Energy From Waste

Energy from Waste (EfW) facilities are seen as the most beneficial option for dealing with the UK’s waste problem (due to the extensive growth in population and subsequent waste generation). Not only does energy recovery provide a purpose for the once valueless waste sent to landfills, but it also provides a dependable source of renewable energy.

Due to the harmful gases that waste incineration produces, these plants are governed by strict environmental regulations. All waste burning plants, including small waste incineration plants, must meet the stringent emissions limit set by the Industrial Emissions Directive (2010/75/EU) 

Waste Delivery & Storage

Refuse trucks dump the waste at the waste tip bunker and it is stored until the grabber crane moves the waste into the furnace. There are many different types of waste materials accumulating which poses several dangers. 

In biomass sites, this area is also used to store the wood pellets used to fuel the incinerator. Wood dust is one of the major causes of fires within the biomass industry. 

Hazardous Gas Safety

Within the waste delivery and storage areas, fixed gas detectors are installed to continuously monitor the risk of oxygen depletion, Carbon Monoxide (CO) and combustible gases.

Throughout the gasification process, whilst patrolling the site, EC&I technicians should always wear personal single CO monitors to continuously detect the threat of the silent killer.

Mitigate Fire Risk

Friction sparks can cause fires or explosions.

Wood dust in wood chip and wood pellet biomass storage is prone to self-heating and explosion. We would highly recommend the installation of flame detection.

Breathe Safely

During the transport of powders and wood chips, fine particles become airborne. Respirators are worn by workers in the prevention of inhaling dangerous substances which protects the respiratory tract.

For short-term use, a half-face mask is suitable. For protection over the course of several hours, a powered air respirator should be worn.

Feed Chute

Waste recycling in incineration plants starts with the delivery and incineration of waste. The waste reaches the combustion chamber via a falling chute, which is followed by a hydraulic feed device.

Point Level Detection

The “high“ and “low“ limit values should be detected and alarmed. The plant operator looks for a device that measures the point level to control the filling level.

Limit Level Monitoring

To optimise the process, a limit level monitor measures limit levels in a falling chute.

The detection of the limit levels guarantees a constant filling of the combustion grate and thereby a continuous firing.

Material Flow Measurement

In most combustion type processes with high-temperature conditions, Nitrogen Oxides (NOx) are produced and are highly dangerous when emitted to the atmosphere. 

Sites will need to evaluate their SCR or SNCR methods to effectively regulate NOx emissions by injecting either an ammonia (NH3), coke or lime reagent directly into the process.

These reagent materials are stored in silos. Via a rotary valve, they are blown into a conveying air flow to clean the exhaust gas stream.

Prevent Material Flow Blockages

At the cyclone outlet, the flow monitors signal the status of flow or no flow. A non-existent material flow after the valve indicates a blockage in the cyclone or silo.

Using our preventative flow detection monitors, it is now possible to quickly detect a blockage issue before it happens to avoid unwanted downtime and expensive maintenance.

Reagent Flow Measurement

Reagent flow monitors are perfectly suited for incineration plants where they can be used to regulate the desired volume of reagent by a screw conveyor or rotary valve in flue gas treatment in a bid to control costs. 

Storage Silos

Reagents for the flue gas cleaning such as hydrated lime or activated carbon are stored in silos. These bulk chemicals are delivered to the process by feeding into a pneumatic blow line. 

Extreme dust generation and material build-up are the main challenges.

Prevent Overflowing

In many bulk material processes; storage silos, pipelines, ducts or free-fall sections, limit levels inside a storage tank need to be monitored to prevent overflowing using continuous level measurement.

Reliable Limit Levels

For optimum process control, reliable level measurement is essential to ensure that adequate quantities of reagent are stored correctly.

An advanced and reliable contactless level sensor complies with the requirements in this application.

Process Control

Raw Gas Measurement

When waste is incinerated, high volumes of pollutants are released which threaten the environment. Control of stack emissions is no longer enough to ensure compliance with regulatory ELVs.

Raw gas measurement optimises the process by recording the level of pollutants in the gas stream to better control abatement.

During abatement, Ammonia (for NOx) and lime reagent (for HCl) is injected into the scrubber to control emissions. Activated carbon is also injected to adsorb total organic carbons and heavy metals.

With known quantities, raw gas analysers can help control how much absorbent is needed to neutralise raw gas concentrations.

NOx Abatement

To achieve compliance with NOx emission limits, the optimisation of two processes are important for the removal of nitrogen from flue-gases – selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR). In both systems, the flow rate and control of an ammonia (NH3) based urea reagent must be continuously adjusted in line with raw gas measurement analysis.

