Biomass Conversion and Cofiring
Biomass Cofiring and Biomass Conversion with the Nalco MobotecSystem™
There are three major goals for power plant management, all of which influence operational costs:
- Optimize the combustion process
- Reduce emissions to achieve maximum availability
- Support the reliability of utility boilers operating on various fuels
Modern combustion processes must be fuel-flexible; that is, able to accommodate changing fuel supplies.The Nalco Mobotec System can enable boilers to switch to biomass cofiring or burn up to 100 percent biomass with no change in boiler load capacity—while meeting strict emission control requirements.
Substituting biomass for coal as a clean power fuel reduces carbon dioxide (CO2) emissions, a significant greenhouse gas. These CO2 reductions are achieved because biomass is considered a carbon neutral fuel.
Optimum Combustion for Biomass Conversion and Biomass Cofiring
Because of lower heating value and differences in density, a proportionately greater volume of biomass must be burned to obtain steam generation comparable to that of coal or oil combustion. During biomass combustion, gas phase temperature distribution changes and ash-melting temperature declines. This situation can lead to slagging, fouling and corrosion.
The Nalco Mobotec System increases the volume of combustion, which results in superior mixing of the large amount of volatiles released from biomass. The system also provides better control of boiler furnace temperature distribution. By controlling oxygen distribution and residence time, the Nalco Mobotec System lowers NOx combustion and provides more complete combustion of biomass char particles.
Reduction of Slagging, Fouling and Corrosion
Biomass contains ash-forming elements such as potassium, sodium, calcium, magnesium, silica and aluminum. These elements can lead to slagging, fouling and high temperature corrosion during combustion. Mixing of the ash from coal and biomass during direct cofiring of these fuels enhances these elements’ negative effects by lowering the melting temperature for the biomass ash. The Nalco Mobotec System injects anti-slagging and fouling chemistries that dramatically reduce these undesirable effects, enabling easy removal of ash deposition.
A Cost-effective Solution for Improving Combustion Efficiency
The Nalco Mobotec System allows fuel switching to cofiring biomass with coal or to 100 percent biomass firing. This system secures complete combustion and inhibits formation of pollutants such as NOx, CO, soot and particulates. High combustion efficiency not only provides for CO2 reductions, but also reduces slagging, fouling and corrosion and offers substantial economic advantages. A typical Nalco Mobotec System can pay for itself within a very short period of time.
Comparison of NOx Reduction Before and After Nalco MobotecSystem