One of the points which arises regularly in debates about the merits of hazardous waste incineration is that as a process, it contributes to national targets set under the Kyoto Protocol.
The Kyoto Protocol of 1997 demands an emission reduction of climate-affecting gases in various industrial sectors. In this context CO2 is one of the relevant gases and waste management is one of the relevant sectors. Referring to the situation in Europe, waste incineration is one of the major sources of CO2 in the waste management sector. The Kyoto Protocol, however, only covers CO2-emissions originating from fossil fuels, whereas the incineration of renewable materials, e.g. wood, is considered to be climate-neutral since it does not make any net contribution to the CO2 inventory of the atmosphere. Unlike the situation with municipal waste, there is little if any information on the CO2-emissions caused by the incineration of hazardous waste in specialized plants, and the renewable fraction in these materials.
According to the Kyoto Protocol, mandatory reductions of the emissions of greenhouse gases are demanded for the first time.The most important greenhouse gas related to waste incineration is CO2. It is not only the total amount of the emitted CO2 that is of interest, but also the portion of renewable materials or renewable carbon that is included in the waste.
A paper has recently been published which addresses this area in some considerable detail:
Hazardous waste incineration in context with carbon dioxide
Tim Reinhardt, Ulf Richers and Horst Suchomel
Waste Management Research 2008; 26; 88
For copyright reasons, this article cannot be published on this website, but the findings are summarised below:
The authors undertook a detailed study of the hazardous waste incineration plant near Biebesheim in Germany, in which they first undertook continuous measurement of the CO2 output of the plant for 136 days. They then performed measurements using radioactive isotopes to determine the amount of the Carbon contained in the CO2 which originated from renewable materials. It was then possible to extrapolate this data into annual averages.
Their findings are perhaps the most authoritative empirical ever produced for the incineration of hazardous waste:
In summary, they found that an average of 196kg of Carbon is released in Carbon Dioxide for every metric tonne of material incinerated. (For information, this equates to a total weight of 588kg of CO2). At the Biebesheim plant, only 10% of this Carbon was found to be organic-based (thus from renewable sources). The remainder was, in effect, new CO2 entering the environment.
This study also provides the interesting reference information that the percentage of CO2 in the output gases was 9.2%. This is helpful in extrapolating these findings when considering the impact of any other hazardous waste incineration plant. Interestingly, the percentage of CO2 within the exhaust is unlikely to change significantly even if a higher calorific yield hazardous waste is used, but the the volume of gases being emitted from the site will increase. This is because there is a finite amount of oxygen within any cubic metre of gas which can be used to enable the combustion process, so the greater the carbon to be incinerated, the greater the airflow required.
What matters greatly from this report is that it presents irrefutable evidence that the incineration of hazardous waste does not fall to be disregarded by the Kyoto protocol as it produces non-renewable carbon dioxide in considerable quantities.