This study investigates the influence of using ground palm oil fuel ash(G-POFA) from 10%-30% as cement replacement(by weight) on the cement mortar's pH under various curing conditions. These findings were suppleme...This study investigates the influence of using ground palm oil fuel ash(G-POFA) from 10%-30% as cement replacement(by weight) on the cement mortar's pH under various curing conditions. These findings were supplemented by thermal gravimetric analysis(TGA). Moreover, the resistance of G-POFA blended cement mortars to water absorption and sorptivity was determined. Further, the k-value test was carried out to explain the pozzolanic and filler behavior of G-POFA and to support the results obtained from TGA. It was found that there was no significant impact of several curing conditions on the pH of mortars. The mortar with 10% G-POFA in replacement of cement(G-POFA-10) exhibited the best resistance against water absorption and sorptivity.展开更多
This paper presented a study on the strength and chloride resistance of mortars made with ternary blends of ordinary Portland cement (OPC), ground palm oil fuel ash (POA), and classified fly ash (FA). The mortar...This paper presented a study on the strength and chloride resistance of mortars made with ternary blends of ordinary Portland cement (OPC), ground palm oil fuel ash (POA), and classified fly ash (FA). The mortar mixtures were made with Portland cement type I containing 0-40wt% FA and POA. FA and POA with 1wt%-3wt% retained on a sieve No.325 were used. The compressive strength and rapid chloride penetration depth of mortars were determined. The results reveal that the use of ternary blended cements produces good strength mortars. The use of the blend of FA and POA also produces high strength mortars and excellent resistance to chloride penetration owing to the synergic effect of FA and POA. A mathematical analysis and two-parameter polynomial model were presented to predict the compressive strength. The mathematical model correlated well with the experimental results. The computer 3-D graphics of strength of the ternary blended mortars were also constructed and could be used to aid the understanding and the proportioning of the blended system.展开更多
This study investigated the removal of hexavalent chromium, Cr(VI) from aqueous solution by adsorption using palm oil fuel ash (POFA), an agricultural waste from the palm oil industry. POFA adsorbent was characterized...This study investigated the removal of hexavalent chromium, Cr(VI) from aqueous solution by adsorption using palm oil fuel ash (POFA), an agricultural waste from the palm oil industry. POFA adsorbent was characterized by X-ray diffraction (XRD) analysis. Batch adsorption study revealed that the optimum conditions for the removal were as follows: pH 2, adsorbent dosage 80 g/L and contact time of 6 min, which resulted in 92% removal and 0.464 mg/g maximum adsorption capacity. Adsorption isotherm and kinetic studies showed that Freundlich isotherm and pseudo-second-order kinetic models fitted best to the experimental data. Column adsorption study at 5 mL/min of flow rate showed that 90% removal was obtained at 2 min of contact time which represented its breakthrough point. The column reached saturation at 30 min and the maximum column adsorption capacity recorded was 0.412 mg/g. The column adsorption behavior showed good fit with both Thomas and Yoon-Nelson kinetic models. These findings suggested that the utilization of POFA as a low-cost adsorbent to remove Cr(VI) from wastewater, either in batch or fixed bed adsorption system is not only effective, but concurrently will help to reduce wastes from the palm oil industry.展开更多
This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to wa...This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to water.The interest of this paper is to shed light on the thermomechanical and above all water effects of heavy fuel oil on a sample of silty clayey soil.To achieve this,we used heavy fuel oil added in different proportions to silty clayey soil,to make sample of bricks on which tests were carried out.At the end of the experimental tests carried out on materials made(bricks)with our soil sample,it appears that heavy fuel oil moderately reduces the mechanical resistance of bricks and slightly increases thermal diffusion through them.On the contrary,we note a very good water resistance of the bricks thanks to the heavy fuel oil,in particular their water absorption by capillarity.This confirms that the mixture of heavy fuel oil and a silty-clayey soil used as a coating makes it possible to prevent the infiltration of water into the walls of raw soil constructions.However,its use as a construction material does not guarantee very good mechanical resistance,and slightly increases thermal diffusion.展开更多
Through continuous equipment technology transformation and full utilization of Ma Steel's abundant gas,the boiler no longer relies on fuel oil for stable combustion during boiler startup,sliding parameter shutdown...Through continuous equipment technology transformation and full utilization of Ma Steel's abundant gas,the boiler no longer relies on fuel oil for stable combustion during boiler startup,sliding parameter shutdown,and RB,thus achieving safe and stable operation of the boiler under any abnormal working conditions,and achieving good economic and social benefits.展开更多
