To produce low olefin gasoline with high octane number by Fischer-Tropsch (F-T) wax fluid catalytic cracking (FCC) process, operating conditions optimization were carried out in the pilot-scale riser and turbulent flu...To produce low olefin gasoline with high octane number by Fischer-Tropsch (F-T) wax fluid catalytic cracking (FCC) process, operating conditions optimization were carried out in the pilot-scale riser and turbulent fluidized bed (TFB) FCC unit. The experimental results in the riser indicated that under the condition of low reaction temperature and regenerated catalyst temperature, large catalyst-to-oil weight ratio (C/O) and long reaction time, the gasoline olefin content could be reduced to 20.28 wt%, but there is large octane number loss owing to a great loss in high octane number olefin. Therefore, a novel FCC process using the TFB reactor was proposed to strengthen the aromatization reaction. The reaction performance of TFB reactor were investigated. The result demonstrated that the TFB reactor has more significant effect in reducing olefins and improving aromatics. At the expense of certain gasoline yield, the gasoline olefin content reduced to 23.70 wt%, aromatics content could increase to 26.79 wt% and the RON was up to 91.0. The comparison of reactor structure and fluidization demonstrated that the TFB reactor has higher catalyst bed density. The reaction heat and coke combustion heat was calculated indicating the feasibility of its industrial application of the TFB process.展开更多
Although detergent additives for gasoline have been widely commercialized,their formulas are often kept confidential and there is still no standardized method for quickly detecting the main active ingredients and eval...Although detergent additives for gasoline have been widely commercialized,their formulas are often kept confidential and there is still no standardized method for quickly detecting the main active ingredients and evaluating their effectiveness,which makes their regulation difficult.An overview of the current state of the development and application of detergent additives for gasoline in China and other regions,as well as a review of the rapid detection and performance evaluation methods available for analyzing detergent additives are given herein.The review focuses on the convenience,cost,efficiency,and feasibility of on-site detection and the evaluation of various methods,and also looks into future research directions,such as detecting and evaluating detergent additives in ethanol gasoline and with advanced engine technologies.展开更多
The comprehensive characterization of heavy aromatic hydrocarbons in gasoline is important to optimize the blending process and understand the correlation between aromatics content and engine particulate emissions.How...The comprehensive characterization of heavy aromatic hydrocarbons in gasoline is important to optimize the blending process and understand the correlation between aromatics content and engine particulate emissions.However,most current analysis methods can only provide the composition of C_(8)/C_(8-) aromatics.In this study,a simple and fast gas chromatography-mass spectrometry(GC-MS)method to identify and quantify C_(9+)aromatics in gasoline was developed.A selected ion monitoring model was employed to eliminate interference from non-aromatic compounds in the detection of target compounds,as well as that between target compounds with different molecular formulas.The identification of C_(9+)aromatics was based on the retention time of model compounds,combined with characteristic mass fragment ions,boiling points,and retention indexes.Seventy-nine C_(9)–C_(12)aromatic compounds were quantified based on the calibration of representative model compounds,and the method demonstrated good linearity,and high accuracy and precision.Furthermore,the developed methodology was successfully applied to the analysis of gasoline fractions from the reforming,pyrolysis,straight-run,delayed coking,and catalytic cracking processes,as well as commercial gasolines.The results showed that C_(9)aromatics were the predominant aromatics in all gasoline samples,followed by C10 aromatics.Alkylbenzenes such as C_(9)H_(12)and C_(10)H_(14)were the main components in the reforming,straight-run,delayed coking,and catalytic cracking gasoline fractions,as well as in the commercial gasolines,in which 1,2,4-trimethylbenzene and 3-ethyltoluene were dominant;in contrast,aromatics with higher degrees of unsaturation such as indene were the most abundant aromatics in the pyrolysis gasoline fraction.展开更多
Gasoline compression ignition(GCI)has been considered as a promising combustion concept to yield ultralow NOX and soot emissions while maintaining high thermal efficiency.However,how to improve the low-load performanc...Gasoline compression ignition(GCI)has been considered as a promising combustion concept to yield ultralow NOX and soot emissions while maintaining high thermal efficiency.However,how to improve the low-load performance becomes an urgent issue to be solved.In this paper,a GCI engine model was built to investigate the effects of internal EGR(i-EGR)and pre-injection on in-cylinder temperature,spatial concentration of mixture and OH radical,combustion and emission characteristics,and the control strategy for improving the combustion performance was further explored.The results showed an obvious expansion of the zone with an equivalence ratio between 0.8∼1.2 is realized by higher pre-injection ratios,and the s decreases with the increase of pre-injection ratio,but increases with the increase of i-EGR ratio.The high overlap among the equivalentmixture zone,the hightemperature zone,and the OH radical-rich zone can be achieved by higher i-EGR ratio coupled with higher preinjection ratio.By increasing the pre-injection ratio,the combustion efficiency increases first and then decreases,also achieves the peak value with a pre-injection ratio of 60%and is unaffected by i-EGR.The emissions of CO,HC,NOX,and soot can also be reduced to low levels by the combination of higher i-EGR ratios and a pre-injection ratio of 60%.展开更多
Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly ...Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly exposed to gasoline fumes and automobile engine products from vehicle exhaust. This increases the risk of acute and chronic respiratory diseases and carcinogenesis among them. The risk of health complications tends to increase with the duration of exposure. The study aimed to determine the proportion of gasoline attendants with lung function impairment. Methods and Materials: Two hundred and eight eligible participants were recruited for this study. A cross-sectional analytical study was carried out in Esan West local government area of Edo state, Nigeria. The study was carried out for a period of six months from December 2015 to May 2016. A questionnaire was used to obtain information on demographic characteristics, work history, mode of exposure and duration of exposure to petrol fumes. Lung function was assessed using a DTspiro spirometer (Model POP 10. Serial no 110843-005);also the anthropometric parameters of the respondent were measured. Statistical analysis was done using IBM SPSS version 20.0. Frequency and percentages were used to present categorical data. The mean and standard deviation of continuous variables were calculated and compared using the student’s t-test. The criteria of significant association were assumed for a p-value less than 0.05. Results: A total of one hundred and forty petrol pump attendants and one hundred and forty controls participated in this study. The mean age for petrol pump attendants was 24 ± 3.1 years and 23 ± 2.8 years for the control group. There were no significant differences in the gender distribution and anthropometric parameters as observed in this study. The lung impairment pattern observed in this study was obstructive in twelve (8.6%) gasoline pump attendants and restrictive pattern in thirty-nine (27.9%) gasoline pump attendants, while only four (2.9%) had an obstructive pattern and twelve (8.6%) had a restrictive pattern of lung impairment among the control group. This implies that a restrictive pattern was predominant. This study also observed that there was an increase in the number of gasoline pump attendants with declined lung function compared to the control group. Conclusion: Restrictive pattern of lung impairment was more predominant than the obstructive pattern among gasoline pump attendants. As a result, public health interventions should be instituted among these individuals, especially in developing countries.展开更多
Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly ...Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly exposed to gasoline fumes and automobile engine products from vehicle exhaust. This increases the risk of acute and chronic respiratory diseases and carcinogenesis among them. The risk of health complications tends to increase with the duration of exposure. The study aimed to determine the proportion of gasoline attendants with lung function impairment. Methods and Materials: Two hundred and eight eligible participants were recruited for this study. A cross-sectional analytical study was carried out in Esan West local government area of Edo state, Nigeria. The study was carried out for a period of six months from December 2015 to May 2016. A questionnaire was used to obtain information on demographic characteristics, work history, mode of exposure and duration of exposure to petrol fumes. Lung function was assessed using a DTspiro spirometer (Model POP 10. Serial no 110843-005);also the anthropometric parameters of the respondent were measured. Statistical analysis was done using IBM SPSS version 20.0. Frequency and percentages were used to present categorical data. The mean and standard deviation of continuous variables were calculated and compared using the student’s t-test. The criteria of significant association were assumed for a p-value less than 0.05. Results: A total of one hundred and forty petrol pump attendants and one hundred and forty controls participated in this study. The mean age for petrol pump attendants was 24 ± 3.1 years and 23 ± 2.8 years for the control group. There were no significant differences in the gender distribution and anthropometric parameters as observed in this study. The lung impairment pattern observed in this study was obstructive in twelve (8.6%) gasoline pump attendants and restrictive pattern in thirty-nine (27.9%) gasoline pump attendants, while only four (2.9%) had an obstructive pattern and twelve (8.6%) had a restrictive pattern of lung impairment among the control group. This implies that a restrictive pattern was predominant. This study also observed that there was an increase in the number of gasoline pump attendants with declined lung function compared to the control group. Conclusion: Restrictive pattern of lung impairment was more predominant than the obstructive pattern among gasoline pump attendants. As a result, public health interventions should be instituted among these individuals, especially in developing countries.展开更多
According to advantages of neural network and characteristics of operatingprocedures of engine, a new strategy is represented on the control of fuel injection and ignitiontiming of gasoline engine based on improved BP...According to advantages of neural network and characteristics of operatingprocedures of engine, a new strategy is represented on the control of fuel injection and ignitiontiming of gasoline engine based on improved BP network algorithm. The optimum ignition advance angleand fuel injection pulse band of engine under different speed and load are tested for the samplestraining network, focusing on the study of the design method and procedure of BP neural network inengine injection and ignition control. The results show that artificial neural network technique canmeet the requirement of engine injection and ignition control. The method is feasible for improvingpower performance, economy and emission performances of gasoline engine.展开更多
The extractive desulfurization of a model gaso- line containing several alkyl thiols and aromatic thiophenic compounds was investigated using two imidazolium-based ionic liquids (ILs), 1-butyl-3-methylimidazolium te...The extractive desulfurization of a model gaso- line containing several alkyl thiols and aromatic thiophenic compounds was investigated using two imidazolium-based ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrachloroaluminate, and 1-octyl-3-methylimidazolium te- trafluoroborate, as extractants. A fractional factorial design of experiments was employed to evaluate the effects and possible interactions of several process variables. Analysis of variance tests indicated that the number of extraction steps and the IL/gasoline volume ratio were of statistically highly significant, but none of the interactions were significant. The results showed that the desulfurization efficiency of the model gasoline by the ILs could reach 95.2 % under the optimal conditions. The optimized conditions were applied to study the extraction of thiophenic compounds in model gasoline and several real gasoline samples; the following order was observed in their separation: benzothio- phenc 〉 thiophcne 〉 3-methylthiophene 〉 2-methylthiophene, with 96.1% removal efficiency for benzothiophene. The IL extraction was successfully applied as a complementary process to the adsorptive desulfurization with acti- vated Raney nickel and acetonitrile solvent. The results indicated that the adsorptive process combined with IL extraction could provide high efficiency and selectivity, which can be regarded as a promising energy efficient desulfurization strategy for production of low-sulfur gasoline.展开更多
Olefin alkylation of thiophenic sulfur process was carried out in model gasoline, using Hβ zeolites with different Si/Al2 ratios as catalysts. In particular, the influence of acid properties of Hβ zeolites on its ca...Olefin alkylation of thiophenic sulfur process was carried out in model gasoline, using Hβ zeolites with different Si/Al2 ratios as catalysts. In particular, the influence of acid properties of Hβ zeolites on its catalytic ability for the thiophene alkylation, xylene alkylation and hexene oligomerization was investigated. The results showed that the acidity of the Hβ zeolite was increased with the decrease of Si/Al2 ratio, but its catalytic ability was not always increased. In fact, it reached the maximal catalytic ability at Si/Al2 ratio of 66, and under the reaction conditions of 60 ℃, 1.5 MPa, WHSV 3.0 h^-1 and time on stream 2 h. At the ratio, the conversion of thiophene, xylene, and oligomerized hexene were 96.6%, 2.7% and 2.8%, respectively. An optimal Si/Al2 ratio exists for the catalytic performance of Hβ zeolite. By investigating the coke deposition of the used Hβ zeolite catalysts, it has been found that the optimal Si/Al2 ratio is attributed to the combined effect of the carbocation activation capability and the hydrogen transformation capability of the Hβ zeolite catalyst.展开更多
