Example of Energy-Use Reduction at Paper Mills
At paper mills, paper is created through a pulping process and paper-milling process. In the paper milling process, the water content is removed from the wet paper that will become the finished paper through the application of pressure and a mechanical water removal process. After that, the paper is dried with a dryer and rolled up. The dryer used in this process is formed from a metal cylinder. The paper is spread over the surface, which is then heated. To heat the dryer, steam is passed through the interior. Heating accounts for most of the overall energy usage at the plants. Therefore, reducing the energy used in the process was an important challenge at paper mills. Kurita Water Industries noted that water from the steam adhering to the inside of the dryer caused a drop in heat conduction efficiency. At many paper mills, we have proposed adding a water treatment chemical that forms a water-repellent film to the steam, so that the film adheres to the inside of the dryer and improves heat conduction efficiency. This chemical is called Kurita PJ Technology. Plants that have adopted Kurita PJ Technology are able to reduce their per-unit use of steam by around 5-10% per year on average, with the reduction in energy leading to a reduction in CO2 emissions.