To optimise this process, it is essential to use an analysis system for simultaneous and continuous monitoring of NH3. The Cross Stack TDL sensor offers real time monitoring and minimal maintenance requirements.

Combustion Optimisation

Continuous monitoring of the flue gases on a boiler or burner makes economical sense

 

  • Poor combustion can produce corrosive CO compounds on the boiler wall and ash deposits in the boiler.
  • Continuously measuring O2 and CO allows for immediate adjustment of the air injection and better control of feeders, which optimises the efficiency of the combustion process and cuts energy costs.

Dust Measurement

Baghouse Performance Monitoring

Multi-chamber bag filters are becoming increasingly common to effectively contain and measure particulates. The baghouse is equipped with hundreds of filter bags.

Predictive Bag Filter Row Monitoring

Over time, filter bags will burst, and it is important to identify and replace the defective bag as quickly as possible. A dust leak locate filter is a valuable filter-maintenance tool giving advance warning of filter deterioration before catastrophic failure enabling users to make significant savings in spares, maintenance time and lost production time.

Broken Bag Leak Filter

The dust leak alert filter is particularly suited for use on fabric filter baghouses. It provides reliable and robust monitoring of particulate dust levels and leaks from faulty bag media where performance approvals are not required.

Broken Bag Detection Failure

A basic dust filter detects significant increases in particulate loading providing advanced warnings of filter media degradation in baghouses. The dust filter can achieve both cost savings in terms of reduced baghouse maintenance and lost production and in addition achieve reductions in emissions to atmosphere.

Ash Control

 

Managing Ash Residue with Moisture Measurement

The installation of continuous online moisture measurement has multiple benefits for Energy from Waste plants.

There are savings in transportation of ash due to weight of excess moisture, to savings in water usage for dust suppression.

EFW plants also use moisture measurement to reduce the risk of dust and ash build up which prevents blockages on the conveyor, which would otherwise result in shutting down the boiler.

Ash Level Detection

The dust particles which pass through the baghouse filter are collected on the surface of the bag filter. As the fly ash is shaken off, it falls into the collection hopper. To determine whether the hopper is full, point level measurements are taken.

Flow Detection at Ash Transportation

Ash transportation in most cases is done by air slide systems. It is essential to ensure material flow inside the transportation system. Any plugging or interruption in the material flow must be avoided.

A flow monitor will detect the flow of ash to define a Flow or NoFlow condition. 

Flue Gas Emissions

Continuous Emission Monitoring Systems (CEMS) consist of gas and particulate analysers, temperature, flow, and opacity monitors that are integrated with a data acquisition system to ensure full environmental regulatory compliance of the Industrial Emissions Directive (2010/75/EU).

Gas Emissions Monitoring

The Heated Fourier Transform IR technology is designed for measurements of hot, wet, and soluble sample gases. It is the most popular MCERTS certified CEM with the capabilities of continuously measuring up to 14 gases including Ammonia.

Whereas for measuring corrosive samples on a dry basis measurement, the IR Gas Filter Correlation based technology monitoring system measures up to 10 gases simultaneously. 

Particulate Emissions Monitoring

Particulate measurement systems are generally used to monitor dust emissions to the atmosphere. They can also be deployed as valuable baghouse filter condition monitoring and preventative maintenance planning systems.

This facilitates both the extension of service life for bag filter elements, and a significant reduction in reactive maintenance downtime.

Flue Gas Velocity & Flow Monitoring

Our accredited flue gas monitors facilitate stack gas velocity, volumetric flow, temperature, and pressure within the flue when linked to gas and dust CEMS.  

They are designed to work in high temperatures and applications with high dust loadings. 

Case Study - IR Sensors Overcome Silicone Dust Problem at Waste Facility

Discover how an a1-cbiss site survey revealed the inadequate use of pellistor sensors at a waste facility following the issues with their hydrocarbon gas readings.

News - New Calibration Requirements Set by the EA

The EA are keen to improve the accuracy of CO2 data and other pollutants reported under the Pollution Inventory and therefore are asking all EfW plant operators to calibrate their CO2 and N2O CEMS and flow meters by 2023. Find out exactly what the EA are asking for, and how to make sure you're still compliant.

Talk with the Experts

Contact us - Our application specialists will identify the best product for your needs based on the information that you can provide. If you're unsure about what's important, consider booking a site survey.

Book a site survey - Our specialists consider your process, your site conditions and work with you to understand your needs. It is the most effective means of ensuring your system is completely fit for purpose.