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Development of a combined approach for improvement and optimization of karanja biodiesel using response

Sunil DHINGRA, Gian BHUSHAN, Kashyap Kumar DUBEY

《能源前沿（英文）》 2013年 第7卷 第4期   页码 495-505 doi: 10.1007/s11708-013-0267-5

摘要： This paper described the production of karanja biodiesel using response surface methodology (RSM) and genetic algorithm (GA). The optimum combination of reaction variables were analyzed for maximizing the biodiesel yield. The yield obtained by the RSM was 65% whereas the predicted value was 70%. The mathematical regression model proposed from the RSM was coupled with the GA. By using this technique, 90% of the yield was obtained at a molar ratio of 38, a reaction time of 8 hours, a reaction temperature of 40 oC, a catalyst concentration of 2% oil, and a mixing speed of 707 r/min. The yield produced was closer to the predicted value of 94.2093%. Hence, 25% of the improvement in the biodiesel yield was reported. Moreover the different properties of karanja biodiesel were found closer to the American Society for Testing & Materials (ASTM) standard of biodiesel.

关键词： optimization of karanja biodiesel     genetic algorithm (GA)     response surface methodology (RSM)     percentage improvement in the biodiesel yield     properties of biodiesel    

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Improvement in growth yield of single-walled carbon nanotubes with narrow chirality distribution by pulse

Bin Xu, Toshiro Kaneko, Toshiaki Kato

《化学科学与工程前沿（英文）》 2019年 第13卷 第3期   页码 485-492 doi: 10.1007/s11705-019-1831-2

摘要： A pulse plasma chemical vapor deposition (CVD) technique was developed for improving the growth yield of single-walled carbon nanotubes (SWNTs) with a narrow chirality distribution. The growth yield of the SWNTs could be improved by repetitive short duration pulse plasma CVD, while maintaining the initial narrow chirality distribution. Detailed growth dynamics is discussed based on a systematic investigation by changing the pulse parameters. The growth of SWNTs with a narrow chirality distribution could be controlled by the difference in the nucleation time required using catalysts comprising relatively small or large particles as the key factor. The nucleation can be controlled by adjusting the pulse on/off time ratio and the total processing time.

关键词： single-walled carbon nanotubes     chirality-controlled synthesis     pulse plasma chemical vapor deposition    

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ALKALINE PRETREATMENT AND AIR MIXING FOR IMPROVEMENT OF METHANE PRODUCTION FROM ANAEROBIC CO-DIGESTION

《农业科学与工程前沿（英文）》 2023年 第10卷 第3期   页码 424-436 doi: 10.15302/J-FASE-2023506

摘要：

● Integration of alkaline pretreatment and air mixing for co-digestion was validated.

关键词： sodium hydroxide     air injection     cumulative methane yield     kinetic modeling analysis     digestate    

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Metakaolinite as a catalyst for biodiesel production from waste cooking oil

Jorge RAMIREZ-ORTIZ, Merced MARTINEZ, Horacio FLORES

《化学科学与工程前沿（英文）》 2012年 第6卷 第4期   页码 403-409 doi: 10.1007/s11705-012-1224-2

摘要： The use of metakaolinite as a catalyst in the transesterification reaction of waste cooking oil with methanol to obtain fatty acid methyl esters (biodiesel) was studied. Kaolinite was thermally activated by dehydroxylation to obtain the metakaolinite phase. Metakaolinite samples were characterized using X-ray diffraction, N adsorption-desorption, simultaneous thermo-gravimetric analyse/differential scanning calorimetry (TGA/DSC) experiments on the thermal decomposition of kaolinite and Fourier-transform infrared spectrometer (FTIR) analysis. Parameters related to the transesterification reaction, including temperature, time, the amount of catalyst and the molar ratio of waste cooking oil to methanol, were also investigated. The transesterification reaction produced biodiesel in a maximum yield of 95% under the following conditions: metakaolinite, 5 wt-% (relative to oil); molar ratio of oil to methanol, 1∶23; reaction temperature, 160°C; reaction time, 4 h. After eight consecutive reaction cycles, the metakaolinite can be recovered and reused after being washed and dried. The biodiesel thus obtained exhibited a viscosity of 5.4?mm ?s and a density of 900.1 kg?m . The results showed that metakaolinite is a prominent, inexpensive, reusable and thermally stable catalyst for the transesterification of waste cooking oil.