Carbon deposition during methanol to hydrocarbons leads to the quick deactivation of ZSM-5 catalyst and it is one of the major problems for this technology. Decreasing the crystal size or introducing mesopores into ZS...Carbon deposition during methanol to hydrocarbons leads to the quick deactivation of ZSM-5 catalyst and it is one of the major problems for this technology. Decreasing the crystal size or introducing mesopores into ZSM-5 zeolites can improve its diffusion property and decrease the coke formation. In this paper, nano-sized ZSM-5 zeolite with intercrystalline mesopores combining the mesoporous and nano sized structure was fabricated. For comparison, the mesoporous ZSM-5 and nano-sized ZSM-5 were also prepared. These catalyst samples were characterized by XRD, BET, NH3-TPD, TEM, Py-IR and TG techniques and used on the conversion of methanol to gasoline in a fixed-bed reactor at T=405 degrees C, WHSV =4.74 h(-1) and P=1.0 MPa. It was found that the external surface area of the nano-sized ZSM-5 zeolite with intercrystalline mesopores reached 104 m(2)/g, larger than that of mesoporous ZSM-5 (66 m(2)/g) and nano sized ZSM-5 (76 m(2)/g). Catalytic lifetime of the nano-sized ZSM-5 zeolite with intercrystalline mesopores was 93 h, which was only longer than that of mesoporous ZSM-5 (86 h), but shorter than that of nano sized ZSM-5 (104 h). Strong acidity promoted the coke formation and thus decreased the catalytic lifetime of the nano-sized ZSM-5 zeolite with intercrystalline mesopores though it presented large external surface that could improve the diffusion property. The special zeolite catalyst was further dealuminated to decrease the strong acidity. After this, its coke formation rate was slowed and catalytic lifetime was prolonged to 106 h because of the large external surface area and decreased weak acidity. This special structural zeolite is a potential catalyst for methanol to gasoline reaction. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
ZSM-5/MCM-41 composite molecular sieve was prepared by the nano-assembling method.The ZSM-5 molecular sieve,the MCM-41 molecular sieve,the ZSM-5/MCM-41 mechanical mixture and the ZSM-5/MCM-41 composite molecular sieve...ZSM-5/MCM-41 composite molecular sieve was prepared by the nano-assembling method.The ZSM-5 molecular sieve,the MCM-41 molecular sieve,the ZSM-5/MCM-41 mechanical mixture and the ZSM-5/MCM-41 composite molecular sieve were characterized by X-ray powder diffractometry,N<sub>2</sub> adsorption isotherms,temperature programmed desorption of ammonia and scanning electron microscopy and their properties were analyzed.Using FCC gasoline as the feed,activities of different molecular sieves for reducing olefin content were investigated in a continuous high-pressure micro-reactor unit under the following conditions:a reaction temperature of 400℃,a reaction time of 2 h,a weight hourly space velocity of 3h<sup>-1</sup>,and a reaction pressure of 2.0 MPa.The results showed that the HMCM-41 molecular sieve had low reaction performance,and the HZSM-5 molecular sieve demonstrated high aromatization activity,while the ZSM-5/MCM- 41 composite molecular sieve exhibited a best olefin-reducing performance because of its high isomerization activity and moderate aromatization activity.With a largest olefin-reducmg capability and a reasonable distribution of products,the composite molecular sieve was more suitable for FCC gasoline upgrading compared to other three catalysts.展开更多
Gasoline compression ignition (GCI) is one of the most promising combustion concepts to maintain low pollutant emissions and high efficiency. However, low load combustion stability and firing in cold-start operations ...Gasoline compression ignition (GCI) is one of the most promising combustion concepts to maintain low pollutant emissions and high efficiency. However, low load combustion stability and firing in cold-start operations are two major challenges for GCI combustion. Strategies including negative valve overlap (NVO), advanced injection strategies, fuel reforming, and intake preheating have been proposed in order to solve these difficulties;however, the cold start is still an obstacle. The objective of this work is to study effective methods to achieve GCI engine cold start-up. This work combines NVO, in-cylinder fuel reforming, and intake preheating to achieve quick firing under cold-start conditions and the subsequent warmup conditions. The results show that start of injection (SOI) during the intake stroke yields the best fuel economy, and injection during the compression stroke has the potential to extend the low load limit. Furthermore, SOI during the NVO period grants the ability to operate under engine conditions with cold intake air and coolant. With highly reactive products made by in-cylinder fuel reforming and fast heat accumulation in the combustion chamber, the NVO injection strategy is highly appropriate for GCI firing. An additional assisted technical method, such as intake preheating, is required to ignite the first firing cycle for a cold-start process. With the combination of NVO, in-cylinder fuel reforming, and intake preheating, the GCI engine successfully started within five combustion cycles in the experiment. After the firing process, the engine could stably operate without further intake preheating;thus, this method is appropriate for engine cold-start and warm-up.展开更多
Co–Mo catalysts applied on the hydrodesulfurization(HDS) for FCC gasoline were prepared with Zn–Al layered double hydroxides(LDHs) to improve their performances,and the effects of pore structures and acidity on ...Co–Mo catalysts applied on the hydrodesulfurization(HDS) for FCC gasoline were prepared with Zn–Al layered double hydroxides(LDHs) to improve their performances,and the effects of pore structures and acidity on HDS performances were studied in detail. A series of Zn–Al/LDHs samples with different pore structures and acidities are synthesized on the bases of co-precipitation of OH-,CO2-,Al3+,and Zn2+. The neutralization p H is a main factor to affect the pore structures and acidity of Zn–Al/LDHs,and a series of Zn–Al/LDHs with different pore structures and acidities are obtained. Based on the representative samples with different specific surface areas(SBET) and acidities,three Co Mo/LDHs catalysts were prepared,and their HDS performances were compared with traditional Co Mo/Al2O3 catalysts. The results indicated that catalysts prepared with high SBETpossessed high HDS activity,and Br?nsted acid sites could reduce the thiol content in the product to some extent. All the three catalysts prepared with LDHs displayed little lower HDS activity but higher selectivity than Co Mo/Al2O3,and could restrain the reactions of re-combination between olefin and H2 S which could be due to the existence of Br?nsted acid sites.展开更多
Ethoxymethxoymethane (EMM) was conveniently prepared by acetalization of aqueous formaldehyde with methanol andethanol in a batch reactive distillation mode using a cation-exchange resin catalyst for the first time....Ethoxymethxoymethane (EMM) was conveniently prepared by acetalization of aqueous formaldehyde with methanol andethanol in a batch reactive distillation mode using a cation-exchange resin catalyst for the first time. EMM was found tO be asignificant cosolvent of methano1/gasoline blends, ? 2009 Ai You Hao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All fights reserved.展开更多
