Thermo Fisher Scientific Mercury Freedom™ Hg-CEMS Continuous Emission Monitoring System

Overview

The Thermo Fisher Scientific Mercury Freedom™ Hg-CEMS is a fully integrated, U.S.-manufactured continuous emission monitoring system engineered for regulatory-grade quantification of elemental mercury (Hg⁰), oxidized mercury (Hg²⁺), and total mercury in flue gas streams from coal-fired power plants, waste incinerators, cement kilns, and other industrial combustion sources. It operates on the principle of cold vapor atomic fluorescence spectrometry (CVAFS), coupled with a proprietary dry catalytic conversion technology that quantitatively reduces Hg²⁺ to Hg⁰ without aqueous reagents or liquid effluent generation. Unlike wet-chemistry or gold-amalgam-based systems, the Mercury Freedom™ platform eliminates SO₂-induced interference through physical separation and spectral selectivity—achieving an SO₂ rejection ratio exceeding 8.4×10⁸:1—and maintains stable calibration across high-dust, high-moisture, and high-temperature sampling environments (e.g., pre-ESP or post-air-heater locations). The system meets and exceeds all performance criteria defined in U.S. EPA Performance Specification 12A (PS-12A), 40 CFR Part 60 Appendix B, and Part 75 requirements for compliance reporting, including weekly system integrity testing (SIT) and quarterly accuracy audits.

Key Features

• Dry Catalytic Conversion: Patented NEMA 4X stainless-steel probe-integrated converter thermally reduces Hg²⁺ to Hg⁰ using solid-phase catalysts—no water, acids, or chemical consumables required; eliminates wastewater disposal and corrosion risks.
• Ultra-Low Detection Capability: CVAFS detection limit of 2 ng/m³ (300-second averaging), validated per EPA PS-12A; optional MaxSense™ configuration extends sensitivity to 0.008 µg/m³ for sub-regulatory monitoring.
• In-Situ Probe Design: 83i probe assembly features glass-coated 316L stainless steel wetted surfaces, heated aluminum thermal management, and inertial filtration—enabling reliable operation at >90% RH, >200 °C, and >10 g/m³ particulate loading.
• Full-System Diagnostics: Embedded self-calibration routines verify analyzer optics, critical orifice flow, zero air purity, and dilution ratio without external PCs; automated daily zero/span checks supported by 81i mercury vapor calibrator.
• Regulatory-Ready Data Architecture: i-Series platform supports FDA 21 CFR Part 11-compliant audit trails, electronic signatures, and secure data logging; all measurements timestamped, version-controlled, and exportable in CSV/Excel format.
• Modular I/O & Integration: Standard 10-relay status outputs, 16 digital inputs, and configurable analog I/O (6× 4–20 mA out, 8× 0–10 V in); native Modbus TCP, Ethernet/IP, and iPort remote access enable seamless integration with DCS, SCADA, and CEMS data acquisition systems (DAS).

Sample Compatibility & Compliance

The Mercury Freedom™ Hg-CEMS is validated for use across diverse flue gas matrices—including high-SO₂ (>3,000 ppm), high-NOₓ (>500 ppm), and high-Cl⁻ environments—without signal quenching or spectral overlap. Its dilution sampling architecture (25:1 to 100:1) mitigates condensation effects and thermal degradation, while the dry conversion process ensures stoichiometric recovery of Hg²⁺ species per EPA Method 29 and ASTM D6784. All hardware components comply with NEMA 4X ingress protection, ATEX/IECEx Zone 2 electrical safety standards, and ASME B31.1 piping codes. Each system ships with NIST-traceable calibration documentation; optional on-site NIST溯源 calibration services are available via certified mercury permeation sources maintained under ISO/IEC 17025-accredited procedures.

Software & Data Management

The i-Series operating software provides intuitive, menu-driven navigation with customizable soft keys for rapid access to calibration logs, diagnostic reports, and real-time trend plots. All measurement data—including raw fluorescence counts, dilution-corrected concentrations, probe temperature/pressure, and converter efficiency metrics—are stored locally on industrial-grade flash memory (≥8 GB) and synchronized via encrypted TLS 1.2 to enterprise historian systems. Audit trails record operator actions, parameter changes, and calibration events with immutable timestamps and user IDs—fully compliant with GLP, GMP, and EPA 40 CFR Part 75 data validation protocols. Remote firmware updates, alarm notifications (email/SMS), and live video-assisted troubleshooting are enabled via Thermo’s iRemote cloud portal.

Applications

• Continuous compliance monitoring for MATS (Mercury and Air Toxics Standards) and EU IED (Industrial Emissions Directive) reporting
• Real-time optimization of activated carbon injection (ACI) dosing in coal-fired boilers
• Performance verification of wet FGD scrubbers and SCR catalysts for mercury re-emission control
• Source apportionment studies requiring speciated Hg⁰/Hg²⁺ differentiation
• Stack testing support for Method 29, EPA Draft OTM-32, and ISO 15202 field validation
• Long-term emissions trend analysis under GHG reporting programs (e.g., EPA eGRID, EU ETS)

FAQ

Does the system require gold amalgam traps or consumable reagents?
No. The Mercury Freedom™ Hg-CEMS uses a dry catalytic converter and CVAFS detection—eliminating gold traps, potassium permanganate solutions, and associated maintenance costs.

Can it measure oxidized mercury independently of elemental mercury?
Yes. By configuring the 83i probe to operate in “Hg²⁺-only” mode (bypassing the converter), the system quantifies oxidized mercury directly; total mercury is measured with the converter engaged.

How is weekly system integrity testing (SIT) performed?
The integrated HgCl₂ generator (mounted on the 83i probe) produces trace-level oxidized mercury in situ—enabling full-path SIT without heated sample lines or external calibration gases.

Is NIST traceability available for Chinese installations?
Yes. Thermo Fisher maintains a China-based NIST-traceable mercury calibration laboratory with a certified permeation source, enabling local audit-ready calibrations without transcontinental instrument shipment.

What cybersecurity protections are implemented?
The i-Series platform includes role-based access control, TLS 1.2 encryption for remote sessions, disabled default credentials, and regular security patching aligned with IEC 62443-3-3 industrial cybersecurity standards.