Efficiency Enhancement by pH Swing in Indirect Carbonation using Paper Sludge Ash and Acid

( Dami Kim ),( Myoung-jin Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2015 No.-

Carbon dioxide has steadily increased in atmosphere since the industrial revolution, and it is the main cause of the global warming. In this study, carbon dioxide is stored in the form of insoluble calcium carbonate through indirect carbonation using paper sludge ash (PSA) as a raw material and acids (acetic acid and hydrochloric acid) as solvents. Acid is very efficient to extract calcium from PSA, which is as high as 55%. However, since the pH of calcium extractant obtained using acid is as low as 6 and carbon dioxide is not present in the form of CO₃ ^2- at the low pH, carbonation reaction does not occur to form calcium carbonate. Sodium hydroxide, therefore, is added into the calcium extractant to increase pH up to 13. The amount of sodium hydroxide is calculated based on the equivalent of calcium in the extractant. Then, carbon dioxide is injected into the calcium extractant for 30 minutes at a flow rate of 0.05 L/min. The calcium extractant is prepared in advance using 40 g of PSA and 1L of 0.7 M acid, and 35mL of 50% sodium hydroxide is added into the extractant to adjust pH. During carbonation, liquid samples are taken at designated intervals to measure pH and calcium concentration. After the carbonation is completed, white solids are collected to dry at 105℃ for 12 hours, which weigh 30.0 g and 33.1 g from the extractants using acetic acid and hydrochloric acid, respectively. The white solids are found to be highly pure calcite by XRD analysis. Based on the solid mass, the amounts of carbon dioxide sequestrated in PSA are calculated to be 330.4 kg CO₂/ton PSA and 363.7 kg CO₂/ton PSA using acetic acid and hydrochloric acid as solvents, respectively.

Efficiency Enhancement by pH Swing in Indirect Carbonation using Paper Sludge Ash and Acid

Dami Kim,Myoung-Jin Kim 한국폐기물자원순환학회 2015 한국폐기물자원순환학회 학술대회 Vol.2015 No.05

Carbon dioxide has steadily increased in atmosphere since the industrial revolution, and it is the main cause of the global warming. In this study, carbon dioxide is stored in the form of insoluble calcium carbonate through indirect carbonation using paper sludge ash (PSA) as a raw material and acids (acetic acid and hydrochloric acid) as solvents. Acid is very efficient to extract calcium from PSA, which is as high as 55%. However, since the pH of calcium extractant obtained using acid is as low as 6 and carbon dioxide is not present in the form of CO32- at the low pH, carbonation reaction does not occur to form calcium carbonate. Sodium hydroxide, therefore, is added into the calcium extractant to increase pH up to 13. The amount of sodium hydroxide is calculated based on the equivalent of calcium in the extractant. Then, carbon dioxide is injected into the calcium extractant for 30 minutes at a flow rate of 0.05 L/min. The calcium extractant is prepared in advance using 40 g of PSA and 1L of 0.7 M acid, and 35mL of 50% sodium hydroxide is added into the extractant to adjust pH. During carbonation, liquid samples are taken at designated intervals to measure pH and calcium concentration. After the carbonation is completed, white solids are collected to dry at 105℃ for 12 hours, which weigh 30.0 g and 33.1 g from the extractants using acetic acid and hydrochloric acid, respectively. The white solids are found to be highly pure calcite by XRD analysis. Based on the solid mass, the amounts of carbon dioxide sequestrated in PSA are calculated to be 330.4 kg CO2/ton PSA and 363.7 kg CO2/ton PSA using acetic acid and hydrochloric acid as solvents, respectively.

