Thermya Information Review

Thermya is a French engineering company specializing in biomass energy recovery. They have developed a biomass torrefaction process whereby non-food biomass such as wood and wood co-products, bark, hemp straw, cereals straw, corn straw, wheat bran, and rice hull are dried out and compacted for future use.

According to Thermya, raw biomass has a high water content, which varies according to its nature. Wood, for example, contains 45 to 60% of water. The presence of water generates many constraints in the biomass valorization chain and affects how well it can be used by motors and ovens. The important physical volume and very low density of raw biomass restricts the productivity of its collection. Due to its physico-chemical nature, raw biomass requires high-pressure compacting operations to be transformed into pellets. From an energy use point of view, raw biomass performs poorly: its combustion in thermal power station boilers demands costly fittings and on-going maintenance.

Torrefaction of biomass brings solutions to the above-mentioned drawbacks; it drastically reduce biomass transformation and utilization costs while considerably improving its energy efficiency. In short, turning raw biomass products into usable fuel. The TORSPYD torrefaction process developed by Thermya consists in heating the biomass through a soft thermal treatment in order to eliminate its water content and break its fibers. The torrefaction process dries up the biomass, makes it irreversibly hydrophobic (water repellent) and concentrates its energy potential into an easily transportable solid fuel. To learn more, visit the official Thermya website at www.thermya.com

At the end of the TORSPYD torrefaction process, the biomass has been converted into BioCoal, a high-quality green fuel. From a logistical point of view, the TORSPYD BioCoal brings many advantages:

• It has retained 90% of the initial biomass mass
• Its moisture content is below 1%
• It has become irreversibly hydrophobic
• It can be stored and transported outside without any degradation risk linked to climate conditions
• It is immune to all biological attacks (rotting, fermentation, etc...)
• It is extremely friable and can therefore be easily crushed or compacted (pelletization).

From an energetical point of view, the TORSPYD BioCoal has many assets:

• BioCoal torrefied by TORSPYD still contains 95% of the initial biomass energy potential
• Mixed with coal, BioCoal can be co-fired in thermal power stations or industrial boilers without any modification of the combustion systems
• BioCoal ignites instantaneously, therefore it boosts coal's combustion, reduces the ash content and improves the boiler's global energy performance.

The TORSPYD torrefaction process is aimed at:

• Electricity producers operating coal-fired power stations - The TORSPYD BioCoal is a very efficient alternative to coal in co-firing or gasification applications. It can be co-fired or substituted to coal in traditional industrial kilns fitted with powder burners, without any modification of the installations.
• Forestry operators - The TORSPYD torrefaction process gives additional value to all forestry residues, including forest resources destructed by xylophagous insects or storms.
• Pellet producers - The TORSPYD torrefaction process considerably increases the value of traditional wood pellets as it drastically reduces production and raw material costs. Torrefaction indeed opens up new supply sources for raw material and eliminates the usual biomass preparation constraints (sawdust is not required).
• Businesses and entities involved in Research and Development of gasification processes - Torrefaction is an optimal and relevant biomass preparation method in view of its gasification.

Illustrated above, the TORSPYD process is a continuous thermal treatment where 2 flows move vertically in opposite directions: the gas flow, which moves from bottom to top, and the biomass flow, which moves from top to bottom. A temperature gradient is constantly maintained in the column filled with crushed biomass. When a given biomass particle moves progressively from the top to the bottom of the TORSPYD column, it first loses its water. Once dried, the biomass particle continues progressing down, crossing gradually warmer zones, which provokes the devolatilisation (untangling) of a small quantity of organic substances in the gas flow, until it reaches the lower zone, where the hemicellulose polymers are broken. This phenomenon then continues up to the point where the biomass particle reaches the lower grid. In the meantime, once it has reached the top of the column, lost its heat and is loaded with organic volatiles, the gas flow is reclaimed, heated and reinjected at the bottom of the column, where it starts a new cycle. The torrefied product obtained at the bottom of the column is called BioCoal.

As of today, THERMYA is the only provider of a fully operational industrial process specifically developed and dedicated to biomass torrefaction. TORSPYD's technical performance lies with the achievement of its initial objectives: optimizing both energy and mass yields, ensuring a homogeneous production (in a continuous process) and the quality of the torrefied material, achieving the lowest operating and maintenance costs. More specifically, the TORSPYD process manages to avoid the formation of tars or pyrolitic juices and integrates, in the torrefaction process, the management of light organic gases coming out of the torrefaction column. Besides, as the torrefaction process is directly driven by continuous measurements right inside the biomass, controlling the biomass residence time has become a consequence of the process as opposed to an essential key to its functioning.