Facing increasingly strict environmental regulations on transportation fuels, China National Petroleum Corp. (CNPC), the second largest supplier of petroleum products in China, needs to upgrade its transportation fu...Facing increasingly strict environmental regulations on transportation fuels, China National Petroleum Corp. (CNPC), the second largest supplier of petroleum products in China, needs to upgrade its transportation fuels. Using the scenario-based analysis method, this paper analyzes how the emission related properties, including antiknock index, and sulfur, olefin, benzene and aromatics contents of gasoline produced by CNPC, vary with the change in the configuration of gasoline production units in the future 5-15 years. The results showed that for CNPC to upgrade its gasoline, the share of fluid catalytic cracking (FCC) naphtha must be reduced, but just increasing reformate or alkylate and isomerate will result in excessive increase in benzene and aromatics contents or a great loss of gasoline octane number. Therefore, CNPC should suitably control the capacity of its FCC units and increase the capacity of reformer, alkylation and isomerization units. Most importantly, CNPC should dramatically expand the capacity of its hydrotreating or non-hydrotreating gasoline upgrading units to decrease the olefin and sulfur contents in FCC gasoline that takes a dominant share of about 80% in the gasoline pool of China.展开更多
Methanol to gasoline reaction was investigated on two prepared ZSM-5 catalysts. The first one was a conventional catalyst denoted as ZSM-5(C) and the other was a hierarchical catalyst-ZSM-5(S) which was prepared b...Methanol to gasoline reaction was investigated on two prepared ZSM-5 catalysts. The first one was a conventional catalyst denoted as ZSM-5(C) and the other was a hierarchical catalyst-ZSM-5(S) which was prepared by incorporation of table sugar in catalyst gel during the synthesis procedure. The catalysts were characterized by FTIR, XRD, FE-SEM, N2 adsorption-desorption, NH3-TPD and TGA analytical technics. The proposed material showed pore modification as well as acidity moderating properties in ZSM-5 catalyst. The methanol to gasoline reaction was conducted in a fixed bed reactor with a WHSV of 1.5 h-1.Methanol conversions, gasoline yield and selectivity in production for the synthesized catalysts were determined by gas chromatography method. The sugar modified catalyst converted more methanol than the conventional one and an enhancement in catalyst’s life time was observed. The selectivity to aromatics and durene were reduced compared to the conventional catalyst, so the gasoline quality was also further improved. The coking rate of catalysts was calculated employing TGA method. A reduction in coking rate and an increase in coke capacity of the modified catalyst were observed.展开更多
A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the so...A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the solid state reaction method.The crystal phase and morphology of LTF-x were characterized by XRD and SEM respectively.Catalytic pyrolysis performance of LTF-x was performed by TG-DTG and the distribution patterns of gaseous,liquid and solid products from BL was investigated using a fixed-bed micro-reactor.The optimal reaction conditions were determined:the pyrolysis temperature was 600℃,the mass ratio of mBL:mLTF-0.2 was 3:1,the veloeity of earrier gas was 100 ml·min-1.The gaseous produets were mainly eomposed of CO2,CO,CH4 and CnHm(n=2-4,m=2 n+2 or m=2 n),The main aryl oxygen-containing compounds in liquid products were phenolics,guaiacols,syringols and phenylates,the rest were benzenes,furans,esters and carboxylic acid.The total contents of aryl oxygencontaining compounds were from 62% up to more than 72% under the action of the perovskite.Moreover,the LTF-0.2 sample had nice regenerability.展开更多
The color changes of one representative FCC gasoline were studied. The red substance in the FCC gasoline was concentrated and separated by chromatography and analyzed by elemental analysis and gas chromatography-mass ...The color changes of one representative FCC gasoline were studied. The red substance in the FCC gasoline was concentrated and separated by chromatography and analyzed by elemental analysis and gas chromatography-mass spectrometry (GC-MS). The main components of the red substance were found to be aromatic amines. Complexes formed from quinones and aromatic amines are the reason why gasoline being red, and acids can destroy the complex by reaction with aromatic amines leading to decoloration of red gasoline. A mechanism for the color change of gasoline is proposed.展开更多
Light cycle oil(LCO) with high content of poly-aromatics was difficult to upgrade and convert,which had hindered upgrading fuel quality to meet with the standard of automotive diesel for the purpose of sustainable dev...Light cycle oil(LCO) with high content of poly-aromatics was difficult to upgrade and convert,which had hindered upgrading fuel quality to meet with the standard of automotive diesel for the purpose of sustainable development.The hydrocracking behaviors of typical aromatics in LCO of naphthalene and tetralin were investigated over NiMo and CoMo catalysts.Several characterization methods including N2-adsoprtion and desorption,ammonia temperature-programmed desorption(NH3-TPD),Pyridine infrared spectroscopy(Py-IR),CO infrared spectroscopy(CO-IR),Raman and X-ray photoelectron spectroscopy(XPS) were applied to determine the properties of different catalysts.The results showed that CoMo catalyst with high concentration of S-edges could hydrosaturate more naphthalene to tetralin but exhibit lower yield of high-value light aromatics(carbon numbers less than 10) than NiMo catalyst.NiMo catalyst with high concentration of Mo-edges also presented a higher selectivity of converting naphthalene into cyclanes than CoMo catalyst.Subsequently,the naphthalene and LCO hydrocracking performances were also investigated over different catalysts systems.The activity evaluation and kinetic analysis results showed that the naphthalene hydrocracking conversion and the yield of light aromatics for CoMo-AY/NiMo-AY grading catalysts were higher than NiMo-AY/CoMo-AY grading catalysts at same condition.A stepwise reaction principle was proposed to explain the high efficiency of CoMo-AY/NiMoAY grading catalysts.Finally,the LCO hydrocracking evaluation results confirmed that CoMo-AY/NiMoAY catalysts grading system with low carbon deposition and high stability could remain high percentage of active phases,which was more efficient to convert LCO to high-octane gasoline.展开更多
The aromatization of light alkenes in liquefied petroleum gas (LPG) with and without dimethyl ether (DME) addition in the feed was investigated on a modified ZSM-5 catalyst.The results showed that under the given reac...The aromatization of light alkenes in liquefied petroleum gas (LPG) with and without dimethyl ether (DME) addition in the feed was investigated on a modified ZSM-5 catalyst.The results showed that under the given reaction conditions the selectivity of alkenes to high-octane gasoline blending components was markedly enhanced and the formation of propane and butanes was greatly suppressed with the addition of DME.It was also found that the distribution of C5+ components was changed a lot with DME addition into the LPG feed.The formation of branched hydrocarbons (mainly C6 C8 i-paraffin) and multi-methyl substituted aromatics,which are high octane number gasoline blending components,was promoted significantly,while the content of n-paraffins and olefins in C5+ components was decreased obviously,indicating that in addition to the oligomerization,cracking,hydrogen-transfer and dehydrogenation-cyclization of alkenes,the methylation of the formed aromatics and olefins intermediates also plays an important role in determining the product distribution due to the high reactivity of surface methoxy groups formed by DME.And this process,in combination with the syngas-to-methanol/DME technology,provides an alternative way to the production of high-octane gasoline from coal,natural gas or renewable raw materials.展开更多
基金supported by the National Key Research and Development Program of China(2017YFB0602504)the General Program of National Natural Science Foundation of China(22178385).