A study on encapsulating probiotics through indirect carbonation using oyster shells

( Youjeong Lee ),( Sehun Kim ),( Myoung-jin Kim ) 한국폐기물자원순환학회 2022 ISSE 초록집 Vol.2022 No.-

About 300,000 tons of oyster shells are produced annually in Korea, but many of them are piled up without being reused. Oyster shells are suitable for use as a source of calcium after calcination because their primary gradient is calcium carbonate. Recently, the probiotics market has been growing rapidly as interest in health has increased. Commercially distributed probiotics require encapsulation (coating), and the survival rate of probiotics varies depending on the capsule material and manufacturing process. Existing technologies necessitate multiple coatings of probiotics, mainly by adding alginate, protein, polysaccharide, and other chemicals. Such additional processing cause problems such as long manufacturing time, process complexity, and increased production cost. Furthermore, many probiotics die due to coating deformation during freeze-drying, and the number of probiotics that die in the body despite coating is considerable. In this study, we developed a technology to encapsulate probiotics with calcium carbonate produced by indirect carbonation using oyster shells as a calcium source. We added probiotics to the hydrated suspension of the calcined shells and injected carbon dioxide to produce probiotics encapsulated with calcium carbonate (PEC). It was confirmed through SEM, CLSM, and TGA analyses that the probiotics were encapsulated with calcium carbonate and the probiotics within the capsule were alive. Through indirect carbonation using oyster shells, we developed a technology for encapsulating probiotics, which was more economical than the existing probiotic coating technology. Furthermore, since the capsule shape was not deformed during the drying process of PEC and probiotics were protected from gastric juice and bile, the intestinal arrival rate of probiotics was high, enabling the efficient intake of probiotics. In addition, since the encapsulated calcium carbonate was dissolved in the body, there would be advantageous to consume calcium nutrients.

