The effect of polycyclic aromatic hydrocarbons(PAHs)on the stability of the hydrogenation catalyst for production of ultra-low sulfur diesel was studied in a pilot plant using Ni-Mo-W/γ-Al_(2)O_(3)catalyst.The mechan...The effect of polycyclic aromatic hydrocarbons(PAHs)on the stability of the hydrogenation catalyst for production of ultra-low sulfur diesel was studied in a pilot plant using Ni-Mo-W/γ-Al_(2)O_(3)catalyst.The mechanisms of catalyst deactivation were analyzed by the methods of elemental analysis,nitrogen adsorption-desorption,thermogravimetry-mass spectrometry(TG-MS)technology,X-ray photoelectron spectroscopy(XPS)and high resolution transmission electron microscopy(HRTEM).The results demonstrated that PAHs had little effect on the activity of catalyst at the beginning of operation,during which the reaction temperature was increased by only 1-4℃.However,the existence of PAHs significantly accelerated the deactivation of catalyst and weakened the stability of catalyst.This phenomenon could be explained by the reason that the catalyst deactivation is not only related to the formation of carbon deposit,but is also closely related to the loss of pore volume and the decrease of Ni-W-S phase ratio after adding PAHs.展开更多
The deactivation of a Ni-Mo-W/Al_2O_3 catalyst during ultra-low-sulfur diesel production was investigated in a pilot plant. The reasons of catalyst deactivation were analyzed by the methods of elemental analysis, BET ...The deactivation of a Ni-Mo-W/Al_2O_3 catalyst during ultra-low-sulfur diesel production was investigated in a pilot plant. The reasons of catalyst deactivation were analyzed by the methods of elemental analysis, BET and TG-MS. The results showed that the catalyst deactivation rate was notable at the beginning of run, and then gradually reached a steady state after 448 h. In the initial period the catalyst deactivation may mainly be caused by the formation of the carbon deposits. The carbon deposits blocked the catalyst pores and the accessibility of active center decreased. The TG-MS analysis identified three types of carbon species deposited on the catalysts, viz.: the low temperature carbon deposit with high H/C atomic ratio, the medium temperature carbon deposit, and the high temperature carbon with low H/C atomic ratio. The amount of high temperature carbon deposits on the catalyst determined the overall activity and, therefore the high temperature carbon was a major contributor to the deactivation of Ni-Mo-W catalyst.展开更多
The need for cleaner fuels has resulted in a continuing worldwide trend to reduce diesel sulfur and aromatics. There are many approaches to reducing sulfur and aromatics in diesel. Most of them have a common drawback ...The need for cleaner fuels has resulted in a continuing worldwide trend to reduce diesel sulfur and aromatics. There are many approaches to reducing sulfur and aromatics in diesel. Most of them have a common drawback of high cost because of adopting two stages of hydrotreating and using noble-metal catalyst, especially for reducing aromatics. The attempt to resolve this issue has led to the recent development of the Single Stage Hydrotreating (SSHT) process by Research Institute of Petroleum Processing (RIPP), SINOPEC.The SSHT process is a single-stage hydrotreating technology for producing low sulfur and low aromatics diesel. The process uses one or two non-noble-metal catalysts system and operates at moderate pressure. When revamping an existing unit to meet low aromatics diesel specification, the only thing to do is to add a reactor or replace the existing reactor, In pilot plant tests, the SSHT technology has successfully treated SRGO (Straight Run Gas Oil), LCO (Light Cycle Oil) or the blend of them. It is shown that by using the SSHT process diesel with sulfur of 30 ppm and aromatics of 15 m% can be produced from Middle-East SRGO and diesel with aromatics content of 25 m% can be produced from cracked feed, such as FCC-LCO. High diesel yield and cetane number gain (from cracked feed stocks) give the SSHT technology a performance advantage compared to conventional hydrocracking and hydrotreating processes.The lower investment and operating cost is another advantage. The first commercial application of the SSHT technology has been in operation since September 2001.展开更多
In this work,fatty acid and its derivatives were adopted as lubricity additives for low sulfur diesel.Tribological evaluation obtained from the High-Frequency Reciprocating Rig(HFRR)apparatus showed that the lubricati...In this work,fatty acid and its derivatives were adopted as lubricity additives for low sulfur diesel.Tribological evaluation obtained from the High-Frequency Reciprocating Rig(HFRR)apparatus showed that the lubricating performance of the additives increased in the following order:stearic acid>glycol monopalmitate>stearyl alcohol>ethyl palmitate>cetyl ethyl ether.The adsorption behavior of the additives on Fe(110)surface and Fe2O3(001)surface was investigated by molecular dynamics(MD)simulations to verify their lubricity performance.The results suggested that adsorption energies of the additives on Fe(110)surface are determined by the van der Waals forces,while adsorptions on Fe2O3(001)surface are significantly attributed to the electrostatic attractive forces.Higher values of adsorption energy of the additives on Fe2O3(001)surface indicate that the additive has more efficient lubricity enhancing properties.展开更多
