• 한국대기환경학회지
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• 제20권4호
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• pp.429-436
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• 2004

Circulating fluidized bed combustion (hereafter CFBC) technology enables an efficient combustion for the materials with low heating values such as high ash coal and sludges. It also has desulfation function by adding limestone directly to combustor. The CFBC has been considered as one of the best processes for low grade coal containing with large contents of ash and sulfur. In this paper, in order to various tests were performed to find the optimum desulfation condition for CFBC using Korean Anthracite. We surveyed possible parameters and conducted desulfation efficiency test in D Thermal Power Plant. In addition, the result of some fundamental theoretical consideration was discussed with CFBC. Optimum limestone size could be considered to be 0.1-0.3mm irrespective of combustion temperature and Ca/S molar ratio variation. Desulfation efficiency increased as the molar ratio increased. Because desulfation process occurs at the surface at higher temperature, inner side of limestone can＇t be utilized. When surface area is not appropriate, some SO$_2$ emit without reaction. Optimum molar ratio should be decided after considering chemical and physical properties of limestone and coal thoroughly such as particle size, pore size and HGI. Commercial CFBC is operated at Ca/S 1.6. Combustor temperature 840-87$0^{\circ}C$ shows good desulfation efficiency.

• Journal of Advanced Marine Engineering and Technology
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• 제37권8호
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• pp.855-861
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• 2013

저온에서 NOx 저감률이 높은 작은 기공을 갖는 Cu-chabazite SCR 촉매는 150 에서 $300^{\circ}C$ 범위의 낮은 배기가스 온도를 갖는 박용 디젤엔진에 적용성이 높다. 불행하게도, 박용디젤엔진용 연료는 체적베이스로 1.5% 이상의 높은 레벨의 황을 함유 할 수 있다. 이것은 공연비 50:1로 엔진 운전시에 배기가스에 이산화황의 레벨이 500 ppm에 해당된다. 배기가스에 포함되어 있는 높은 레벨의 이산화황은 Cu-chabazite SCR 촉매의 NOx 저감률을 감소시키는 역할을 할 수 있다. 본 연구에서는 Cu-chabazite SCR촉매의 황 피독에 의한 NOx 저감 성능을 연구하기 위하여 벤치플로 시스템을 구축하였다. Cu-chabazite SCR 촉매를 황 피독 시키기 위하여 5% 이산화탄소, 14% 산소, 5% 물과 나머지 질소로 만들어진 배기가스에 500 ppm의 이산화황을 각각 150, 200, 250, $300^{\circ}C$에서 2시간씩 노출 시켰다. 황 피독후 Cu-chabazite SCR 촉매의 불활성 한계를 측정하기 위하여 저온(150~$300^{\circ}C$)에서 NOx 저감 성능을 평가하였다. 또한, 600 과 $700^{\circ}C$에서 각각 30분씩 탈황 작업을 수행하여, 황 피독된 Cu-chabazite SCR 촉매의 NOx 저감 성능이 회복될 수 있는 온도를 결정하였다.

• Applied Biological Chemistry
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• 제42권2호
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• pp.140-146
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• 1999

청각(1.2 kg)을 0.8% 염산 수용액(24 l)으로 추출한 추출물을 메탄올 환류, 에탄올 침전 및 투석하여 활성이 약 2배 증가된 조다당(CF-1)으로부터 2종의 항응고활성 다당류를 정제하였다. 정제는 CF-1의 DEAE-Toyopearl이온교환 크로마토그래피와 Sephadex G-75, Sephadex G-100, Sepharose CL-6B 겔여과 크로마토그래피, HPLC 등을 이용하였다. 최종 정제 다당류획분인 CF-1-VIa-1과 CF-1-VIIa-1는 분자량이 각각 80,000과 40,000 Da 이었으며, 주구성당으로서 arabinose와 galactose가 약 2:1의 몰비율로 풍부하게 함유되어 있었고, 구성당 잔기에 $12{\sim}13%$의 유황을 함유하는 함황성 다당류들이었다. CF-1-VIa-1와 CF-1-VIIa-1의 항응고활성을 $2.5\;{\mu}g/mL$의 농도에서 비교하였을 때 APTT활성은 대조군에 비하여 각각 262초, 250초이었고 TT활성은 각각 130초, 70초이었으며, 분자량이 큰 CF-1-VIa-1이 다소 높은 항응고활성을 보였다. CF-1-VIa-1와 CF-1-VIIa-1의 desulfation과 sulfation을 통한 항응고활성을 비교한 결과 desulfation시 항응고활성이 각각 약 80%와 50%로 감소하였으나 sulfation시에는 약 30%와 20%로 그 활성이 증가하였다. 두 다당류는 헤파린과 달리 농도 의존적으로 불용성 피브린의 형성을 억제하므로써 antithrombin III 비의존적 트롬빈 저해활성을 나타내었으며, 칼슘이온의 킬레이트에 의한 혈액응고 저해효과는 나타내지 않았다.

