Biodiesel is one of the most popular prospective alternative fuels and can be obtained from a variety of sources. Waste frying oil is one such source along with the various raw vegetable oils. However, some specific t...Biodiesel is one of the most popular prospective alternative fuels and can be obtained from a variety of sources. Waste frying oil is one such source along with the various raw vegetable oils. However, some specific technical treatments are required to improve certain fuel properties such as viscosity and calorific value of the biodiesel being obtained from waste cooking oil methyl ester (WCOME). Various treatments are applied depending on the source and therefore the composition of the cooking oil. This research investigated the performance of WCOME as an alternative biofuel in a four-stroke direct injection diesel engine. An 8-mode test was undertaken with diesel fuel and five WCOME blends. The best compromise blend in terms of performance and emissions was identified. Results showed that energy utilization factors of the blends were similar within the range of the operational parameters (speed, load and WCOME content). Increasing biodiesel content produced slightly more smoke and NOx for a great majority of test points, while the CO and THC emissions were lower.展开更多
In this paper,the surface activated crumb rubber with waste cooking oil(WCO)was studied to improve the performance of crumb rubber modified asphalt.The activated waste crumb rubber modified asphalt(OCRMA)with differen...In this paper,the surface activated crumb rubber with waste cooking oil(WCO)was studied to improve the performance of crumb rubber modified asphalt.The activated waste crumb rubber modified asphalt(OCRMA)with different amount of crumb rubber was prepared to study the microscopic appearance of OCRMA by scanning electron microscope and fluorescence microscope and analyze the surface performance.The rheological properties and microscopic mechanism of OCRMA were characterized by dynamic shear rheological test,multiple stress creep recovery(MSCR)test,BBR test and infrared spectroscopy.The results show that the dissolution degree of waste crumb rubber is improved after WCO activation,and the compatibility with asphalt components is enhanced,and the stable cross-linking structure is formed,which improves the asphalt performance.The several new absorption peaks,which were obvious,were all caused by the composition of WCO,that is,there was no significant chemical change during the interaction between the activated crumb rubber and base asphalt.Compared with the common waste crumb rubber modified asphalt(CRMA),activation with WCO can significantly reduce the viscosity of CRMA,decrease the difference of segregation softening point by 27%,and enhance the low temperature performance by 30%.The aging degree is greatly reduced,and the anti-aging performance of OCRMA is increased by about 20%with the same dosage.The high temperature performance,though higher than that of base asphalt,decreases to some extent.After comprehensive analysis,the optimal dosage of crumb rubber for OCRMA is 30%.展开更多
Biodiesels produced from various feedstocks have been considered as alternative fuels used in internal combustion engines without major modifications.This research focuses on producing biodiesel from waste cooking oil...Biodiesels produced from various feedstocks have been considered as alternative fuels used in internal combustion engines without major modifications.This research focuses on producing biodiesel from waste cooking oil(WCOSD)by the catalytic cracking method using MgO as the catalyst and comparing the engine operating characteristics of the test engine when using WCOSD and traditional diesel(CD)as test fuels.As a result,the brake power of the test engine fueled WCOSD,and traditional diesel is similar.However,the engine fuel consumption in the case of using WCOSD is slight increases in some operating conditions.Also,the nitrogen oxides emissions of the test engine fueled WCOSD are higher than those of CD at all tested conditions.The trend is opposite for hydrocarbon emission as the HC emission of the engine fueled by WCOSD reduces 26.3%on average.The smoke emission of the test engine in case of using WCOSD is lower 17%on average than that of CD.However,the carbon monoxide emissions are lower at the low and medium loads and higher at the full loads.These results show that the new biodiesel has the same characteristics as those of commercial biodiesel and can be used as fuel for diesel engines.展开更多