关键词： biodiesel     metakaolinite     transesterification     waste cooking oil    

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Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1198-1210 doi: 10.1007/s11705-021-2133-z

摘要： Sulfonic acid functionalized mesoporous silica based solid acid catalysts with different morphology were designed and fabricated. The synthesized materials were characterized by various physicochemical and spectroscopic techniques like scanning electron microscope-energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area, thermogravimetric analysis and n-butylamine acidity. The shape of catalysts particles plays an important role in its activity. The sulfonic acid functionalized mesoporous silica catalysts of spherical shape and the cube shape were assessed for catalytic activity in biodiesel production. The catalytic biodiesel production reaction over the catalysts were studied by esterification of free fatty acid, oleic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, catalyst amount, reaction temperature and reaction time on catalytic activity were investigated to optimize the conditions for maximum conversion. It was sulfonated cubic shape mesoporous silica which exhibited better activity as compared to the spherical shape silica catalysts. Additionally, the catalyst was regenerated and reused up to three cycles without any significant loss in activity. The present catalysts exhibit superior performance in biodiesel production and it can be used for the several biodiesel feedstock’s that are rich in free fatty acids.

关键词： solid acid catalyst     mesoporous silica     sulfonic acid     biodiesel     esterification     oleic acid    

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Application of heterogeneous catalysis to biodiesel synthesis using microalgae oil

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1343-9

摘要：

• Microalgae oil application for biodiesel synthesis is discussed.

关键词： Biodiesel     Heterogeneous catalysis     Transesterification     Microalgae oil    

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Simulation analysis of methanol flash distillation circulation process in biodiesel production with supercritical

Zhengjiao TANG, Cunwen WANG, Weiguo WANG, Jia GUO, Yuanxin WU, Jinfang CHEN, Yigang DING

《能源前沿（英文）》 2011年 第5卷 第1期   页码 93-97 doi: 10.1007/s11708-010-0028-7

摘要： High methanol-to-oil ratio is required to obtain a high conversion of oil for the production of biodiesel with supercritical methanol. Recovering the methanol of a stream issuing from a transesterification supercritical reactor by flash distillation instead of evaporation was analyzed. The one-stage and two-stage flash distillation processes were presented and compared. The difference of the recovery percentage of methanol of the above two flash processes is less than 0.5% and the methanol concentration in the vapor for the one-stage process decreases rapidly when feed temperature increases. The process in which the product of transesterification of soybean oil with supercritical methanol is cooled to an appropriate temperature (about 240°C) first and then flashed was put forward. The effect of cooling temperature, feed pressure and flash pressure on methanol concentration and recovery percentage was investigated. According to this study, when the feed pressure range is 15–30 MPa, the flash pressure equals 0.4 MPa, and cooling temperature range is 240°C–250°C, the recovery percentage of methanol is not less than 85%, and the concentration of the vapor in mass fraction of methanol is approximately 99%. Thus, the vapor leaving the flash tank can be directly circulated to the transesterification reactor.

关键词： supercritical methanol     biodiesel     recovery     flash distillation    

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Challenge of biodiesel production from sewage sludge catalyzed by KOH, KOH/activated carbon, and KOH/