WTO Compatibility of Carbon Motivated Border Tax Adjustments

LEE Soyoung(이소영) 대한국제법학회 2010 國際法學會論叢 Vol.55 No.2

탄소세의 도입은 교토의정서의 발효이후 그 중요성이 부각되고 있으며 국경세조정은 탄소세의 도입으로 인한 경쟁력 약화 등의 문제를 해결하기 위한 방안으로 논의되고 있다. 그렇다면 과연 탄소세가 WTO내에서 허용하고 있는 국경세조정의 대상이 될 수 있는가의 문제가 제기된다. 이에 대한 논의는 GATT 제 3조 제2항에서 규정하고 있는 제품에 “직접적 또는 간접적으로 적용되는 내국세 또는 기타 과징금”이라는 문구의 해석과 현행 WTO 보조금협정의 관련 규정의 해석 및 적용에서 시작된다. 현재 WTO는 직접세와 간접세를 구분하여 간접세의 경우에 대해서만 국경세조정을 허용하고 있다. 최종제품에 “직접적 또는 간접적”으로 부과되는 간접세에 있어서 “간접적”의 명확한 의미에 대해서는 아직까지 구체적으로 설명되어진 바가 없다. 따라서 국경세조정과 관련하여 최종제품에 “간접적”으로 부과되는 세금의 범위가 어디까지인가의 문제가 제기되며, 이는 최종제품의 투입요소에 부과되는 세금의 문제와도 직결된다. 특히 그 범위와 관련하여 과연 최종제품에 물리적으로 체화되는 투입요소에 부과하는 세금만이 “간접적”의 범위에 해당되는지, 혹은 탄소세와 같이 최종제품의 공정, 생산과정에 사용되어 완전하게 소비되는 투입요소에 부과하는 세금도 “간접적”의 범위에 해당되는지의 문제가 제기된다. 현재 수입제품과 수출제품에 대한 국경세조정은 각각 별개의 규정에 따라 규율되지만, 과거 작업반은 국경세조정에 관한 규정은 수입제품과 수출제품에 대하여 동일하게 도착지 원칙을 적용하고 대칭적으로 해석해야 한다는 가정에 근거하였다. 이를 토대로 살펴보면, 보조금협정은 수출제품에 물리적으로 체화된 투입요소이외에도 생산과정에서 소비되는 에너지 요소에 부과되는 전단계누적간접세의 면제, 경감 또는 유예를 허용함으로써 최종제품에 “간접적”으로 부과하는 “간접세”의 범위를 확대시킨 것으로 해석할 수 있다. 또한 Superfund 사건에서 패널의 결론을 바탕으로 하여 생산과정에서 소비되는 투입요소에 대한 “간접세”는 GATT 제3조 2항의 목적상 최종 제품에 “간접적”으로 부과되는 것이라고 해석할 수 있다. 이러한 해석을 적용한다면, 탄소세는 최종제품에 “간접적”으로 부과되는 세금으로서 WTO내에서 국경세조정이 가능한 대상이라고 볼 수 있을 것이다. Carbon taxes are one policy governments might use for reducing GHG emissions. However, unilateral carbon taxes have the effect of hindering competitiveness of domestic products both at home and abroad. One possible solution is to team up carbon taxes with border tax adjustment(BTA). Yet, uncertainties and ambiguities remain as to whether such carbon motivated BTA would be found compatible in the legal framework of WTO if challenged, since BTA is only allowed for taxes levied directly or indirectly on products. Ultimately, the question will turn on how broadly the WTO would interpret the meaning and scope of the phrase "directly or indirectly" for the purpose of GATT Article Ⅲ:2 and corresponding provisions in the ASCM. While it is generally clear that "indirect taxes," as in taxes imposed on products as such, are eligible for BTA, the question as to whether "indirect taxes" on inputs used in the production of final products are adjustable for the purpose of BTA needs further clarification. And it accompanies the question of whether inputs used in the production process should mean to cover only physically incorporated inputs or also non-physically incorporated inputs. Tax adjustments upon importation and exportation for the purpose of BTA need separate consideration as different legal provisions apply under current WTO rules. Nevertheless, it should be noted that the Working Party on BTA agreed that GATT provisions on tax adjustments applied the destination principle identically to imports and exports. Against this background, Annex II of the ASCM seems to have broadened the range of taxes that are border adjustable by providing that the rebate of PSCI taxes on "energy inputs" of final products is permissible upon exportation. And as one can imply from the Panel ruling of the Superfund case and the legislative history, “indirect taxes” imposed on inputs that are completely consumed in the production process would fall within the scope of "indirect taxes," applied at least "indirectly" to a final product for the purpose of GATT Art. Ⅲ:2. This interpretation leads to the conclusion that carbon taxes could be framed as border adjustable within the WTO.