The authors performed economic assessment of producing biodiesel at pilot scale using used cooking oil as feed-oil in a Bio-Pro 380 EX biodiesel reactor. The overall results suggest that the biodiesel production using...The authors performed economic assessment of producing biodiesel at pilot scale using used cooking oil as feed-oil in a Bio-Pro 380 EX biodiesel reactor. The overall results suggest that the biodiesel production using used cooking oil is a viable project even at large or medium scale. The payback period for producing biodiesel at a pilot scale of 31,320 liters per year was 1.5 years, which was 1 month longer than the payback period for a large plant capacity of 66,000 liters per year. The study demonstrated that the unit selling price and unit production cost are sensitive to the economic feasibility of biodiesel production, since price variations of BWP 1 result in at least a 13% increase and 12% decrease in profit, respectively. The study further revealed that feed-oil (used cooking oil) was the most expensive among all the inputs accounting for 61%, followed by methanol and direct labour with 19% and 13% respectively. The overall energy recorded to produce approximately 360 liters of biodiesel contributed to 2% only, suggesting that Bio-Pro 380 EX biodiesel reactor is relatively a low energy intensity processor. The situation is suitable for the promotion of biodiesel particularly in countries where initiatives to stimulate the development of biofuels are at its infant stage Botswana included.展开更多
Arawana Brand cooking oil produced by the Nanhai Fat Industrial Company, Ltd, is a refined product from imported quality rape oil and fragrant peanut oil and sesame oil imported fromthe United States. The oil is prepa...Arawana Brand cooking oil produced by the Nanhai Fat Industrial Company, Ltd, is a refined product from imported quality rape oil and fragrant peanut oil and sesame oil imported fromthe United States. The oil is prepared using a unique prescription and skills, and contains rich vitamin E and unsaturated fatty acid without展开更多
The dynamic characteristics of cooking-related particle size distributions in real-world settings are not fully understood.Through a real-world campaign in a naturally-ventilated apartment in the northwest US,this stu...The dynamic characteristics of cooking-related particle size distributions in real-world settings are not fully understood.Through a real-world campaign in a naturally-ventilated apartment in the northwest US,this study investigates the temporal profiles of size-resolved particle number concentrations(PNCs)ranging from 0.3 to 10µm from frying cooking activities.The cooking scenarios included various combinations of window ventilation,venting range hood(VRH)use,and portable air cleaner(PAC)utilization.Following a standardized pan-frying protocol throughout seven scenarios,real-time PNCs of 16-size bins were measured in the kitchen.The PNCs were empirically compared among size bins,periods,and scenarios.The most abundant size ranges of cooking-related particles were 0.3–0.579µm in number(45%–71%of the total)and 2.685–5.182µm in mass(48%–57%of the total).Compared with the scenario without any cooking-fume mitigating measures,keeping the kitchen windows open reduced the mean PNCs during and within 1-h after cooking for PM_(0.3-2.5),PM_(2.5-10),and PM_(0.3-10)by 78%,92%,and 79%,respectively.By contrast,utilizing a VRH during cooking reduced the corresponding levels by 21%,69%,and 25%,respectively.Combined with running the VRH,using a PAC in the kitchen led to additional reductions of 84%,88%,and 84%,respectively.Additionally,the removal efficiencies of the three strategies generally increased with particle sizes.展开更多
Ship auxiliary engines contribute large amounts of air pollutants when at berth.Biodiesel,including that from waste cooking oil(WCO),can favor a reduction in the emission of primary pollutant when used with internal c...Ship auxiliary engines contribute large amounts of air pollutants when at berth.Biodiesel,including that from waste cooking oil(WCO),can favor a reduction in the emission of primary pollutant when used with internal combustion engines.This study investigated the emissions of gaseous intermediate-volatile organic compounds(IVOCs)between WCO biodiesel and marine gas oil(MGO)to further understand the differences in secondary organic aerosol(SOA)production of exhausts.Results revealed that WCO exhaust exhibited similar IVOC composition and volatility distribution to MGO exhaust,despite the differences between fuel contents.While WCO biodiesel could reduce IVOC emissions by 50%as compared to MGO,and thus reduced the SOA production from IVOCs.The compositions and volatility distributions of exhaust IVOCs varied to those of their fuels,implying that fuel-component-based SOA predicting model should be used with more cautions when assessing SOA production of WCO and MGO exhausts.WCO biodiesel is a cleaner fuel comparing to conventional MGO on ship auxiliary engines with regard to the reductions in gaseous IVOC emissions and corresponding SOA productions.Although the tests were conducted on test bench,the results could be considered as representative due to the widely applications of the test engine and MGO fuel on real-world ships.展开更多
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 dehydrox...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, Nz adsorption-desorption, simultaneous thermogravimetric analyse/differential scanning calorimetry (TGA/DSC) experiments on the thermal decomposition of kaolinite and Fourier-transform infrared spectrometer (FTIR) analysis. Parameters related to the transesterificaion 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℃; 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 mm2" s-1 and a density of 900.1 kg-m-3. The results showed that metakaolinite is a prominent, inexpensive, reusable and thermally stable catalyst for the transesterification of waste cooking oil.展开更多
