Stramproy, green gas as power source

At the beginning of 2009 De Jong Thermal Engineering received a challenging order from the Limburg company Stramproy Contracting B.V. for the design and construction of a (post-)combustion unit as part of a biomass processing installation.

Stramproy Contracting designed a special processing line in-house for the thermo-chemical pre-treatment of biomass. This principle makes it possible to render biomass streams more suitable for use as fuel in power plants and other applications. In the process combustible gas is released as a secondary stream. This fuel serves as direct source of energy for the primary process, for which DJTE has invented a process-specific combustion installation.

The challenge
The gaseous fuel released varies during production in terms of both composition and supply. In all cases, however, the gas has to be optimally converted into a hot air flow. The heart of the designed installation is formed by a combination of a specific mixing body, supporting flame stabilisers and a turbulent combustion zone. However, the high-temperature combustion takes place under tightly controlled process conditions so that licensed emission levels are achievable.

Result
The (post-)combustion plant is just one of the many stages in the overall process; careful coordination and integration has provided the client company Stramproy Contracting B.V. with an overall installation with which processing of biomass is achieved in a flexible, reliable and energy-responsible manner.

Key figures for ABI

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process gas	ca.3.000 m3/h @ 300 °C
exhaust temperature	800 °C
combined thermal power	3 MW
production cycle	24 uur per dag / 7 dagen per week
primairy process	torrefactie