Case Study 15
Blast Furnace Hot Stove Heat Recovery Technology for Chinese Steel Industries
Teruo Okazaki
Nippon Steel Corporation, Japan
Keywords: Japan, China, steel industry, industrial energy conservation,
certified emission reduction, N
S
Summary
This industrial sector case study is on the technology for energy saving in
steel manufacturing, transferred from Nippon Steel Corporation (NSC) to steel
industries in the Peoples Republic of China (P.R. China). This project was a
part of the Green Aid Plan proposed by the Ministry of International Trade and
Industry (MITI), Japan for energy saving and environmental protection in P.R.
China. Two examples of actual technology transfer projects illustrate the barriers
encountered and countermeasures for overcoming them.
Background
In the Peoples Republic of China, roughly three quarters of the energy consumed
comes from coal. The total amount of CO2 emitted in P.R. China is the second
highest in the world. P.R. China produces the largest amount of crude steel
in the world. But the specific energy consumption for producing each tonne of
crude steel is higher than that of some developed countries such as Japan and
the US. Japan had achieved a 20% reduction in energy consumption through technology
upgrades as early as 1993. Japan supplies steel products to both international
and domestic markets with the lowest energy consumption. As a part of the Green
Aid Plan to promote energy savings and environmental protection in China, MITI
in Japan launched the "Japan - China model project for blast furnace, hot
stove, waste heat recovery."
Approach
The project, located in Laiwu, demonstrates and disseminates the blast furnace
hot stove waste heat recovery technology. The operation of the equipment started
in October 1995. The waste heat in the exhaust gas, at a temperature from 200
to 300oC, was recovered and used efficiently to preheat the combustion air and
the fuel gas by adopting an organic oil as a heating medium. This process technology
can be applied to existing hot stoves of blast furnaces, because the heat exchangers
are separately installed and connected with the transfer lines where the hot
oil is circulated by pumps. As a result, the operating index has been improved
significantly, reducing the fuel ratio of blast furnaces by approximately 7%.
Further studies in this area were done for diffusing this technology within
P.R. China. For successful implementation, the operating skills were developed
under a set of training courses for operators using the actual equipment used
in Japan. Through this training, the operators could get information related
to both operation and improvement techniques. Japanese engineers were also sent
to the site for the further transfer of related information.
Impacts
Incentives and benefits applied to both NSC and P.R. China. NSC profited through
technology upgrade. For P.R. China, facing increasingly competitive international
and domestic markets, being able to reduce the cost of steel produced by saving
energy while reducing GHG emissions is a positive development . There were certain
barriers associated with technology transfer, such as the import of equipment
components. It will be beneficial for them to be locally made to cut down the
costs. However, these parts purchased domestically could cause some reliability
problems.
Lessons Learned
Maintenance technology is also essential for sound operation. It is important
to transfer not only maintenance procedure manuals, but also maintenance skills
by providing actual training on-site. For most developing countries, indigenous
availability of parts appears to be critical for economic viability and sustainable
development.
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