Porous ceramics are used in various industrial applications based on their physical properties, including isolation, storage, and thermal barrier properties. However, traditional manufacturing environments require additional steps to control artificial pores and limit deformities, because they rely on limited molding methods. To overcome this drawback, many studies have recently focused on fabricating porous structures using additive manufacturing techniques. In particular, the binder jet technology enables high porosity and various types of designs, and avoids the limitations of existing manufacturing processes. In this study, we investigated process optimization for manufacturing porous ceramic filters using the binder jet technology. In binder jet technology, the flowability of the powder used as the base material is an important factor, as well as compatibility with the binder in the process and for the final print. Flow agents and secondary binders were used to optimize the flowability and compatibility of the powders. In addition, the effects of the amount of added glass frit, and changes in sintering temperature on the microstructure, porosity and mechanical properties of the final printed product were investigated.

Ceramic membranes can be applied under extreme operating conditions such as low pH, high pressure and high temperature. In particular SiC has excellent mechanical properties and also has excellent properties related to membrane performance. However, high processing temperature increases cost of SiC products and thus limit’s its use. In this study oxidation bonding technique was used to fabricate cost-effective SiC microfiltration membrane at low temperature. The oxidation behavior at different thermal treatments was related with pore morphology and ultimately the membrane permeability. We have found that the membrane made by coating of oxidation bonded SiC layer over clay-bonded SiC support, sintered at 1000-1100°C could make a defect-free microfiltration membrane with pure water permeability above 700 LMH per bar. The membrane has narrow pore size distribution with average pore size about 0.1 μm.

세라믹 소재는 고분자 나노섬유 분리막과 비교하여 우수한 열안정성과 고투과 물성을 가짐으로써 지난 10여 년간 많은 주목을 이끌어왔다. 최근 들어 높은 다공도와 유량을 가지는 세라믹 섬유 분리막이 금속 산화물을 이용하여 주로 전기 방사법에 의해 제조되어 왔는데, 이러한 세라믹 분리막의 제조 단가를 감소하며 성능을 향상시키기 위해 나노섬유의 선택층 을 가지는 세라믹 분리막들이 전기방사 공정과 개질 과정을 통해 개발되었다. 본 리뷰에서는 최근 수년간 세라믹 섬유 분리 막의 개발을 위한 연구 동향에 대하여 정리하였다.

In this study, the porous ceramic filter was developed to be able to remove both dust and hazardous gas contained in fuel gas at high temperature. The porous ceramic filters were fabricated and used as a catalyst support. And the effects have been investigated such as the mean particle size, organic content and addition of foaming agent on the porosity, compressive strength and pressure drop of ceramic filters. With the increase of mean powder size and the organic content for the cordierite filter, the porosity was increased, but the compressive strength and pressure drop were decreased. From the results of the research, the optimum condition for the fabrication of ceramic filters could be acquired and they had the porosity of 58%, the compressive strength of 13.4 MPa and the pressure drop of 250 Pa. It was expected that this ceramic filter was able to be applied to the glass melting furnace, combustor, and dust/toxic gas removal filter.

In this study, diatomite based materials were investigated as a support filter for silica particle coating. Thesilica sol for coating was synthesized by a stöber process. The diatomite support was dry-pressed at 10 MPa and sin-tered at 1200˚C for 1 hour. The coating sol was prepared as a mixture of EtOH and silica sol. The diatomite supportwas coated by a dip-coating process. Silica coated diatomite filter was sintered at 1000~1200˚C for 1 hour. The largestpore size was decreased with increasing concentration ratio of coating sol. The gas and water permeability of silicacoated diatomite decreased with increasing of concentration ratio of the coating sol.

To evaluate parameters influencing on the dust removal of the High Temperature Filter(HTF) system, a computer simulation of fluid dynamics inside the system had been performed. The results showed that the optimum pulse jet periods were 50ms and 90ms for the 1000mm and 1500mm long filter elements respectively. Dust removal effect was very excellent under the pulse jet pressure of 3 bar. But the distance between the pulse jet nozzle and the venturi of a filter element had no meaningful effect on the performance with the variation from 5mm to 10mm. Compared to the dispersion mode of pulse jet, the collective mode of pulse jet flow was preferable in maintaining the pressure inside the system stable.