Waste cooking oil(WCO)has received attention on rejuvenating aged asphalt binder widely in recent years.This study evaluated the rejuvenation effects of WCO on aged asphalt binder on the micro-scale using molecular dy...Waste cooking oil(WCO)has received attention on rejuvenating aged asphalt binder widely in recent years.This study evaluated the rejuvenation effects of WCO on aged asphalt binder on the micro-scale using molecular dynamics(MD)simulation.First,the representative molecules of WCO and asphalt binders were selected.The molecular mixture model was then developed.The thermodynamic properties were investigated,including density,cohesive energy density,solubility parameter,and surface free energy.The results show that WCO can restore the thermodynamic properties of aged asphalt binder to some extent and WCO has different influences on electrostatic interactions and van der Waals effects.From the diffusion behavior and molecular structure of asphalt binder,WCO can improve the molecular mobility and restore the colloidal structure.Besides,the adhesion work and moisture susceptibility of asphalt binder-aggregate interfaces(calcite and quartz)were evaluated.The results show that WCO can improve adhesion work between asphalt binder and aggregates since WCO can change molecular structure of asphalt binders and certain adhesion work exists between WCO and aggregates.Also,it can mitigate the moisture susceptibility of asphalt binder-aggregate interfaces(calcite and quartz).The study demonstrates that the MD simulation can help to understand the rejuvenation effects of WCO on aged asphalt binder on the micro-scale.展开更多
Biodiesel is derived from waste cooking oil (WCO) by transesterification. Methylester was prepared by mixing diesel and biodiesel oils as 20% by volume. Nano particles asTiO2, Al2O3 and CNTs were blended with biodiese...Biodiesel is derived from waste cooking oil (WCO) by transesterification. Methylester was prepared by mixing diesel and biodiesel oils as 20% by volume. Nano particles asTiO2, Al2O3 and CNTs were blended with biodiesel blend at different concentrations of 25,50, and 100 mg/l to enhance the physicochemical fuel characteristics to obtain clean and effi-cient combustion performance. An experimental setup was incorporated into a diesel engine toinvestigate the influence of these nano-materials on engine performance, exergy analysis, combustion characteristics and emissions using WCO biodiesel-diesel mixture. Enriching methylester mixture with 100 ppm titanium, alumina and CNTs (B20T100, B20A100 andB20C100) increased the thermal efficiency by 4%, 6% and 11.5%, respectively compared toB20. Biodiesel blending with nano additives B20T100, B20A100 and B20C100 decreasedthe emissions of CO (11%, 24% and 30%, respectively), HC (8%, 17% and 25%, respectively)and smoke (10%, 13% and 19%, respectively) compared to B20. However, the noticeable increase of NOx was estimated by 5%, 12% and 27% for B20T100, B20A100 and B20C100,respectively. Finally, the results showed the rise in peak cylinder pressure by 5%, 9% and 11% and increase in heat release rate by 4%, 8% and 13% for B20T100, B20A100 andB20C100, respectively. The fuel exergy of B20T100, B20A100 and B20C100 are lower thanbiodiesel blend B20 by 6.5%, 16% and 23% but the exergetic efficiency are increased by 7%,19% and 30% at full load about B20.展开更多
The paper discussed the physical and chemical properties of cooking oil vapor(COV) and its biological effects. The study showed that: (1)By ultraviolet spectrophotometry, the method to determine the concentration of C...The paper discussed the physical and chemical properties of cooking oil vapor(COV) and its biological effects. The study showed that: (1)By ultraviolet spectrophotometry, the method to determine the concentration of COV was simple, reliable and suitable; (2)At 220℃, about 60%-80% particles′ diameter of COV were less than 10 μm which referred to they are capable of reaching the deeper parts of the respiratory tract; (3)Pulmonary toxicity study of COV revealed that in acute toxicity test, there was lung tissue injury in rats and the degree increased as the concentration of oil vapor increased; subacute test in rats indicated that pulmonary injury might be the result of lipid peroxidation brought about by the activation of more general free radical system; (4)The average concentration of emitted oil vapor in the environment ranged from 0.10 to 0.20 mg/m3, the emission outlets in most restaurants were very simple or located in residential areas without any filtering device; (5)Irritative effect threshold levels of COV to volunteers and the effects on occupational exposed cooks also suggested that COV might produce harmful effects on pulmonary function in occupationally exposed personnel.展开更多