In this study, a homogeneous alkaline catalyst was used in the production of biodiesel from raw and refined castor oil feedstock. The effect of potassium hydroxide (KOH) as a catalyst between the two feedstocks, raw a...In this study, a homogeneous alkaline catalyst was used in the production of biodiesel from raw and refined castor oil feedstock. The effect of potassium hydroxide (KOH) as a catalyst between the two feedstocks, raw and refined castor oil was compared. The transesterification technique was utilized in this study, aiming to investigate the effect of different parameters, which include the reaction temperature, methanol-to-oil mole ratio, and catalyst concentration at a constant period of 90 minutes. The result revealed the performance of the KOH catalyst on raw castor oil yielded 98.49% FAME, which was higher than the refined castor oil which yielded 97.9% FAME. The optimal conditions obtained from refined castor oil were applied to raw castor oil because of the same properties. The fuel quality of castor oil and produced biodiesel were tested for physicochemical properties.展开更多
Energy obtained from a variety of non-renewable sources is considered unsustainable. Various fossil fuels, such as petroleum, coal, and natural gas, are among these sources. The combustion of fossil fuels resulted in ...Energy obtained from a variety of non-renewable sources is considered unsustainable. Various fossil fuels, such as petroleum, coal, and natural gas, are among these sources. The combustion of fossil fuels resulted in the generation of greenhouse gases, which increased the amount of carbon dioxide in the atmosphere. Global warming and ozone layer degradation are the negative consequences. In a country like India, where consumable oils are still imported, it is sense to look at the possibility of using such unpalatable oils in CI engines that aren’t often utilized as cooking oil. Palm oil is a vegetable oil obtained from the monocarp of the oil palm’s crop. The main goal is to provide a low-cost, high-performance alternative to diesel. The possibility of palm oil as a realistic, modest, and effective hotspot for the generation of biodiesel is investigated in this research. The article is focused on the comparison of palm oil and diesel in terms of characteristics.展开更多
This paper analyzes the role of price discovery of Shanghai fuel oil futures market by using methods, such as unit root test, co-integration test, error correction model, Granger causality test, impulse-response fimct...This paper analyzes the role of price discovery of Shanghai fuel oil futures market by using methods, such as unit root test, co-integration test, error correction model, Granger causality test, impulse-response fimction and variance decomposition. The results showed that there exists a strong relationship between the spot price of Huangpu fuel oil spot market and the futures price of Shanghai fuel oil futures market. In addition, the Shanghai fuel oil futures market exhibits a highly effective price discovery function.展开更多
Oxidative desulfurization(ODS)has been proved to be an efficient strategy for the production of clean fuel oil.Numerous metal-based materials have been employed as excellent ODS catalysts,but being hindered by their h...Oxidative desulfurization(ODS)has been proved to be an efficient strategy for the production of clean fuel oil.Numerous metal-based materials have been employed as excellent ODS catalysts,but being hindered by their high-cost and potential secondary pollution.In this work,we employed graphene analogous hexagonal boron nitride(h-BN)as a metal-free catalyst for ODS with hydrogen peroxide(H2O2)as the oxidant.The h-BN catalyst was characterized and proved to be a few-layered structure with relatively high specific surface areas.The h-BN catalyst showed a 99.4%of sulfur removal in fuel oil under the optimized reaction conditions.Besides,the h-BN can be recycled for 8 times without significant decrease in the catalytic performance.Detailed mechanism analysis found that it is the boron radicals in h-BN activated H2O2 to generate·OH species,which can readily oxidize sulfides to corresponding sulfones for separation.This work would provide another choice in choosing metal-free catalysts for ODS.展开更多
This study aims to evaluate the subacute toxic effects of oil under different treatments on marine organism by simulating natural contaminative processes. In this study, 120# (RMD15) fuel oil was selected as the pol...This study aims to evaluate the subacute toxic effects of oil under different treatments on marine organism by simulating natural contaminative processes. In this study, 120# (RMD15) fuel oil was selected as the pollutant and marine medaka (Oryzias melastigma) embryos as the experimental organism. The developmental toxicity of different volume concentrations (0.05%, 0.2%, 1% and 5%) of water-accommodated fractions, biologically-enhanced water-accommodated fractions, and chemically-enhanced water-accommodated fractions on the embryos in different exposure time (8, 15 and 22 d) were compared and the content of relevant polycyclic aromatic