Energy conservation technologies
During the 1990s the replacement to suspension preheater kilns (SP kilns) or suspension preheater kilns with a precalciner (NSP kilns) was progressed, and the replacement was completed in 1997. As a result of the replacement, no further room for major gains in energy conservation (See Figure 2).
Nonetheless, the Japanese cement industry has adopted energy conservation technologies.
Table 1 shows the energy conservation efficiency and the diffusion rates of main technologies and equipment. The power generated by waste heat recovery is effective for recovery of thermal energy and the introduction of it is expected.
Table 1 Energy conservation technologies and diffusion rates in Japan.
| Process |
Technology or Equipment
|
Energy conservation efficiency
|
Diffusion rate (%)
|
| FY 2010 |
FY 2020
(Expected) |
| Raw materials |
Vertical roller mills  |
Specific electric energy consumption :
reduction of approx. 30 % as compared with ball mill
Clinker production : increase of 60-80 % (as compared with ball mill) |
46 |
* |
| Burning |
Vertical roller mills for coal |
Specific electric energy consumption :
reduction of 20-25 % as compared with ball mill |
90 |
96 |
| Air beam type clinker coolers |
Specific thermal energy consumption :
reduction of approx. 42-167 MJ/t-clinker.
Specific electric energy consumption :
reduction of approx. 0.5-1.5 kWh/t-clinker |
50 |
57 |
| Finishing |
Pre-grinding roller mill systems |
Specific electric energy consumption in finishing process:
reduction of 10-20 %
Grinding capacity of finishing ball mill : increase of 30-60%. |
48 |
* |
| Vertical roller mills for grinding of blast furnace slag |
Specific electric energy consumption at 4,000cm2/g :
reduction of 60 % or less as compared with ball mill |
73 |
78 |
| Upgrading of separators of ball mill |
Specific electric energy consumption ; reduction of 10-20 %
Grinding capacity of finishing (ball) mill:
increase of 15-25%. |
53 |
* |
| Other |
Power generation by waste heat recovery |
Power generation :
approx. 35-40 kWh/t-clinker |
60 |
68 |
(*) There are no plan to introduce equipment at FY 2013
The CEMENT TASK FORCE of the ASIA-PACIFIC PARTNERSHIP ON CLEAN DEVELOPMENT & CLIMATE published a booklet of “Energy Efficiency and Resource Saving Technologies in Cement Industry” (2009) , where a part of the booklet (p.66-129) was provided by JCA.
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