CANAPE: First Broads Charcoal Manufactured

16 April 2019 - Published by Harry Mach
After much anticipation, the Biochar Burner has arrived in the Broads for the first production of charcoal. As an initial test, the team converted waste willow and alder form wet woodland coppicing into approximately 150kg of charcoal over two days.

The testing also provided an opportunity to train interested parties so they can borrow the retort and produce their own charcoal for sale. Eight organisations, including the RSPB and local contractors who work for conservation organisations, now have trained operators. They will be able to borrow the retort for tests on their own sites, under agreement.

Our Biochar Burner is an Exeter Retort. It can be moved from site to site, as it is small enough to be mounted on a trailer. CANAPE will use the machine to test the possibility of marketing wet woodland charcoal from a variety of sites in the Broads and surrounding areas.  The product is being marketed via a wholesaler and through direct sales as a local, sustainable and high quality pure product with no additives.

Partners will build up a stock with the first trials with consumers beginning in June. We expect to be able to produce approximately 100kg per burn fully loaded.

The production of biochar from wetland reed will also be tested. When added to soil the biochar benefit sandy or drought-prone soils or heavy clay or waterlogged soils. It works to store fertiliser and water.

How this works

The retort consists of two cylindrical chambers, one inside the other. Wood is loaded into the inner chamber, which is then sealed. A fire lit at the bottom of the outer chamber then heats the sealed chamber.

 Retort with inner chamber loaded with wood

Above - retort loaded with wood ready to be converted to Charcoal

The heat causes the wood to release moisture as steam. Once it is completely dry, the pyrolysis process will begin. Pyrolysis is the conversion of wood (or other organic material) to charcoal, by heating it in an oxygen free atmosphere.

As the wood pyrolysises, it releases syngas, which is directed back to the fire beneath the chamber. There it ignites, and provides heat for the completion of the process. Once all the wood has converted to charcoal, the release of syngas stops. At this point, the machine is shut down. Once it has cooled, the charcoal is unloaded.

It may seem counterintuitive that by burning wood and gas we are combating climate change. However, the project is low-carbon as;

  1. For conservation purposes these trees will be removed anyway
  2. As these are sites managed for conservation, there is no overall loss of carbon storage or tree cover from removing them
  3. The carbon is wood is “biogenic,” meaning it has been recently removed from the atmosphere by the growth of plants. This contrasts with fossil carbon such as coal, which has been locked away from the atmosphere for millions of years.

The charcoal we sell is also displacing charcoal that is imported from distant countries (such as Indonesia and Nigeria) , and often produced from tropical woods that are not always sustainably managed. It is also often produced in environmentally damaging kilns that are not capable for reusing greenhouse gases produced by the process, so are polluting the air.  Whereas our retort uses the syngas produced to provide heat for the pryrolysis.

Charcoal ready to be unloaded from the burner

Charcoal Ready to be unloaded from the burner.