hydrocarbons (PAHs) was studied (in dispersion and in vivo). The subacute toxic effects were assessed in terms of antioxidant activities of enzymes (superoxide dismutase, catalase and glutathione S-transferase) and the blue sac disease (BSD) indexes.The results showed that the BSD indexes of the treatment groups were significantly higher than the respective control groups and showed positive correlations with both concentration and exposure time. The experiments with three antioxidant enzymes indicated that enzymatic activities of the embryos changed dramatically under the oxidation stress of petroleum hydrocarbons, especially after adding the dispersants. With the increase of petroleum hydrocarbon concentration and exposure time, the three enzymes showed different degrees of induction and inhibition effects.展开更多
It is known that increasing the injection pressure reduces the breakup length and the droplet size.Adding pulses,on the other hand,helps to atomize the liquid into finer droplets,similar to airassisted injectors but w...It is known that increasing the injection pressure reduces the breakup length and the droplet size.Adding pulses,on the other hand,helps to atomize the liquid into finer droplets,similar to airassisted injectors but without altering the airtofuel concentration.To further reduce the droplet size and breakup length,a novel injector type,called''Pulsed PressureSwirl"(PPS),is introduced in this work,which is a combination of pressureswirl and ultrasonic pulsed injectors.A pressureswirl atomizer was designed and fabricated specifically for Mazut HFO(Heavy Fuel Oil).The droplet formation process and droplet size distribution have been studied experimentally(by shadowgraphy high speed imaging)and numerically(with the opensource VolumeofFluid code Gerris).Changing liquid injection pressure effect on the spray angle and film thickness has been quantified.These simulations have been used to study the primary breakup process and quantify the droplet size distributions,using different injection pulse frequencies and pressures.The numerical results have revealed that the new injector concept successfully produces finer droplets and results in a decrease in the breakup length,especially when applying high pulse frequencies,with no significant changes in the spray angle.展开更多
Combustion of heavy fuels is one of the main sources of greenhouse gases, particulate emissions, ashes, NOxand SOx. Gasification is an advanced and environmentally friendly process that generates combustible and clean...Combustion of heavy fuels is one of the main sources of greenhouse gases, particulate emissions, ashes, NOxand SOx. Gasification is an advanced and environmentally friendly process that generates combustible and clean gas products such as hydrogen. Some entrained flow gasifiers operate with Heavy Fuel Oil(HFO) feedstock. In this application, HFO atomization is very important in determining the performance and efficiency of the gasifiers.The atomization characteristics of HFO(Mazut) discharging from a pressure-swirl atomizer(PSA) are studied for different pressures difference(Δp) and temperatures in the atmospheric ambient. The investigated parameters include atomizer mass flow rate( _m), discharge coefficient(CD), spray cone angle(θ), breakup length(Lb), the unstable wavelength of undulations on the liquid sheet(λs), global and local SMD(sauter mean diameter) and size distribution of droplets. The characteristics of Mazut sheet breakup are deduced from the shadowgraph technique. The experiments on Mazut film breakup were compared with the predictions obtained from the liquid film breakup model. Validity of the theory for predicting maximum unstable wavelength was investigated for HFO(as a highly viscous liquid). A modification on the formulation of maximum unstable wavelength was presented for HFO. SMD decreases by getting far from the atomizer. The measurement for SMD and θ were compared with the available correlations. The comparisons of the available correlations with the measurements of SMD andθ show a good agreement for Ballester and Varde correlations, respectively. The results show that the experimental sizing data could be presented by Rosin-Rammler distributions very well at different pressure difference and temperatures.展开更多
A method of synchronous-high-derivative spectfluor for identification of crude oil and fuel oil pollution is studied. The best operation conditions for the 2nd and 4th deriv, are set. To differentiate oil-spill at riv...A method of synchronous-high-derivative spectfluor for identification of crude oil and fuel oil pollution is studied. The best operation conditions for the 2nd and 4th deriv, are set. To differentiate oil-spill at river and sea, this method is rapid and simple, and the spectra have high resolution power as 'fingerprint'.展开更多
This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate: n-C10 to n-C15 were lost...This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate: n-C10 to n-C15 were lost gradually in 24 weeks and the relative abundance of alkanes with long chains (〉n-C19) increased markedly. The aromatic compounds with less than two tings (except C4N) were completely lost in 24 weeks and CnP and CnD became the main aromatics in the heavy fuel oil after 24 weeks. The ratios of n- C1/Pristane (Pr) and n-C18 Phytane (Ph) were suitable for identifying lightly weathered (3 weeks) heavy fuel oil. The ratios of n-ClT/n-C18 and Pr/Ph were suitable for identifying moderately weathered heavy fuel oil (12 weeks); the ratios of C2D/C2P and C3D/C3P did not change significantly in 24 weeks and were more suitable for identifying moderately weathered heavy fuel oil (24 weeks).展开更多
