Predictive emission monitoring system
Software-based predictive emission monitoring system (PEMS) for continuous real-time monitoring of pollutants such as NOX, SO2, CO, HC or reference variables such as O2.
PEMS are an innovative and cost-effective approach to continuous monitoring of emission sources as an alternative to continuous emissions monitoring systems (CEMS).
Functionality:A predictive emission monitoring system cannot measure emissions directly and instead uses an empirical model to predict emissions based on historical and real-time process data.
- Software-based monitoring, monitoring of primary pollutants (NOX, SOX, CO) and O2, CO2, VOC, HCl, NH3, H2S etc.
- PEMS define the relationship between a number of characteristic process parameters for an emission source and the corresponding emission concentration.
- PEMS uses an empirical model to predict emissions based on historical and real-time process data.
- PEMS provide a reasonable alternative to CEMS (AMS) where there is a reliable and predictable correlation between plant operating conditions and emissions.
- US EPA 40 CFR Part 60
- US EPA 40 CFR Part 75
- Performance Specification 16 (PS-16)
- CEN/TS 17198
- Significantly lower capital expenditures
- A fraction the operating and maintenance costs of a CEMS
- Maintenance and repair costs virtually eliminated
- Manpower requirements significantly reduced. Plant staff can focus on operational issues
- Valid results for all operating conditions reflected in the model including startups or shutdowns
- Accuracy/precision equal to CEMS
- Resilient to missing inputs – sensor failure does not impair data availability
- Models can be built by staff on site or third party consultants
- PEMS can be used as diagnostic tool to lower emissions
PEMS are used in a wide variety of plants around the world, particularly in the United States, but also in the Middle East and some parts of Asia. In Europe, PEMS are currently only commonly found in selected countries.
PEMS solutions are industry independent and are able to deal with emissions from many different applications. However, fuels should not vary in their calorific values and composition. PEMS are typically used for gas and oil-fired plants in the utility, petrochemical, chemical and steel sectors or other industrial plants.
In particular they are tailored for:
- Gas or liquid-fired emission sources
- Reciprocal internal combustion engines (RICE)
- Biogas plants
- Duct burners
- Chemical oxidizers
- Regenerative thermal oxidizers
- Process heaters
- Olefin furnaces
- Crude oil heaters
- Offshore plants
Suitable fuel types are for example:
- Fuel oils
- Natural gas
- Refinery gas
- Process gas
- Combined fuels