Characterization and Minimization of Fine Particulate Emissions from Waste Incinerators by Real-Time Monitoring of Size-Resolved Mass and Chemical CompositionEPA Grant Number: R828192
Title: Characterization and Minimization of Fine Particulate Emissions from Waste Incinerators by Real-Time Monitoring of Size-Resolved Mass and Chemical Composition
Investigators: Smith, Kenneth A. , Worsnop, Douglas R.
Current Investigators: Smith, Kenneth A. , Boudries, Hacene , Worsnop, Douglas R.
Institution: Massachusetts Institute of Technology
Current Institution: Massachusetts Institute of Technology , Aerodyne Research Inc.
EPA Project Officer: Hahn, Intaek
Project Period: June 1, 2000 through May 1, 2003
Project Amount: $335,000
RFA: Combustion Emissions (1999) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air
There is a critical need for real-time quantification of pollutants associated with fine particulates (those smaller than 2.5 microns) in the exhaust of waste and sewage sludge incinerators. The particulate control systems currently used in waste incinerators are least efficient for those particle sizes for which the health effects are largest due to their deep penetration into the human lung. In addition, these particulates tend to be enriched in condensible toxic organics, acid salts, and metals.
We propose a research program to characterize and quantify the emissions of several important particulate-borne pollutants in the exhaust of waste incinerators. The measurements will be performed with a novel Aerosol Mass Spectrometer (AMS) developed at Aerodyne Research, Inc. For aerosols containing volatile-and semi-volatile species, the AMS can provide quantitative information on chemical composition as a function of particle size in real-time. An aerodynamic inlet delivers a particle beam into vacuum where the aerodynamic particle diameter is determined via particle time-of-flight. Chemical composition is measured via flash evaporation of the particle followed by electron impact ionization and positive ion detection with a quadrupole mass spectrometer (QMS). Based on current laboratory calibrations, the detection limit (DL, is estimated to be 1 part per million for the volatile and semi-volatile species present in the fine particles at a typical particle concentration in incinerator exhaust of 100 mgm.
In order to enhance the sensitivity and selectivity of the instrument for polycyclic aromatic hydrocarbons (PAHs) and chlorinated aromatics (CAs), the AMS will be coupled with a Resonance-Enhanced Multi-Photon Ionization/Time of Flight Mass Spectrometer (TEMPI/TOFMS) system, currently under development by a team from the Massachusetts Institute of Technology MIT) and Aerodyne Research, Inc. (ARI) under EPA funding. A DL as low as 10 ppt of the particle mass for PAHs and CAs may be achievable with TEMPI-TOFMS. This DL will be determined during this project.
Experiments will be carried out in several incinerators: a pilot-scale municipal waste incinerator, a medical waste incinerator, an industrial VOC incinerator, a sewage sludge incinerator, and a full-scale municipal waste incinerator. The measurements that will be performed while sampling incinerator exhaust are: size-resolved particulate mass and chemical composition. The latter will include particulate-bound inorganics (e.g. sulfate and nitrate), PAHs, and CAs. The variations of these emissions with waste composition. combustion parameters, air-pollution control system parameters, and during transients in the facility (such as start-ups, shutdowns, and setpoint changes) will be analyzed in order to determine those operating practices that minimize emissions. At the end of this project. a mobile commercial instrument with the capability of performing the above measurements in real-time will be available to the research and regulatory communities.