• Tribology and Lubricants
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• v.27 no.2
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• pp.109-114
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• 2011

The low temperature characteristics of automotive diesel have been legally regulated due to the fact that solid particle in diesel at low temperature can cause severe problems in the vehicle. The biodiesel is well known for eco-friendly fuel, which is one of the most popular alternative petrodiesel, but it is easy to solidified at low temperature than petrodiesel at low temperature. For that reason, in this study, we investigated the low temperature fuel characteristics of diesel-biodiesel blends which were prepared to mix 6 different kinds of biodiesel to winter diesel fuel, respectively. Also, we confirmed to improve low temperature fuel characteristics by pour point depressant.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.542-547
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• 2010

n-Paraffin and saturated fatty acid methyl esters in the diesel and bio-diesel fuel crystallize at low temperature. Many articles have addressed various solutions for the low temperature crystallization problem and one of them is the use of methacrylate copolymers. In this work, we synthesized a series of copolymers in the reaction condition of 70 : 30 molar ratio of lauryl methacrylate (LMA) (or stearyl methacrylate (SMA)) and alkyl methacrylates. The structures of the copolymers were characterized by $^1H$-NMR and FT-IR spectroscopy, and the molecular weight of copolymers were obtained from Gel Permeation Chromatography (GPC) method. The concentrations of additives were 500~1000 ppm and 1000~10000 ppm in diesel fuels and bio-diesel fuel (BD5 and BD20), respectively. The addition of copolymers changes the many properties of fuel such as the pour point (PP), cloud point (CP) and cold filtering plugging point (CFPP). For example, the low temperature properties of the copolymers containing SMA ($PSMAmR_2n$) were excellently improved about 15, 7, and $10^{\circ}C$ for PP, CP and CFPP, respectively.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.4
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• pp.15-23
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• 2002

In most cryogenic liquid rocket engines, liquid oxygen manifold and injector are not thermally insulated from room temperature environment fur reducing system complexity and the weight. This feature of cryogenic liquid rocket engine results in the situation that cryogenic liquid oxygen flow is easy to be vaporized especially in the vicinity of the manifold and the injector wall. The research in this paper is focused on two-phase flow phenomena of liquid oxygen in rocket engine. Vapor fraction was estimated by comparing the measured two-phase flow pressure drop in engine manifold and the injector with ideal single phase pressure drop. Heat flux into cryogenic flow is estimated by measuring the wall temperature on the engine manifold to examine boiling characteristics. Suitable correlations for cryogenic two-phase flow were also reviewed to see their applicability. In addition, the effect of vapor generation in liquid rocket engine manifold and injector on engine performance and stability was considered.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.497-503
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• 2008

A variety of techniques has been employed in order to reduce problems caused by the crystallization of paraffin and saturated fatty acid esters in diesel fuel containing biodiesels. Methacrylate copolymers are known as additives which reduce the pour point and cold filtering plugging point (CFPP) of diesel fuels. This paper describes the synthesis, characterization and low temperature properties, having as an initial step the synthesis of the alkyl methacrylate monomers by esterification of methacrylic acid with C12, C18, and C22 fatty alcohols. The copolymerization of these monomers with styrene was then performed, with molar ratios of 30:70, 50:50 and 70:30 for styrene:alkyl methacrylate. All copolymers were characterized by $^1H-NMR$, FT-IR, and gel permeation chromatography (GPC). The poly(styrene-co-alkyl methacrylate)s (PStmSMAn) leads to a large reduction in the pour point and CFPP of poly(styrene-co-alkyl methacrylate) in ultra low sulfur diesel (ULSD) and BD5 with treated 100~5000 ppm of poly(styrene-co-alkyl methacrylate). BD5 fuel containing 5000 ppm of the copolymer (PSt82SMA18) showed a $25^{\circ}C$ and $9^{\circ}C$ reduction in their pour points and CFPP, respectively.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.356-359
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• 2012

SNCR 기술은 SCR에 비해 탈질 효율은 떨어지지만 촉매없이 고온 배출가스에 NH3 또는 요소수를 직접 분사하여 질소와 물로 환원시키는 방법이므로 초기 투자비 및 운영비가 적어 최근 국내 대다수의 소각장, 산업용 보일러 등에 널리 적용되고 있다. 단, SNCR 기술은 급격한 온도 강하나 접근의 불용이성, 불균일한 혼합, 액적의 증발시간 지연, 불균일한 운전 조건 등의 영향을 크게 받으며, 특히 반응 온도가 가장 중요한 변수로서 최적 반응 온도 영역대가 약 800~$1,000^{\circ}C$라는 점에서 이상적인 반응 온도 조건을 찾아서 환원제를 분무하는 것이 매우 중요하다. 이에 본 연구에서는 열유동 전산해석을 통해 스토커식 소각로의 폐기물 성상별 화염 온도 분포를 예측하고 적정 반응 온도 영역을 확인하여 요소수 주입 고도를 선정, 폐기물 성상별 분무 조건을 확립하고자 수치 해석적 연구를 수행하였다. 폐기물 성상(고질/중질/저질 폐기물)별로 화염 온도를 예측한 결과, 최적 반응 온도 영역대가 약 800~$1,000^{\circ}C$, 폐기물 성상의 심한 변화 때문에 소각로의 효율적인 연소 조건 제어에 어려움 등을 고려하여 약 700~$1,000^{\circ}C$ 온도 영역대를 환원제 분무 온도로 선정하였다. 폐기물별로 발열량에 따른 화염 온도가 모두 다르기 때문에 환원제 분무 위치를 3지점으로 선정하여 각 지점별로 분무 운전 조건을 확립하였다.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.232-240
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• 2012

Bio-diesel (BD) is the mono alkyl esters of long chain fatty acids derived from renewable feed stocks like vegetable oils or animal fats. Bio-diesel shows poorer fuel properties than that of diesel fuel in a cold condition. For the diesel fuel, many cold flow improvers have been developed; however, since primary ingredients of bio-diesel are different from those of the diesel fuel, there is a limit to the cold flow improvement when the same cold flow improvers are added to bio diesel. In this study, to improve low temperature properties of bio-diesel, we developed a cold flow improver using an alkyl methacrylate monomer, prepared via ester reaction, and maleic anhydride and also conducted a ring opening reaction using amine. We characterized the products using $^1H-NMR$, FT-IR and GPC methods. In addition, the cold flow improvements of the products in Soybean BD and Palm BD in the concentration rage of 1000~10000 ppm were investigated. It was found that the addition of LMA2SMA6MA2-C8A in Soybean BD improved the pour point by $12.5\;^{\circ}C$.