National Yunlin University of Science and Technology (YunTech) has used fly ash released by the generation of electricity to create a type of highly insulating material that can lower the temperature of a room by 2 degrees Celsius.
Professor Tsai Cho-liang of the Department of Construction Engineering said at present, coal-fired power plant operators in Taiwan produce quite a lot of fly ash—some 1.6 million metric tons in the case of Taiwan Plastics, and another 1.4 million for Taiwan Power Co.
In earlier times, when environmental laws were not so stringent, operators landfilled the ash or shipped it offshore for dumping. Today, however, with more rigorous regulations in place, the majority are stockpiling the material and waiting to reuse it.
Tsai said the most common use of the fly ash is as a filler in concrete. With an appropriate amount of fly ash added, the flow of concrete can be improved and its cracking reduced. This increases the strength of the material, and produces a more useful material as well.
In the past, fly ash was primarily added to concrete, Tsai said, but he and a group of researchers have discovered that the addition of fly ash to cement mortar improves its ability to resist pressure. Over the course of a year’s experimentation, they discovered that replacing 30 percent each of the cement and sand in mortar yielded a material that kept structures cooler and had better resistance to pressure than conventional materials.
If the material were used in insulating blocks on the roof of a building, or on exterior walls as a coating material or primer, it is estimated that the room temperature inside could be reduced from 1 to 2 C, which would yield appreciable savings in power costs.
Tsai emphasized that with global warming, the fact that a waste product like fly ash has insulating properties needs further research. He plans to talk to industry leaders to draft a cooperation plan to get the new insulating blocks into production.
