Yong Bin Lai

Study on Cold Flow Properties of Typical Materials Biodiesel and its Blends

The chemical compositions of biodiesel are analyzed by gas chromatograph-mass spectrometer (GC-MS), and theirs molecular structure are investigated on the basis of the hybrid orbital theory. Cold filter plugging point (CFPP) of biodiesel is studied by CFPP tester, the solution crystallization theory and the similarity-intermiscibility principle. Good correlation models are proposed for prediction biodiesel CFPP by chemical compositions and CFPP of biodiesel-petrodiesel blends by biodiesel ratio. The study shows that biodiesel is mainly composed of SFAME (C14:0C24:0) and UFAME (C16:1C22:1, C18:2 and C18:3). Carbon atoms of the alkyl for SFAME arrange in a zigzag pattern by CCC=109.5°. C-C carbon atoms of the alkyl arrange in a zigzag pattern by CCC=109.5°, too, carbon chain is curved by C=C in CCC=122.0°, and curved degree increases with increasing unsaturated degree. CFPP of biodiesel is mainly determined by chemical compositions. CFPP increases with the amount and carbon chain length of SFAME. CFPP of biodiesel-petrodiesel blends is mainly determined by chemical compositions and ratio of biodiesel. To lower SFAMEC20 biodiesel, such as PME, CSME, WME, SBME and RME, it blending with-10PD can formed a eutectic mixture. CFPP of the eutectic mixture is-12 °C. The biodiesel ratio for the lowest CFPP rang increases with decreasing SFAME. Such as, SFAME contents in PME, CSME, WME, SBME and RME are 35.86, 32.12, 31.04, 18.29 and 14.69 w% respectively, and the range of biodiesel ratio is 520, 1020, 2030, 3050 and 4060 v% respectively. To higher SFAMEC20 biodiesel, such as PNME, CFPP increases with PNME ratio.

Ignition Quality of Biodiesel from Cottonseed and Soybean Oil

The thermal analysis has been employed to yield information on the biodiesel ignition quality since the ignition quality influences the combustion and exhaust emissions of the fuels in a compression ignition (CI) engine. The chemical compositions of -10 petrodiesel (-10PD), soybean-based biodiesel (SME) and cottonseed-based biodiesel (CME) are analyzed by gas chromatography-mass spectrometry (GC-MS). Ignition temperature of -10PD, SME and CME is determined by thermogravimetry-differential scanning calorimetry (TG-DSC). The study shows that the biodiesel is mainly composed of fatty acid methyl esters: C14:0–C24:0, C16:1–C22:1, C18:2 and C18:3. Biodiesel ignition quality is better than petrodiesel. The ignition temperature of CME and SME is 207.4 and 213.9 °C respectively. The ignition quality of biodiesel is better with shorter carbon chain lengths and more saturated fatty acid methyl ester (SFAME).

Improving the Cold Flow Properties of Biodiesel Derived from Palm

The chemical compositions of biodiesel derived from palm (PME) were analyzed by gas chromatography-mass spectrometry (GC-MS). The cold flow properties of PME were studied by multifunctional low temperature tester, differential scanning calorimetry (DSC) and solution crystallization theory. Three approaches for improving cold flow properties of PME were put forward: crystallization fractionation, blending with winter petrodiesel and treating with cold flow improver (CFI) additives. A good correlation model was proposed for prediction cold filter plugging point (CFPP) by winter petrodiesel blending ratio. The study shows that the PME was mainly composed of saturated fatty acid methyl esters (SFAME): C14:0-C24:0 and unsaturated fatty acid methyl esters (UFAME): C16:1-C22:1, C18:2 and C18:3. The mass fraction of SFAME and UFAME was 35.86% and 62.83%, respectively. The CFPP of PME was 8°C. Crystallization fractionation and blending with -10 petrodiesel (-10PD) decreased the CFPP to 0 and -12°C, respectively. Treating with CFI additives (volume fraction ≤ 1.5%) decreased the CFPP of PME and PME/-10PD to 2 and -26°C, respectively. This study has effectively improved cold flow properties of PME and provided theoretical support for using PME during cold weather.

