Monday, 27 February 2017 15:19

New carbon capture & exchange technology is attractive option for industry

Mark Stacey, MD of Crown International, outlines his company's involvement in a cost-effective carbon capture and exchange technology partnership.

crown carbon capture1 copyFigures from the London School of Economics suggesting that electricity generation currently accounts for over 25% of the UK's carbon emissions. The energy industry has looked towards renewable energy production to replace traditional electricity production but, what if the carbon produced by the existing generation processes could be captured and neutralised or, better still, turned into useful by-products that could generate new value streams or potential alternative sources of energy?

Of course, carbon capture and exchange technologies already exist but, to date, these have proved too expensive to develop, build and operate to deliver a viable solution for the industry.

Four years ago, we were approached by a fellow Bristol-based company that was looking to develop an exciting new technology to overcome these challenges.

They had the technology, we had the manufacturing expertise, and a partnership was born that today, following two successful pilot projects for the Department of Energy & Climate Change (DECC), has demonstrated not only that the technology works, but also that it delivers in both environmental and financial terms sufficiently to make it an attractive option for the industry.

This new carbon capture and exchange technology uses flue gas carbon dioxide as a feed stock for conversion into a range of valuable commodities, including formats and industrial alcohols.

Figures from the two DECC trials suggest that it not only captures 90% of CO2 at 99% purity, but at a net product value (NPV) of just £47 per tonne of CO2 abated. This compares to up to £75 per tonne for existing technologies. (NPV = the present value of a sum of money, in contrast to some future value it will have when it has been invested at compound interest.)

So how does the process work?

As you'd expect from the name, it's a two-stage carbon capture and exchange process.

In stage one, the flue gas is captured from the power plant's flue stack at temperatures up to 270 degrees C. It is then cooled via a bespoke Condensing Economiser (CE), which recovers heat and water and also acts as the input gas monitoring point. From here, the gas moves into a wash column, where a continually circulating metal ion solution acts as the gas capture and carrying medium, removing and converting or destroying any Nitrous Oxide (NOx) and Sulphur Oxide (SOx) present.

Once this process is complete, the conversion process can get underway.

crown carbon capture2 copyThe remaining carbon dioxide gas flows into a second stage wash column where the gas is captured and separated. It then undergoes an electrochemical/resin process to be converted into High Grade Hydro-Carbon gas and/or liquid by-products for on-site reuse or sale. These can include industrially-valuable by-products such as formic acid, ethylene, methanol and syngas, depending on the individual design of the processing plant. The remaining remediated cooled flue gas is then emitted from the wash column stack (which also acts as the output gas monitoring point).

Where the technology really scores is that it uses a modular design, allowing it to be easily retrofitted onto existing power stations and scaled up or down to suit industrial locations generating anywhere between five and 100 Ktonnes of CO2 a year.

The fact that it takes just one to two years to install, from design to production, means operators can begin to see a return on the their investment within just one year. Combine this with the fact that independent consultants have assessed the technology as offering operating cost reductions of between £840,000 and £1,470,000 versus existing carbon capture and exchange technologies, and a projected value stream of around £22 million per year for the carbon captured and converted, and the financial incentives for adoption are clear, even before we take into account the potential carbon levies.

More importantly, the role adopting such technology could play in helping the UK reach its carbon emission targets should not be underestimated.

The DECC projects demonstrated that the process could simultaneously capture in excess of 95% of CO2 and 85% of the NOx in the pilot sites' flue gas emissions.

By treating carbon as a raw material feedstock for the production of valuable formates, rather than as an expensive waste material to be disposed of at high financial and environmental cost, the process creates a value stream from the by-products. Re-using these by-products, rather than releasing them into the atmosphere, has the potential to significantly reduce CO2 emissions across the energy generation sector.

If, as the LSE report states, the electricity sector is responsible for 25% of current emissions,that would be a significant step forward on its own. But, with the energy generation and industrial sectors combined being responsible for 42% of UK CO2 emissions, adopting this technology across both sectors could represent the step-change we are looking for.

The key to success of any carbon capture technology lies in making sure it is commercially attractive enough for energy companies to invest time and resources in adopting. The results of the DECC trials suggest the benefits of this new technology are clear.