Woody Biomass


Climate change resulting from the use of fossil fuels and the reduction of fossil fuel reserves in the world, set new challenges in the field of utilization of renewable sources of energy, where forest resources and biomass resources in general are one of the main sources for renewable energy. The increasing utilization of forest reserves in order to obtain clean energy has the effect that these resources are not renewed in accordance with the degree of exploitation.

Clarendon team is acknowledging this and has developed a plan of action providing a resource for the production of high-quality energy pellets and production of electricity from renewable energy sources without disturbing the natural balance.



The development of industrial plantations of woody biomass yields in full resources necessary for the pellet plant production. Unused portion of the woody biomass (plantation waste) in the pellets production process is used for biomass gasification process for production of electricity.
As the most suitable crop selected is the fast-growing “Paulownia Shan Tong” tree. This type of wood has significant ecological importance and calorific value of dry wood equal to brown coal.

Resources for the production of pellets is obtained after five years of growth (initial period is 7 years of growth) when the entire trees are cut and used, followed by growth of new trees from the roots. Number of growth cycles is between 5 and 7, continuously yielding woody resource for almost 40 years.

One of the main processes for the production of electricity and heat from renewable sources is the gasification of wood biomass.


The gasifier is a thermal reactor which thermally cracks the biomass into a gaseous state by the application of intense heat in a controlled oxygen starved atmosphere. The biomass is fed at the top of the reactor and moves downwards towards the grate by gravity. During this motion, it passes through the “drying”, “pyrolysis”, “controlled combustion” and “reduction” zones in that order.

A very important factor for the application of biomass gasification process is the existence of cheap resources. Industrial plantation biomass provides up to 30% residues that are not suitable in the production of pellets ENplus class A1. This wood waste from plantation and waste from the preparation of biomass for the production of pellets is a resource that is fully used in the gasification process and the production of electricity and thermal energy.


Today, wood pellets are probably the largest traded solid biomass commodity used specifically for energy purposes and in terms of traded volume can be compared to bio-diesel or bio-ethanol. Wood pellets have relatively favorable conditions for transportation: low moisture content and relatively high energy density (about 17-17.6 GJLHV/ton). While handling of wood pellets still requires great care, the advantages over other solid biomass types such as wood chips or agricultural residues are their store-ability, relatively easy handling and typically lower transport costs for distances larger than 50 to 100 km compared to other solid biomass types such as wood chips.

The importance of wood pellets for small and medium scale heat production and large scale power generation is continuously increasing across Europe. Pellet use can contribute substantially to renewable heat and electricity targets set by the EU Renewable Energy Directive.

Besides the established national pellet markets (e.g. Sweden, Austria), which are still growing strongly, additional pellet markets are emerging across Europe. This diversity regarding market development stages is accompanied by the development of heterogeneous demand and trade structures.

In countries such as Germany, Austria and Italy, wood pellets are exclusively used in heat production for the residential sector while the industrial use for power generation prevails in the United Kingdom, the Netherlands and Belgium.

Clarendon is focused and determined in production of the highest quality pellets, known as ENplus-A1 pellets. The ENPlus quality certification is a major step towards establishing pellets as a widely used energy commodity. This system, based on the EN 14961-2 standard, is managed by the European Pellet Council (EPC) from January 2011. Today, EPC enjoys the support of large parts of the European and even World pellet sector. 103 producers and 134 traders are ENPlus certified amounting to a total of more than 4 million tons of ENPlus certified pellets.

The ENPlus certification program covers three pellet quality classes with different demands on the used raw material as well as the wood pellet characteristics. They correspond to classes of the EN 1491-2.