The focus on alternative and more sustainable methods of power generation is getting stronger every year.

In recent years, electric cars have become a reality and wind turbines are a common, if not universally welcomed, sight across the UK and Europe.

Burning wood for heat and energy is not anything new but the subject is certainly not without its controversies within the timber sector.

The large-scale burning of wood by power companies has brought them into conflict with wood-based panel manufacturers, as the former’s financial buying clout upsets the market for low grade forest thinnings and waste wood, bringing them into competition with the wood-based panel manufacturing industry’s own feedstock purchasing.

Indeed, biomass (whether timber, crop or food waste) now provides 11% of the UK’s electricity, according to the Renewable Energy Association, which says this is equivalent to the output of four Sizewell B Nuclear power stations and takes the equivalent of 1.3 million cars off the road every year.

Earlier this year the then environment secretary Michael Gove visited Norbord’s Cowie plant and heard about the potential for a ‘dramatic’ reduction in the availability of waste and virgin wood due to increasing demand for the material to be used as a fuel in biomass.

Data from the Wood Recyclers Association shows the level of processed waste wood in the UK going into the biomass sector rose 24% to 2.1 million tonnes in 2018. Biomass also now accounts for more than 56% of the processed waste wood market usage, up from 46% in 2017. There is also less waste wood overall, with total volumes falling by 500,000 tonnes last year to 4.5 million tonnes.

We are on safer ground when focusing on timber product manufacturers using their own wood waste more efficiently and to reduce their costs. In fact, it is becoming a top priority for a lot of producers in the timber trade.

Developments in biomass boiler and monitoring technology are making the process as efficient as ever for wood-based manufacturers.

JELD-WEN Biomass Boiler Investment

When you have as much wood waste as leading UK joinery product manufacturer JELD-WEN, lowering emissions and reducing waste costs is very high on the agenda.

The company has five facilities in the UK, with its Penrith site in Cumbria producing a massive 35,000 doors every week.

With such intensive manufacturing, JELD-WEN quickly identified biomass as an ideal technology to power its manufacturing facilities and heat the plant, as well as use a more sustainable fuel source and significantly lower its carbon footprint.

Together with Nifes Consulting and Rural Energy it created a holistic solution that included two 990kW Austrian-made Herz industrial biomass steam boilers.

A brand-new steel framed plant room was built to house the new boilers, plus a new two-storey office complex, two new flues and a new fuel delivery system, with fuel stored in an external silo, adjacent to the factory.

The large steam boilers were customised to include a specially designed moving grate combustion chamber, modified to suit dusty fuel. With a continuous self-replenishing fuel source, a large shredder was also installed at the factory to enable the reject wood and timber waste product to be chopped up and transported to the main silos for storage.

As principle contractor, Rural Energy was also responsible for keeping the site operational – carefully managing the removal of the old wood boiler and switch over to the new Herz boilers whilst keeping the process steam operating.

In collaboration with Nifes and JELD-WEN, Rural Energy designed a system that would meet new emissions standards and suit the manufacturing plant.

The project was completed in October. It is also expected to help the company cut its running costs as well as receive an additional income from the Renewable Heat Incentive (RHI) scheme.

Emissions Monitoring

“The installation of the new biomass system was an important investment for us, and we are pleased to receive support from the government’s RHI scheme, which provides financial payback for the use of renewable fuels such as biomass boilers, air and ground source heat pump and solar thermal,” said Hamish White, plant manager from JELDWEN in Penrith.

Mr White explained that AMETEK Land flue gas and dust analysers and monitors complete the system by ensuring continuous emissions monitoring.

As the production site is governed by local authority legislation, the company is required to monitor and control the emissions from its boiler.

An AMETEK Land FGA 930 flue gas emissions analyser and a dust monitor had previously been installed on the company’s old boiler.

AMETEK Land distributor Focal-Point Technology supplied and installed an FGA 930 flue gas analyser and a 4400 opacity and dust monitor on each of the two new stacks. The data acquisition system was provided by EMACCS.

The FGA is designed to measure carbon monoxide, nitric oxide and oxygen in flue gases. It is an integrated solution for Continuous Emissions Monitoring Systems (CEMS) applications in smaller combustion processes. It allows them to benefit from better process control, which lowers fuel costs and keeps emissions within compliance levels.

A pair of sensors is used to analyse each of the species in the sampled flue gas, alternating every 30 minutes, which extends sensor lifetime and ensures a stable baseline, delivering high sensitivity and low drift.

The two new 4400 dust and opacity monitors are a cost-effective solution for the continuous monitoring of dust, smoke and particulates in industrial applications. The 4400 has a lightweight design which made installation and positioning simple at the JELD-WEN plant.

The 4400 is a cross-duct design with a transceiver mounted on one side and a passive retro-reflector mounted on the other side of the stack. It uses AMETEK Land’s patented three-LED light source to effectively monitor the dust emissions. An air purge protects the delicate optical components from the hot, dirty process conditions.

All the signals from the analysers are fed into an EMACCS Continuous Emission Monitoring Data Acquisition System (CEM-DAS) to allow consistent and accurate monitoring.

The AMETEK Land instruments monitor compliance to Process Guidance Note 1/12(13) for combustion of waste wood. This gives guidance on the conditions appropriate for the control of emissions into the air from the combustion of fuel manufactured from, or comprised of, waste wood in appliances.

“This was a challenging project which required a robust and highly effective solution,” said Graham Clark of Focal Point Technology.

“The combination of FGAs and 4400 from AMETEK Land will provide peace of mind that JELD-WEN is complying with legislation and their emissions are being minimised. This equipment is suitable for use in many different industrial processes and is rapidly growing for use in biomass, waste wood combustion, and Small Waste Incineration Plant (SWIP) applications.”

This new system will help JELD-WEN to improve its sustainability credentials, reducing both its particulate emissions, wood waste levels and carbon footprint.

In addition, the company will benefit from lower energy and waste disposal costs as well as additional income from the Renewable Heat Incentive scheme.