Equipment Showcase: Continuous Emissions Monitoring Systems and Gas Analyzers

A continuous emissions monitoring system (CEMS) is required in the U.S. under Environmental Protection Agency (EPA) regulations to continuously collect, record, and report emissions data. CEMS are used to monitor flue gas for emissions such as sulfur oxides (SOx), oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), mercury (Hg), and nitrogen oxides (NOx) to provide information for combustion control in power plants and other industrial facilities. There are dozens of manufacturers and suppliers of CEMS equipment worldwide; analysts say the global market for CEMS tops $1 billion annually for ambient and stack applications. A handful of CEMS manufacturers and suppliers are featured here.

Monitoring System Engineered to Meet Tough Standards

The DataStak Monitoring System offered by Nationwide Boiler provides real-time, unified data. It utilizes electrochemical cells and is a smaller alternative to larger and more expensive CEMS systems. The DataStak provides O2, NOx, CO, and CO2 measurements in addition to real-time boiler efficiency, fuel usage, and carbon footprint calculations. The system incorporates common industry standard components, including an Allen-Bradley CompactLogix programmable logic controller (PLC) with simple touchscreen operation, and an electrochemical analyzer system. The DataStak has been engineered to fulfill monitoring requirements in certain air districts in California. The operator interface panel is built to National Electrical Manufacturers Association 4 and UL508 standards, and the emissions monitoring equipment is built to ISO standards. Alarms can be configured for high emissions, high stack temperature, O2 or combustion air/fuel ratio problems, and other issues prone to occur. It can be easily retrofitted to any brand boiler, and the outage required for installation is only hours. Nationwide Boiler Inc., Fremont, California

Nationwide Boiler


Less-Expensive Option for Non-Compliant Uses

NOVA Analytical Systems’ 7200 Flue Gas Analyzer System has capability in the non-compliant CEMS category, used by facilities looking for a less-expensive CEMS alternative. Such facilities at least annually, though, need to measure emissions with EPA-compliant equipment, generally done by a mobile CEMS service. NOVA systems require an annual relative accuracy test audit (RATA) to evaluate the reporting accuracy of the analyzer. The 7200 system uses measurement technologies including: O2, CO, NOx, and nitric oxide (NO) by electrochemical sensor, with a NOx calculation based on the nitric oxide measurement; CO, CO2, and SOx by infrared sensor; and stack temperature by Type K thermocouple, in a range from 32F to 1,800F (0C to 1,000C). The NOVA continuous flue gas analyzers can be modified with extra filtration devices for improved sample quality. NOVA analyzers use high-volume pumps for quick analysis times. In the company’s stack gas analyzers, the detectors and sensors can reach 90% of reading in less than 30 seconds in most cases. NOVA Analytical Systems, Hamilton, Ontario, and Niagara Falls, New York


Monitoring Solutions Has Variety of Analyzers

Monitoring Solutions offers a variety of emissions analyzer equipment for upgrades and replacements. The company offers analyzers for NOx, sulfur dioxide (SO2), CO, CO2, O2, total hydrocarbons (THC), ammonia (NH3), and more, for both dilution and extraction systems. Its eight California Analytical Instruments (CAI) models include the 700 FTIR (Fourier transform infrared spectroscopy), which analyzes CO, CO2, NO, nitrogen dioxide (NO2), SO2, nitrous oxide (N2O), hydrochloric acid (HCI), NH3, methane (CH4), and many other gases using FTIR technology. The 700 FTIR can be controlled via a rack-mount PC or laptop with OPUS software. It has high sensitivity with a 10.2-meter optical path. It has applications for process control, stack gases (CEM and MACT [maximum achievable control technology]), volatile organic compound (VOC) abatement, and scrubber efficiency. Unlike other FTIR analyzers, the 700 FTIR does not require liquid nitrogen (LN2), eliminating the need to repeatedly fill LN2 dewars. Monitoring Solutions, Indianapolis, Indiana

Monitoring Solutions

Emissions Monitoring for Process Boilers and Furnaces

Siemens targets the refining, hydrocarbon processing, and chemical plant markets with the company’s 40 CFR 60, 63, and 75 CEMS emissions monitoring package, which is designed to operate in a general purpose, environmentally-controlled shelter or cabinet. The standard monitoring requirements are based on the EPA’s Clean Air Act as detailed in 40 CFR-Part 60 and 63, as well as local and state requirements. The basic system is designed to monitor predefined ranges of NOx, CO, and O2 in process boilers and furnaces. The key features of the system are low maintenance and high uptime; Siemens says the system also is economical compared to other CEMS. The system has two major components: the analysis rack and the sample probe box. The analysis rack contains Siemens analyzers, a Siemens system controller, and a Sample Conditioning System. The probe box is mounted at the sample extraction point, usually on a stack or duct. The probe box is designed to extract and filter the hot wet sample from the stack or duct. The probe box also provides for calibration through the probe and blowback of the probe filter. The filtered sample is then drawn to the analysis rack via a pump through a heated line for water removal by a chiller and predefined quantification by the analyzers. The system is designed to measure predefined ranges of NOx, CO, and O2. Siemens Industry, Alpharetta, Georgia


AMETEK System Works in Natural Gas Applications

AMETEK Process Instruments’ THERMOX Model WDG-IV analyzers measure O2, combustibles, and CH 4 in natural gas-fired applications. The model is ideal for gas-fired power boilers or for boilers using natural gas during startup and shutdown. The analyzers monitor O2 and combustibles for maximum fuel efficiency. The WDG-IV is available with AMETEK’s TM2000 analyzer, which protects industrial processes by quickly responding to changes using a zirconium oxide sensor. It operates within a wide range from 0.1 ppm to 100% O2 and can accurately respond from atmosphere to low ppm O2 levels in seconds. The TM2000 also can detect excess combustibles process upsets in the presence of very low ppm O2 readings, a benefit particularly important in cryogenic gas generating processes, where the TM2000 can distinguish between an O2 upset condition and a condition caused by excess combustibles. The WDG-IV analyzer has a close-coupled extractive design for fast response in a wide range of flue gas applications up to 3,000F. AMETEK Process Instruments, Newark, Delaware


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