Clinker CoolingTechnologies & Measures
|Technology or Measure||Energy Savings Potential||CO2 Emission Reduction Potential Based on Literature||Costs||Development Status|
|Conversion to High-Efficiency Grate Coolers|
Fuel consumption in the kiln can be reduced by as much as 8%, or by 0.27 GJ/t-clinker, but electricity consumption will increase by around 3 kWh/t-clinker.
Compared with the third generation grate cooler, fourth generation coolers can help reduce heat consumption for clinker making by 10% to 18%, and power consumption of the cooler by 20% (NDRC, 2009. p.43)
According to MIIT, this technology consumes 4 kWh of electricity per ton of clinker processed, and can achieve heat recovery rates up to 74% – enabling an improvement of 4 to 6%.
For a 5000 tpd plant, high efficiency grate coolers are reported to have the potential to reduce annual coal consumption by 4000 to 5000 tons (MIIT, 2012. p.22).
In a 3000 tpd Chinese plant, installation of high efficiency grate cooler reportedly reduced annual energy consumption by 99.35 TJ (3390 tce) (MIIT, 2012, p.22)
In a 5500 tpd Chinese plant, installation of high efficiency grate cooler reportedly reduced annual energy consumption by 156.2 TJ (5330 tce) (MIIT, 2012, p.22)
The cost of a cooler conversion is estimated to be between US $.044 and $5.5/annual tonne clinker capacity, depending on the degree of reconstruction needed. Annual operation costs of the cooler can increase by US $0.11/t clinker. Estimated payback period: 1-2 years (LBNL, 2008).
The cost for the conversion from a planetary cooler to an efficient reciprocating grate cooler of newest generation with a capacity of 6,000 tons per day is estimated to €15 - 20 million. These costs can vary widely due to the site specific conditions (new exhaust air fan and cooler filter, foundations and other construction cost, shortening of the kiln). The retrofit of an old grate cooler demands an investment of €1 – 3 million. (ECRA, 2009)
Fourth generation coolers are reported to have 20% lower installation costs, and 70 to 80% less maintenance costs (NDRC, 2009. p.43)
For a 5000 tpd plant, the installation and annual operational costs for a high-efficiency grate cooler are reported to be 20 million RMB and 5 million RMB, respectively. Resulting payback time is reported to be 3.5 years(MIIT, 2012, p.22)
In a 3000 tpd Chinese plant, high efficiency grate cooler was installed at a cost of 8 million RMB and over a period of 3 months. The annual cost savings amounted to 2.37 million RMB, resulting in a payback time of 3.5 years (MIIT, 2012, p.22)
In a 5500 tpd Chinese plant, the technology was installed at a cost of 10 million RMB and over a period of 3 months. The annual cost savings amounted to 3.7 million RMB, resulting in a payback time of 3 years. MIIT, 2012, p.22)
|Revolving disc clinker cooler|
|Optimized Heat Recovery in Clinker Cooler|
Savings of 0.05 to 0.16 GJ/t clinker through the improved operation of the grate cooler is reported.
Investments are estimated to be US $0.11 to $0.33/annual tonne clinker capacity. Estimated payback period: 1-2 years.
|Variable Frequency Drive for Clinker Cooler Fans|
0.04 - 0.17 kWh/ton clinker are reported
This technology can be deployed at a cost of around US $0.01 per annual ton clinker capacity.