CKD를 이용한 간접광물탄산화에서 이산화탄소 제거 특성

이상민,김연진,최충연,이지연 한국도시환경학회 2018 한국도시환경학회지 Vol.18 No.3

Since the Paris agreement of 2015, Korea has also been obliged to reduce its CO2 emissions by 30% compared to BAU by 2020, and actively should pursue CO2 reduction efforts. This is a study of indirect carbonation which can remove carbon dioxide through indirect mineral carbonation and utilize precipitated carbon carbonate (PCC) with calcium carbonate as industrial material. Calcium eluate obtained from CKD instead of natural mineral as carbonation material and HCl as solvent was used for sequestration of carbon dioxide. As a result of XRF and SEM-EDS analysis to investigate the physi-chemical characteristic of CKD, the calcium content was found to be 46.38%, which is suitable for mineral carbonation. As a result of the calcium ion extraction test by pH of CKD, 18,820 mg Ca2+/L calcium ion was extracted at pH 12 for carbonation reaction. The effect of ‘extraction pH by CKD’ and ‘the mixed gas flow rate including CO2’ on the mineral carbonation reaction were investigated and the removal ratio of CO2 was found to be 40.5% at a flow rate of 13.33 cm3/s of CO2 mixed gas flow rate at pH 12, And the highest PCC production ratio over removed CO2 gas was 73%. 2015년 파리협약이후 우리나라 역시 2020년 CO2 발생량을 30% 감축의무를 부과받아 이산화탄소 감축노력을 적극적으로 수행해야할 상황이 되었다. 본 연구는 간접광물탄산화를 통해 이산화탄소를 제거하고 탄산칼슘성분을 가진 PCC를산업용 재료로 활용할 수 있는 간접탄산화에 대한 연구이다. 탄산화 재료로서 천연광물 대신 Cement Kiln Dust(CKD)를이용한 간접광물탄산화 공정에서 HCl을 용매로 이용하여 CKD로부터 얻은 칼슘 용출액을 이산화탄소를 고정화를 위한간접탄산화 공정을 이용하였다. CKD의 물리화학적 특성을 알기 위해 XRF, SEM-EDS 분석을 진행한 결과 칼슘함량이46.38%로 광물탄산화를 위한 재료로서 적합하다고 분석되었다. CKD의 pH별 칼슘이온 용출실험을 진행한 결과 pH 12에서 18,820 mg Ca2+/L로 탄산화 반응에 충분한 칼슘이 용출되었다. 광물탄산화 반응에서 CKD 용출액의 pH와 이산화탄소 혼합가스 유입유량이 이산화탄소 제거에 어떤 특성을 갖는지 실험한 결과 pH 12의 CKD 용출액과 이산화탄소 혼합가스 유입유량 13.33 cm3/s에서 CO2 제거율이 40.5%를 나타내고 CO2 제거량 당 PCC생성율이 73%로서 가장 높은 결과를 보였다.

Optimum Conditions for Extracting Ca from CKD to Store CO2 Through Indirect Mineral Carbonation

김명진,박세영,김다미,정성수 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.3

Cement Kiln Dust (CKD), a by-product of the cement industry, was used as the raw material to determine the optimum conditions of Ca extraction, which could ultimately be used for indirect mineral carbonation. CKD was a suitable raw material for mineral carbonation due to its high CaO content (42.7%) and fine particle size (23.08 μm), not requiring a pretreatment such as grinding and pH adjustment. Extractions were conducted by varying the factors such as the solvent type, reaction time, temperature, solid-liquid ratio, solvent concentration, and stirring speed, which could affect the Ca extraction. The solvents used (hydrochloric acid, acetic acid, ammonium chloride, ammonium acetate, and sodium citrate) resulted in high Ca extraction efficiencies, and the resultant Ca extract (except for hydrochloric acid) had sufficiently high pH for the carbonation reaction. The optimum conditions set for extracting Ca from the CKD were: 30 min reaction time, 25°C reaction temperature, 1:10 solid-liquid ratio, 1.74 M solvent concentration, and 250 rpm stirring speed. Under these conditions, Ca extraction efficiencies were very high and depended on the solvent used: hydrochloric acid (94.3%), acetic acid (93.7%), ammonium chloride (86.9%), ammonium acetate (85.3%), and sodium citrate (70%). Calcium carbonate was produced by reacting CO2 with Ca extracted with ammonium chloride and ammonium acetate.