Xuemin Wu,Fenfen Zhu,Juanjuan Qi,Luyao Zhao,Fawei Yan,Chenghui Li

《环境科学与工程前沿（英文）》 2017年 第11卷 第2期 doi: 10.1007/s11783-017-0913-y

摘要： The preparation reactions were catalyzed by base solid catalysts. The preparation reactions were catalyzed by two loaded catalysts and KOH. KOH/activated carbon was a better catalyst for biodiesel production. The considerable compounds content, abundance, and low costs involved has led to the proposal to use sewage sludge as raw material for biodiesel production. The transesterification reaction is catalyzed using an acid catalyst instead of base catalysts because of the high free fatty acid concentration. However, the use of a base catalyst, particularly a solid base catalyst, has certain advantages, including faster reaction speed and easier separation. In this study, we utilize in situ transesterification by base catalyst (KOH, KOH/activated carbon (AC) and KOH/CaO) with sewage sludge as raw material. Many conditions have been tested to increase biodiesel yield through single-factor tests, including mass fraction and catalyst dosage. Preliminary experiments have optimized reaction time and temperature. However, the three catalysts did not work better than H SO , which had a maximum yield of 4.6% (dry sewage sludge base) considering the purity by KOH, KOH/CaO, and KOH/AC. The features of the catalyst were analyzed using XRD, BET and SEM. As to BET of KOH/AC and the good spiculate formation of KOH crystal appears to be essential to its function. As for KOH/CaO, the formation of K O and absorption points is likely essential.

关键词： Biodiesel     Sewage sludge     Base catalyst     In situ transesterification    

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Transesterification of soybean oil to biodiesel over kalsilite catalyst

Guang WEN, Zifeng YAN

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 325-329 doi: 10.1007/s11705-010-0574-x

摘要： The transesterification reaction of soybean oil with methanol over kalsilite-based heterogeneous catalysts was investigated. The kalsilite was synthesized from potassium silicate, potassium hydroxide, and aluminum nitrate aqueous solutions by controlling the pH value at 13. After calcination in air at 1200°C, a very porous kalsilite (KAlSiO ) was obtained with surface pores ranging from 0.2 to 1.0 μm. However, this kalsilite had relatively low catalytic activity for the transesterification reaction. A biodiesel yield of 54.4% and a kinematic viscosity of 7.06 cSt were obtained at a high reaction temperature of 180°C in a batch reactor. The catalytic activity of kalsilite was significantly enhanced by introducing a small amount of lithium nitrate in the impregnation method. A biodiesel yield of 100% and a kinematic viscosity of 3.84 cSt were achieved at a temperature of only 120°C over this lithium modified catalyst (2.3 wt-% Li). The test of this lithium modified catalyst in pellet form in a laboratory-scale fixed-bed reactor showed that it maintained a stable catalytic performance with a biodiesel yield of 100% over the first 90 min.

关键词： kalsilite     heterogeneous catalyst     transesterification     biodiesel    

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Calculation and analysis of sub/supercritical methanol preheating tube for continuous production of biodiesel

Wen CHEN, Weiyong YING, Cunwen WANG, Weiguo WANG, Yuanxin WU, Junfeng ZHANG,

《能源前沿（英文）》 2009年 第3卷 第4期   页码 423-431 doi: 10.1007/s11708-009-0075-0

摘要： Biodiesel is an important renewable energy. Supercritical methanol transesterification for biodiesel has recently been concerned because of its obvious advantages. The tubular reactor is an ideal reactor for continuous preparation of biodiesel via supercritical methanol transesterification. A methanol preheating tube is necessary for the tubular reaction system because the reaction temperature for supercritical methanol transesterification is usually 520―600K. Therefore, in the range of 298―600K, changes of the density, isobaric capacity, viscosity and thermal conductivity of sub/supercritical methanol with temperature are first discussed. Then on the basis of these thermophysical properties, an integration method is adopted for the design of sub/supercritical methanol preheating tube when methanol is preheated from 298K to 600K at 16MPa and the influencing factors on the length of the preheating tube are also studied. The computational results show that the Reynolds number and the local convection heat-transfer coefficient of sub/supercritical methanol flowing in ф6mm×1.5mm preheating tube change drastically with temperature. For the local overall heat transfer coefficient and the average overall heat transfer coefficient , temperature also has an important influence on them when the inlet velocity of methanol is lower than 0.5m/s. But when the inlet velocity of methanol is higher than 0.5m/s, and almost keep invariable with temperature. Additionally, both the outlet temperature and the inlet velocity of methanol are the key affecting factors for the length of the preheating tube, especially when the outlet temperature is over the critical temperature of methanol. At the same time, the increase of tin bath’s temperature can shorten the required length of the preheating tube. At the inlet flow rate of 0.5m/s, the required length of the preheating tube is 2.0m when methanol is preheated from 298K to 590K at 16MPa with keeping the tin bath’s temperature 620K, which is in good agreement with the experimental results.

