Revising AM0025: Burning sludge as a fuel is a bad idea (Newsletter #9)

The Board may approve a recommendation by the Methodology Panel to revise AM0025 “Avoided emissions from organic waste through alternative waste treatment processes”. The draft revision shall clarify that project activities that process and upgrade biogas from anaerobic digestion to the quality of natural gas and then distribute it as energy via natural gas distribution grid can use the approved methodology AM0053 in conjunction with this methodology. The revised methodology would also allow organic industrial waste eg. organic sludge generated from the effluent treatment plant of a pulp and paper manufacturing process to be co-fired as fuel in industrial boilers.

However, CDM Watch and the Global Alliance for Incinerator Alternatives (GAIA)[1] believe that allowing sludge from effluent treatment plants to be burned as fuel is a bad idea. In the case of paper mills (the proposed project), this sludge contains high quantities of chlorine (which is typically used in the paper bleaching process). Burning chlorine in the presence of organic matter is sure to produce high quantities of organochlorine emissions, including dioxins, furans, PCBs, and other persistent organic pollutants (POPs). These POPs are specifically regulated by the Stockholm Convention on POPs[2] which enjoins parties to undertake the “continuing minimization and, where feasible, ultimate elimination” of these POPs; and to use “best available techniques” to reduce their emission, in particular in new sources. These would include, at a minimum, a variety of pollution control technologies (spray drier, activated carbon and lime injection, baghouse filters, selective catalytic reduction, fly ash vitrification, etc) that are not used in industrial boilers of the type envisaged. Nor is the revision specific to sludge from paper mills; it envisions using other sludges, from other industries or from municipal sewage, which are even more heavily contaminated and contain a wider variety of chemical contaminants (including heavy metals and industrial chemicals and their breakdown products).

CDM Watch commends the attempt to improve this important methodology. However, none of the suggested changes correct a very basic flaw in the methodology which is that it simply does not count any biogenic emissions of CO2. As recent studies in the scientific literature[3] have shown, this is a fundamental accounting error that significantly skews project-by-project GHG emissions calculations.

Action to be taken by the Board: Effluent sludge is an extremely contaminated substance. Burning it will release significant quantities of toxic pollutants and create new ones. Industrial boilers are particularly ill-equipped to deal with the emissions generated. As such, it is inappropriate for the CDM to subsidize major new sources of toxic emissions and in particular, as a UN body, the CDM has an obligation to avoid undermining other UN treaties (in this case, the Stockholm Convention) already in force. CDM Watch urges the Board to refer the revision request back to the methodology panel to excise references to sludge and to address the biogenic carbon issue.


[1] http://www.no-burn.org/section.php?id=85

[2] http://chm.pops.int/Portals/0/Repository/convention_text/UNEP-POPS-COP-CONVTEXT-FULL.English.PDF

[3] e.g.: Searchinger, et al., (2009), Fixing a Critical Climate Accounting Error, Science 326:527-528;  Mellillo, et al., (2009), Indirect Emissions from Biofuels: How Important?, Science 326:1397-1399;  Wise, et al., (2009), Implications of Limiting CO2 Concentrations for Land Use and Energy, Science 324:1183-1186