간접광물탄산화 반응 중 PCC와 non-PCC에 의한 CO2 저감특성 및CO2 저감 메커니즘

이상민,김연진 한국도시환경학회 2017 한국도시환경학회지 Vol.17 No.4

As the global CO2 sequestration problem and necessity arise, mineral carbonation using industrial byproducts, which is one of the more efficient CO2 reduction technologies, is actively being studied. This study presents a CO2 fixation model for the results of labscale mineral carbonation experiments using waste concrete and was conducted for the purpose of deriving CO2 fixation mechanism. The amount of CO2 fixation was 0.039 mol, 0.017 mol, 0.008 mol per the number of pH swing, and the amount of PCC (Precipitated calcium carbonate) was 0.019 mol, 0.004 mol, and 0.0003 mol per the number of pH swing, respectively, as a result of mineral carbonation experiments according to the number of reuse of waste concrete. Respectively. In order to understand the characteristics of CO2 reduction by mineral carbonation, the first inflection point, the second inflection point, and the last inflection point, which occur during mineral carbonation reaction, are defined and their characteristics are analyzed. CO2 fixation model is presented. CO2 fixation model is separated into PCC section where CO2 is removed as calcium carbonate and non-PCC section where CO2 is reduced as a carbonate form of aqueous phase. In order to characterize the CO2 reduction by non-PCC, a regression linear equation for the relation between the NaOH concentration and the CO2 fixation was derived and applied to the mineral carbonation analysis using waste concrete. The calculated amount of CO2 fixation from non-PCC were 0.373 mol, 0.087 mol, and 0.027 mol, respectively, in the pH adjusting contactor reuse frequency, which is 3 to 10 times higher than the total CO2 fixation. It is considered that there are additional factors, not simply CO2 fixation by NaOH concentration from pH, and further studies are needed to identify and analyze the influence factors on the amount of CO2 fixation from non-PCC. 전세계적으로 CO2 저감 문제와 필요성이 대두되면서 보다 효율적인 CO2 저감기술 중 하나인 산업부산물을 이용한 광물탄산화에대한 연구가 활발히 진행되고 있다. 본 연구는 폐콘크리트를 이용한 Lab-scale 광물탄산화 실험결과에 대한 CO2 저감특성 모델을 제시하고 CO2의 저감 메카니즘을 도출하기 위한 목적으로 실시되었다. 폐콘크리트를 적용한 pH 조정조 재이용 횟수에 따른 광물탄산화 실험결과 CO2 고정량은 횟수별로 0.039 mol, 0.017 mol, 0.008 mol이었으며 탄산칼슘인 PCC(Precipitated calcium carbonate) 생성량은 횟수별로 0.019 mol, 0.004 mol, 0.0003 mol이었다. 광물탄산화에 의한 CO2 저감특성을 파악하기 위하여 광물탄산화 반응추이 중 발생하는 첫 번째 변곡점, 두 번째 변곡점, 그리고 최종 CO2 포화점인 마지막 변곡점을 정의하고 그 특징을 파악하여 탄산칼슘 합성에 의한 PCC(Precipitated calcium carbonate)로서 CO2가 적용되는 PCC구간(PCC section)과 수용액상의 탄산염 형태로 CO2 가 저감되는 non-PCC 구간으로 구분하여 PCC와 non-PCC에 의한 CO2 저감 모델을 제시하였다. Non-PCC에 의한 CO2 저감특성 파악을 위하여 NaOH 농도와 CO2 고정량의 관계에 대한 회귀직선식을 도출하여 폐콘크리트를 이용한 광물탄산화 해석에 적용하였고산출된 non-PCC에 의한 CO2 고정량은 pH 조정조 재이용 횟수별로 0.373 mol, 0.087 mol, 0.027 mol로 총 CO2 고정량에 비하여 3~10 배 높은 값을 나타내었다. 단순히 pH를 이용한 NaOH농도에 의한 CO2 고정이 아닌 추가적인 요인들이 있을 것으로 판단되며 non- PCC에 의한 CO2 고정량에 미치는 영향인자의 파악 및 해석을 목적으로 하는 연구가 추가적으로 필요할 것으로 판단된다.

Evaluation of the leaching characteristics of low-grade nickel laterite waste rock for indirect carbon sequestration application

Ramon Christian P. Eusebio,Bernard Jomari B. Razote,Hannah Jelsy T. Del Pilar,Richard D. Alorro,Arnel B. Beltran,Aileen H. Orbecido 한국자원공학회 2020 Geosystem engineering Vol.23 No.4