关键词： sub/supercritical methanol     preheating tube     integration method     biodiesel    

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Optimization of pretreatment of Jatropha oil with high free fatty acids for biodiesel production

Supriyono SUWITO, Giuliano DRAGONE, Hary SULISTYO, Bardi MURACHMAN, Suryo PURWONO, José TEIXEIRA

《化学科学与工程前沿（英文）》 2012年 第6卷 第2期   页码 210-215 doi: 10.1007/s11705-012-1282-5

摘要： A central composite rotatable design and response surface methodology were used in order to investigate the individual and combined effects of the ethanol-to-oil ratio, H SO concentration, temperature and time of reaction on the reduction of free fatty acid (FFA) in jatropha oil. A quadratic polynomial model relating the reaction variables with FFA reduction was developed, presenting a good coefficient of determination ( = 0.893). For reducing FFA to less than 1%, the optimal combination was found to be 0.62 v·v ethanol-to-oil ratio (14.9 v·v ethanol-to-FFA ratio), 1.7% v·v H SO concentration, and 79 min reaction time at a reaction temperature of 54°C. These results are of great relevance to maximize methyl esters formation by transesterification using an alkaline catalyst.

关键词： biodiesel     biofuel     esterification     free fatty acids     jatropha curcas oil    

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PLANT DENSITY, IRRIGATION AND NITROGEN MANAGEMENT: THREE MAJOR PRACTICES IN CLOSING YIELD GAPS FOR AGRICULTURAL

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期 doi: 10.15302/J-FASE -2020355

摘要：

Agriculture faces the dual challenges of food security and environmental sustainability. Here, we investigate current maize production at the field scale, analyze the yield gaps and impacting factors, and recommend measures for sustainably closing yield gaps. An experiment was conducted on a 3.9-ha maize seed production field in arid north-western China, managed with border and drip irrigation, respectively, in 2015 and 2016. The relative yield reached 70% in both years. However, drip irrigation saved 227 mm irrigation water during a drier growing season compared with traditional border irrigation, accounting for 44% of the maize evapotranspiration (ET). Yield variability under drip irrigation was 12.1%, lower than the 18.8% under border irrigation. Boundary line analysis indicates that a relative yield increase of 8% to 10% might be obtained by optimizing the yield-limiting factors. Plant density and soil available water content and available nitrogen were the three major factors involved. In conclusion, closing yield gaps with agricultural sustainability may be realized by optimizing agronomic, irrigation and fertilizer management, using water-saving irrigation methods and using site-specific management.

 

关键词： boundary line analysis     irrigation method     precision agriculture     spatial variability     yield gaps     yield-limiting factors    

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Numerical simulation of biodiesel fuel combustion and emission characteristics in a direct injection

Yi REN, Ehab ABU-RAMADAN, Xianguo LI,

《能源前沿（英文）》 2010年 第4卷 第2期   页码 252-261 doi: 10.1007/s11708-010-0036-7

摘要： The effect of the physical and chemical properties of biodiesel fuels on the combustion process and pollutants formation in Direct Injection (DI) engine are investigated numerically by using multi-dimensional Computational Fluid Dynamics (CFD) simulation. In the current study, methyl butanoate (MB) and -heptane are used as the surrogates for the biodiesel fuel and the conventional diesel fuel. Detailed kinetic chemical mechanisms for MB and -heptane are implemented to simulate the combustion process. It is shown that the differences in the chemical properties between the biodiesel fuel and the diesel fuel affect the whole combustion process more significantly than the differences in the physical properties. While the variations of both the chemical and the physical properties between the biodiesel and diesel fuel influence the soot formation at the equivalent level, the variations in the chemical properties play a crucial role in the NO emissions formation.

关键词： biodiesel     diesel engine     CFD simulation     combustion     pollutant formation    

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Exploring differentiated improvement strategies of cultivated land quality in China

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023523

摘要：

● Cultivated land quality can be considered in four dimensions: suitability, contiguity, resistance, and ecological stress.