Renewable biofuels have gained increasing attention as a potential alternative fuel to decrease CO_(2) emission from combustion of fossil fuels.The aims of the work were to modify Thai dolomite by adding magnesium car...Renewable biofuels have gained increasing attention as a potential alternative fuel to decrease CO_(2) emission from combustion of fossil fuels.The aims of the work were to modify Thai dolomite by adding magnesium carbonate(MgCO_(3))at various contents(0-30 wt%),and used as catalyst in pyrolytic catalysis cracking(PCC)process to produce light biofuels including gasoline and kerosene.All catalysts were calcined at 600℃ for 4 h prior to the characterization and experiments.The physicochemical properties were done by various techniques such as X-ray diffractometer(XRD),N2 adsorption-desorption,thermogravimetric analyzer and differential thermal analyzer(TGA-DTA),Field-emission scanning electron microscope(FE-SEM),and energy dispersive X-ray spectroscopy(EDX).The experiments of PCC process were carried out at different reaction temperatures of 450-550℃.The results from XRD and SEM-EDX confirmed that the Mg was successfully added in Thai dolomite.The Mg content in the catalysts increased with increasing MgCO_(3) loadings.The calcination temperature of 600℃ cannot completely convert CaCO3 to CaO form.The pyrolytic oil and distilled oil yields and quality were affected by both Mg content and reaction temperature.In addition,pyrolytic oil was completely distillated according to ASTM D86 to separate into gasoline,kerosene,and diesel.The light biofuel production was enhanced with increasing Mg content in the reaction temperatures of 500 and 550℃.The appropriate condition was suggested at reaction temperature of 500℃ with 20 wt%Mg/dolomite catalyst as it showed the highest production yield of about 84 vol%and light biofuel yield of about 65 vol%.展开更多
The physical performance of recycled asphalt was used as the main evaluation index to study the optimal range of a self-made rejuvenator.Through the penetration,viscosity and gel permeation chromatography(GPC)tests,th...The physical performance of recycled asphalt was used as the main evaluation index to study the optimal range of a self-made rejuvenator.Through the penetration,viscosity and gel permeation chromatography(GPC)tests,the diffusion degree of the rejuvenator under different temperatures and time process was analyzed,and the diffusion efficiency of the rejuvenator was evaluated from the macro and micro perspective.The regeneration mechanism of the rejuvenator in the aged asphalt was also analyzed using the Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM)and chemical composition tests.The research results showed that the optimum rejuvenator content was about 3%.Higher temperature and longer time were beneficial to improving the permeability and diffusion of the rejuvenator.During the aging process,the light components were reduced,and more macromolecular asphaltenes were generated as well as a large number of carbonyl and sulfoxide.After diffusion and regeneration,the light components in the asphalt were supplemented,the wrinkles and gullies of the aged asphalt were almost improved to the surface state of the matrix asphalt.展开更多
The activity of Mo_(2) C-based catalyst on vegetable oil conversion into biofuel could be greatedly promoted by tuning the carbon content,while its modification mechanism on the surface properties remained elusive.Her...The activity of Mo_(2) C-based catalyst on vegetable oil conversion into biofuel could be greatedly promoted by tuning the carbon content,while its modification mechanism on the surface properties remained elusive.Herein,the exposed active sites,the particle size and Lewis acid amount of Ni-Mo_(2) C/MCM-41 catalysts were regulated by varying CH_(4) content in carbonization gas.The activity of Ni-Mo_(2) C/MCM-41 catalysts in jatropha oil(JO)conversion showed a volcano-like trend over the catalysts with increasing CH_(4) content from 15%to 50%in the preparation process.The one prepared by 25%CH_(4) content(NiMo_(2) C(25)/MCM-41)exhibited the outstanding catalytic performance with 83.9 wt%biofuel yield and95.2%C_(15)-C_(18) selectivity.Such a variation of activity was ascribed to the most exposed active sites,the smallest particle size,and the lowest Lewis acid amount from Ni^(0) on the Ni-Mo_(2) C(25)/MCM-41 catalyst surface.Moreover,the Ni-Mo_(2) C(25)/MCM-41 catalyst could also effectively catalyze the conversion of crude waste cooking oil(WCO)into green diesel.This study offers an effective strategy to improve catalytic performance of molybdenum carbide catalyst on vegetable oil conversion.展开更多
