Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to incre...Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to increasing consumer awareness, thus contributing to the rising demand for natural hydrocolloids. Gum Arabic from Acacia senegal var. kerensis is a natural gum exhibiting excellent water binding and emulsification capacity. However, very little is reported on how it affects the rheological properties of wheat dough. The aim of this study was therefore, to determine the rheological properties of wheat dough with partial additions of gum Arabic as an improver. Six treatments were analyzed comprising of: flour-gum blends prepared by adding gum Arabic to wheat flour at different levels (1%, 2% and 3%), plain wheat flour (negative control), commercial bread flour and commercial chapati flour (positive controls). The rheological properties were determined using Brabender Farinograph, Brabender Extensograph and Brabender Viscograph. Results showed that addition of gum Arabic significantly (p chapati. These findings support the need to utilize gum Arabic from Acacia senegal var. kerensis as a dough improver.展开更多
Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant (PPDs) that resulted from the high content of paraffin, certain poly-acrylic a...Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant (PPDs) that resulted from the high content of paraffin, certain poly-acrylic acid derivatives (PADE) with-COOR, -COOH,-CONHR, and -COO-NH3^+R groups by molecular design on the mechanics of diesel; PPDs were synthesized and evaluated as cold flow improver for Daqing 0^# diesel in this paper. The pure PADE was superior to the commercial PPDs and displayed a substantial ability of wax crystals dispersion. There was a synergistic effect among the PADE and T1804 and secondary amine. The synergism clearly improved the low temperature performance of Daqing diesel products and could reduce the cold filter plugging point of 0^# diesel by 6-7 ℃.展开更多
Synthesis of a cold flow improver (MAVA-a) for diesel fuel and its effect on solidifying point (SP) and cold filter plugging point (CFPP) of diesel fuels were investigated, The cold flow improver was prepared by...Synthesis of a cold flow improver (MAVA-a) for diesel fuel and its effect on solidifying point (SP) and cold filter plugging point (CFPP) of diesel fuels were investigated, The cold flow improver was prepared by using maleic anhydride (MA) and vinyl acetate (VA) as raw materials, toluene as solvent, dibenzoyl peroxide (BPO) as initiator, through alternating polymerization under nitrogen to obtain a binary-polymer and then through aminolysis by using a higher carbon amine as aminating agent at a temperature of 80 ℃. A cold flow improver was designed and prepared for No. 0 diesel fuel from Zhang Jia-Gang Petrochemical Company according to the contents of n-paraffin and its carbon number distribution in the No. 0 diesel fuel. It was also used together with two kinds of ethene-vinyl acetate copolymer improvers (EVA) separately. The test result showed that the CFPP of the No. 0 diesel fuel could be lowered by 3-5 ℃ when the improver MAVA-a was used. The CFPP was lowered by 8℃ when the improver MAVA-a was used together with EVA-2.展开更多
Commonly used flow improvers in oilfields,such as ethylene–vinyl acetate copolymer(EVA),poly(octadecyl acrylate)(POA),and polymethylsilsesquioxane(PMSQ)are proven to be effective to enhance the flowability of crude o...Commonly used flow improvers in oilfields,such as ethylene–vinyl acetate copolymer(EVA),poly(octadecyl acrylate)(POA),and polymethylsilsesquioxane(PMSQ)are proven to be effective to enhance the flowability of crude oil.However,the addition of these flow improvers may change the stability of the emulsion and make the crude oil treatment process challenging.In this research,the impacts of different flow improvers on the interfacial properties of the emulsions containing asphaltenes are systematically investigated.The co-adsorption behaviors of the flow improvers and asphaltenes are analyzed through dynamic interfacial tension(DIFT).The rheological properties of the interfacial layer after the adsorption are explored via dilational viscoelasticity.Significant difference is observed in the structural properties of the interface adsorbed by different flow improvers,which is attributed to different interactions between the flow improvers and asphaltenes.To investigate these interactions,conductivity,asphaltenes precipitation,dynamic light scattering(DLS),and contact angle experiments are conducted systematically.Results show that EVA and POA can alter the interfacial properties by changing the asphaltene dispersion state.The interaction between EVA and asphaltenes is stronger than that between POA and asphaltenes due to the difference in molecular structures.Unlike EVA and POA,the change of interfacial property with the addition of PMSQ is attributed to the partial adsorption of asphaltenes on PMSQ.展开更多
The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an ...The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an autoclave. The product distribution of n-pentane isomerization could be improved by such improvers as benzene, cyelohexane, and methyl cyclohexane at the expense of conversion of n-pentane. The optimal product distribution improver was determined to be cyclohexane. The yield of isomerate and the selectivity of liquid isoalkanes increased, whereas the conversion of n-pentane decreased, with increasing cyclohexane amount. At the same conversion of n-pentane, the research octane number (RON) of liquid product, with cyclohexane amount of 0.5 wt%, was about 1.3 higher than that without cyclohexane. At the same reaction conditions, the presence of cyclohexane enhanced the yield of isomerate, the selectivity of liquid isoalkanes, and the RON of the liquid product, but reduced the conversion of n-pentane.展开更多
