Summary
• Heating factories, kilns and offices by biomass makes commercial sense.
• Briquetting can provide revenue.
• The wood pellet market is growing.

Biomass energy for timber companies – be they sawmills, joineries or furniture producers – is not just the environmental choice, it makes commercial sense.

Multiple savings created by eliminating wood waste removal costs and conventional fuel charges, as well as the prospect (for water-heating burners) of earning Renewable Heating Incentive (RHI) payments from the government provide a compelling case.

Landfill tax alone is now £64 per tonne and that doesn’t include waste transport.

Mawera UK has been supplying its Austrian-made biomass boilers for 30 years. It’s known for some big installations such as at sawmiller James Jones & Sons and kitchen furniture manufacturer Symphony Group.

A 3.3MW Mawera FSR3300 plant at James Jones’s Aboyne mill runs 24/7, 52 weeks of the year on wet wood chips, bark, sawdust and other sawmill residues, in order to heat kilns.

Fuel storage accommodates 380m³, with feedstock tolerances allowing for chip sizes up to 350mm long and a maximum moisture content of 60%.

Range of benefits

“It has been a steep learning curve, particularly in terms of managing the fibre moisture levels,” said Aboyne site manager Francis Wilbur. “But the benefits to the Aboyne site and to the group as a whole have been huge. Not only has it substituted our fuel oil use, it has also helped our sawn timber life cycle assessment calculations, thereby benefiting our customers and end users.”

Northampton-based Ranheat Engineering Ltd’s recent installations include large 980kW projects for a pallet manufacturer and a coffin maker, while a 300kW boiler for Westbury Joinery is now yielding RHI payments.

Ranheat has been increasing the efficiency of its boilers with thermal economisers, achieving lower flue temperatures and reducing emissions, while its warm air biomass heaters are now eligible for Enhanced Capital Allowance.

Ranheat director Chris Franklin said the government’s recent acceptance of oxygen trim in lieu of continuous monitoring of emissions was a welcome step. The equipment controls the oxygen content automatically and helps keep the boiler running at peak efficiency.

Meanwhile, new government emissions guidance in Policy Guidance Note 1/12 reduces the emissions regulation threshold for new biomass boiler installations to 400kW – within the scope of many medium-sized woodworking companies. Emissions limits are also expected to form part of the RHI, as soon as October.

Refurbished boilers

Fercell Engineering Ltd says the refurbished boiler market is also lively and gives companies a more cost-effective option. It dismantles old boilers, shot blasts them, and then rebuilds and resprays, replacing any deficient parts, before testing and certification.

Fercell’s Aylesford factory also supplies new biomass heaters up to 4MW, as well as being the base for Weima UK’s shredding and briquetting technology, where customers can test their waste first. The Weima Ultra Shredder is the latest machine to be launched.

Warm air biomass heater manufacturer Wood Waste Technology last year added shredding and briquetting technology to its portfolio by becoming the UK distributor for Gross.

Briquetting machines compress wood shavings and dust into a cylindrical form, making the waste easier to handle and ideal as fuel due to its high calorific value. Businesses use briquettes in their own biomass heaters or sell them to generate additional revenue.

“In today’s manufacturing environment, every penny counts and there’s increased emphasis on environmental impact,” said Kurt Cockcroft, managing director of Wood Waste Technology. “By investing in shredding and briquetting technology, wood waste stops being a cost and starts becoming an asset with value.”

JJ Smith & Co (Woodworking Machinery) has added a wood waste area to its showroom, showcasing Höcker Polytechnik briquetting and Untha shredding technology. It works with burner providers to supply a turnkey solution.

Moisture content

Choosing the right boiler for the specific wood fuel and moisture content is an important consideration, said George Fletcher, Viessmann UK technical sales manager (wood boilers).

“The furniture manufacturing trade uses considerably more MDF than it used to,” he said, adding that some boilers were not suitable if panel products were the main wood waste.

Viessmann supplies Mawera and KOB brands and Mr Fletcher advises a spend of £500-700 per kW boiler rating, so about £50,000-70,000 for a 100kW project.

Viessmann, like many other biomass technology suppliers, is Austrian.

“This has been driven by necessity as Austria has no other natural energy resources other than wood,” said Mr Fletcher. “Wood pellet tankers are a more common sight on the road than petrol tankers.”

The UK is not at that stage but he predicted dramatic growth in demand. And with pellet fuel efficiency of 3,300kWh per m³ compared to 800kWh per m³ for woodchip you can see why.

Sawmiller Balcas Timber Ltd is now the UK’s largest producer and supplier of wood pellets, producing 150,000 tonnes of Brites annually from its Enniskillen and Invergordon plants.

Brites are accredited under ENplus – a European standard for premium quality wood pellets – and are sold and delivered to homes and businesses throughout the UK and Ireland. The Enniskillen combined heat and power plant provides power to manufacture Brites and helps saves Balcas more than £1m a year in electricity costs.

Paula Keelagher, Brites market development manager, Ireland, believes the wood pellet market will continue to expand.