Both Omega-6 and Omega-3 fatty acids are essential nutrients important for cellular structure and function but cannot be synthesized by the human body and must be obtained from food.These two classes of fatty acids ar...Both Omega-6 and Omega-3 fatty acids are essential nutrients important for cellular structure and function but cannot be synthesized by the human body and must be obtained from food.These two classes of fatty acids are metabolically and functionally different and antagonistically regulate many physiological and pathological processes.Thus,the relative balance between Omega-6 and Omega-3 fatty acids are critical for good health.However,today’s diet contains too much Omega-6 but too little Omega-3,leading to a severe imbalance with a very high Omega-6/Omega-3 ratio(>10)in most people.Many lines of evidence suggest that this imbalance is a key factor contributing to the development of modern chronic diseases.A growing number of studies ranging from laboratory research to clinical trials have shown that balancing the tissue ratio of Omega-6/Omega-3 fatty acids by increasing tissue levels of Omega-3 fatty acids and/or decreasing the content of Omega-6 fatty acids are very beneficial for the prevention and treatment of many life-threating chronic diseases as well as for health promotion of the general public.Therefore,development and production of foods rich in Omega-3-fatty acids should be considered as a key health program to balance essential fat intake and thereby improve the nutritional and health status of all people.展开更多
文摘Biodiesel is one of the most popular prospective alternative fuels and can be obtained from a variety of sources. Waste frying oil is one such source along with the various raw vegetable oils. However, some specific technical treatments are required to improve certain fuel properties such as viscosity and calorific value of the biodiesel being obtained from waste cooking oil methyl ester (WCOME). Various treatments are applied depending on the source and therefore the composition of the cooking oil. This research investigated the performance of WCOME as an alternative biofuel in a four-stroke direct injection diesel engine. An 8-mode test was undertaken with diesel fuel and five WCOME blends. The best compromise blend in terms of performance and emissions was identified. Results showed that energy utilization factors of the blends were similar within the range of the operational parameters (speed, load and WCOME content). Increasing biodiesel content produced slightly more smoke and NOx for a great majority of test points, while the CO and THC emissions were lower.
基金This study was supported by Hunan Provincial Natural Science Foundation(Project No.2021JJ30709)Changsha Municipal Natural Science Foundation(Project No.kq2007029)Practice Innovation and Entrepreneurship Enhancement Program for Postgraduate of Changsha University of Science&Technology(Project No.SJCX202112).
文摘In this paper,the surface activated crumb rubber with waste cooking oil(WCO)was studied to improve the performance of crumb rubber modified asphalt.The activated waste crumb rubber modified asphalt(OCRMA)with different amount of crumb rubber was prepared to study the microscopic appearance of OCRMA by scanning electron microscope and fluorescence microscope and analyze the surface performance.The rheological properties and microscopic mechanism of OCRMA were characterized by dynamic shear rheological test,multiple stress creep recovery(MSCR)test,BBR test and infrared spectroscopy.The results show that the dissolution degree of waste crumb rubber is improved after WCO activation,and the compatibility with asphalt components is enhanced,and the stable cross-linking structure is formed,which improves the asphalt performance.The several new absorption peaks,which were obvious,were all caused by the composition of WCO,that is,there was no significant chemical change during the interaction between the activated crumb rubber and base asphalt.Compared with the common waste crumb rubber modified asphalt(CRMA),activation with WCO can significantly reduce the viscosity of CRMA,decrease the difference of segregation softening point by 27%,and enhance the low temperature performance by 30%.The aging degree is greatly reduced,and the anti-aging performance of OCRMA is increased by about 20%with the same dosage.The high temperature performance,though higher than that of base asphalt,decreases to some extent.After comprehensive analysis,the optimal dosage of crumb rubber for OCRMA is 30%.
文摘Biodiesels produced from various feedstocks have been considered as alternative fuels used in internal combustion engines without major modifications.This research focuses on producing biodiesel from waste cooking oil(WCOSD)by the catalytic cracking method using MgO as the catalyst and comparing the engine operating characteristics of the test engine when using WCOSD and traditional diesel(CD)as test fuels.As a result,the brake power of the test engine fueled WCOSD,and traditional diesel is similar.However,the engine fuel consumption in the case of using WCOSD is slight increases in some operating conditions.Also,the nitrogen oxides emissions of the test engine fueled WCOSD are higher than those of CD at all tested conditions.The trend is opposite for hydrocarbon emission as the HC emission of the engine fueled by WCOSD reduces 26.3%on average.The smoke emission of the test engine in case of using WCOSD is lower 17%on average than that of CD.However,the carbon monoxide emissions are lower at the low and medium loads and higher at the full loads.These results show that the new biodiesel has the same characteristics as those of commercial biodiesel and can be used as fuel for diesel engines.
