Lime Kiln Modifications

The lime kiln calcines the CaCO3 in lime mud to generate CaO. Several modifications are possible to decrease energy consumption in the kiln. Evaporation energy can be reduced by installing high efficiency filters to decrease the water content of the kiln intake. Higher efficiency refractory insulation bricks can be fitted to increase heat transfer in the kiln. Heat energy can be recovered from the lime and from the kiln-off gas to preheat input lime and combustion air. Furthermore, such improvements may also improve the rate of recovery of lime from green liquor, thus reducing a mill’s requirement for additional purchased lime (Kramer et al., 2009. p.93).

Development Status Products
Commercial

Lime Kiln ModificationsCosts & Benefits

Parent Process: Chemical Recovery
Energy Savings Potential

One published estimate suggests that newer high-performance refractory use can lead to lime kiln energy savings of up to 5%.
Average energy savings by the combined application of described measures are estimated to be 0.50 GJ/t pulp (Kramer et al., 2009. p.93).

CO2 Emission Reduction Potential
Costs

For these measures, investment cost of about $2.5/t [for the year 2000]pulp has been assumed (Martin et al., 2000. p.27).

Lime Kiln Modifications Publications

Energy Efficiency Improvement and Cost Saving Opportunities for the Pulp and Paper Industry

This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels.

Page Number: 

93

Opportunities to Improve Energy Efficiency and Reduce Greenhouse Gas Emissions in the U.S. Pulp and Paper Industry

Published July 2000

Page Number: 

27