One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearin...One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearing characteristics. Viscosity Index (VI) is one approach used widely in the lubricating field to assess the variation of viscosity with temperature. The VI of both mineral and synthetic base oils can be improved by the addition of polymeric viscosity modifiers (VMs). VI improvement by VMs is widely attributed to the polymer coil size expanding with increasing temperature. However, there is very little physical data supporting this generally accepted mechanism. To address this issue, intrinsic viscosity measurements and Small-Angle Neutron Scattering (SANS) have been used to study the variation of polymer coil size with changing temperature and concentration in a selection of solvents. The results will show that coil size expansion with temperature is not necessary to achieve significant elevation of viscosity index.展开更多
The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The struct...The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The structure of the synthesized polymer flow improver additive was confirmed by IR spectroscopy and the crystal structure of the flow improver additives were determined by X-ray diffrac- tion analysis. The structure of wax crystals was also studied at the same time. The results showed that the wax crystal structure was closely related with the crystal structure of the flow improver, which could change the pour point depression and viscosity reduction behavior of the crude oil. When the wax crystal structure matched well with that of the additive, the wax crystals were dispersed satisfactorily, resulting in favorable effects in terms of pour point depression and viscosity reduction. The new synthe- sized aminated polymer flow improver additive was most efficient for treating super-viscous crude oils. The super-viscous crude oil had a high content of resins and asphaltenes, which might aggregate onto the surface of wax crystals to form blocks to limit the crude oil fluidity. However, amination of copolymers having similar structure with the resins and asphaltenes contained in crude oil could dissolve the huge polar groups to make the deposit formation difficult.展开更多
The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amid...The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl longchain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efficiencies of dendritic long-chain esters were not only influenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efficiencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efficiencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil.展开更多
Biochar has been widely applied as a soil amendment in many parts of the world,which can enhance soil organic carbon (SOC) sequestration and nutrient availability beyond the fertilizer effect.Enriched in poly-condense...Biochar has been widely applied as a soil amendment in many parts of the world,which can enhance soil organic carbon (SOC) sequestration and nutrient availability beyond the fertilizer effect.Enriched in poly-condensed aromatic C forms,biochar-C is difficult to be degraded and can hold carbon in soils for hundreds to thousands of years.展开更多
This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank ...This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank angle degree(CAD)before top dead center(BTDC)and a set of constant ignition timing tests while also keeping the 10℃AD BTDC injection and adding ignition improver(2-ethylhexylnitrate-,2-EHN)to the fuel mixtures.Soot particles were characterized using DMS-500 instrument in terms of mass,size,and number.The experimental results showed that adding 2-EHN to the model fuel blends reduced the soot surface area,soot mass concentration and soot mean size.Replacing 20 vol%of a C 7-heptane with 20 vol%methyl-decanoate(an oxygenated C 11 molecule)did not affect the ignition delay or rate of fuel air premixing,the peak in-cylinder pressure or heat release rates.Toluene addition(0−22.5 vol%)to heptane increased the mean size of the soot particles generated by only 3%while also resulted in a slight increase in the peak cylinder pressure and peak heat release rates.Blending toluene and methyl-decanoate into heptane without adding 2-EHN increased the premix phase fraction by at least 13%.However,by adding 2-EHN(4×10^(−4)−1.5×10^(−3)),the premixed phase fraction decreased by at least 11%.展开更多
In the practice of petroleum industry, adding cold flow improver (CFI) to lower the fuel's cold filter plugging point (CFPP) is an effective and economic way for improving the cold flow performance of diesel fuel...In the practice of petroleum industry, adding cold flow improver (CFI) to lower the fuel's cold filter plugging point (CFPP) is an effective and economic way for improving the cold flow performance of diesel fuel. This paper described the synthesis and evaluation of the performance of dibehenyl fumarate-vinyl acetate (FV) copolymer for improving the cold flow performance of the tested diesel fuels. The carbon distribution in n-alkanes of the tested diesel samples were analyzed by gas phase chromatography. The structure of the copolymer was confirmed by the 1H NMR spectroscopy. The wax crystals morphologies with and without adding the FV additive were investigated by means of polarizing microscope. The test results indicated that the FV additive could depress CFPP of the tested diesel samples by 2℃ and 4℃, respectively, when dosage of the additive was 0.08 m%. The additive can modify the size and shape of the wax crystals and inhibit the formation of larger wax crystal lattices.展开更多
Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil ...Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil bulk density, soil pH and soil salt content, increase soil organic matter and 1 000-grain weight, thereby enhancing wheat yield. With the increase of soil improver application amount, soil physical-chemical properties became better and wheat yield increased. However, there was no significant difference in the treatments with the application amounts of 3%, 4% and 5%. In addition, the treatment of reducing nitrogen showed no superiority in soil physical-chemical properties and wheat yield, indicating that sufficient nitrogen was essential for the growth of wheat.展开更多
La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3+(CO-)3 that weakens the bridge adhesion of carbon structural units and alters the lattice str...La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3+(CO-)3 that weakens the bridge adhesion of carbon structural units and alters the lattice structures, thus reducing the activation energy of the pulverized coal and accelerating the burning process. Research shows that La2O3 can form the active species La3+(CO-)3, which weakens the bridge adhesion of carbon structural units and alters the lattice structures of the fixed carbon, hence decreasing the activation energy of the pulverized coal and accelerating the burning process.展开更多
The aim of this study was to optimize composite breads of wheat and whole millet flour by the use of natural improvers. Three types of local malted cereals were used as natural improvers. The millet flour was fermente...The aim of this study was to optimize composite breads of wheat and whole millet flour by the use of natural improvers. Three types of local malted cereals were used as natural improvers. The millet flour was fermented with EPSs producing LAB strain prior to use. The technological characteristics of the composite flours were determined using an alveograph. The physico-chemical and nutritional characteristics of the composite breads were determined using standard methods and their sensory profiles were evaluated by a panel of 35 consumers. The alveograph results showed an increase in dough resistance, deformation and a decrease in extensibility and elasticity with the level of incorporation of millet flour. From the results of physico-chemical analyses of composite breads, no significant difference (p > 0.05) was observed in the use of the three types of local cereal malts except for the incorporation of 50% of the millet flour. The control sample presented the lowest acidity and dry matter value, the highest water content and pH value. No significant difference (p > 0.05) was observed in the use of the three types of cereal malts for the macronutrient contents of the composite bread samples. However, differences were observed according to the levels of incorporation. Macronutrients results showed an increase in protein content (11.17% ± 0.28% - 14.01% ± 0.10%/DM);crude fat content (1.86% ± 0.05% - 2.48% ± 0.20%/DM) and a decrease in carbohydrates content (85.36% ± 0.54% - 81.06% ± 0.36%/ DM). Regarding the content of mineral elements, significant differences (p < 0.05) were observed in the use of the three types of cereal malts for the incorporation of 15% (Mg and Fe content), 30% (Fe, Zn and K) and 50% (content of Zn, K, Na and Mg) of millet flour. The free amino acid profile revealed three essential amino acids such as valine, isoleucine and lysine. Breads incorporated with 30% of whole millet flour were the most appreciated by consumers.展开更多
Polyalkylmethacrylate (PAMA) based viscosity index improver (VII) and pour point depressant (PPD), with the versatile chemistry and unique performance characteristics, are widely used in advanced formulations, enablin...Polyalkylmethacrylate (PAMA) based viscosity index improver (VII) and pour point depressant (PPD), with the versatile chemistry and unique performance characteristics, are widely used in advanced formulations, enabling fluids to meet rheological requirement of modern specifications. This paper will be dedicated to the application of PAMA in helping China automotive lubricant formulators tackle the challenges of improving fuel economics from using lower viscosity fluids, of better protection strengthten in transmission performance and meeting new global specifications for low temperature performance.展开更多
文摘Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to increasing consumer awareness, thus contributing to the rising demand for natural hydrocolloids. Gum Arabic from Acacia senegal var. kerensis is a natural gum exhibiting excellent water binding and emulsification capacity. However, very little is reported on how it affects the rheological properties of wheat dough. The aim of this study was therefore, to determine the rheological properties of wheat dough with partial additions of gum Arabic as an improver. Six treatments were analyzed comprising of: flour-gum blends prepared by adding gum Arabic to wheat flour at different levels (1%, 2% and 3%), plain wheat flour (negative control), commercial bread flour and commercial chapati flour (positive controls). The rheological properties were determined using Brabender Farinograph, Brabender Extensograph and Brabender Viscograph. Results showed that addition of gum Arabic significantly (p chapati. These findings support the need to utilize gum Arabic from Acacia senegal var. kerensis as a dough improver.