文摘The authors performed economic assessment of producing biodiesel at pilot scale using used cooking oil as feed-oil in a Bio-Pro 380 EX biodiesel reactor. The overall results suggest that the biodiesel production using used cooking oil is a viable project even at large or medium scale. The payback period for producing biodiesel at a pilot scale of 31,320 liters per year was 1.5 years, which was 1 month longer than the payback period for a large plant capacity of 66,000 liters per year. The study demonstrated that the unit selling price and unit production cost are sensitive to the economic feasibility of biodiesel production, since price variations of BWP 1 result in at least a 13% increase and 12% decrease in profit, respectively. The study further revealed that feed-oil (used cooking oil) was the most expensive among all the inputs accounting for 61%, followed by methanol and direct labour with 19% and 13% respectively. The overall energy recorded to produce approximately 360 liters of biodiesel contributed to 2% only, suggesting that Bio-Pro 380 EX biodiesel reactor is relatively a low energy intensity processor. The situation is suitable for the promotion of biodiesel particularly in countries where initiatives to stimulate the development of biofuels are at its infant stage Botswana included.
文摘Arawana Brand cooking oil produced by the Nanhai Fat Industrial Company, Ltd, is a refined product from imported quality rape oil and fragrant peanut oil and sesame oil imported fromthe United States. The oil is prepared using a unique prescription and skills, and contains rich vitamin E and unsaturated fatty acid without
基金the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(22qntd4308)a special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-05)State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex(No.SCAPC202106).
文摘The dynamic characteristics of cooking-related particle size distributions in real-world settings are not fully understood.Through a real-world campaign in a naturally-ventilated apartment in the northwest US,this study investigates the temporal profiles of size-resolved particle number concentrations(PNCs)ranging from 0.3 to 10µm from frying cooking activities.The cooking scenarios included various combinations of window ventilation,venting range hood(VRH)use,and portable air cleaner(PAC)utilization.Following a standardized pan-frying protocol throughout seven scenarios,real-time PNCs of 16-size bins were measured in the kitchen.The PNCs were empirically compared among size bins,periods,and scenarios.The most abundant size ranges of cooking-related particles were 0.3–0.579µm in number(45%–71%of the total)and 2.685–5.182µm in mass(48%–57%of the total).Compared with the scenario without any cooking-fume mitigating measures,keeping the kitchen windows open reduced the mean PNCs during and within 1-h after cooking for PM_(0.3-2.5),PM_(2.5-10),and PM_(0.3-10)by 78%,92%,and 79%,respectively.By contrast,utilizing a VRH during cooking reduced the corresponding levels by 21%,69%,and 25%,respectively.Combined with running the VRH,using a PAC in the kitchen led to additional reductions of 84%,88%,and 84%,respectively.Additionally,the removal efficiencies of the three strategies generally increased with particle sizes.
基金financially supported by the National Natural Science Foundation of China(Nos.41403084,41807341,4171101108 and 41603090)the Project from Shanghai Committee of Science and Technology(No.16ZR1414800)
文摘Ship auxiliary engines contribute large amounts of air pollutants when at berth.Biodiesel,including that from waste cooking oil(WCO),can favor a reduction in the emission of primary pollutant when used with internal combustion engines.This study investigated the emissions of gaseous intermediate-volatile organic compounds(IVOCs)between WCO biodiesel and marine gas oil(MGO)to further understand the differences in secondary organic aerosol(SOA)production of exhausts.Results revealed that WCO exhaust exhibited similar IVOC composition and volatility distribution to MGO exhaust,despite the differences between fuel contents.While WCO biodiesel could reduce IVOC emissions by 50%as compared to MGO,and thus reduced the SOA production from IVOCs.The compositions and volatility distributions of exhaust IVOCs varied to those of their fuels,implying that fuel-component-based SOA predicting model should be used with more cautions when assessing SOA production of WCO and MGO exhausts.WCO biodiesel is a cleaner fuel comparing to conventional MGO on ship auxiliary engines with regard to the reductions in gaseous IVOC emissions and corresponding SOA productions.Although the tests were conducted on test bench,the results could be considered as representative due to the widely applications of the test engine and MGO fuel on real-world ships.
文摘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, Nz adsorption-desorption, simultaneous thermogravimetric analyse/differential scanning calorimetry (TGA/DSC) experiments on the thermal decomposition of kaolinite and Fourier-transform infrared spectrometer (FTIR) analysis. Parameters related to the transesterificaion 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℃; 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 mm2" s-1 and a density of 900.1 kg-m-3. The results showed that metakaolinite is a prominent, inexpensive, reusable and thermally stable catalyst for the transesterification of waste cooking oil.