In this paper, the impact of limiting thermostat on the rupture event occuring in Fuel-Oil burner fuel pre-heaters' resistant (heat generating) wires is inspected numerically. Gaseous fuel content in the pipeline h...In this paper, the impact of limiting thermostat on the rupture event occuring in Fuel-Oil burner fuel pre-heaters' resistant (heat generating) wires is inspected numerically. Gaseous fuel content in the pipeline has also been issued as a possibility. Heater's inner temperature distributions have been simulated by an in-house MATrix LABoratory (MATLAB) script in order to understand the resistant wire exposure to high temperatures by numerous scenarios. It is concluded that the effect of fuel flowrate is not a major effect on the wires' fate because of the limiting thermostat co-working. The main difference between the calculations is the effect of thermostat cut off function. The numerical simulations enlightened the dominant effect of thermostat sensing delay, so the overheating event. Intolerable delay results with a quick drop in the thermal efficiency and an increased possibility on wire rupture due to overheating which means a burner malfunction. Referring to the first numerical simulation results, a distributed and reduced heat flux was implemented with the same fluid and thermodynamic properties on a revised pre-heater model with an increased heater plate. The increment, thus the reduction on the heat flux of the ribbon wires has been noted as the key for safe operation.展开更多
The concept of converting recycled oils to clean biodiesel aims towards reducing the amount of waste oils to be treated and lowering the cost of biodiesel production. Samples of waste oils were prepared from Spent Fry...The concept of converting recycled oils to clean biodiesel aims towards reducing the amount of waste oils to be treated and lowering the cost of biodiesel production. Samples of waste oils were prepared from Spent Frying oil collected from local hotels and restaurants in Khartoum, Sudan. Selected methods to achieve maximum yield of biodiesel using the waste feedstock were presented and compared. Some properties of the feedstock, such as free fatty acid content and moisture content, were measured and evaluated. Biodiesel yield recovery obtained, from Base-transesterification process about 92%. Produced Biodiesel specifications were also analyzed and discussed in Base-transesterification process. Kinematic viscosity of biodiesel was found to be 5.51 mm2·s?1 at 40?C, the flash point was 174.2?C and Cetane No of 48.19. Biodiesel was characterized by its physical and fuel properties according to ASTM and DIN V 51606 standards.展开更多
The conversion of waste frying oil into a valuable methyl ester (biodiesel) has been successfully conducted and also the acid pre-treatment process was carried out prior to the main biodiesel production process for lo...The conversion of waste frying oil into a valuable methyl ester (biodiesel) has been successfully conducted and also the acid pre-treatment process was carried out prior to the main biodiesel production process for lowering waste frying oil free fatty acid (FFA) content below 1%. The physicochemical properties of biodiesel were analyzed to ensure the product could meet the standards of fuel properties. The methanolysis was selected as the biodiesel production technique under various mixing speeds namely 350, 400 and 450 rpm, while the other parameters are maintained at the optimum process conditions such as methanol to oil molar ratio is 6:1, percentage of catalyst loading is 1.0% wt, reaction temperature is 60℃, and reaction time is 50 min. Also, the investigation on the kinematic viscosity, density and flash point of biodiesel was performed against a number of rpm. The standards of ASTM D 6751 were applied to measure the entire prescribed properties of biodiesel. The highest yield of biodiesel obtained was 99%. The values of flash point, kinematic viscosity and density were in the range of specified limitations. Other biodiesel properties fulfilled the diesel engine application requirements.展开更多
