Welcome to the LaSalle BioEnergy immersive experience.
Understand how compressed wood pellets are manufactured using
sustainably sourced forest biomass.
The wood products industry produces large quantities of residual materials. Drax is making use of this and forming part of a virtuous cycle that benefits the forestry sector, rural communities and the environment.
Even the most technologically-advanced sawmills can only use around 60% of a log to create high-quality timber.
The ‘waste’ products from timber production such as bark, shavings, sawdust and wood chips can’t be used to create lumber, but they aren’t worthless. In fact, these residuals have long been used to make paper, cardboard or fiber-board.
With pulp and paper markets declining, wood pellet manufacturers can use the same residuals.
Use of mill residuals and dry shavings reduces the energy required to make a pellet, as such material does not need to be de-barked, chipped and re-sized in the same way as roundwood.
Some of the material has a low moisture content and is therefore able to enter the process after the dryer, which effectively increases the capacity of each plant.
This drives down the average GHG emission per tonne of pellets produced and also the cost per kilowatt-hour (KWh) of electricity per tonne of pellets used in power generation.
The 'tipper' or 'truck dump' unloads cargoes of bark, wood chips and sawmill residues in just two minutes.
The tipper can lift up to 60 tonnes and unload four or five trucks an hour, predominantly coming from the sawmill co-located with the pellet plant.
More info on the 'tipper' or 'truck dump': https://www.drax.com/technology/this-is-how-you-unload-a-wood-chip-truck/
The debarked logs must be chipped into small, uniformly-sized pieces before they can used to create pellets.
A wood chipper at the end of the drum debarker uses multiple spinning blades to cut the logs into chips roughly 10mm long and 3mm thick.
The chips are then delivered on a conveyor belt to the woodchip pile, where they await the next step in the manufacturing process.
A crane takes the roundwood and thinnings either directly from a log truck or from the woodyard.
Wood is fed into a rotating drum debarker.
This machine tumbles the logs against one another to dislodge the bark.
A conveyor belt redirects the bark to a storage area for use as a fuel for the dryer while the debarked logs are readied for chipping.
Pellet manufacturing costs are set to come down as we plan to reduce the amount of debarking and increase the amount of bark -- or 'hog fuel' as it is known -- to make pellets.
Our biomass is sourced from established, responsibly managed working forests where more carbon is absorbed than removed.
Working forests in the US South are not threatened by deforestation.
Annual wood growth increased by 112% between 1953 and 2015, and inventory increased by 108%.
Data about our biomass supply chain: http://forestscope.info/
Responsible Sourcing: A policy for biomass from sustainable forests: https://www.drax.com/sustainability/responsible-sourcing/
The crane places low grade roundwood and thinnings in the woodyard, where it is staged for processing.
Working forests are commonly managed to produced sawlogs – high value wood that can be sawn to make timber for construction or furniture.
For a forester to optimise the quality and quantity of sawlogs, regular thinning is required. Thinning is the process of periodically felling a proportion of the forest to aid its overall health and vigour.
This means there are fewer trees fighting for the same resources (water, sunshine, soil). More than that, thinning can promote diversity by providing more light and space for other flora.
As well as thinnings, we use low grade roundwood which includes small trees, tree tops or misshapen trees not suitable for use in a sawmill.
Once de-barked, the bark or 'hog fuel' is used as a renewable fuel for our furnaces that heat the dryer, used later in the process. This ensures that no part of the tree is wasted during the process.
In the future we'll use more 'hog fuel' as a pellet feedstock, presenting a cost saving.
Wood chips sometimes include unwanted material like sand, metal or stones.
To remove this waste, the chips pass through a screener to ensure only properly-sized chips reach the dryer.
In our US supply chain, 1,060,480 tonnes of pellets were made from sawmill residues - approximately one pellet out of every four.
Pellet and hammermill upgrades planned at our three US plants will enable greater utilisation of low-cost sawmill residues and dry shavings.
In our Canadian supply chain, 80% of pellets are made from residues.
Wood chips are screened for quality. The wood chips sometimes include unwanted material like sand, bark or stones. To remove this waste, the chips pass through a screener to ensure only properly-sized chips reach the dryer.
The dried wood is fed into a series of hammer mills, these contain spinning shafts mounted with hammers. The hammer mills shred the chips into a fine fibre, the last step before pelletising.
The chips and sawmill residues enter an industrial dryer, where they are exposed to a stream of super-heated air produced by burning the bark or 'hog fuel' from the drum debarker.
The dryer reduces the moisture level in the wood chips from 50% down to roughly 12% – a critical step in ensuring the quality and energy content of the finished pellets.
LaSalle BioEnergy is regularly cleaned to prevent a buildup of wood dust this assists plant safety and efficiency.
The dried and hammered wood fibre is fed into the pellet mill.
A rotating arm forces the material through metal dies.
These dies contain a number of uniform small holes.
The intense pressure heats up the wood fibre and binds it together as it passes through the die.
This process forms the compressed wood pellets.
Corn is used to clean the pelletisation dies.
Regular cleaning helps them to operate more efficiently.
The newly formed compressed wood pellets descend from the dies upstairs.
They are shaken free of any imperfections or wood dust.
Pellets are then transported to large storage silos, where they can cool and harden while awaiting shipment via rail to the Port of Greater Baton Rouge.
Compressed wood pellets have similar properties to coal but their use in power generation leads to over 80% less CO2 including supply chain emissions.
Like coal, pellets are ground into dust using mills at Drax Power Station.
Both the mills and furnaces in North Yorkshire required little conversion.
Our biomass power units operates at a similar efficiency to coal units, if marginally better.
In 2019, we began a three-year turbine upgrade at Drax Power Station.
The high-pressure steam turbine upgrade will enhance efficiency and reduce the cost of electricity production.
The efficiencies will be gained by fitting new, high tech pipework and valves, with new high efficiency blading and long life seals within the turbines on biomass units 1, 2 and 3.
Giving up coal: Tony Juniper questions if using biomass can be the right thing to do for forests and climate change: https://www.drax.com/sustainability/giving-up-coal/
Climate change is the biggest challenge of our time: Drax Group CEO Will Gardiner answers FAQs:
Compressed wood pellets are loaded into closed-top grain wagons rather than open-top coal cars to protect pellets from the elements.
Unlike coal, if pellets get wet, they quickly deteriorate and cannot be used as fuel at Drax Power Station.
The rail wagons are designed to carry 143 US short tons each.
One wagon equates to just under four truckloads of pellets.
Three recent initiatives represent run rate savings of £10/MWh on 450,000 tonnes of wood pellets per year from LaSalle BioEnergy:
1) A new conveyor system, this rail loading bay and rail spur, which became operational in May 2019, reducing transportation costs to the Port of Greater Baton Rouge.
2) A co-location agreement with Hunt Forest Products for low-cost sawmill residues. These are sourced from the now operational sawmill next door.
3) Increased rail capacity at the port.
When Drax began operating in Louisiana with a rail spur at Morehouse BioEnergy, we were limited to 45-car trains.
This is being increased to 80-car ‘unit trains,’ each nearly a mile long and capable of carrying almost double the volume once an enlarged chambering yard is commissioned at the port of Greater Baton Rouge.
Unit trains will deliver major fuel, cost and carbon footprint savings from Morehouse and LaSalle BioEnergy.
Our goal is to make biomass power generation economically viable without direct support by 2027.
Baton Rouge Transit at the Port of Greater Baton Rouge is operated in partnership with Host Terminals.
At peak operation, the facility is capable of loading approximately 40 vessels per year.
All of our US South facilities are strategically placed to reduce shipping times, reduce emissions, and lower costs.