基金financially supported by the Fundamental Research Funds for the Central Universities(Grant Nos.DUT20JC50 and DUT17RC(3)006)National Natural Science Foundation of China(Grant No.51508137)support of Network and Information Center of Dalian University of Technology for Materials Studio 7.0。
文摘Waste cooking oil(WCO)has received attention on rejuvenating aged asphalt binder widely in recent years.This study evaluated the rejuvenation effects of WCO on aged asphalt binder on the micro-scale using molecular dynamics(MD)simulation.First,the representative molecules of WCO and asphalt binders were selected.The molecular mixture model was then developed.The thermodynamic properties were investigated,including density,cohesive energy density,solubility parameter,and surface free energy.The results show that WCO can restore the thermodynamic properties of aged asphalt binder to some extent and WCO has different influences on electrostatic interactions and van der Waals effects.From the diffusion behavior and molecular structure of asphalt binder,WCO can improve the molecular mobility and restore the colloidal structure.Besides,the adhesion work and moisture susceptibility of asphalt binder-aggregate interfaces(calcite and quartz)were evaluated.The results show that WCO can improve adhesion work between asphalt binder and aggregates since WCO can change molecular structure of asphalt binders and certain adhesion work exists between WCO and aggregates.Also,it can mitigate the moisture susceptibility of asphalt binder-aggregate interfaces(calcite and quartz).The study demonstrates that the MD simulation can help to understand the rejuvenation effects of WCO on aged asphalt binder on the micro-scale.
文摘Biodiesel is derived from waste cooking oil (WCO) by transesterification. Methylester was prepared by mixing diesel and biodiesel oils as 20% by volume. Nano particles asTiO2, Al2O3 and CNTs were blended with biodiesel blend at different concentrations of 25,50, and 100 mg/l to enhance the physicochemical fuel characteristics to obtain clean and effi-cient combustion performance. An experimental setup was incorporated into a diesel engine toinvestigate the influence of these nano-materials on engine performance, exergy analysis, combustion characteristics and emissions using WCO biodiesel-diesel mixture. Enriching methylester mixture with 100 ppm titanium, alumina and CNTs (B20T100, B20A100 andB20C100) increased the thermal efficiency by 4%, 6% and 11.5%, respectively compared toB20. Biodiesel blending with nano additives B20T100, B20A100 and B20C100 decreasedthe emissions of CO (11%, 24% and 30%, respectively), HC (8%, 17% and 25%, respectively)and smoke (10%, 13% and 19%, respectively) compared to B20. However, the noticeable increase of NOx was estimated by 5%, 12% and 27% for B20T100, B20A100 and B20C100,respectively. Finally, the results showed the rise in peak cylinder pressure by 5%, 9% and 11% and increase in heat release rate by 4%, 8% and 13% for B20T100, B20A100 andB20C100, respectively. The fuel exergy of B20T100, B20A100 and B20C100 are lower thanbiodiesel blend B20 by 6.5%, 16% and 23% but the exergetic efficiency are increased by 7%,19% and 30% at full load about B20.
文摘The paper discussed the physical and chemical properties of cooking oil vapor(COV) and its biological effects. The study showed that: (1)By ultraviolet spectrophotometry, the method to determine the concentration of COV was simple, reliable and suitable; (2)At 220℃, about 60%-80% particles′ diameter of COV were less than 10 μm which referred to they are capable of reaching the deeper parts of the respiratory tract; (3)Pulmonary toxicity study of COV revealed that in acute toxicity test, there was lung tissue injury in rats and the degree increased as the concentration of oil vapor increased; subacute test in rats indicated that pulmonary injury might be the result of lipid peroxidation brought about by the activation of more general free radical system; (4)The average concentration of emitted oil vapor in the environment ranged from 0.10 to 0.20 mg/m3, the emission outlets in most restaurants were very simple or located in residential areas without any filtering device; (5)Irritative effect threshold levels of COV to volunteers and the effects on occupational exposed cooks also suggested that COV might produce harmful effects on pulmonary function in occupationally exposed personnel.
基金This work received a scholarship from the Thailand Research Fund(TRF)through the Royal Golden Jubilee Ph.D.(RGJ)program(Grant No.PHD/0150/2561).