文摘To produce low olefin gasoline with high octane number by Fischer-Tropsch (F-T) wax fluid catalytic cracking (FCC) process, operating conditions optimization were carried out in the pilot-scale riser and turbulent fluidized bed (TFB) FCC unit. The experimental results in the riser indicated that under the condition of low reaction temperature and regenerated catalyst temperature, large catalyst-to-oil weight ratio (C/O) and long reaction time, the gasoline olefin content could be reduced to 20.28 wt%, but there is large octane number loss owing to a great loss in high octane number olefin. Therefore, a novel FCC process using the TFB reactor was proposed to strengthen the aromatization reaction. The reaction performance of TFB reactor were investigated. The result demonstrated that the TFB reactor has more significant effect in reducing olefins and improving aromatics. At the expense of certain gasoline yield, the gasoline olefin content reduced to 23.70 wt%, aromatics content could increase to 26.79 wt% and the RON was up to 91.0. The comparison of reactor structure and fluidization demonstrated that the TFB reactor has higher catalyst bed density. The reaction heat and coke combustion heat was calculated indicating the feasibility of its industrial application of the TFB process.
基金This work was supported by the SINOPEC Research Project(No.121052-2).
文摘Although detergent additives for gasoline have been widely commercialized,their formulas are often kept confidential and there is still no standardized method for quickly detecting the main active ingredients and evaluating their effectiveness,which makes their regulation difficult.An overview of the current state of the development and application of detergent additives for gasoline in China and other regions,as well as a review of the rapid detection and performance evaluation methods available for analyzing detergent additives are given herein.The review focuses on the convenience,cost,efficiency,and feasibility of on-site detection and the evaluation of various methods,and also looks into future research directions,such as detecting and evaluating detergent additives in ethanol gasoline and with advanced engine technologies.
基金This work was supported by the research project of Sinopec Research Institute of Petroleum Processing Co.,Ltd.(G720007).
文摘The comprehensive characterization of heavy aromatic hydrocarbons in gasoline is important to optimize the blending process and understand the correlation between aromatics content and engine particulate emissions.However,most current analysis methods can only provide the composition of C_(8)/C_(8-) aromatics.In this study,a simple and fast gas chromatography-mass spectrometry(GC-MS)method to identify and quantify C_(9+)aromatics in gasoline was developed.A selected ion monitoring model was employed to eliminate interference from non-aromatic compounds in the detection of target compounds,as well as that between target compounds with different molecular formulas.The identification of C_(9+)aromatics was based on the retention time of model compounds,combined with characteristic mass fragment ions,boiling points,and retention indexes.Seventy-nine C_(9)–C_(12)aromatic compounds were quantified based on the calibration of representative model compounds,and the method demonstrated good linearity,and high accuracy and precision.Furthermore,the developed methodology was successfully applied to the analysis of gasoline fractions from the reforming,pyrolysis,straight-run,delayed coking,and catalytic cracking processes,as well as commercial gasolines.The results showed that C_(9)aromatics were the predominant aromatics in all gasoline samples,followed by C10 aromatics.Alkylbenzenes such as C_(9)H_(12)and C_(10)H_(14)were the main components in the reforming,straight-run,delayed coking,and catalytic cracking gasoline fractions,as well as in the commercial gasolines,in which 1,2,4-trimethylbenzene and 3-ethyltoluene were dominant;in contrast,aromatics with higher degrees of unsaturation such as indene were the most abundant aromatics in the pyrolysis gasoline fraction.
基金sponsored by the projects of National Natural Science Foundation of China (Grant Nos.51806127 and 52075307)Key Research and Development Program of Shandong Province (Grant No.2019GHZ016).
文摘Gasoline compression ignition(GCI)has been considered as a promising combustion concept to yield ultralow NOX and soot emissions while maintaining high thermal efficiency.However,how to improve the low-load performance becomes an urgent issue to be solved.In this paper,a GCI engine model was built to investigate the effects of internal EGR(i-EGR)and pre-injection on in-cylinder temperature,spatial concentration of mixture and OH radical,combustion and emission characteristics,and the control strategy for improving the combustion performance was further explored.The results showed an obvious expansion of the zone with an equivalence ratio between 0.8∼1.2 is realized by higher pre-injection ratios,and the s decreases with the increase of pre-injection ratio,but increases with the increase of i-EGR ratio.The high overlap among the equivalentmixture zone,the hightemperature zone,and the OH radical-rich zone can be achieved by higher i-EGR ratio coupled with higher preinjection ratio.By increasing the pre-injection ratio,the combustion efficiency increases first and then decreases,also achieves the peak value with a pre-injection ratio of 60%and is unaffected by i-EGR.The emissions of CO,HC,NOX,and soot can also be reduced to low levels by the combination of higher i-EGR ratios and a pre-injection ratio of 60%.
文摘Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly exposed to gasoline fumes and automobile engine products from vehicle exhaust. This increases the risk of acute and chronic respiratory diseases and carcinogenesis among them. The risk of health complications tends to increase with the duration of exposure. The study aimed to determine the proportion of gasoline attendants with lung function impairment. Methods and Materials: Two hundred and eight eligible participants were recruited for this study. A cross-sectional analytical study was carried out in Esan West local government area of Edo state, Nigeria. The study was carried out for a period of six months from December 2015 to May 2016. A questionnaire was used to obtain information on demographic characteristics, work history, mode of exposure and duration of exposure to petrol fumes. Lung function was assessed using a DTspiro spirometer (Model POP 10. Serial no 110843-005);also the anthropometric parameters of the respondent were measured. Statistical analysis was done using IBM SPSS version 20.0. Frequency and percentages were used to present categorical data. The mean and standard deviation of continuous variables were calculated and compared using the student’s t-test. The criteria of significant association were assumed for a p-value less than 0.05. Results: A total of one hundred and forty petrol pump attendants and one hundred and forty controls participated in this study. The mean age for petrol pump attendants was 24 ± 3.1 years and 23 ± 2.8 years for the control group. There were no significant differences in the gender distribution and anthropometric parameters as observed in this study. The lung impairment pattern observed in this study was obstructive in twelve (8.6%) gasoline pump attendants and restrictive pattern in thirty-nine (27.9%) gasoline pump attendants, while only four (2.9%) had an obstructive pattern and twelve (8.6%) had a restrictive pattern of lung impairment among the control group. This implies that a restrictive pattern was predominant. This study also observed that there was an increase in the number of gasoline pump attendants with declined lung function compared to the control group. Conclusion: Restrictive pattern of lung impairment was more predominant than the obstructive pattern among gasoline pump attendants. As a result, public health interventions should be instituted among these individuals, especially in developing countries.
