Feasibility Study of Sewage Sludge Incineration CDM project in Singapore

Global Environment Centre Foundation(GEC)

Reports of CDM/JI Feasibility Studies

Title of Feasibility Study (FS)Feasibility Study of Sewage Sludge Incineration CDM project in Singapore
FYFY 2008
Main Implementing EntityThe Japan Research Institute, Limited
FS Partner(s)Kajima Corporation
Location of Project ActivitySingapore (The Tuas industrial area, at the western end of the main island of Singapore)
Summary of FS ReportSummary (PDF151KB)
Description of Project ActivityAll of the sewage sludge that comes from sewage treatment plants in Singapore is transported to the Changi sewage sludge and solid waste disposal site at the eastern end of the main island of Singapore and is dumped as landfill. The dumped sewage sludge at the Changi sewage sludge and solid waste disposal site undergoes anaerobic degradation, produces methane gas, and it is emitted into the atmosphere without being processed through methods such as flaring.
In this project, all of the sewage sludge that is currently being dumped in the Changi sewage sludge and solid waste disposal site is to be incinerated by ECO, which is a waste disposal company of Singapore, in the Tuas industrial area located at the western end of the main island of Singapore. By doing so, the dumped volume is reduced to only incineration ash while the amount of methane emitted into the atmosphere becomes zero.
The technology that is used in this project is sewage sludge drying & incinerating technology. The incinerator that ECO (ECO Industrial Environmental Engineering Pte. Ltd.) will incorporate is a high-performance incinerator VORTEX, which has made many creditable achievements in Japan. The VORTEX incinerator applies technology where air that is needed for combustion is blown out like fire-feeding bamboo pipes from the lower part of the agitating rotating arm inside the furnace to agitate the objects to be burned and completely incinerated. In addition, the heat that is generated from the incineration process is used in the drying process.
The project is to commence in April 2009 and structures such as the incineration facility are under construction.
Targeted GHGCH4
Category of Project ActivityWaste Management
Duration of Project Activity/ Crediting PeriodApril 2009-March 2019 / April 2009-March 2019
Baseline Scenario (including Methodology to be applied)Project Boundaries
The boundaries of the project are sewage sludge drying/incineration facilities and exhaust gas/wastewater disposal facilities that are needed afterwards.
Applied Methodology
The methodology to be applied in the project is the approved methodology AM0025 "Avoided emissions from organic waste through alternative waste treatment processes (version 11)".
Five alternatives for the disposing and treating of waste products have been conceived if there are no project activities in this project:
  • M1: The sewage sludge incineration business if there is no income through CDM businesses,
  • M2: The composting of sewage sludge,
  • M3: The melting of sewage sludge,
  • M4: Dumping of sewage sludge in solid waste disposal sites that accompanies recovering gas from disposal sites, and
  • M5: Dumping of sewage sludge in solid waste disposal sites that does not accompany recovering gas from disposal sites.
The baseline of the project will be set as "M5: Dumping of sewage sludge in solid waste disposal sites that does not accompany recovering gas from disposal sites" because investment analyses show that there is no profitability with M1, there is not much profitability with M2 because there is no demand for compost, there is not much profitability with M3 because it costs more than M1, and there is no profitability with M4 at all because it produces no income.
Demonstration of AdditionalityIn this project, "Option III: benchmark analyses (when income other than CDM income can also be anticipated)" will be adopted from the verification method shown in the additionality manual. The IRR will be adopted for examinations as the most appropriate financial indicator for this project. The assessment figures (benchmark) show Singapore's prime rate (2007) as 5.33%. IRR calculations based on these conditions for when the project is not implemented as a CDM business show 4.49%, which is lower than the assessment figure, and that there is low profitability for it to be run as a business.
IRR sensibility analyses in cases where incineration ash disposal costs, electrical power rates, and natural gas rates each fluctuate from -10% to +10% showed that they were all below the assessment figures (5.33%). Therefore, it has been confirmed that this project is not appealing financially as an investment.
Estimation of GHG Emission Reductions1,045,473tCO2/10years
Monitoring Plan (including Methodology to be applied)The amount of sewage sludge brought to the drying & incinerating plant that is involved in the baseline emission calculations have been measured in scales of trucks with the AM0025 monitoring methodology. The electrical power, amount of fuel consumption, amount of exhaust gas, and the concentration ratios of methane and nitrous oxide in the exhaust gas that are produced through project activities and involved in the calculations of the emission volume of the project have been directly measured along with factors such as the carbon content of the incineration ash that is involved in the calculations of the leakage emissions.
Environmental Impact AnalysisAnother way that this project will help improve the environment besides reducing greenhouse gas emissions is by greatly reducing landfill disposals because sewage sludge will be incinerated. Furthermore, the implementing of this project is not expected to cause any major impacts on the environment or surrounding areas because the site where it will be implemented is in an industrial area and there are facilities such as power generation facilities and incineration facilities nearby.
The incinerators used in the project will have extremely low effects on the environment because they incorporate Japanese technology and emissions of SOx, NOx, etc. are much lower than those of the standard values. Exhaust gas, wastewater, etc. are processed appropriately with devices such as scrubbers and treatment equipment, and the incineration ash is treated at the Semakau solid waste disposal site.
Issues and Tasks for Project MaterialisationConstruction has already begun for this project and operation of the sewage disposal and sludge incineration business is to begin in April 2009. The validation of the CDM industrialization has been initiated and the procedures to get approval from Singapore’s government have begun. Therefore, efforts in CDM industrialization are proceeding smoothly.
Co-benefits EffectsThis CDM project will improve the reducing the volume of landfill disposal. This project is been planning that reduce the volume of landfill disposal from 639t/d in the current situation to 73t/d.