文摘Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant (PPDs) that resulted from the high content of paraffin, certain poly-acrylic acid derivatives (PADE) with-COOR, -COOH,-CONHR, and -COO-NH3^+R groups by molecular design on the mechanics of diesel; PPDs were synthesized and evaluated as cold flow improver for Daqing 0^# diesel in this paper. The pure PADE was superior to the commercial PPDs and displayed a substantial ability of wax crystals dispersion. There was a synergistic effect among the PADE and T1804 and secondary amine. The synergism clearly improved the low temperature performance of Daqing diesel products and could reduce the cold filter plugging point of 0^# diesel by 6-7 ℃.
基金Supported by the Basic Research Program of the State Key Laboratory of Heavy Oil Processing (200310) China University of Petroleum,Beijing,China
文摘Synthesis of a cold flow improver (MAVA-a) for diesel fuel and its effect on solidifying point (SP) and cold filter plugging point (CFPP) of diesel fuels were investigated, The cold flow improver was prepared by using maleic anhydride (MA) and vinyl acetate (VA) as raw materials, toluene as solvent, dibenzoyl peroxide (BPO) as initiator, through alternating polymerization under nitrogen to obtain a binary-polymer and then through aminolysis by using a higher carbon amine as aminating agent at a temperature of 80 ℃. A cold flow improver was designed and prepared for No. 0 diesel fuel from Zhang Jia-Gang Petrochemical Company according to the contents of n-paraffin and its carbon number distribution in the No. 0 diesel fuel. It was also used together with two kinds of ethene-vinyl acetate copolymer improvers (EVA) separately. The test result showed that the CFPP of the No. 0 diesel fuel could be lowered by 3-5 ℃ when the improver MAVA-a was used. The CFPP was lowered by 8℃ when the improver MAVA-a was used together with EVA-2.
基金supported by the National Natural Science Foundation of China(51704315)。
文摘Commonly used flow improvers in oilfields,such as ethylene–vinyl acetate copolymer(EVA),poly(octadecyl acrylate)(POA),and polymethylsilsesquioxane(PMSQ)are proven to be effective to enhance the flowability of crude oil.However,the addition of these flow improvers may change the stability of the emulsion and make the crude oil treatment process challenging.In this research,the impacts of different flow improvers on the interfacial properties of the emulsions containing asphaltenes are systematically investigated.The co-adsorption behaviors of the flow improvers and asphaltenes are analyzed through dynamic interfacial tension(DIFT).The rheological properties of the interfacial layer after the adsorption are explored via dilational viscoelasticity.Significant difference is observed in the structural properties of the interface adsorbed by different flow improvers,which is attributed to different interactions between the flow improvers and asphaltenes.To investigate these interactions,conductivity,asphaltenes precipitation,dynamic light scattering(DLS),and contact angle experiments are conducted systematically.Results show that EVA and POA can alter the interfacial properties by changing the asphaltene dispersion state.The interaction between EVA and asphaltenes is stronger than that between POA and asphaltenes due to the difference in molecular structures.Unlike EVA and POA,the change of interfacial property with the addition of PMSQ is attributed to the partial adsorption of asphaltenes on PMSQ.
