billion tonnes of CO2 annually by 2040, or 1% of what is stored today. For now, in the IEA’s words, CCS remains “way off target”...

From Issue 14