The demand for fuel oil is ever increasing with the advance of the modern world, whereas worldwide reserves of fossil oils are diminishing at an alarming rate. However, there exist large stockpiles of vegetable oil fe...The demand for fuel oil is ever increasing with the advance of the modern world, whereas worldwide reserves of fossil oils are diminishing at an alarming rate. However, there exist large stockpiles of vegetable oil feedstocks that could be exploited to produce fuel oil, called biodiesel with the aid of biotechnology. Initially, the biodiesel produced from vegetable oil did not attract much attention because of its high cost. However, the recent increase in petroleum prices and the uncertainties of petroleum availability led to the renewal of interest in biodiesel production from such sustainable resources (i.e., vegetable oil feedstocks). This research focuses on the production of biodiesel from plant resources, and further investigates the influences of key process parameters, such as the molar ratio of methanol to oil, catalyst concentration, reaction temperature, reaction period and stirring speed on the biodiesel yield. This investigation is to determine the optimum process parameters for maximum biodiesel yield. The biodiesel was produced from three vegetable oil feedstocks, namely palm, soybean and sunflower oil via a transesterification process. It was observed that all the process parameters significantly influenced the biodiesel yield. The maximum biodiesel yields for palm, sunflower and soybean oil feedstocks were found to be 87.5%, 83.6% and 80.2%, respectively at optimum condition. The results suggest that through proper optimization of the process parameters the biodiesel yields could be maximized. In conclusion, the production of biodiesel from plant resources would be regarded as a sustainable solution to the ever increasing demand of fuel oils.展开更多
文摘This study investigates the influence of using ground palm oil fuel ash(G-POFA) from 10%-30% as cement replacement(by weight) on the cement mortar's pH under various curing conditions. These findings were supplemented by thermal gravimetric analysis(TGA). Moreover, the resistance of G-POFA blended cement mortars to water absorption and sorptivity was determined. Further, the k-value test was carried out to explain the pozzolanic and filler behavior of G-POFA and to support the results obtained from TGA. It was found that there was no significant impact of several curing conditions on the pH of mortars. The mortar with 10% G-POFA in replacement of cement(G-POFA-10) exhibited the best resistance against water absorption and sorptivity.
文摘This paper presented a study on the strength and chloride resistance of mortars made with ternary blends of ordinary Portland cement (OPC), ground palm oil fuel ash (POA), and classified fly ash (FA). The mortar mixtures were made with Portland cement type I containing 0-40wt% FA and POA. FA and POA with 1wt%-3wt% retained on a sieve No.325 were used. The compressive strength and rapid chloride penetration depth of mortars were determined. The results reveal that the use of ternary blended cements produces good strength mortars. The use of the blend of FA and POA also produces high strength mortars and excellent resistance to chloride penetration owing to the synergic effect of FA and POA. A mathematical analysis and two-parameter polynomial model were presented to predict the compressive strength. The mathematical model correlated well with the experimental results. The computer 3-D graphics of strength of the ternary blended mortars were also constructed and could be used to aid the understanding and the proportioning of the blended system.
文摘This study investigated the removal of hexavalent chromium, Cr(VI) from aqueous solution by adsorption using palm oil fuel ash (POFA), an agricultural waste from the palm oil industry. POFA adsorbent was characterized by X-ray diffraction (XRD) analysis. Batch adsorption study revealed that the optimum conditions for the removal were as follows: pH 2, adsorbent dosage 80 g/L and contact time of 6 min, which resulted in 92% removal and 0.464 mg/g maximum adsorption capacity. Adsorption isotherm and kinetic studies showed that Freundlich isotherm and pseudo-second-order kinetic models fitted best to the experimental data. Column adsorption study at 5 mL/min of flow rate showed that 90% removal was obtained at 2 min of contact time which represented its breakthrough point. The column reached saturation at 30 min and the maximum column adsorption capacity recorded was 0.412 mg/g. The column adsorption behavior showed good fit with both Thomas and Yoon-Nelson kinetic models. These findings suggested that the utilization of POFA as a low-cost adsorbent to remove Cr(VI) from wastewater, either in batch or fixed bed adsorption system is not only effective, but concurrently will help to reduce wastes from the palm oil industry.
文摘This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to water.The interest of this paper is to shed light on the thermomechanical and above all water effects of heavy fuel oil on a sample of silty clayey soil.To achieve this,we used heavy fuel oil added in different proportions to silty clayey soil,to make sample of bricks on which tests were carried out.At the end of the experimental tests carried out on materials made(bricks)with our soil sample,it appears that heavy fuel oil moderately reduces the mechanical resistance of bricks and slightly increases thermal diffusion through them.On the contrary,we note a very good water resistance of the bricks thanks to the heavy fuel oil,in particular their water absorption by capillarity.This confirms that the mixture of heavy fuel oil and a silty-clayey soil used as a coating makes it possible to prevent the infiltration of water into the walls of raw soil constructions.However,its use as a construction material does not guarantee very good mechanical resistance,and slightly increases thermal diffusion.
