Technology to reduce CO2 emissions during cement production (1990s, Taiheiyo Cement)

Technology to reduce CO2 emissions during cement production (1990s, Taiheiyo Cement)
In Japan in the 1990s, global warming rapidly became a national issue and the need to reduce CO2 emissions increased in all industrial sectors. In particular, the cement industry attracted attention as a major source of CO2 emissions, not only from fuels, but also from calcination of limestone, which is an unavoidable source of CO2 emissions. 1997 Kyoto Protocol imposed an obligation to reduce CO2 emissions, which led to calls for drastic measures through technological innovation.
Taiheiyo Cement responded to this demand by establishing a new firing process that simultaneously achieves energy conservation and CO2 emission reduction in the firing process. The amount of heat required in the main kiln has been significantly reduced by efficiently preheating and partially calcinating the raw materials before feeding them into the kiln through the use of advanced preheaters and precalciner. This has reduced fuel consumption and CO2 emissions.
Furthermore, by replacing coal and heavy oil with alternative fuels such as waste tire waste plastic paper waste biomass, the company has simultaneously broken away from its dependence on fossil fuels and advanced waste treatment. The characteristics of the cement kiln, which is capable of high-temperature processing, functioned as the core of the zero-emission type process.
In addition, low-temperature firing technologies, such as optimization of mineral composition and addition of auxiliary agents to lower the firing temperature, were also advanced, resulting in both energy savings and CO2 reduction. These efforts are the basis for the Japanese cement industry to achieve one of the world's highest levels of energy efficiency, and were recognized as a pioneering example of a recycling-oriented society and global warming countermeasures.