Discarded Coal Bottom Ash becomes a New Eco-friendly Material!
-Patent applications related to coal bottom ash -
According to the Korean Intellectual Property Office (KIPO), there were 484 patent applications related to bottom ash** among the coal ash*-related applications over the past 10 years ('10 ~ '19). During the last 3 years ('17 ~ '19), the average annual number of such applications was 56 cases, and this is an increase of 24% compared to the 45 cases over the previous three years ('14 ~ '16). This increase is attributed to the government's policy of encouraging coal ash recycling after the National Assembly enacted the ‘Framework Act on Resource Circulation’ in May 2016.
* Coal ash is a by-product remaining after burning coal in coal-fired power plants, and is divided into fly ash collected in the air due to its small size and bottom ash falling on the boiler floor due to its relatively large size.
** Fly ash, which accounts for about 85% of total coal ash, is mostly recycled for construction materials such as concrete, while bottom ash, which accounts for about 15%, is mostly buried because it contains chlorine, a hazardous substance.
<Number of patent applications by year ('10 ~ '19, total 484 cases)>
Looking at the total of 484 cases filed over the past 10 years by technology, 158 cases (33%) are for light aggregate purposes, 151 cases (31%) are for concrete and cement purposes (replacement of concrete admixtures, cement raw materials, cement secondary products and cement clinker manufacturing materials), 37 cases (8%) are for aggregates for fill, cover, roads and drainage purposes, 33 cases (7%) are for top soil fertilizer source purposes and 31 cases (6%) are for raw materials purposes such as ceramic materials and insulation materials, and among these, applications related to recycling of bottom ash accounted for a large portion (total 425 cases, 88%). In addition, 59 cases (12%) were filed for bottom ash purification, screening, and transportation.
<Number of patent applications by technology ('10 ~ '19, total 484 cases)>
Comparing the cumulative number of applications over the past three years ('17 ~ '19) to applications for the previous three years ('14 ~ '16), concrete admixtures such as ready-mixed concrete increased 82% (33 cases → 60 cases) and raw materials purposes such as for ceramic materials and insulation increased 78% (9 cases → 16 cases). From this, it is considered that efforts to utilize bottom ash for high value-added purposes, not just for the landfilling purposes, became active.
<Number of patent applications by purpose ('10 ~ '19, total 484 cases)>
By applicant, small and medium-sized enterprises (SMEs) filed 234 cases (48%), individuals filed 98 cases (20%), universities filed 52 cases (11%), public companies filed 32 cases (7%), and foreigners filed a relatively insignificant 13 cases (3%). This is because industrial by-products processing is mainly done by SMEs in Korea, and it is difficult for foreign companies to enter due to the difficulties of transporting coal bottom ash.
<Application Trend by Type of Applicant ('10 ~ '19, total 484 cases)>
According to the status of the top applicants, Korea South-East Power Co., Ltd. filed 12 cases; Korea Southern Power Co., Ltd. filed 9 cases; Korea Midland Power Co., Ltd. filed 9 cases; Daewoong. Co., Ltd., which is one of the SMEs manufacturing binding materials for buildings and articles, filed 11 cases; Gongju University, which is a university researching artificial lightweight aggregates, filed 9 cases; and the Korea Institute of Civil Engineering and Building Technology, which is an institute researching cement substitute material for concrete, filed 9 cases. This shows that many companies are actively working to recycle bottom ash as a resource.
<Top applicant numbers ('10 ~ '19)>
The Director of the Basic Materials Chemistry Examination Bureau of KIPO said, "The development of technology using discarded coal bottom ash, which until now has been thrown away, can solve the problems of waste disposal expense, shortage of landfill, and environmental problems, while contributing to a resource virtuous cycle by replacing natural aggregates such as sand and gravel. Since added value can be created through development of new eco-friendly materials from otherwise discarded coal bottom ash, it is important to try to ensure market competitiveness through the securing of intellectual property rights."