• 한국수산과학회지
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• 제44권6호
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• pp.630-634
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• 2011

Enzymatic hydrolysate of porphyran from Porphyra yezoensis was prepared by treatment with ${\beta}$-agarase. The hydrolysate was fractioned into molecular sizes of <3, 3-30, and 30-300 kDa using an ultrafiltration membrane. The membrane fractions were further separated into neutral and anionic fractions using Dowex $1{\times}8$ ion exchange chromatography. After hydrolysis of porphyran with ${\beta}$-agarase, 23.2% of the starting porphyran was recovered as a neutral fraction of low-molecular weight (<3 kDa), and 28.9% remained as an enzyme-resistant anionic fraction of high molecular weight (>300 kDa). Desulfation of porphyran and $^{13}C$-NMR analysis of the anionic fraction of low molecular weight (<3 kDa) showed that the anionic fraction has a backbone consisting of 3-linked ${\beta}$-D-galactose units alternating with either 4-linked a-L-galactose 6-sulfate or 3, 6-anhydro-a-L-galactose units. These results indicate that porphryan is a copolymer of two moieties, about 25% of which are composed of neoagarose moieties and 75% as anionic moieties.

• 한국환경과학회지
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• 제15권6호
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• pp.587-592
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• 2006

The advantage of CFBC(Circulating fluidized bed combustor) is that it can apply to various fuel sources including the lower rank fuel and remove SOx by means of direct supply of limestone to the combustor without additional desulfation facility. In this paper, we denote characteristics of fly and bed ash to reuse finer limestone usually abandoned(used spec[Coarse LS] 0.1mm under 25%, new spec[Fine LS] 0.1mm under 50%). According to the results, the chemical composition of fly ash was as follows; $SiO_2\;40.8%,\;Al_2O_3\;31.9%,\;CaO\;10.7%,\;K_2O\;4.46%$ in the case of coarse limestone and $SiO_2\;41.1%,\;Al_2O_3\;31.3%,\;CaO\;10.9%,\;K_2O\;4.66%$ in the case of fine limestone. The chemical composition of bed ash was as follows; $SiO_2\;54.2%,\;Al_2O_3\;33.1%,\;CaO\;1.56%,\;K_2O\;4.34%$ in the case of coarse limestone and $SiO_2\;53.8%,\;Al_2O_3\;32.6%,\;CaO\;2.21%,\;K_2O\;4.45%$ in the case of fine limestone. It showed that there was no significant change in chemical composition. And it is conformed that there was no significant change in particle size and shapes.

• Food Science and Biotechnology
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• 제17권5호
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• pp.1097-1101
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• 2008

The objective of this study was to identify and quantify glucosinolates (GSLs) in Brassica napus cv. Hanakkori and its parents and to evaluate its potential bitter taste. 'Hanakkori' materials were cultivated with commercial chemical nutrients (20 kg/ha, N-P-K: 16-10-10) at the field. GSLs were isolated by means of extraction with 70%(v/v) boiling methanol (MeOH) followed by desulfation from those plants by reversed-phase high performance liquid chromatography (HPLC) and identified by electronic spray ionization-mass spectrometry (ESI-MS) analysis. In 'Hanakkori', 11 GSLs were identified as progoitrin, glucoraphanin, glucoalyssin, gluconapoleiferin, gluconapin, 1-methylpropyl, glucobrassicanapin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin. The total GSL contents were 109 and 36.1 mmol/kg dry weights (d.w.) for the seeds and edible parts, respectively. The major GSLs (>5 mmol/kg d.w.) in the seeds were progoitrin (78.8), gluconapin (10.7), and glucobrassicanapin (7.81), whereas they in the edible parts were progoitrin (16.1) and glucobrassicanapin (8.58). In addition, the bitter taste in the edible parts was presumably related with the presence of progoitrin (>45% to the total GSL).