文摘Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly exposed to gasoline fumes and automobile engine products from vehicle exhaust. This increases the risk of acute and chronic respiratory diseases and carcinogenesis among them. The risk of health complications tends to increase with the duration of exposure. The study aimed to determine the proportion of gasoline attendants with lung function impairment. Methods and Materials: Two hundred and eight eligible participants were recruited for this study. A cross-sectional analytical study was carried out in Esan West local government area of Edo state, Nigeria. The study was carried out for a period of six months from December 2015 to May 2016. A questionnaire was used to obtain information on demographic characteristics, work history, mode of exposure and duration of exposure to petrol fumes. Lung function was assessed using a DTspiro spirometer (Model POP 10. Serial no 110843-005);also the anthropometric parameters of the respondent were measured. Statistical analysis was done using IBM SPSS version 20.0. Frequency and percentages were used to present categorical data. The mean and standard deviation of continuous variables were calculated and compared using the student’s t-test. The criteria of significant association were assumed for a p-value less than 0.05. Results: A total of one hundred and forty petrol pump attendants and one hundred and forty controls participated in this study. The mean age for petrol pump attendants was 24 ± 3.1 years and 23 ± 2.8 years for the control group. There were no significant differences in the gender distribution and anthropometric parameters as observed in this study. The lung impairment pattern observed in this study was obstructive in twelve (8.6%) gasoline pump attendants and restrictive pattern in thirty-nine (27.9%) gasoline pump attendants, while only four (2.9%) had an obstructive pattern and twelve (8.6%) had a restrictive pattern of lung impairment among the control group. This implies that a restrictive pattern was predominant. This study also observed that there was an increase in the number of gasoline pump attendants with declined lung function compared to the control group. Conclusion: Restrictive pattern of lung impairment was more predominant than the obstructive pattern among gasoline pump attendants. As a result, public health interventions should be instituted among these individuals, especially in developing countries.
文摘According to advantages of neural network and characteristics of operatingprocedures of engine, a new strategy is represented on the control of fuel injection and ignitiontiming of gasoline engine based on improved BP network algorithm. The optimum ignition advance angleand fuel injection pulse band of engine under different speed and load are tested for the samplestraining network, focusing on the study of the design method and procedure of BP neural network inengine injection and ignition control. The results show that artificial neural network technique canmeet the requirement of engine injection and ignition control. The method is feasible for improvingpower performance, economy and emission performances of gasoline engine.
基金National Iranian Oil Refining & Distribution Company(NIORDC) and Research & Development (R&D) center of this company for their financial support during the completion of this work
文摘The extractive desulfurization of a model gaso- line containing several alkyl thiols and aromatic thiophenic compounds was investigated using two imidazolium-based ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrachloroaluminate, and 1-octyl-3-methylimidazolium te- trafluoroborate, as extractants. A fractional factorial design of experiments was employed to evaluate the effects and possible interactions of several process variables. Analysis of variance tests indicated that the number of extraction steps and the IL/gasoline volume ratio were of statistically highly significant, but none of the interactions were significant. The results showed that the desulfurization efficiency of the model gasoline by the ILs could reach 95.2 % under the optimal conditions. The optimized conditions were applied to study the extraction of thiophenic compounds in model gasoline and several real gasoline samples; the following order was observed in their separation: benzothio- phenc 〉 thiophcne 〉 3-methylthiophene 〉 2-methylthiophene, with 96.1% removal efficiency for benzothiophene. The IL extraction was successfully applied as a complementary process to the adsorptive desulfurization with acti- vated Raney nickel and acetonitrile solvent. The results indicated that the adsorptive process combined with IL extraction could provide high efficiency and selectivity, which can be regarded as a promising energy efficient desulfurization strategy for production of low-sulfur gasoline.
基金the National 973 Project of China(No.2005CB221403)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant:DICP K2007D3)
文摘Olefin alkylation of thiophenic sulfur process was carried out in model gasoline, using Hβ zeolites with different Si/Al2 ratios as catalysts. In particular, the influence of acid properties of Hβ zeolites on its catalytic ability for the thiophene alkylation, xylene alkylation and hexene oligomerization was investigated. The results showed that the acidity of the Hβ zeolite was increased with the decrease of Si/Al2 ratio, but its catalytic ability was not always increased. In fact, it reached the maximal catalytic ability at Si/Al2 ratio of 66, and under the reaction conditions of 60 ℃, 1.5 MPa, WHSV 3.0 h^-1 and time on stream 2 h. At the ratio, the conversion of thiophene, xylene, and oligomerized hexene were 96.6%, 2.7% and 2.8%, respectively. An optimal Si/Al2 ratio exists for the catalytic performance of Hβ zeolite. By investigating the coke deposition of the used Hβ zeolite catalysts, it has been found that the optimal Si/Al2 ratio is attributed to the combined effect of the carbocation activation capability and the hydrogen transformation capability of the Hβ zeolite catalyst.
