Young-Jin Kim

The cement industry is an energy-intensive sector with significant CO 2 emissions owing to the high-temperature calcination processes and fuel combustion involved in clinker production. As the realization of carbon neutrality accelerates, the introduction of fuels to replace existing fossil fuels is being deliberated for the cement sector. In the domestic cement industry, various waste-derived alternative fuels, such as waste synthetic resins, waste tires, and waste wood, are utilized. This can contribute to the reduction of greenhouse gas emissions and promote resource recycling. As of 2021, the domestic cement industry has used approximately 2.245 million tons of the alternative fuels, accounting for 35 % of the total fuel consumption in the cement industry. Alternative fuels emit lower CO 2 than fossil fuels, such as bituminous coal. However, the domestic utilization rate of alternative fuels is low compared to that of major European countries. Accordingly, a multifaceted approach, includes institutional improvement, quality control, and supply and demand stabilization is required. This study investigated the current status of alternative fuel use in the domestic cement industry, overseas applications, and the characteristics of each fuel. Additionally, it explored ways to utilize carbon-free fuels such as hydrogen and ammonia to realize carbon neutrality in the cement industry in the future.

요 약 본 연구에서는 소석회(Ca(OH)2)의 비표면적과 세공 부피를 증가시켜 배연탈황(FGD) 공정에서의 SO2 제거 효율을 향상시키는 고기 능성 소석회 제조 공정을 개발하였다. 생석회(CaO)를 1 mm 이하로 분쇄하고 200 mesh 이하로 체질한 후, 생석회 대비 물 비율(W/CaO) 은 0.5, 수화수 온도 45 ℃, 에틸렌글리콜 4 %를 첨가하여 건식수화 공정을 적용하였다. 또한, 후처리 단계에서 건조 온도를 350 ℃로 설 정하여 최적의 비표면적 39.1 m 2 /g과 세공 부피 0.177 cm 3 /g를 달성하였다.

요 약 에틸렌글리콜을 첨가제로 사용하여 첨가제와 원료의 혼합방식 및 건조 온도 조건을 변화시켜 소석회(Ca(OH)2)의 비표면적 향상 실험 을 실시하였다. 원료와 첨가제인 에틸렌글리콜을 먼저 건식 방식으로 혼합 후에 물과 반응하는 조건에서 소석회의 비표면적이 크게 향상 하는 경향을 나타냈다. 건조 온도 변화 실험에서는 온도가 증가함에 따라

요 약 본 연구는 다양한 산업부산물을 활용하여 고강도 클링커를 제조하기 위해 원료 배합 설계 및 이에 따른 클링커 주요 광물상(C3S, C2S, C3A, C4AF)의 형성 특성을 분석하였다. 실험을 통해 원료 대체율 및 Modulus 조건(LSF, SM, IM)이 클링커의 주요 광물상의 형성과 물 리적 특성에 미치는 영향을 확인하였다. 소성온도 1,500 ℃, LSF 100, SM 2.7, IM 1.5의 Modulus 조건에서 제조된 A-1 클링커는 C3S 생 성량이 75.0 %으로 확인되었으며

In an effort to achieve the goal of carbon neutrality, countries around the world are aiming to phase out coal-fired power plants. Due to various reasons, electricity production through coal-fired power generation and sulfur oxide (SOx) emissions are expected to continue in the future. In the South Korea, sodium bicarbonate (NaHCO 3) and lime materials are used to treat SOx, and most of the sodium bicarbonate is imported. Therefore, this research was conducted to replace sodium bicarbonate by improving the physical properties of lime materials using domestic limestone. Limestone was heat-treated through a box-type electric furnace and a vertical electric furnace. Due to the structural characteristics of the vertical electric furnace, a lime material(quicklime) was possible to improve the physical properties like a specific surface area and a pore volume. Then, they were reached to 22.33 m 2 /g specific area and 0.14 cc/g pore volume.

The lime industry accounts for about 75% of greenhouse gases generated from process emissions, and because large amounts of fossil fuels are used, the intensity of greenhouse gas emissions per unit of product production is quite high. In order to respond more accurately and quickly to greenhouse gas regulations, including the domestic emissions trading system, it is necessary to establish a system for accurately identifying greenhouse gas emission sources and calculating emissions for each lime manufacturing process. In this study, in order for limestone processing companies to effectively respond to the domestic greenhouse gas emissions trading system, the operation method, input raw materials, and fuel differences for each type of limestone kiln were identified through field surveys, and the greenhouse gas emission intensity was analyzed As a results, it was confirmed that greenhouse gas emissions were reduced when using a Parallel flow regenerative kiln compared to an improved shaft kiln even when the same amount of limestone was used.

In this study, soda lime was prepared from slaked lime to expand the scope of limestone use. To evaluate carbon dioxide absorption, an extruder-type and disc-type pelletizers were used to make the soda lime using bentonite as an additive. Regardless of the pelletizing process, the peak of CaCO 3 was confirmed in soda lime due to its reaction with carbon dioxide. Furthermore, it was confirmed that both calcite and aragonite were present together. The soda lime prepared using the disc-type pelletizer showed a larger specific surface area than that prepared using the extruder-type pelletizer did, and the specific surface area improved on adding bentonite. The carbon dioxide absorption rate increased under the sample condition with an enhanced specific surface area.

Domestic limestone industries need to prepare for the introduction of a paid allocation according to The 4th emission trading system. The limestone industry must reduce its greenhouse gas (GHG) emissions through process improvements (such as fuel conversion and increase in kiln efficiency) and system improvements (such as reflecting purity of raw materials and lime kiln dust factors). In addition, the limestone industry is currently classified within the same category as the cement industry. Therefore, when allocating emission allowances for greenhouse gas, it is possible that a low adjustment factor will be applied for the limestone industry due to differences in the industrial scale, raw materials, and product characteristics. The limestone and cement industries should thus be classified as two separate industries. Since unslaked lime and light-burnt dolomite are essential materials in a number of domestic industries, governmental support is essential to become a carbon-neutral and sustainable industry.