Recarbonize the world
Exploring Biochar for carbon sequestration

Log Burners, their future?

The UK government has decided to crack down on open fires in the home and log burners. As from February 2021 it will be illegal to burn ordinary coal or non kiln dried wood on an open fire or enclosed log burning stove in your home. The reason for this is the burning of coal and ‘wet’ logs causes a large emission of particulates – smoke, in layman’s terms. While there are many arguments for and against this ban, it is undeniable that the level of particulates in the air of cities is far above internationally recognised safe levels. Indeed, even in the countryside it can get unpleasantly high when people illegally burn rubbish at night and an inversion layer traps the pollution near the ground.

While coal production in this country is all but finished, there remains the question as to what will happen to the woodlands and log merchants? In rural areas, the use of wood as a fuel is often the difference between a properly heated house and fuel poverty.

The cost of buying and running an industrial kiln drier is likely to be beyond the reach of many suppliers of cord wood.

What are the options for the various parties?

The end user;

  • Buy certified kiln dried wood
  • Buy certified smokeless coal products
  • Find an alternative heat source

The producers of logs;

  • Buy kiln drying equipment and pass the cost onto the customer
  • Work out a way of reducing water levels to achieve certification without a commercial kiln
  • Find an alternative market for the timber

Let us look at the end user first. In places like London, the growth in use of log burners is not driven by economic necessity, rather, it is a rich person’s demonstration of wealth. They can afford to have logs sent in from Essex or other nearby rural counties. In this case, certified kiln dried wood is a necessary and affordable restriction.
In rural Suffolk, while there are quite a lot of rich people with log burners, there are poorer houses where locally produced logs are a fuel lifeline. Their only real alternatives are electric or oil heating, neither of which are cheap. Many people in cities don’t realise that the price of electricity in some rural areas is higher, as is the delivery of oil. Mains gas supply is often non-existent and the use of propane is not cheap either.

Now what about the producers?
An example is the coppicing that takes place at Bradfield Woods, a Suffolk nature reserve. These woods have been coppiced for over 900 years and the main driver today is to maintain biodiversity. However, one of the ways that this vital work is financed is through the sale of logs, mostly Ash. Kiln drying using a commercial kiln dryer would push the price of logs up beyond the reach of many customers.
This is just a suggestion, a ‘straw man’ if you like;
Assuming the certification of firewood logs will be done by testing the moisture content of the logs.
At present the felled green timber is carted to the splitting yard, the logs are cut and split and then stored in an open sided barn to dry naturally.
How about getting a pyrolysing retort with a heat exchanger on the gas recirculation pipe or even the chimney. Link the heat exchanger to distribution pipes laid on the floor of the barn and buried in concrete. Making charcoal/biochar from Ash and Hazel would heat the floor of the barn where the split logs are stored. The temperature of the drying floor is not as critical as if it was kiln drying millable lumber, the logs just needs to be dried. The biochar can either be sold as fuel or used as a soil amendment around the coppiced Ash stools. The use of biochar soil amendments has been shown to reduce the impact of the disease Ash Die-back.
Building the drying floor and the retort will have a cost. There will be an added process of running the retort and dealing with its output. However, the price of high quality Ash lump-wood charcoal could pay for the extra processing. As coppicing is only done in the winter months, the people involved will probably be quite happy firing up the retort to make charcoal and dry the split logs.

The outcome of this would be that Suffolk Wildlife Trust can go on selling firewood because it can be certified as dry. The price of the dried logs has been kept as low as is practical. Some of the Ash logs become superior lump-wood barbecue charcoal and the smaller bits can become biochar for helping save the Ash trees.