The reduction of CO₂ emissions is high on the agenda of the UN climate summit in Copenhagen in December. A new climate change agreement must be reached to replace the Kyoto protocol, which will expire in 2012. Energy-intensive companies are already working to reduce CO₂ emissions. They participate in CO₂ emission trading and consequently have to report their emissions. For these companies, ECN has developed and patented a method that also accurately determines the proportion of ‘green CO₂’ in flue gases.

ECN calls its green CO₂ indicator the 14Credits method. The 14Credits measurement method is remarkably simple, which makes it easier for companies to participate in CO₂ emission trading. The costs of this method are also lower than those of other methods. “The idea evolved over a coffee, in 1997”, explains Bas Wardenaar, Marketing & Relations Manager with the ECN’s Engineering & Services unit. “That is the year the Kyoto Protocol was adopted. We wondered how you could tell if CO₂ originated from biofuels or fossil fuels. We came to the conclusion that the best way to measure this was to analyse the CO₂ in the flue gases. The common carbon-14 dating method enables you to determine the age of the C in the CO₂. The carbon-14 isotope is practically non-existent in fossil fuels but is present in biofuels. We applied and patented this principle to enable companies to determine, fairly easily and very accurately, what mixture of biofuels and fossil fuels they had used.”

How green is a car tyre?

ECN’s 14Credits method (from measurement to instant report) is ready to be marketed. An important component of the 14Credits measurement method is in a case: the 14Campler. It is an appliance that takes samples from flue gases. Companies participating in CO₂ emission trading have to measure the total CO₂ emission with specific equipment. They can add the 14Campler to this. The fact that combustion plants sometimes operate at a lower capacity calls for an intelligent sampling method. ECN has a patented solution: during a period of a few days up to a month the 14Campler collects and stores small quantities of CO₂ almost continuously. The stored CO₂ then goes to ECN. There, the concentration of C14 isotopes is measured and the average ratio of ‘young CO₂’ to ‘old CO₂’ determined. ECN then uses the data from the existing CO₂ measuring apparatus to calculate how much biofuel and how much fossil fuel was actually fired. ECN sends the result to the company concerned. The company can then use the report for reports in the context of the CO₂ emission trading and green electricity certificates.

Dating
The quantity of young CO₂ is determined according to the same principle as the C14 carbon dating method used to determine the age of a painting or mammoth remains. “In recent years the University of Groningen has worked hard to make this method suitable to determine young CO₂ in the combustion gases of biofuels”, Mr Wardenaar says. “One of the locations where the 14Credits measurement method was tested is Essent’s Amer power station in the Dutch province of Noord-Brabant. Beforehand there was a determination how much biofuel and how much fossil fuel, in this case coal, would go into the boiler furnaces. Comparing the results of the measurements with the calculations showed excellent correlation. In terms of error margin our method proved to be at least as good as if not better than the advance determination of the ratio of biofuels to fossil fuels”, Mr Wardenaar explains.

Removing doubts
The 14Credits method is interesting for companies that participate in CO₂ emission trading. This is because they can deduct the emission of CO₂ generated from biofuels from their total CO₂ emission and consequently pay less. At present they have to determine the quantities of biofuel and fossil fuels they have mixed by taking samples of the solids. ECN’s 14Campler can determine this fairly simply and very accurately afterwards. Wardenaar: “Furthermore, when it comes to fuel, it is not always possible to draw a clear divide between fossil and non-fossil. In 2000 we conducted measurements for the German cement industry. Among other things, they used old car tyres as fuel. Despite the fact that car tyres contain a considerable amount of natural rubber, the German government does not recognise tyres as green fuel because these ratios cannot be measured by traditional measurement methods. But with our measurement method we can indicate precisely how green the car tyres really are.”
It’s actually the opposite for biodiesel. Wardenaar: “The government considers that as 100% green fuel. This is not actually the case as it contains approx. 10% methanol of fossil origin. Our 14Campler demonstrates this infallibly. Our method enables us to determine exactly how green all those fuels really are.”
Another example is bioplastics. The government puts them conveniently in the same category as other plastics. “The CO₂ from bioplastics is non-deductible, so to speak”, Mr Wardenaar explains. “Our method can change that. Bioplastics will then more likely be used as fuel during the waste stage.”

European standards
Companies are not yet allowed to use the ECN method to officially report their CO₂ emissions. Wardenaar: “There is currently an American standard that sets out the determination of green CO₂ in combustion gases. The procedure for European standards is ongoing. In effect, our method has already been accepted but we still have to go through the official procedure. It will probably all be sorted by 2012. There will then also be an ISO standard which sets out precisely how this method should be used, officially. We will then need accreditation from Lloyds or another recognised organisation. They will check that everything is according to the rules. Once we have received the standard and the accreditation, our figures on the CO₂ in fuel gases may be used for official emission reports. Our laboratory work is already ISO 17025 accredited, our sampling method is soon to follow.”
ECN conducts the sampling and analyses itself. “Should the flood of orders outgrow our capacity, we may consider setting up a separate business for this work or contracting it our under licence. The same applies to the manufacture of the patented 14Campler”, Bas Wardenaar said. 

Only one in the world
The sector of industry is certainly interested. Wardenaar: “Considering the fact that CO₂ originating from green fuels is deductible for European CO₂ emission trading, it is definitely worth measuring the percentage of it accurately. ECN is currently the first and only organisation in the world to be able to measure this so accurately and efficiently”, he concludes.

Contact
Bas Wardenaar
ECN Engineering & Services
Phone: +31 (0)22 456 4632
E-mail: Bas Wardenaar 

Info
Surf to www.14credits.nl for further details of this measurement method.

Text: Erik te Roller

This ECN Newsletter article may be published without permission provided reference is made to the source:  www.ecn.nl/nl/nieuws/newsletter-en/