The solid-phase extraction using Pd-Al2O3 as the stationary phase was employed to pre-separate the sulfur compounds in straight-run diesel. The isolating effect was evaluated quantitatively by gas chromatography with ...The solid-phase extraction using Pd-Al2O3 as the stationary phase was employed to pre-separate the sulfur compounds in straight-run diesel. The isolating effect was evaluated quantitatively by gas chromatography with a sulfur chemiluminescence detector to harvest a satisfactory result. The identification of the structure of sulfur compounds by comprehensive two-dimensional gas chromatography coupled with the time-of-flight mass spectrometry indicated that cyclo-sulfides, benzothiophenes, dibenzothiophenes, dihydro-benzothiophenes and tetrahydro-dibenzothiophenes were included in straightrun diesel obtained from the Arab medium crude(AM). A total of 259 individual compounds were detected and their molecular structures were identified. The analytical method was approved as an effective way to characterize the composition of sulfur compounds, which reduced the interference of other compounds, facilitated the data presentation and provided more detailed information about molecular composition of sulfur compounds.展开更多
In an urban-transit bus, fueled by biodiesel in Toledo, Ohio, single inhalable particle samples in October 2008 were collected and detected by scanning electron microscopy and energy dispersive X-ray spectrometry （SE...In an urban-transit bus, fueled by biodiesel in Toledo, Ohio, single inhalable particle samples in October 2008 were collected and detected by scanning electron microscopy and energy dispersive X-ray spectrometry （SEM/EDS）. Particle size analysis found bimodal distribution at 0.2 and 0.5 μm. The particle morphology was characterized by 14 different shape clusters： square, pentagon, hexagon, heptagon, octagon, nonagon, decagon, agglomerate, sphere, triangle, oblong, strip, line or stick, and unknown, by quantitative order. The square particles were common in the samples. Round and triangle particles are more, and pentagon, hexagon, heptagon, octagon, nonagon, decagon, strip, line or sticks are less. Agglomerate particles were found in abundance. The surface of most particles was coarse with a fractal edge that can provide a suitable chemical reaction bed in the polluted atmospheric environment. The three sorts of surface patterns of squares were smooth, semi-smooth, and coarse. The three sorts of square surface patterns represented the morphological characteristics of single inhalable particles in the air inside the bus in Toledo. The size and shape distribution results were compared to those obtained for a bus using ultra low sulfur diesel.展开更多
基金financially supported by the Hydrogenation Process and Hydrogenation Catalyst Laboratory (RIPP,SINOPEC)
文摘The effect of polycyclic aromatic hydrocarbons(PAHs)on the stability of the hydrogenation catalyst for production of ultra-low sulfur diesel was studied in a pilot plant using Ni-Mo-W/γ-Al_(2)O_(3)catalyst.The mechanisms of catalyst deactivation were analyzed by the methods of elemental analysis,nitrogen adsorption-desorption,thermogravimetry-mass spectrometry(TG-MS)technology,X-ray photoelectron spectroscopy(XPS)and high resolution transmission electron microscopy(HRTEM).The results demonstrated that PAHs had little effect on the activity of catalyst at the beginning of operation,during which the reaction temperature was increased by only 1-4℃.However,the existence of PAHs significantly accelerated the deactivation of catalyst and weakened the stability of catalyst.This phenomenon could be explained by the reason that the catalyst deactivation is not only related to the formation of carbon deposit,but is also closely related to the loss of pore volume and the decrease of Ni-W-S phase ratio after adding PAHs.
基金financially supported by the Hydrogenation Process and Hydrogenation Catalyst Laboratory (RIPP, SINOPEC)
文摘The deactivation of a Ni-Mo-W/Al_2O_3 catalyst during ultra-low-sulfur diesel production was investigated in a pilot plant. The reasons of catalyst deactivation were analyzed by the methods of elemental analysis, BET and TG-MS. The results showed that the catalyst deactivation rate was notable at the beginning of run, and then gradually reached a steady state after 448 h. In the initial period the catalyst deactivation may mainly be caused by the formation of the carbon deposits. The carbon deposits blocked the catalyst pores and the accessibility of active center decreased. The TG-MS analysis identified three types of carbon species deposited on the catalysts, viz.: the low temperature carbon deposit with high H/C atomic ratio, the medium temperature carbon deposit, and the high temperature carbon with low H/C atomic ratio. The amount of high temperature carbon deposits on the catalyst determined the overall activity and, therefore the high temperature carbon was a major contributor to the deactivation of Ni-Mo-W catalyst.