基金support was provided by the National Science Foundation of China(Grant Nos.20806091,20976194,and 21036008)
文摘The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an autoclave. The product distribution of n-pentane isomerization could be improved by such improvers as benzene, cyelohexane, and methyl cyclohexane at the expense of conversion of n-pentane. The optimal product distribution improver was determined to be cyclohexane. The yield of isomerate and the selectivity of liquid isoalkanes increased, whereas the conversion of n-pentane decreased, with increasing cyclohexane amount. At the same conversion of n-pentane, the research octane number (RON) of liquid product, with cyclohexane amount of 0.5 wt%, was about 1.3 higher than that without cyclohexane. At the same reaction conditions, the presence of cyclohexane enhanced the yield of isomerate, the selectivity of liquid isoalkanes, and the RON of the liquid product, but reduced the conversion of n-pentane.
文摘One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearing characteristics. Viscosity Index (VI) is one approach used widely in the lubricating field to assess the variation of viscosity with temperature. The VI of both mineral and synthetic base oils can be improved by the addition of polymeric viscosity modifiers (VMs). VI improvement by VMs is widely attributed to the polymer coil size expanding with increasing temperature. However, there is very little physical data supporting this generally accepted mechanism. To address this issue, intrinsic viscosity measurements and Small-Angle Neutron Scattering (SANS) have been used to study the variation of polymer coil size with changing temperature and concentration in a selection of solvents. The results will show that coil size expansion with temperature is not necessary to achieve significant elevation of viscosity index.
文摘The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The structure of the synthesized polymer flow improver additive was confirmed by IR spectroscopy and the crystal structure of the flow improver additives were determined by X-ray diffrac- tion analysis. The structure of wax crystals was also studied at the same time. The results showed that the wax crystal structure was closely related with the crystal structure of the flow improver, which could change the pour point depression and viscosity reduction behavior of the crude oil. When the wax crystal structure matched well with that of the additive, the wax crystals were dispersed satisfactorily, resulting in favorable effects in terms of pour point depression and viscosity reduction. The new synthe- sized aminated polymer flow improver additive was most efficient for treating super-viscous crude oils. The super-viscous crude oil had a high content of resins and asphaltenes, which might aggregate onto the surface of wax crystals to form blocks to limit the crude oil fluidity. However, amination of copolymers having similar structure with the resins and asphaltenes contained in crude oil could dissolve the huge polar groups to make the deposit formation difficult.
基金supported financially by the Heilongjiang Postdoctorial Financial Foundation of China (Project NO. LBH-Zo8290)The Daqing Oil Field of China was thanked for providing the financial support and the crude oil
文摘The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl longchain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efficiencies of dendritic long-chain esters were not only influenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efficiencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efficiencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil.
文摘Biochar has been widely applied as a soil amendment in many parts of the world,which can enhance soil organic carbon (SOC) sequestration and nutrient availability beyond the fertilizer effect.Enriched in poly-condensed aromatic C forms,biochar-C is difficult to be degraded and can hold carbon in soils for hundreds to thousands of years.
文摘This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank angle degree(CAD)before top dead center(BTDC)and a set of constant ignition timing tests while also keeping the 10℃AD BTDC injection and adding ignition improver(2-ethylhexylnitrate-,2-EHN)to the fuel mixtures.Soot particles were characterized using DMS-500 instrument in terms of mass,size,and number.The experimental results showed that adding 2-EHN to the model fuel blends reduced the soot surface area,soot mass concentration and soot mean size.Replacing 20 vol%of a C 7-heptane with 20 vol%methyl-decanoate(an oxygenated C 11 molecule)did not affect the ignition delay or rate of fuel air premixing,the peak in-cylinder pressure or heat release rates.Toluene addition(0−22.5 vol%)to heptane increased the mean size of the soot particles generated by only 3%while also resulted in a slight increase in the peak cylinder pressure and peak heat release rates.Blending toluene and methyl-decanoate into heptane without adding 2-EHN increased the premix phase fraction by at least 13%.However,by adding 2-EHN(4×10^(−4)−1.5×10^(−3)),the premixed phase fraction decreased by at least 11%.
基金supported by the Basic Research Program of the State Key Laboratory of Heavy Oil Processing(200310),China University of Petroleum,Beijing,China.