Study on Cold Flow Properties of Waste Cooking Methyl Ester

The chemical compositions of waste cooking methyl ester (WCME) were analyzed by GC-MS, and the cold flow properties of WCME were studied by cold filer plugging point tester and viscosity tester. Through blending with petrodiesel and adding cold flow improver (CFI), the cold flow properties of WCME were improved efficiently. The study shows that WCME was mainly composed of saturated fatty acid methyl ester (SFAME) and unsaturated fatty acid methyl ester (UFAME), and contents of SFAME and UFAME were 27.63 and 71.81 w%, respectively. The cold filer plugging point (CFPP) of WCME was 0 °C, and the viscosity of it was 4.41 mm2·s-1 at 40 °C. Blending with 0 petrodiesel (0PD) and-10 petrodiesel (-10PD) decreased the CFPP of WCME to-4 °C and-13 °C, respectively. Meanwhile with WCME blending ratio increasing the viscosities of blending oils increased at the same temperature, and the viscosities increased gradually when the temperature decreased. Treating with CFI could significantly reduce the CFPP of blending oils which were composed of WCME and petrodiesel. The viscosities of blending oils with adding CFI were slightly higher than those with out CFI.

Prediction of the Cold Flow Properties in Biodiesel Blends

The chemical compositions of biodiesel are analyzed by GC-MS, and their molecular structures are investigated on the basis of the hybrid orbital theory. The CFPP of biodiesel is studied by CFPP tester, the solution crystallization theory and the similarity-intermiscibility principle. Good correlation models are proposed for predict CFPP of biodiesel by chemical compositions and the CFPP of biodiesel-petrodiesel blends by biodiesel ratio. The study shows that biodiesel is mainly composed of SFAME (C14:0～C24:0) and UFAME (C16:1～C22:1, C18:2 and C18:3 ). Carbon atoms of the alkyl for SFAME arrange in a zigzag pattern by ∠CCC=109.5°. C-C carbon atoms of the alkenyl arrange in a zigzag pattern by ∠CCC=109.5°, too, carbon chain is curved by C=C in ∠CCC=122.0°, and curved degree increases with increasing unsaturated degree. CFPP of biodiesel is mainly determined by chemical compositions. CFPP increases with the amount and carbon chain length of SFAME. CFPP of biodiesel-petrodiesel blends is mainly determined by chemical compositions and ratio of biodiesel. To lower SFAME≥C20:0 biodiesel, such as PME, CSME, WME, SBME and RME, it blending with -10PD can formed a eutectic mixture. CFPP of the eutectic mixture is -12 °C. The biodiesel ratio for the lowest CFPP rang increases with decreasing SFAME. Such as SFAME contents in PME, CSME, WME, SBME and RME are 35.86、32.12、31.04、18.29 and 14.69 w% respectively, and the range of biodiesel ratio is 5～20、10～20、20～30、30～50 and 40～60 v% respectively. To higher SFAME≥C20:0 biodiesel, such as PNME, CFPP increases with PNME ratio.

Flow Field and its Flowability in a Stirred Tank with a Plate Propeller

The flow field produced by a plate propeller in a fully baffled flat bottomed cylindrical stirred tank with the diameter of 300 mm was measured using phase doppler particle analyzer. The radial distributions of the time-averaged, fluctuation velocity and turbulent kinetic energy were analyzed. The effects of off-bottom clearance and baffle on the flow field were investigated. The results showed that the fluctuation velocity and turbulent kinetic energy increased with increasing off-bottom clearance in the impeller region; meanwhile, the maximum values of the time-averaged and fluctuation velocity moved to the center of the stirred tank. The maximum axial velocity decreased with increasing off-bottom clearance in the bulk flow. The turbulent kinetic energy was higher in the impeller region. The maximum value of the turbulent kinetic energy increased with increasing off-bottom clearance and occurred near the end of the impeller. The baffle hindered the tangential velocity and exerted strong influence on the turbulent kinetic energy. The flow field in front of the baffle reflected the distribution of the turbulent kinetic energy in the impeller region.

