Alternative Approaches to Continuous Compliance Monitoring for Gas Turbines Under 40 CFR Part 60, Part 75, and Part 98 Regulations in the United States

Abstract

Quantifying emissions and complying with environmental regulations are important issues for gas turbine plants. These objectives can often be met with either a CEMS (Continuous Emission Monitoring System) using gas analyzers or a software only PEMS (Predictive Emissions Monitoring System). PEMS interface directly with the turbine control system and represent a lower cost alternative to traditional CEMS. PEMS are a compliance monitoring alternative consisting of a model of the turbine operations and its emissions. PEMS can be used to track plant combustion efficiency. PEMS can allow for more efficient operation of the plant because the PEMS system tracks excess emissions and can be used to determine the causes of and reduce pollution. This paper reviews the use of PEMS at three different turbine facilities and highlights the costs and benefits of using a PEMS for documenting emissions of priority pollutants and Green House Gases (GHG), but also in terms of overall plant efficiency, operator awareness and involvement, improvements in process control, waste and emission minimization, and in focusing the available manpower resources on core plant operations as opposed to non-core analyzer-based compliance systems. The PEMS were used for compliance with 40 CFR Part 60 and in some cases also Part 75. In addition, the Part 60 PEMS were subjected to the new performance standard (PS-16) published earlier this year by U.S. EPA.