Brussels, 22 Oct 2003
On-going trials of the predictive emission-monitoring model developed in the RESPEC project show this tool can offer a realtime, cost-saving alternative to continuous emission monitoring for many industrial processes.
Development of a system to reduce the output of air pollutants from major industrial plant, as well as cutting running costs, is very welcome at a time when European companies in all sectors are under pressure to reduce environmental pollution and operating costs. The RESPEC tool is an advanced mathematical model that takes into account the operating conditions of industrial plant such as power stations and factories, allowing prediction of their air pollutant emission. Adjustment of the operating conditions then permits reduction of pollutants. The cost savings - about 35% - come from the elimination of continuous emission measurements, plus installation and maintenance of equipment. Processes operate at a greater efficiency because of the optimisation of conditions.
Integrated approach to pollution control
The basis for efforts to reduce air pollution is the 1996 European Directive 96/61/EC on integrated pollution prevention and control (IPPC). This is concerned with installations where the potential for pollution is significant. It covers power stations, oil and gas refineries, coal gasification and liquefaction plant, and processing plant for metals and minerals, chemical production and waste management.
Taking an integrated approach to pollution control is intended to prevent emissions into air, water or soil wherever practicable, and where it is not, to minimise them. At present the pollutant emissions from these activities are measured by continuous monitoring.
The Commission-funded RESPEC project set out to develop a means of combining data on all the known variables to predict the output in terms of potential pollutants. In the case of a power station, for example, these variables could include type of fuel, operating temperature, composition of the primary airflow between the fuel mills, and the burner. Air pollutants that can be predicted are carbon monoxide and dioxide, sulphur dioxide, mixed oxides of nitrogen (NOx) and particles.
Antonio Gimenez Alonso of Spanish project co-ordinator Tecnatom explains that the duration of combustion, the primary air/fuel ratio and total air/fuel ratio are the most important parameters in power plant furnaces, as they influence the possible development of hot spots, which encourage production of NOx.
"The main advantage of RESPEC is that it is a tool able to produce a lot of information in a short time, enabling the operator to modify the relation between fuel, primary air and secondary air, and to achieve combustion improvement in a short time or modify the flame configuration to reduce pollutant emission," he says.
RESPEC operates in realtime, predicting the level of pollutants continuously every 30 seconds. The information is transmitted to the operators, who modify the conditions to reduce the pollutants. The innovative aspect of RESPEC is the mathematical model, based on neural networks and fuzzy logic. It is not patented, but Gimenez Alonso believes that Tecnatom may do so in the future.
Tecnatom specialises in modelling and emission determination using computational fluid dynamics. The Instituto de Soldadura e Qualidade is a leading Portuguese authority on measuring and certification, while British partner Cinar is expert in mathematical modelling on neural networks. Steria from France is a software company responsible for development of the RESPEC software, and a Spanish electricity provider has been testing the prototype RESPEC system in two of its coal-fired power stations.
System now ready for market
The original RESPEC project was completed in December 2001; the system is now ready for the market. Gimenez Alonso is looking forward confidently to a major market - not only in the EU but also in the Middle East. He believes that predictive monitoring may become linked to regulatory requirements. In the USA, the Environmental Protection Agency (EPA) has already replaced the use of continuous monitoring with predictive systems.
In the EU, Member States are responding to Directive 2001/80/EC on the limitation of emissions of certain pollutants into the air from large combustion plant. This Directive amends the earlier Directive 88/609/EEC , and tightens the limits on air pollution from new combustion plants in line with the technical progress in this sector, with stricter limits in particular for sulphur dioxide, NOx and dust particles. It also specifically includes gas turbines, in order to regulate NOx emissions, as their use in electricity generation is growing. Its limit values are maxima; Member States may adopt stricter levels.