본 연구는 알루미나 기반의 기능성 세라믹 필터의 물리적 특성(강도와 기공률)에 대하여 소결 온도와 영가철(ZVI) 함량의 영향을 파악하는 것이다. 기능성 세라믹 필터의 제조공정은 다양한 소결 온도(1150℃, 1250℃)와 ZVI 함량(10, 20, 30, 50%)조건에서 수행하였다. 소결온도와 ZVI 함량의 증 가됨에 따라 기능성 세라믹 필터의 강도는 증가하였지만 기공률은 감소하였다. 기능성 세라믹 필터의 강도와 기공률은 50%의 ZVI 함량과 1250℃의 조건에서 각각 99.01 MPa과 34.5%로 나타났다.

사용후핵연료의 고온 열처리공정 중에 발생되는 핵분열 가스는 세슘, 테크네튬, 요오드, 삼중수소, 크립톤, 제논 등이다. 이들 다양한 핵분열 가스를 단/장반감기/열발생 핵종별로 선택적으로 포집하여 고준위폐기물 발생량 최소화 및 최적화기술 개발은 시급한 문제로 다가오고 있다. 이들 핵종 중 방사성 기체상 세슘은 선택적 배기체 처리공정에서 석탄회 필터를 이용한 고온 흡착법으로 포집한다. 배기체 처리장치에서 기체상 세슘을 포집 후 발생되는 세슘 폐필터 고화방법은 밀도가 높고, 열적 안정성이 우수하며, 내침출성이 우수한 고화방법이 개발되어야 한다. 세슘 폐필터 고화방법 중 기체상 세슘을 포집한 세슘 폐필터 자체를 소결하여 안정한 고화체로 제조하는 방법이 시도되고 있다. 본 연구는 기체상 세슘이 포집된 세슘 폐필터(Cs 함량 : 6 ~ 24 wt%)를 분쇄, 혼합 후 소결시켜 세슘 폐필터 세라믹 고화체를 제조하여 이의 침출특성을 PCT-A 정적침출시험법 (ASTM Standard C1285-02)을 이용하여 평가하였다. 세슘 폐필터 자체만으로 대기 분위기하에서 각각 1,000℃부터 1,500℃까지 3시간 동안 열처리하여 얻어진 세라믹 고화체는 세슘함량이 감소할수록 고화체의 제조온도는 낮아졌다. 세슘함량이 6 ~ 24 wt%인 세슘폐필터를 단순 열처리만 하여도 밀도가 ~2.7 g/cm³ 으로서 일반적인 붕규산유리 고화체의 밀도인 ~2.5 g/cm³와 비슷하였다. 한편 세슘함량 12 ~ 24 wt.%인 세슘잉곳의 세슘 휘발율은 8wt.% 이하로 매우 우수한 열적 안정성을 나타내었다. 세슘잉곳의 Cs, Si, Al, Na의 mass loss [g/㎡] 값은 EA glass 이하의 값으로 나타났고, 특히 세슘의 mass loss 값은 10-2 ~ 10-1 g/m² 로서 PCT-A 침출률로 환산시 10-3 ~ 10-2 g/(m²·day) 로서 내침출성이 우수하였다.

This work presents an experimental study of the influence of lifting velocity on cake formation during filtration. For design of hot gas cleanup system using ceramic filter reactor, the most important consideration is coating conditions of sorbent in filter surface (for example : lifting velocity, coating weight of sorbent, pulsing interval and removal effect for dechlorination and desulfurization). We studied the optimum operation condition as paticle size and lifting velocity using a ceramic filter reactor at 550oC. Based on the results obtained during cold and hot test, optimum lifting velocity in a ceramic filter reactor was selected 0.68 m/s. Also, the removal behaviour of the ceramic filter during filtration was studied using differential pressure. Optimum removal efficiency for dechlorination and desulfurization accomplished at differential pressure condition over 74 mmH2O.

V2O5/TiO2 catalyst impregnated ceramic candle filters are in principle, capable of performing shallow-bed dust filtration plus a catalytic reaction, promoted by a catalytic deposited in their inner structure. Pilot-scale V2O5/TiO2 catalyst impregnated ceramic candle filters were prepared, characterized and tested for their activity towards the SCR reaction. The effect on NO conversion of operating temperature, gas hourly space velocity, amount of deposited catalyst, pressure drops and long-term experiment (life of catalytic filter) was determined. The following effects of V2O5/TiO2 catalyst impregnated ceramic candle filters in SCR reaction are observed: (1) It increases the activity and widens the temperature window for SCR. (2) When the content of V2O5 catalyst increases further from 3 to 9wt.%, activity of NO increases. (3) NO conversion at first increases with temperature and then decreases at high temperatures (above 400℃ over), possibly due to the occurrence of the ammonia oxidation reaction.