文摘In the practice of petroleum industry, adding cold flow improver (CFI) to lower the fuel's cold filter plugging point (CFPP) is an effective and economic way for improving the cold flow performance of diesel fuel. This paper described the synthesis and evaluation of the performance of dibehenyl fumarate-vinyl acetate (FV) copolymer for improving the cold flow performance of the tested diesel fuels. The carbon distribution in n-alkanes of the tested diesel samples were analyzed by gas phase chromatography. The structure of the copolymer was confirmed by the 1H NMR spectroscopy. The wax crystals morphologies with and without adding the FV additive were investigated by means of polarizing microscope. The test results indicated that the FV additive could depress CFPP of the tested diesel samples by 2℃ and 4℃, respectively, when dosage of the additive was 0.08 m%. The additive can modify the size and shape of the wax crystals and inhibit the formation of larger wax crystal lattices.
基金Supported by the Key Research and Development Program for Industrial Keytechnologies of Shandong Province(2016CYJS05A01-2)the Key Research and Development Program for Public Welfare of Shandong Province(2018GNC111001)the Special Fund for the Construction of Oversea Taishan Scholars
文摘Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil bulk density, soil pH and soil salt content, increase soil organic matter and 1 000-grain weight, thereby enhancing wheat yield. With the increase of soil improver application amount, soil physical-chemical properties became better and wheat yield increased. However, there was no significant difference in the treatments with the application amounts of 3%, 4% and 5%. In addition, the treatment of reducing nitrogen showed no superiority in soil physical-chemical properties and wheat yield, indicating that sufficient nitrogen was essential for the growth of wheat.
基金the National Key Laboratory in University of Science and Technology Beijing of China (KFI3-02) and the Natural Science Foundation of Hebei province (E2013209339).
文摘La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3+(CO-)3 that weakens the bridge adhesion of carbon structural units and alters the lattice structures, thus reducing the activation energy of the pulverized coal and accelerating the burning process. Research shows that La2O3 can form the active species La3+(CO-)3, which weakens the bridge adhesion of carbon structural units and alters the lattice structures of the fixed carbon, hence decreasing the activation energy of the pulverized coal and accelerating the burning process.
文摘The aim of this study was to optimize composite breads of wheat and whole millet flour by the use of natural improvers. Three types of local malted cereals were used as natural improvers. The millet flour was fermented with EPSs producing LAB strain prior to use. The technological characteristics of the composite flours were determined using an alveograph. The physico-chemical and nutritional characteristics of the composite breads were determined using standard methods and their sensory profiles were evaluated by a panel of 35 consumers. The alveograph results showed an increase in dough resistance, deformation and a decrease in extensibility and elasticity with the level of incorporation of millet flour. From the results of physico-chemical analyses of composite breads, no significant difference (p > 0.05) was observed in the use of the three types of local cereal malts except for the incorporation of 50% of the millet flour. The control sample presented the lowest acidity and dry matter value, the highest water content and pH value. No significant difference (p > 0.05) was observed in the use of the three types of cereal malts for the macronutrient contents of the composite bread samples. However, differences were observed according to the levels of incorporation. Macronutrients results showed an increase in protein content (11.17% ± 0.28% - 14.01% ± 0.10%/DM);crude fat content (1.86% ± 0.05% - 2.48% ± 0.20%/DM) and a decrease in carbohydrates content (85.36% ± 0.54% - 81.06% ± 0.36%/ DM). Regarding the content of mineral elements, significant differences (p < 0.05) were observed in the use of the three types of cereal malts for the incorporation of 15% (Mg and Fe content), 30% (Fe, Zn and K) and 50% (content of Zn, K, Na and Mg) of millet flour. The free amino acid profile revealed three essential amino acids such as valine, isoleucine and lysine. Breads incorporated with 30% of whole millet flour were the most appreciated by consumers.
文摘Polyalkylmethacrylate (PAMA) based viscosity index improver (VII) and pour point depressant (PPD), with the versatile chemistry and unique performance characteristics, are widely used in advanced formulations, enabling fluids to meet rheological requirement of modern specifications. This paper will be dedicated to the application of PAMA in helping China automotive lubricant formulators tackle the challenges of improving fuel economics from using lower viscosity fluids, of better protection strengthten in transmission performance and meeting new global specifications for low temperature performance.