文摘The need for cleaner fuels has resulted in a continuing worldwide trend to reduce diesel sulfur and aromatics. There are many approaches to reducing sulfur and aromatics in diesel. Most of them have a common drawback of high cost because of adopting two stages of hydrotreating and using noble-metal catalyst, especially for reducing aromatics. The attempt to resolve this issue has led to the recent development of the Single Stage Hydrotreating (SSHT) process by Research Institute of Petroleum Processing (RIPP), SINOPEC.The SSHT process is a single-stage hydrotreating technology for producing low sulfur and low aromatics diesel. The process uses one or two non-noble-metal catalysts system and operates at moderate pressure. When revamping an existing unit to meet low aromatics diesel specification, the only thing to do is to add a reactor or replace the existing reactor, In pilot plant tests, the SSHT technology has successfully treated SRGO (Straight Run Gas Oil), LCO (Light Cycle Oil) or the blend of them. It is shown that by using the SSHT process diesel with sulfur of 30 ppm and aromatics of 15 m% can be produced from Middle-East SRGO and diesel with aromatics content of 25 m% can be produced from cracked feed, such as FCC-LCO. High diesel yield and cetane number gain (from cracked feed stocks) give the SSHT technology a performance advantage compared to conventional hydrocracking and hydrotreating processes.The lower investment and operating cost is another advantage. The first commercial application of the SSHT technology has been in operation since September 2001.
基金financially supported by "the Fundamental Research Funds for the Central Universities,China"(11CX06036A)
文摘In this work,fatty acid and its derivatives were adopted as lubricity additives for low sulfur diesel.Tribological evaluation obtained from the High-Frequency Reciprocating Rig(HFRR)apparatus showed that the lubricating performance of the additives increased in the following order:stearic acid>glycol monopalmitate>stearyl alcohol>ethyl palmitate>cetyl ethyl ether.The adsorption behavior of the additives on Fe(110)surface and Fe2O3(001)surface was investigated by molecular dynamics(MD)simulations to verify their lubricity performance.The results suggested that adsorption energies of the additives on Fe(110)surface are determined by the van der Waals forces,while adsorptions on Fe2O3(001)surface are significantly attributed to the electrostatic attractive forces.Higher values of adsorption energy of the additives on Fe2O3(001)surface indicate that the additive has more efficient lubricity enhancing properties.
基金financially supported by the National Basic Research Program of China (973 Program) (2012CB224800)
文摘The solid-phase extraction using Pd-Al2O3 as the stationary phase was employed to pre-separate the sulfur compounds in straight-run diesel. The isolating effect was evaluated quantitatively by gas chromatography with a sulfur chemiluminescence detector to harvest a satisfactory result. The identification of the structure of sulfur compounds by comprehensive two-dimensional gas chromatography coupled with the time-of-flight mass spectrometry indicated that cyclo-sulfides, benzothiophenes, dibenzothiophenes, dihydro-benzothiophenes and tetrahydro-dibenzothiophenes were included in straightrun diesel obtained from the Arab medium crude(AM). A total of 259 individual compounds were detected and their molecular structures were identified. The analytical method was approved as an effective way to characterize the composition of sulfur compounds, which reduced the interference of other compounds, facilitated the data presentation and provided more detailed information about molecular composition of sulfur compounds.
文摘In an urban-transit bus, fueled by biodiesel in Toledo, Ohio, single inhalable particle samples in October 2008 were collected and detected by scanning electron microscopy and energy dispersive X-ray spectrometry （SEM/EDS）. Particle size analysis found bimodal distribution at 0.2 and 0.5 μm. The particle morphology was characterized by 14 different shape clusters： square, pentagon, hexagon, heptagon, octagon, nonagon, decagon, agglomerate, sphere, triangle, oblong, strip, line or stick, and unknown, by quantitative order. The square particles were common in the samples. Round and triangle particles are more, and pentagon, hexagon, heptagon, octagon, nonagon, decagon, strip, line or sticks are less. Agglomerate particles were found in abundance. The surface of most particles was coarse with a fractal edge that can provide a suitable chemical reaction bed in the polluted atmospheric environment. The three sorts of surface patterns of squares were smooth, semi-smooth, and coarse. The three sorts of square surface patterns represented the morphological characteristics of single inhalable particles in the air inside the bus in Toledo. The size and shape distribution results were compared to those obtained for a bus using ultra low sulfur diesel.