关键词： China     cultivated land quality     differentiated improvement     food security    

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Influence of cetane number improver on performance and emissions of a common-rail diesel engine fueled with biodiesel-methanol

Wu YU, Gen CHEN, Zuohua HUANG

《能源前沿（英文）》 2011年 第5卷 第4期   页码 412-418 doi: 10.1007/s11708-011-0163-9

摘要： In this paper, the effect of cetane number (CN) improver on performance and emissions, including particulate number concentration and size distribution, of a turbocharged, common-rail diesel engine fueled with biodiesel-methanol were studied. Two volume fractions (0.3% and 0.6%) of CN improver were added to BM30 (30% of methanol in the biodiesel-methanol blend) in the experiment. The results show that, compared with those of biodiesel-methanol blend, the peak value of cylinder pressure increases, the second peak of heat release rate decreases, the start of second heat release are advanced, and the fuel economy and thermal efficiency are improved when CN improver is added to biodiesel-methanol blend. Besides, CO and HC emissions decrease, NO emission varies little and smoke emissions increase slightly. Moreover, exhaust particles of BM30 mainly distribute in nano-size range. Furthermore, particle number concentration decreases and peak of size distribution profile shifts toward large size direction.

关键词： biodiesel     methanol     common-rail (CR) diesel engine     cetane number (CN) improver    

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标题 作者 时间 类型 操作

Development of a combined approach for improvement and optimization of karanja biodiesel using response

Sunil DHINGRA, Gian BHUSHAN, Kashyap Kumar DUBEY

期刊论文

Improvement in growth yield of single-walled carbon nanotubes with narrow chirality distribution by pulse

Bin Xu, Toshiro Kaneko, Toshiaki Kato

期刊论文

ALKALINE PRETREATMENT AND AIR MIXING FOR IMPROVEMENT OF METHANE PRODUCTION FROM ANAEROBIC CO-DIGESTION

期刊论文

Metakaolinite as a catalyst for biodiesel production from waste cooking oil

Jorge RAMIREZ-ORTIZ, Merced MARTINEZ, Horacio FLORES

期刊论文

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

期刊论文

Application of heterogeneous catalysis to biodiesel synthesis using microalgae oil

期刊论文

Simulation analysis of methanol flash distillation circulation process in biodiesel production with supercritical

Zhengjiao TANG, Cunwen WANG, Weiguo WANG, Jia GUO, Yuanxin WU, Jinfang CHEN, Yigang DING

期刊论文

Challenge of biodiesel production from sewage sludge catalyzed by KOH, KOH/activated carbon, and KOH/

Xuemin Wu,Fenfen Zhu,Juanjuan Qi,Luyao Zhao,Fawei Yan,Chenghui Li

期刊论文

Transesterification of soybean oil to biodiesel over kalsilite catalyst

Guang WEN, Zifeng YAN

期刊论文

Calculation and analysis of sub/supercritical methanol preheating tube for continuous production of biodiesel

Wen CHEN, Weiyong YING, Cunwen WANG, Weiguo WANG, Yuanxin WU, Junfeng ZHANG,

期刊论文

Optimization of pretreatment of Jatropha oil with high free fatty acids for biodiesel production

Supriyono SUWITO, Giuliano DRAGONE, Hary SULISTYO, Bardi MURACHMAN, Suryo PURWONO, José TEIXEIRA

期刊论文

PLANT DENSITY, IRRIGATION AND NITROGEN MANAGEMENT: THREE MAJOR PRACTICES IN CLOSING YIELD GAPS FOR AGRICULTURAL

期刊论文

Numerical simulation of biodiesel fuel combustion and emission characteristics in a direct injection

Yi REN, Ehab ABU-RAMADAN, Xianguo LI,

期刊论文

Exploring differentiated improvement strategies of cultivated land quality in China

期刊论文

Influence of cetane number improver on performance and emissions of a common-rail diesel engine fueled with biodiesel-methanol

Wu YU, Gen CHEN, Zuohua HUANG

期刊论文