文摘Through continuous equipment technology transformation and full utilization of Ma Steel's abundant gas,the boiler no longer relies on fuel oil for stable combustion during boiler startup,sliding parameter shutdown,and RB,thus achieving safe and stable operation of the boiler under any abnormal working conditions,and achieving good economic and social benefits.
文摘In this study, a homogeneous alkaline catalyst was used in the production of biodiesel from raw and refined castor oil feedstock. The effect of potassium hydroxide (KOH) as a catalyst between the two feedstocks, raw and refined castor oil was compared. The transesterification technique was utilized in this study, aiming to investigate the effect of different parameters, which include the reaction temperature, methanol-to-oil mole ratio, and catalyst concentration at a constant period of 90 minutes. The result revealed the performance of the KOH catalyst on raw castor oil yielded 98.49% FAME, which was higher than the refined castor oil which yielded 97.9% FAME. The optimal conditions obtained from refined castor oil were applied to raw castor oil because of the same properties. The fuel quality of castor oil and produced biodiesel were tested for physicochemical properties.
文摘Energy obtained from a variety of non-renewable sources is considered unsustainable. Various fossil fuels, such as petroleum, coal, and natural gas, are among these sources. The combustion of fossil fuels resulted in the generation of greenhouse gases, which increased the amount of carbon dioxide in the atmosphere. Global warming and ozone layer degradation are the negative consequences. In a country like India, where consumable oils are still imported, it is sense to look at the possibility of using such unpalatable oils in CI engines that aren’t often utilized as cooking oil. Palm oil is a vegetable oil obtained from the monocarp of the oil palm’s crop. The main goal is to provide a low-cost, high-performance alternative to diesel. The possibility of palm oil as a realistic, modest, and effective hotspot for the generation of biodiesel is investigated in this research. The article is focused on the comparison of palm oil and diesel in terms of characteristics.
文摘This paper analyzes the role of price discovery of Shanghai fuel oil futures market by using methods, such as unit root test, co-integration test, error correction model, Granger causality test, impulse-response fimction and variance decomposition. The results showed that there exists a strong relationship between the spot price of Huangpu fuel oil spot market and the futures price of Shanghai fuel oil futures market. In addition, the Shanghai fuel oil futures market exhibits a highly effective price discovery function.
基金All authors appreciate the financial support from the National Key R&D Program of China(2017YFB0306504)the National Natural Science Foundation of China(No.21722604,21878133 and 21908082)+2 种基金China Postdoctoral Science Foundation(No.2019M651743)Natural Science Foundation of Jiangsu Province(BK20190852,BK20190854)Natural Science Foundation for Jiangsu Colleges and Universities(19KJB530005).
文摘Oxidative desulfurization(ODS)has been proved to be an efficient strategy for the production of clean fuel oil.Numerous metal-based materials have been employed as excellent ODS catalysts,but being hindered by their high-cost and potential secondary pollution.In this work,we employed graphene analogous hexagonal boron nitride(h-BN)as a metal-free catalyst for ODS with hydrogen peroxide(H2O2)as the oxidant.The h-BN catalyst was characterized and proved to be a few-layered structure with relatively high specific surface areas.The h-BN catalyst showed a 99.4%of sulfur removal in fuel oil under the optimized reaction conditions.Besides,the h-BN can be recycled for 8 times without significant decrease in the catalytic performance.Detailed mechanism analysis found that it is the boron radicals in h-BN activated H2O2 to generate·OH species,which can readily oxidize sulfides to corresponding sulfones for separation.This work would provide another choice in choosing metal-free catalysts for ODS.