Enhancing Cold Flow Property of Biodiesel Derived from Cottonseed Oil

The chemical compositions of cottonseed oil biodiesel (CSME) are analyzed by using the gas chromatograph-mass spectrometer (GC-MS). The cold flow properties of CSME is studied by cold filer plugging point (CFPP) tester and crystallization mechanism of biodiesel, three approaches for enhancing cold flow properties of CSME are put forward: crystallization fractionation; blending with winter petrodiesel; and treating with cold flow improver (CFI) additives. A significant correlation model is proposed for predicting CFPP by CSME blending ratio. The study shows that the CSME is mainly composed of saturated fatty acid methyl esters (SFSMEs): C14:0~C24:0 and unsaturated fatty acid methyl esters (UFAMEs): C16:1~C22:1, C18:2 and C18:3. The mass fraction of SFAME and UFAME is 32.12 and 66.19%, respectively. The CFPP of CSME is 6 °C. Crystallization fractionation and blending with-10PD decrease the CFPP of CSME to-1 °C and-12 °C, respectively. Adding Flow Fit, Flow Fit K and T818 additives 1.5 v% decreases the CFPP of CME and CME/-10PD to 0 and-26 °C, respectively. This study has effectively enhanced cold flow properties of CSME and provides technical support for using CSME.

Mechanism of Flow Properties for Biodiesel Blends at Low Temperature

The chemical composition of biodiesel was analyzed by gas chromatography-mass spectrometry. The cold filter plugging point of biodiesel was measured according to GB/T 20828-2007. The cold flow properties of biodiesel were investigated on the basis of the crystallization theory, including chemical composition and molecular structure. Biodiesel might be considered a pseudobinary mixture, namely, high-melting-point saturated fatty acid methyl esters and low–melting-point unsaturated ones. Bilayer crystal structure of biodiesel was founded. Bilayer structure with headgroups aligned next to each other inside the crystal and away from nonpolar bulk liquid was large platelet lamellae. The results showed that biodiesel was mainly composed of saturated fatty acid methyl esters (C14:0～C24:0 ) and unsaturated ones(C16:1～C22:1、C18:2 and C18:3 ). The cold flow properties for biodiesel were determined mainly by the amount and molecular structure of saturated fatty acid methyl esters. The long-straight-chain saturated fatty acid methyl esters tend to have relatively poor cold flow properties. The cold flow properties worsen with increasing the amount and carbon chain length of straight-chain saturated fatty acid methyl esters. The ways of adjusting biodiesel composition and treating with depression of cold filter plugging point were given; they could improve cold flow properties.

Study on Thermal Volatilization of Soybean Biodiesel and Its Blends

Thermal analysis has been employed to yield information on the volatility of the biodiesel/petrodiesel since the volatility influences the ignition quality of the fuels in a compression ignition engine. The chemical composition of -10 petrodiesel (-10PD) and soybean biodiesel (SME) was analyzed by gas chromatography-mass spectrometry. The thermal volatilization of biodiesel and its blends was investigated by thermogravimetry and liquid volatile theory. Volatile index was put forward for describing biodiesel/petrodisel volatility. A good correlation model was proposed for calculate the biodiesel/petrodiesel volatility by biodiesel blending ratio. The study showed that -10PD was mainly composed of long chain alkanes: C8–C26. SME was mainly composed of long chain fatty acid methyl esters: C14:0–C24:0, C16:1–C22:1, C18:2 and C18:3. The volatile indexes of SME and -10PD were, respectively, 1.74E-04 and 3.64E-05. The biodiesel fuel was considerably more volatile in comparison to the petrodiesel fuels. The SME/-10PD volatility had relation to SEM blending ratio, it was better with increasing the SME blending ratio.

Improving Flow Properties of Rapeseed-Based Biodiesel at Low Temperatures

The cold flow properties of rapeseed-based biodiesel (RME) were studied by gas chromatography-mass spectrometry (GC-MS), multifunctional low temperature tester and thermal analysis. Two approaches for reducing cold filter plugging point (CFPP) of RME were investigated: blending with winter petrodiesel, treating with cold flow improver (CFI) additives and the effect of CFI to combustion characteristics of RME. A good correlation model was proposed for prediction CFPP by RME blending ratio. The study shows that the RME was mainly composed of fatty acid methyl esters (FAME): C14:0–C24:0, C16:1–C22:1, C18:2 and C18:3. The mass fraction of saturated fatty acid methyl esters (SFAME) and unsaturated fatty acid methyl esters (UFAME) was 14.69% and 83.40%, respectively. The CFPP of RME was -7 °C. Blending with -10 petrodiesel (-10PD) decreased the CFPP to -12 °C. Treating with CFI additives (volume fraction ≤ 1.5%) decreased the CFPP of RME and RME/-10PD to -11 and -28 °C, respectively. Small amount of CFI additives hardly affected combustion characteristics of biodiesel. This study has effectively improved cold flow properties of biodiesel and provided guide for using biodiesel at low temperatures.