6. Impacts of AFR`S Usage
AFR (Alternative fuels and raw materials) / Green fuel usage in cement industry
has become very dynamic now and may become obligatory tomorrow hence industry
need to prepare themselves to increase the Thermal substitution rate (TSR)
graduallyup to the maximum possible level, of course the biggest challenge
is to maintain the Clinker output level, Sp. fuel & power consumption and the
environmental / ecological balance. Also alkali and Sulphur gasification during AF
burning process and increase in ash content at kiln inlet may lead to erosion and
corrosion of equipment’s and refractories hence its impact on Refractory and other
equipment’s are to be reviewed properly, this may increase maintenance cost
accordingly.
Increased usage (TSR) of AF over fossil fuels shall lead in following benefits:
- Reduction of society wastage
- Fuel security i.e. Saving of fossil fuels
- Reduction of CO2 generation
- Reduction in acid rains and air pollution
- Sustainability
- Reduction in fuel cost
However, there are some impacts are also estimated during usage of various types
of AFR`s which is described as below
Increased usage (TSR) of AF over fossil fuels shall lead in following Impacts - Increase in Fuel consumption
- Increase in Power consumption
- Reduction in Clinker productivity
- Impact on refractory life
- Increase in maintenance cost
- Impact on kiln operation stability
- Impact on Quality of Clinker due to high ash absorption resulting in requirement
of high grade limestone usage - Requirements of chlorine bypass system incurs additional Capex and Opex.
a. Increased in Fuel Consumption:
Moisture content of AFRs converts in additional gas volume and hence require additional fuel to dry up that as a thumb rule 1% of AFR consumes additional Sp. Heat consumption of 2 kcal/kg clinker. b. Increased in Power Consumption Moisture content of AFRs converts in additional gas volume and hence require
additional fuel to dry up which increases additional preheater gas volume and
increase PH fan power consumption for same output.