European Bio-Energy Projects

OPTICOMB
Objectives
The main objective is to increase the
flexibility of biomass combustion plants
with respect of fuel input, and substantially
reduce the emissions with this technology.
To achieve this, results from static studies
(Computational Fluid Dynamics (CFD),
NOx mechanisms, grate design) have to
be implemented with dynamic information
of the plant (control concepts). The project
can be divided into the following
sub-objectives:
• Development and demonstration of
advanced control concepts for biomass
combustion grate systems.
• The development of guidelines, including
demonstration, to minimise the important
emissions of NOx and CO.
• Improvement of the efficiency (technical
and economical) of biomass combustion
plants.
• Design rules for biomass combustion
systems and process control systems.
• The design and testing of a new grate.
Optimisation and design
of biomass combustion
systems
Challenges
The major problems regarding biomass
combustion remain the NOx and CO
emissions, especially when the fuel becomes
more diverse (high peaks during transients).
The continuously changing fuel composition,
the non-linearity of the process, and the multivariability
of the procedure makes it difficult to
decrease the emissions further. Therefore,
classic control strategies are no longer
effective. In order to improve the actual
process control system, advanced control
technologies are needed based on process
models. To achieve this goal, static models
have to be integrated with dynamic models.
At present, no satisfactory tools are available to
describe the NOx formation in the fuel layer and
the gas phase. Therefore, an extensive study on
fuel layer and gas phase NOx formation
mechanisms will be performed. The mechanisms
developed will be integrated in a CFD combustion
model and a static fuel layer model in order to
minimise the CO and NOx emissions.
A new grate will be designed based upon
experimental work and plant data. A dynamic
furnace model is being developed for biomass
combustion. Special measurement techniques
will be used to gather actual plant data (two
plants, diverse fuels) to validate the models.
The stochastic characteristics of the fuel will
be revealed and used together with the dynamic
model to investigate the disturbance rejection
capacity of the plant.
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All information will be used to develop new
control concepts and to design new combustion
systems from a dynamic point of view as well.
These will be tested in an installation.
The environmental survey will be carried out of
the influence of the proposed technology, a
market analysis, information dissemination and
exploitation strategies.
Project structure
The project comprises six work packages with the
following sub-tasks:
• The participants in the consortium are summarised
in the info-box;
• The flow diagram below explains the function
of each partner in the consortium.
Expected impact and exploitation
• A reduction of CO and NOx by 20-50%; and
• A potential reduction of CO2 of 32 million
tonnes per year.