文摘Renewable biofuels have gained increasing attention as a potential alternative fuel to decrease CO_(2) emission from combustion of fossil fuels.The aims of the work were to modify Thai dolomite by adding magnesium carbonate(MgCO_(3))at various contents(0-30 wt%),and used as catalyst in pyrolytic catalysis cracking(PCC)process to produce light biofuels including gasoline and kerosene.All catalysts were calcined at 600℃ for 4 h prior to the characterization and experiments.The physicochemical properties were done by various techniques such as X-ray diffractometer(XRD),N2 adsorption-desorption,thermogravimetric analyzer and differential thermal analyzer(TGA-DTA),Field-emission scanning electron microscope(FE-SEM),and energy dispersive X-ray spectroscopy(EDX).The experiments of PCC process were carried out at different reaction temperatures of 450-550℃.The results from XRD and SEM-EDX confirmed that the Mg was successfully added in Thai dolomite.The Mg content in the catalysts increased with increasing MgCO_(3) loadings.The calcination temperature of 600℃ cannot completely convert CaCO3 to CaO form.The pyrolytic oil and distilled oil yields and quality were affected by both Mg content and reaction temperature.In addition,pyrolytic oil was completely distillated according to ASTM D86 to separate into gasoline,kerosene,and diesel.The light biofuel production was enhanced with increasing Mg content in the reaction temperatures of 500 and 550℃.The appropriate condition was suggested at reaction temperature of 500℃ with 20 wt%Mg/dolomite catalyst as it showed the highest production yield of about 84 vol%and light biofuel yield of about 65 vol%.
基金Funded by the Science and Technology Project of Henan Department of Transportation(No.2020J-2-3)Shaanxi Transportation Science and Technology Project(Nos.17-05K,19-10K,19-28K)。
文摘The physical performance of recycled asphalt was used as the main evaluation index to study the optimal range of a self-made rejuvenator.Through the penetration,viscosity and gel permeation chromatography(GPC)tests,the diffusion degree of the rejuvenator under different temperatures and time process was analyzed,and the diffusion efficiency of the rejuvenator was evaluated from the macro and micro perspective.The regeneration mechanism of the rejuvenator in the aged asphalt was also analyzed using the Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM)and chemical composition tests.The research results showed that the optimum rejuvenator content was about 3%.Higher temperature and longer time were beneficial to improving the permeability and diffusion of the rejuvenator.During the aging process,the light components were reduced,and more macromolecular asphaltenes were generated as well as a large number of carbonyl and sulfoxide.After diffusion and regeneration,the light components in the asphalt were supplemented,the wrinkles and gullies of the aged asphalt were almost improved to the surface state of the matrix asphalt.
基金financially supported by the National Natural Science Foundation of China(No.21972099)the National Natural Science Foundation of China(National Special Scientific Research Instrument and Equipment Development)(No.21427803-2)the 111 project(No.B17030)。
文摘The activity of Mo_(2) C-based catalyst on vegetable oil conversion into biofuel could be greatedly promoted by tuning the carbon content,while its modification mechanism on the surface properties remained elusive.Herein,the exposed active sites,the particle size and Lewis acid amount of Ni-Mo_(2) C/MCM-41 catalysts were regulated by varying CH_(4) content in carbonization gas.The activity of Ni-Mo_(2) C/MCM-41 catalysts in jatropha oil(JO)conversion showed a volcano-like trend over the catalysts with increasing CH_(4) content from 15%to 50%in the preparation process.The one prepared by 25%CH_(4) content(NiMo_(2) C(25)/MCM-41)exhibited the outstanding catalytic performance with 83.9 wt%biofuel yield and95.2%C_(15)-C_(18) selectivity.Such a variation of activity was ascribed to the most exposed active sites,the smallest particle size,and the lowest Lewis acid amount from Ni^(0) on the Ni-Mo_(2) C(25)/MCM-41 catalyst surface.Moreover,the Ni-Mo_(2) C(25)/MCM-41 catalyst could also effectively catalyze the conversion of crude waste cooking oil(WCO)into green diesel.This study offers an effective strategy to improve catalytic performance of molybdenum carbide catalyst on vegetable oil conversion.
文摘Both Omega-6 and Omega-3 fatty acids are essential nutrients important for cellular structure and function but cannot be synthesized by the human body and must be obtained from food.These two classes of fatty acids are metabolically and functionally different and antagonistically regulate many physiological and pathological processes.Thus,the relative balance between Omega-6 and Omega-3 fatty acids are critical for good health.However,today’s diet contains too much Omega-6 but too little Omega-3,leading to a severe imbalance with a very high Omega-6/Omega-3 ratio(>10)in most people.Many lines of evidence suggest that this imbalance is a key factor contributing to the development of modern chronic diseases.A growing number of studies ranging from laboratory research to clinical trials have shown that balancing the tissue ratio of Omega-6/Omega-3 fatty acids by increasing tissue levels of Omega-3 fatty acids and/or decreasing the content of Omega-6 fatty acids are very beneficial for the prevention and treatment of many life-threating chronic diseases as well as for health promotion of the general public.Therefore,development and production of foods rich in Omega-3-fatty acids should be considered as a key health program to balance essential fat intake and thereby improve the nutritional and health status of all people.