基金the Science and Technology Foundation Platform Construction Project of Shanxi Province(No.2015091009)the National Science Foundation for Young Scientists of China(No.21606160)+1 种基金the Qualified Personnel Foundation of Taiyuan University of Technology(No.tyut-rc201454a)School Fund of Taiyuan University of Technology(Nos.1205-04020202 and 1205-04020102)
文摘Carbon deposition during methanol to hydrocarbons leads to the quick deactivation of ZSM-5 catalyst and it is one of the major problems for this technology. Decreasing the crystal size or introducing mesopores into ZSM-5 zeolites can improve its diffusion property and decrease the coke formation. In this paper, nano-sized ZSM-5 zeolite with intercrystalline mesopores combining the mesoporous and nano sized structure was fabricated. For comparison, the mesoporous ZSM-5 and nano-sized ZSM-5 were also prepared. These catalyst samples were characterized by XRD, BET, NH3-TPD, TEM, Py-IR and TG techniques and used on the conversion of methanol to gasoline in a fixed-bed reactor at T=405 degrees C, WHSV =4.74 h(-1) and P=1.0 MPa. It was found that the external surface area of the nano-sized ZSM-5 zeolite with intercrystalline mesopores reached 104 m(2)/g, larger than that of mesoporous ZSM-5 (66 m(2)/g) and nano sized ZSM-5 (76 m(2)/g). Catalytic lifetime of the nano-sized ZSM-5 zeolite with intercrystalline mesopores was 93 h, which was only longer than that of mesoporous ZSM-5 (86 h), but shorter than that of nano sized ZSM-5 (104 h). Strong acidity promoted the coke formation and thus decreased the catalytic lifetime of the nano-sized ZSM-5 zeolite with intercrystalline mesopores though it presented large external surface that could improve the diffusion property. The special zeolite catalyst was further dealuminated to decrease the strong acidity. After this, its coke formation rate was slowed and catalytic lifetime was prolonged to 106 h because of the large external surface area and decreased weak acidity. This special structural zeolite is a potential catalyst for methanol to gasoline reaction. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
文摘ZSM-5/MCM-41 composite molecular sieve was prepared by the nano-assembling method.The ZSM-5 molecular sieve,the MCM-41 molecular sieve,the ZSM-5/MCM-41 mechanical mixture and the ZSM-5/MCM-41 composite molecular sieve were characterized by X-ray powder diffractometry,N<sub>2</sub> adsorption isotherms,temperature programmed desorption of ammonia and scanning electron microscopy and their properties were analyzed.Using FCC gasoline as the feed,activities of different molecular sieves for reducing olefin content were investigated in a continuous high-pressure micro-reactor unit under the following conditions:a reaction temperature of 400℃,a reaction time of 2 h,a weight hourly space velocity of 3h<sup>-1</sup>,and a reaction pressure of 2.0 MPa.The results showed that the HMCM-41 molecular sieve had low reaction performance,and the HZSM-5 molecular sieve demonstrated high aromatization activity,while the ZSM-5/MCM- 41 composite molecular sieve exhibited a best olefin-reducing performance because of its high isomerization activity and moderate aromatization activity.With a largest olefin-reducmg capability and a reasonable distribution of products,the composite molecular sieve was more suitable for FCC gasoline upgrading compared to other three catalysts.
基金the National Natural Science Foundation of China (91641203, 51476114, and 91741119)he National Key Research and Development Program of China (2017YFB0103400).
文摘Gasoline compression ignition (GCI) is one of the most promising combustion concepts to maintain low pollutant emissions and high efficiency. However, low load combustion stability and firing in cold-start operations are two major challenges for GCI combustion. Strategies including negative valve overlap (NVO), advanced injection strategies, fuel reforming, and intake preheating have been proposed in order to solve these difficulties;however, the cold start is still an obstacle. The objective of this work is to study effective methods to achieve GCI engine cold start-up. This work combines NVO, in-cylinder fuel reforming, and intake preheating to achieve quick firing under cold-start conditions and the subsequent warmup conditions. The results show that start of injection (SOI) during the intake stroke yields the best fuel economy, and injection during the compression stroke has the potential to extend the low load limit. Furthermore, SOI during the NVO period grants the ability to operate under engine conditions with cold intake air and coolant. With highly reactive products made by in-cylinder fuel reforming and fast heat accumulation in the combustion chamber, the NVO injection strategy is highly appropriate for GCI firing. An additional assisted technical method, such as intake preheating, is required to ignite the first firing cycle for a cold-start process. With the combination of NVO, in-cylinder fuel reforming, and intake preheating, the GCI engine successfully started within five combustion cycles in the experiment. After the firing process, the engine could stably operate without further intake preheating;thus, this method is appropriate for engine cold-start and warm-up.
文摘Co–Mo catalysts applied on the hydrodesulfurization(HDS) for FCC gasoline were prepared with Zn–Al layered double hydroxides(LDHs) to improve their performances,and the effects of pore structures and acidity on HDS performances were studied in detail. A series of Zn–Al/LDHs samples with different pore structures and acidities are synthesized on the bases of co-precipitation of OH-,CO2-,Al3+,and Zn2+. The neutralization p H is a main factor to affect the pore structures and acidity of Zn–Al/LDHs,and a series of Zn–Al/LDHs with different pore structures and acidities are obtained. Based on the representative samples with different specific surface areas(SBET) and acidities,three Co Mo/LDHs catalysts were prepared,and their HDS performances were compared with traditional Co Mo/Al2O3 catalysts. The results indicated that catalysts prepared with high SBETpossessed high HDS activity,and Br?nsted acid sites could reduce the thiol content in the product to some extent. All the three catalysts prepared with LDHs displayed little lower HDS activity but higher selectivity than Co Mo/Al2O3,and could restrain the reactions of re-combination between olefin and H2 S which could be due to the existence of Br?nsted acid sites.
文摘Ethoxymethxoymethane (EMM) was conveniently prepared by acetalization of aqueous formaldehyde with methanol andethanol in a batch reactive distillation mode using a cation-exchange resin catalyst for the first time. EMM was found tO be asignificant cosolvent of methano1/gasoline blends, ? 2009 Ai You Hao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All fights reserved.
文摘Facing increasingly strict environmental regulations on transportation fuels, China National Petroleum Corp. (CNPC), the second largest supplier of petroleum products in China, needs to upgrade its transportation fuels. Using the scenario-based analysis method, this paper analyzes how the emission related properties, including antiknock index, and sulfur, olefin, benzene and aromatics contents of gasoline produced by CNPC, vary with the change in the configuration of gasoline production units in the future 5-15 years. The results showed that for CNPC to upgrade its gasoline, the share of fluid catalytic cracking (FCC) naphtha must be reduced, but just increasing reformate or alkylate and isomerate will result in excessive increase in benzene and aromatics contents or a great loss of gasoline octane number. Therefore, CNPC should suitably control the capacity of its FCC units and increase the capacity of reformer, alkylation and isomerization units. Most importantly, CNPC should dramatically expand the capacity of its hydrotreating or non-hydrotreating gasoline upgrading units to decrease the olefin and sulfur contents in FCC gasoline that takes a dominant share of about 80% in the gasoline pool of China.