基金The National Natural Science Foundation of China under contract No.41276105/D0608
文摘This study aims to evaluate the subacute toxic effects of oil under different treatments on marine organism by simulating natural contaminative processes. In this study, 120# (RMD15) fuel oil was selected as the pollutant and marine medaka (Oryzias melastigma) embryos as the experimental organism. The developmental toxicity of different volume concentrations (0.05%, 0.2%, 1% and 5%) of water-accommodated fractions, biologically-enhanced water-accommodated fractions, and chemically-enhanced water-accommodated fractions on the embryos in different exposure time (8, 15 and 22 d) were compared and the content of relevant polycyclic aromatic hydrocarbons (PAHs) was studied (in dispersion and in vivo). The subacute toxic effects were assessed in terms of antioxidant activities of enzymes (superoxide dismutase, catalase and glutathione S-transferase) and the blue sac disease (BSD) indexes.The results showed that the BSD indexes of the treatment groups were significantly higher than the respective control groups and showed positive correlations with both concentration and exposure time. The experiments with three antioxidant enzymes indicated that enzymatic activities of the embryos changed dramatically under the oxidation stress of petroleum hydrocarbons, especially after adding the dispersants. With the increase of petroleum hydrocarbon concentration and exposure time, the three enzymes showed different degrees of induction and inhibition effects.
文摘It is known that increasing the injection pressure reduces the breakup length and the droplet size.Adding pulses,on the other hand,helps to atomize the liquid into finer droplets,similar to airassisted injectors but without altering the airtofuel concentration.To further reduce the droplet size and breakup length,a novel injector type,called''Pulsed PressureSwirl"(PPS),is introduced in this work,which is a combination of pressureswirl and ultrasonic pulsed injectors.A pressureswirl atomizer was designed and fabricated specifically for Mazut HFO(Heavy Fuel Oil).The droplet formation process and droplet size distribution have been studied experimentally(by shadowgraphy high speed imaging)and numerically(with the opensource VolumeofFluid code Gerris).Changing liquid injection pressure effect on the spray angle and film thickness has been quantified.These simulations have been used to study the primary breakup process and quantify the droplet size distributions,using different injection pulse frequencies and pressures.The numerical results have revealed that the new injector concept successfully produces finer droplets and results in a decrease in the breakup length,especially when applying high pulse frequencies,with no significant changes in the spray angle.
文摘Combustion of heavy fuels is one of the main sources of greenhouse gases, particulate emissions, ashes, NOxand SOx. Gasification is an advanced and environmentally friendly process that generates combustible and clean gas products such as hydrogen. Some entrained flow gasifiers operate with Heavy Fuel Oil(HFO) feedstock. In this application, HFO atomization is very important in determining the performance and efficiency of the gasifiers.The atomization characteristics of HFO(Mazut) discharging from a pressure-swirl atomizer(PSA) are studied for different pressures difference(Δp) and temperatures in the atmospheric ambient. The investigated parameters include atomizer mass flow rate( _m), discharge coefficient(CD), spray cone angle(θ), breakup length(Lb), the unstable wavelength of undulations on the liquid sheet(λs), global and local SMD(sauter mean diameter) and size distribution of droplets. The characteristics of Mazut sheet breakup are deduced from the shadowgraph technique. The experiments on Mazut film breakup were compared with the predictions obtained from the liquid film breakup model. Validity of the theory for predicting maximum unstable wavelength was investigated for HFO(as a highly viscous liquid). A modification on the formulation of maximum unstable wavelength was presented for HFO. SMD decreases by getting far from the atomizer. The measurement for SMD and θ were compared with the available correlations. The comparisons of the available correlations with the measurements of SMD andθ show a good agreement for Ballester and Varde correlations, respectively. The results show that the experimental sizing data could be presented by Rosin-Rammler distributions very well at different pressure difference and temperatures.
文摘A method of synchronous-high-derivative spectfluor for identification of crude oil and fuel oil pollution is studied. The best operation conditions for the 2nd and 4th deriv, are set. To differentiate oil-spill at river and sea, this method is rapid and simple, and the spectra have high resolution power as 'fingerprint'.
文摘This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate: n-C10 to n-C15 were lost gradually in 24 weeks and the relative abundance of alkanes with long chains (〉n-C19) increased markedly. The aromatic compounds with less than two tings (except C4N) were completely lost in 24 weeks and CnP and CnD became the main aromatics in the heavy fuel oil after 24 weeks. The ratios of n- C1/Pristane (Pr) and n-C18 Phytane (Ph) were suitable for identifying lightly weathered (3 weeks) heavy fuel oil. The ratios of n-ClT/n-C18 and Pr/Ph were suitable for identifying moderately weathered heavy fuel oil (12 weeks); the ratios of C2D/C2P and C3D/C3P did not change significantly in 24 weeks and were more suitable for identifying moderately weathered heavy fuel oil (24 weeks).
