The Biochar Fund is developing highly efficient, village-scale pyrolysis plants that are optimised for biochar, heat and electricity generation ("Combined heat, power and char" - CHPC). These small plants allow for flexible production choices, which is why they are called Flexi-Pyrolysis plants.

Based on slow pyrolysis and gasification, the highly efficient units represent a major efficiency leap compared with traditional cooking and heating methods. From a same amount of feedstock, the power plants generate more char than can be obtained with traditional methods, while simultaneously yielding more useful heat than is available with inefficient open fires or charcoal use. Added to this is electricity, a valuable form of energy that can dramatically transform life in villages. 

Pyrolysis is a thermochemical process in which biomass is heated in the absence of oxygen. During pyrolysis, which takes place at temperatures in the range of 400-800°C, most of the cellulose and hemicellulose and part of the lignin will disintegrate to form smaller and lighter molecules which are gases at the pyrolysis temperature. Depending on the residence time and the temperature, three main products result from pyrolysis in varying ratios: synthesis gas, tars and high-carbon char.

The syngas gas be utilized for the production of reliable, cost-effective and renewable electricity, whereas the biochar is added to acidic and nutrient-poor problem soils.

The Biochar Fund's research is focused on developing units that maximize high-quality char, which is possible by designing high pressure systems that improve char yields. The yield and composition of the charcoal also depends on the pyrolysis temperature. A low temperature gives a higher yield but results in a charcoal with a higher content of volatiles. The fund is researching the optimum pyrolysis temperature for biochar to be used in soils.

Added to this, the Biochar Fund understands that there is a need for optimised pyrolysis plants that allow rural communities to generate electricity and biochar fractions in a flexible and easy way. This flexibility guarantees the capability of farmers to adapt their pyrolysis choices to prevailing market conditions: depending on carbon prices, they can decide to turn more of the biomass into biochar for sequestration into soils by increasing its production, without being forced to produce more electricity than needed. This flexibility thus enhances the overall efficiency of the system and allows for optimal production planning.

The Biochar Fund's Flexi-Pyrolysis plants have a micro-scale (<25kW) capacity and are adapted to village conditions (small electricity demand, biomass capacity, ease of use, servicing).