基金the Petrochemical Research and Technology Company, Tehran, Iran for financial support of this research
文摘Methanol to gasoline reaction was investigated on two prepared ZSM-5 catalysts. The first one was a conventional catalyst denoted as ZSM-5(C) and the other was a hierarchical catalyst-ZSM-5(S) which was prepared by incorporation of table sugar in catalyst gel during the synthesis procedure. The catalysts were characterized by FTIR, XRD, FE-SEM, N2 adsorption-desorption, NH3-TPD and TGA analytical technics. The proposed material showed pore modification as well as acidity moderating properties in ZSM-5 catalyst. The methanol to gasoline reaction was conducted in a fixed bed reactor with a WHSV of 1.5 h-1.Methanol conversions, gasoline yield and selectivity in production for the synthesized catalysts were determined by gas chromatography method. The sugar modified catalyst converted more methanol than the conventional one and an enhancement in catalyst’s life time was observed. The selectivity to aromatics and durene were reduced compared to the conventional catalyst, so the gasoline quality was also further improved. The coking rate of catalysts was calculated employing TGA method. A reduction in coking rate and an increase in coke capacity of the modified catalyst were observed.
基金Supported by the National Natural Science Foundation of China,China(51674089)Heilongjiang Provincial Science Fund for Distinguished Youth Scholar(JC2018002)+2 种基金Heilongjiang Postdoctoral Scientific Research Development Fund of China(LBH-Q16037)the Youth Fund of Northeast Petroleum University(2018QNL-17)Postgraduate Innovative Research Projects of Northeast Petroleum University(YJSCX2017-014NEPU)
文摘A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the solid state reaction method.The crystal phase and morphology of LTF-x were characterized by XRD and SEM respectively.Catalytic pyrolysis performance of LTF-x was performed by TG-DTG and the distribution patterns of gaseous,liquid and solid products from BL was investigated using a fixed-bed micro-reactor.The optimal reaction conditions were determined:the pyrolysis temperature was 600℃,the mass ratio of mBL:mLTF-0.2 was 3:1,the veloeity of earrier gas was 100 ml·min-1.The gaseous produets were mainly eomposed of CO2,CO,CH4 and CnHm(n=2-4,m=2 n+2 or m=2 n),The main aryl oxygen-containing compounds in liquid products were phenolics,guaiacols,syringols and phenylates,the rest were benzenes,furans,esters and carboxylic acid.The total contents of aryl oxygencontaining compounds were from 62% up to more than 72% under the action of the perovskite.Moreover,the LTF-0.2 sample had nice regenerability.
基金supported by the Fundamental Research Funds for the Central Universities (No. 10CX04024A)
文摘The color changes of one representative FCC gasoline were studied. The red substance in the FCC gasoline was concentrated and separated by chromatography and analyzed by elemental analysis and gas chromatography-mass spectrometry (GC-MS). The main components of the red substance were found to be aromatic amines. Complexes formed from quinones and aromatic amines are the reason why gasoline being red, and acids can destroy the complex by reaction with aromatic amines leading to decoloration of red gasoline. A mechanism for the color change of gasoline is proposed.
基金supported by the National Natural Science Foundation of China (Nos. 21878330, 21676298)the National Science and Technology Major Project, the CNPC Key Research Project (2016E-0707)the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award (No. OSR-2019-CPF-4103.2)。
文摘Light cycle oil(LCO) with high content of poly-aromatics was difficult to upgrade and convert,which had hindered upgrading fuel quality to meet with the standard of automotive diesel for the purpose of sustainable development.The hydrocracking behaviors of typical aromatics in LCO of naphthalene and tetralin were investigated over NiMo and CoMo catalysts.Several characterization methods including N2-adsoprtion and desorption,ammonia temperature-programmed desorption(NH3-TPD),Pyridine infrared spectroscopy(Py-IR),CO infrared spectroscopy(CO-IR),Raman and X-ray photoelectron spectroscopy(XPS) were applied to determine the properties of different catalysts.The results showed that CoMo catalyst with high concentration of S-edges could hydrosaturate more naphthalene to tetralin but exhibit lower yield of high-value light aromatics(carbon numbers less than 10) than NiMo catalyst.NiMo catalyst with high concentration of Mo-edges also presented a higher selectivity of converting naphthalene into cyclanes than CoMo catalyst.Subsequently,the naphthalene and LCO hydrocracking performances were also investigated over different catalysts systems.The activity evaluation and kinetic analysis results showed that the naphthalene hydrocracking conversion and the yield of light aromatics for CoMo-AY/NiMo-AY grading catalysts were higher than NiMo-AY/CoMo-AY grading catalysts at same condition.A stepwise reaction principle was proposed to explain the high efficiency of CoMo-AY/NiMoAY grading catalysts.Finally,the LCO hydrocracking evaluation results confirmed that CoMo-AY/NiMoAY catalysts grading system with low carbon deposition and high stability could remain high percentage of active phases,which was more efficient to convert LCO to high-octane gasoline.
基金supported by the "Action Plan of CAS to Support China’s New and Strategic Industries with Science and Technology(2012-2014)"the "Knowledge Innovation Program of the Chinese Academy of Sciences(S201041)""Youth Innovation Promotion Association CAS(2012-2015)"
文摘The aromatization of light alkenes in liquefied petroleum gas (LPG) with and without dimethyl ether (DME) addition in the feed was investigated on a modified ZSM-5 catalyst.The results showed that under the given reaction conditions the selectivity of alkenes to high-octane gasoline blending components was markedly enhanced and the formation of propane and butanes was greatly suppressed with the addition of DME.It was also found that the distribution of C5+ components was changed a lot with DME addition into the LPG feed.The formation of branched hydrocarbons (mainly C6 C8 i-paraffin) and multi-methyl substituted aromatics,which are high octane number gasoline blending components,was promoted significantly,while the content of n-paraffins and olefins in C5+ components was decreased obviously,indicating that in addition to the oligomerization,cracking,hydrogen-transfer and dehydrogenation-cyclization of alkenes,the methylation of the formed aromatics and olefins intermediates also plays an important role in determining the product distribution due to the high reactivity of surface methoxy groups formed by DME.And this process,in combination with the syngas-to-methanol/DME technology,provides an alternative way to the production of high-octane gasoline from coal,natural gas or renewable raw materials.