文摘In this paper, the impact of limiting thermostat on the rupture event occuring in Fuel-Oil burner fuel pre-heaters' resistant (heat generating) wires is inspected numerically. Gaseous fuel content in the pipeline has also been issued as a possibility. Heater's inner temperature distributions have been simulated by an in-house MATrix LABoratory (MATLAB) script in order to understand the resistant wire exposure to high temperatures by numerous scenarios. It is concluded that the effect of fuel flowrate is not a major effect on the wires' fate because of the limiting thermostat co-working. The main difference between the calculations is the effect of thermostat cut off function. The numerical simulations enlightened the dominant effect of thermostat sensing delay, so the overheating event. Intolerable delay results with a quick drop in the thermal efficiency and an increased possibility on wire rupture due to overheating which means a burner malfunction. Referring to the first numerical simulation results, a distributed and reduced heat flux was implemented with the same fluid and thermodynamic properties on a revised pre-heater model with an increased heater plate. The increment, thus the reduction on the heat flux of the ribbon wires has been noted as the key for safe operation.
文摘The concept of converting recycled oils to clean biodiesel aims towards reducing the amount of waste oils to be treated and lowering the cost of biodiesel production. Samples of waste oils were prepared from Spent Frying oil collected from local hotels and restaurants in Khartoum, Sudan. Selected methods to achieve maximum yield of biodiesel using the waste feedstock were presented and compared. Some properties of the feedstock, such as free fatty acid content and moisture content, were measured and evaluated. Biodiesel yield recovery obtained, from Base-transesterification process about 92%. Produced Biodiesel specifications were also analyzed and discussed in Base-transesterification process. Kinematic viscosity of biodiesel was found to be 5.51 mm2·s?1 at 40?C, the flash point was 174.2?C and Cetane No of 48.19. Biodiesel was characterized by its physical and fuel properties according to ASTM and DIN V 51606 standards.
文摘The conversion of waste frying oil into a valuable methyl ester (biodiesel) has been successfully conducted and also the acid pre-treatment process was carried out prior to the main biodiesel production process for lowering waste frying oil free fatty acid (FFA) content below 1%. The physicochemical properties of biodiesel were analyzed to ensure the product could meet the standards of fuel properties. The methanolysis was selected as the biodiesel production technique under various mixing speeds namely 350, 400 and 450 rpm, while the other parameters are maintained at the optimum process conditions such as methanol to oil molar ratio is 6:1, percentage of catalyst loading is 1.0% wt, reaction temperature is 60℃, and reaction time is 50 min. Also, the investigation on the kinematic viscosity, density and flash point of biodiesel was performed against a number of rpm. The standards of ASTM D 6751 were applied to measure the entire prescribed properties of biodiesel. The highest yield of biodiesel obtained was 99%. The values of flash point, kinematic viscosity and density were in the range of specified limitations. Other biodiesel properties fulfilled the diesel engine application requirements.
文摘The demand for fuel oil is ever increasing with the advance of the modern world, whereas worldwide reserves of fossil oils are diminishing at an alarming rate. However, there exist large stockpiles of vegetable oil feedstocks that could be exploited to produce fuel oil, called biodiesel with the aid of biotechnology. Initially, the biodiesel produced from vegetable oil did not attract much attention because of its high cost. However, the recent increase in petroleum prices and the uncertainties of petroleum availability led to the renewal of interest in biodiesel production from such sustainable resources (i.e., vegetable oil feedstocks). This research focuses on the production of biodiesel from plant resources, and further investigates the influences of key process parameters, such as the molar ratio of methanol to oil, catalyst concentration, reaction temperature, reaction period and stirring speed on the biodiesel yield. This investigation is to determine the optimum process parameters for maximum biodiesel yield. The biodiesel was produced from three vegetable oil feedstocks, namely palm, soybean and sunflower oil via a transesterification process. It was observed that all the process parameters significantly influenced the biodiesel yield. The maximum biodiesel yields for palm, sunflower and soybean oil feedstocks were found to be 87.5%, 83.6% and 80.2%, respectively at optimum condition. The results suggest that through proper optimization of the process parameters the biodiesel yields could be maximized. In conclusion, the production of biodiesel from plant resources would be regarded as a sustainable solution to the ever increasing demand of fuel oils.