The potential utilization of waste rock obtained from an active nickel mine site in Mindanao, the Philippines for indirect carbon sequestration is explored in this study. X-ray diffraction (XRD), X-ray fluorescence (XRF), and inductively coupled plasma optical emission spectroscopy (ICP-OES) results showed that the sample is rich in iron, existing in three different forms: goethite (α-FeOOH), chromite (FeCr2O4), and magnetite (Fe3O4). Leaching tests performed using hydrochloric acid (HCl) showed high iron extraction rates, with a maximum average extraction efficiency of 95.35% obtained at 100°C, 4 M HCl, and 1.0 h. Morphological and physicochemical analyses conducted through scanning electron microscopy and Brunauer–Emmett–Teller (BET) method supported the high extraction rates obtained for Fe, which is due to the higher reactivity of the sample to the leaching agent as well as the higher availability of accessible sites for reaction on the sample surface as compared to other mine wastes that are previously utilized. The nickel laterite waste rock sample has the potential to be used as a feedstock for iron carbonation in indirect carbon sequestration; however, challenges such as the use of sulfide source and cost requirements must be addressed in order to fully determine its viability for industrial scale application.

간접탄산염화를 위한 전기로제강슬래그 중 Ca, Fe 및 Si 성분의 초산수용액 침출

윤기병 한국자원리싸이클링학회 2017 資源 리싸이클링 Vol.26 No.1

It has been reported that aqueous indirect carbonation process of calcium silicate mineral could be one of the most promising methods for CO 2 sequestration. The process consists of two main steps, extraction of Ca from calcium silicate and carbonation of the extracted solution by CO 2 . Many types of acids such as HCl and HNO 3 can be used in the extraction step of the process. In the case of using aqueous acetic acid solution as the extraction solvent, acetic acid can be reproduced at the carbonation step of the extracted solution by CO 2 and recycled to extraction step for reuse it. Industrial by-products such as iron and steel slags are potential raw materials of the indirect carbonation process due to their high contents of calcium silicate. In this study, in order to examine the extraction efficiency of domestic electric arc furnace steel slag by aqueous acetic acid solution, extraction experiments of the slag were performed by using the aqueous acetic acid solutions of varying extraction conditions ; acetic acid concentrations, extraction temperatures and times. 이산화탄소 저감을 위한 유효한 방법 중의 하나로 칼슘규산염 광물의 간접탄산염화 공정이 보고되고 있다. 이 공정은 염산, 질산등의 산에 의하여 칼슘규산염으로부터 칼슘성분을 침출하는 단계와 이산화탄소에 의한 침출용액의 탄산염화 단계의 두 과정으로 구성된다. 침출용매로 초산수용액을 사용하는 경우에는 침출용액을 이산화탄소로 탄산염화 하는 과정에서 초산이 재생성 되어 침출단계로 순환되어 침출용매로 재사용될 수 있다. 제철 및 제강슬래그와 같은 산업부산물은 칼슘규산염을 많이 함유하고 있어 간접탄산염화공정의 원료로 사용될 수 있다. 본 연구에서는 초산수용액에 의한 국내 전기로제강슬래그의 침출효율을 조사하기 위하여, 초산수용액 농도, 침출온도 및 침출시간 등의 침출조건 변화에 따른 침출실험을 수행하였다.

한국 건물부문 탄소세 도입 방안

류성룡(Ryu, Seong-Ryong),정창헌(Cheong, Chang-Heon) 한국건축친환경설비학회 2015 한국건축친환경설비학회 논문집 Vol.9 No.6

Carbon tax is very effective method for the reduction of greenhouse gas in building section. This study suggests the carbon tax system of building section in South Korea. Carbon tax can be classified as direct tax type and indirect tax type. The proposed carbon tax system respectively linked to secured property tax, property transfer tax and energy tax type. The carbon tax with direct tax type will make the building owner aware of the importance of building energy. Hence, the carbon tax will enhance the low-carbon structuralization of building sector. The profit gained from carbon tax in building sector must be redistributed to stakeholders in building section as incentives to secure the sustainability of the low-carbon structuralization.