Emission Monitoring Solutions

The key lies in forward-looking planning of industrial facilities and in continuous monitoring of emissions.

Around the world, industries and regions that impact emissions are being prompted to reduce or, ideally, to prevent their generation of hazardous substances and environmental pollution. Here the focus is particularly on areas with intensive energy consumption and major urban industrial centres. They are all united by a common goal: to support effective climate protection and to preserve and restore a clean environment.

In many countries there is a legislative basis for a sustainable, environmentally compatible reduction of greenhouse gas emissions as well as laws and regulations relating to the emission of pollutants. These regulations include specifications for technology and modes of operation for systems as well as specifications detailing the permissible pollutant limits.

The key lies in forward-looking planning of industrial facilities and in continuous monitoring of their emissions. Targeted minimisation of emissions requires them to be reliably determined and analysed both quantitatively and qualitatively. With innovative technologies and proven measurement principles alongside with digital solutions we offer future-oriented solutions – even when subjected to ever increasing environmental and safety-related requirements.

Industries and solutions of emission monitoring

Power plants

Power plants are subject to various requirements. These depend on the fuels used, such as coal, oil or gas. The following pollutants in particular must be continuously measured, depending on applicable local environmental regulations: CO, NOx SO2 and dust as well as reference parameters such as flow rate, temperature, O2 (and H2O, where applicable).

Waste and recycling

Various requirements apply, depending on the type of incineration plant, for example, household waste, industrial waste or hazardous waste. Pollutants such as HCl, HF, NOx, SO2, VOC (Volatile Organic Compounds) and dust load as well as O2 and/or H2O must be continuously measured in accordance with local environmental regulations. Increasingly, the additional parameter of total mercury Hg must also be detected continuously.

Marine industry

Various pollutants are continuously measured in the chimneys of plants for producing cement clinker and cement, as well as for firing and crushing lime. Depending on the local environmental regulations, these should include CO, NOx and SO2, as well as dust. The reference figures of flow rate, O2 and/or H2O are frequently measured. When burning alternative fuels it is also necessary to measure additional components such as HCl, HF, Hg and VOC.

Marine industry

For flue and exhaust gas purification monitoring, the focus is on on-board systems on cargo and passenger ships. Typically, however, these systems are also subject to increased vibrations. In particular, these components are measured: SO2, CO2, NO, NO2 and O2, plus optionally measuring NH3, CH4 and H2O, and the denitrification plants are monitored. Essential requirements are approvals such as the type approval “DNV” in accordance with MARPOL Annex VI, NOx Technical Code 2008 and MEPC.177(58) and effective measuring point switching.

Metals and mining

Plants for calcination, melting or sintering ores as well as the production of non-ferrous metals have rough environmental conditions, such as high dust loads and strong vibrations. The gases produced during the procedures are processed further and must be measured and monitored accordingly.

Chemicals, petro-chemicals and refineries

The handling of large amounts of hazardous substances, highly dynamic markets, tough worldwide competition and strict environmental standards are defining factors. Process automation has a strong influence on the profitability of a plant on many levels and throughout the entire value chain as it ensures smooth operation and maximum safety. The process analysers in particular make a huge contribution to reducing production costs, increasing product yield and safety and complying with local emission regulations.

Oil and gas

Emission measurement technology is used in systems for manufacturing glass and glass fibers, for melting ceramic materials and for firing ceramic products. Typical requirements include fine silicates and borates with high abrasion potential in the flue gases.

Additional areas of application

Endress+Hauser provides emissions monitoring solutions in many other industries that are tailored to the respective measuring task. For example:

• Systems for biological treatment of waste

• Surface treatment with organic substances

• Crematories, cremation

• Mining

Technologies

1. In-situ gas analysis

Thanks to the innovative in-situ measurement technology, the measuring devices can be mounted at the measurement location directly in the duct through which the gas flows.

This device solution features minimal maintenance requirements and very short response times.

Two in-situ versions are available

• Cross-duct version: for representative measurement results across the entire duct cross-section

• Measuring probe versions: optimised for single-sided installation allowing simple integration into an extremely varied range of system conditions. For example, overpressure, wet gases or very high test gas concentrations and dust loads.

Advantages

• Continuous and direct measurement, no sampling

• Cross-duct version for representative measurement results or measuring probe version for simple installation

• GMP measuring probe with open measuring aperture or GPP gas diffusion probe

2. Extractive gas analysis

Extractive gas analysers can be used in a broad range of applications. A partial gas flow is extracted from the gas duct through selected probes, prepared and fed to the analyser module under constant conditions. The entire gas treatment from the extraction and processing to the analysis is optimally designed for the measurement task.

Two variants of measurement technology are available

• Hot-extractive measurement technology: All components that come into contact with the test gas are heated and kept above the dew point. The analysis is done under constantly hot measurement conditions and yields accurate results, even with very narrow measuring ranges. Ideal for detection of multiple gas components as well as water-soluble components such as HCl, HF or NH3.

• Cold-extractive measurement technology: The gas sampling is optionally designed with a heated or unheated test gas line. Gas drying is achieved with a high-performance gas cooler. The “cold” measurement is handled by the analyser.

Advantages

• Configurable analyser modules for a wide applications range

• Customised solutions designed for numerous possible measuring components

• Accurate and reliable measurement results

• Detection of aggressive, corrosive or combustible gases.

Measurement principles

Scattered light backward – Dust measurement via laser-based backscattering

Even if the dust concentrations are very low, the measurement principle laser-based backscattering detects the relevant values with great accuracy. A laser diode irradiates the dust particles in the measurement medium with modulated light in the visible spectrum. A highly sensitive detector detects the light scattered by the particles and transmits the measurement signal to an evaluation unit. The compensation for background radiation and ambient light, automatic checking of the zero point and reference point, as well as a check for contamination mean the system yields stable and reproducible measurement results.

UV spectroscopy – UV resonance absorption spectroscopy (UVRAS)

Endress+Hauser equips cold-extractive process photometers with the measurement principle of UV resonance absorption spectroscopy (UVRAS). The analyser makes use of the fact that certain gases exhibit specific absorption characteristics in the ultraviolet spectrum. In order to achieve this, the test gas is irradiated with ultraviolet light. The concentration of a gas component can then be determined through selective use of the wavelength and measurement of the absorption. In this manner, the analyser is able to measure gas concentrations of, for example, NO2, NH3, SO2 and H2S, by means of interference filter correlation (IFC).

ZAAS – Zeeman atomic absorption spectroscopy

An Hg-discharge lamp emits an element-specific spectrum, which enables an extremely sensitive level of mercury measurement. A magnetic field applied around the discharge lamp creates an additional reference wavelength (the Zeeman effect), which lies outside of the absorption range of Hg atoms. This compensates perfectly for cross sensitivities and lamp aging or contamination. A high temperature converter converts the bound Hg at approximately 1,000°C into elemental Hg. The advantages of this are that no chemicals or catalysers are required, maintenance is minimal and there are no moving parts. The patented direct Hg measurement system makes, e.g., the MERCEM300Z into a reference device for continuous mercury analysis.