Considerations for Procuring a Continuous Emissions Monitoring System

Before a new construction an Energy from Waste (EfW), a power plant or biomass gasification plant is signed over the site operator, it's the responsibility of the EPC (Engineering, Procurement, Construction) to procure and install Continuous Emissions Monitoring Systems (CEMS). We explore the most important considerations for procuring a CEMS.

Why are Continuous Emissions Monitoring Systems Required?

In the UK, large combustion plants and waste incineration plants are only allowed to operate with a permit within the strict conditions of the Industrial Emissions Directive (IED). The IED requires sites to control and reduce the impact of their emissions on the environment.

To monitor pollutants emitted to atmosphere and to ensure measurement parameters are within the permit, this is achieved using CEMS. A CEM system continuously collects, records and reports gas and dust emissions data to the authorities.

A complete CEM system could comprise of:

  • > A sample extraction and conditioning probe (with integrated temperature, pressure, and flow measurement)
  • > Sample lines that transport the gas and dust sample to a conditioning system
  • > Sample conditioning system which may filter, cool, and remove moisture from the sample
  • > Gas analysers
  • > Data acquisition software where gas concentrations are measured, recorded, and stored as data. The data is used to generate reports, alarms or control a process


Which Sites Require CEMS?

The requirement for CEMS depends on various factors; the industry regulations, the size of the plant, which components are being measured and what is required by the environmental permit.

Generally, sites with a combined rated thermal input of greater than 50MW and waste incineration plants require Continuous Emissions Monitoring Systems.

The Environment Agency operates the MCERTS scheme which sets standards obliging sites to use the Best Available Techniques (BAT). BAT highlights the types of CEM needed (in-situ or extractive) and monitoring technique (sensor technology) depending on the gases you need to measure.


Selecting a Suitable CEM System

To ensure that your CEMS provides a good return on investment, it pays to understand which factors maximise system efficiency. CEMS is the result of careful planning, understanding the relative legislation and permit requirements, system positioning, ongoing maintenance, redundancy systems, and cost control. Working with a supplier that has the expertise and experience to help you procure the right system first time and manage ongoing costs is key to this outcome.


Legislation, Approvals & Permit Requirements

In the UK, where continuous monitoring is required, the EA require the Continuous Emissions Monitoring Systems and data acquisition software to be MCERTS accredited for the parameters specified in the permit, and it must comply with EN14181.

In general, the lower the certified range, the better the performance of the CEM is likely to be. This is because the majority of performance standards are expressed as a percentage of the certified range.

With talk of the BREF regulations tightening the emissions monitoring limits, it pays to understand what you need to do and how you need to be doing it. The Environment Agency’s approach to selecting suitable CEMS is to apply range multipliers. The lowest certified range is not to be more than 1.5x the daily average (DA) ELV for waste incineration processes as specified under Chapter IV of the Industrial Emissions Directive (IED) and 2.5x the DA-ELV for large combustion-plant (as specified under Chapter III of the IED) and other types of process.

As there is a linear relationship between certified ranges and uncertainties, these multipliers provide assurance that CEMS with appropriate ranges will meet the uncertainty requirements specified in the incineration and large combustion plant Directives.


System Redundancy

Under the IED, the maximum period allowed for any one episode of abatement or equipment failure must not exceed four hours.

The a1-cbiss duplex philosophy has therefore been specifically developed to assist you in complying with IED by reducing downtime, maximising availability and ensuring you achieve a sound return on your investment.


Maintenance & Calibration

The procurement team should also pay close attention to the potential service costs. Continuous Emissions Monitoring Systems require ongoing maintenance on a regular basis because the process conditions that they're subject to. Problems are less likely to arise is the CEMS have a regular service plan. All customers of a1-cbiss are supported by the UK's largest service network which offers around the clock reliability and performance.

a1-cbiss assemble CEM Systems with top-quality components from reputable brands with the best reliability and lowest maintenance cost.


Supplier Support

a1-cbiss work with you on your journey to compliance and process efficiency. Our strengths enable us to consult with you to design and integrate a monitoring system that not only achieves regulatory compliance but allows you to operate the process efficiently to reduce wastage, control costs and reduce emissions.

Our scope of supply is not simply offering CEMS at lowest price but, rather, a partnership to assist the site operator throughout the system’s lifecycle.


Contact a1-cbiss for support with procuring your CEM System