The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Francisco Ortega - One of the best experts on this subject based on the ideXlab platform.
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light cracked naphtha processing controlling chemistry for maximum propylene production
Catalysis Today, 2005Co-Authors: Avelino Corma, Francisco V Melo, Laurent Sauvanaud, Francisco OrtegaAbstract:As propylene market is expanding, new production paths have to be found. The cracking of light olefins contained in several Naphthas seems to be a good alternative for responding to this demand. Results of light FCC naphtha cracking have shown that selectivity towards propylene is governed by hydrogen-transfer reactions. Thus, the selectivity to propylene may be increased by minimizing these reactions. This can be achieved by cracking the naphtha at high temperature, by using shape-selective catalysts or by working with coked catalysts. Recycling light naphtha in the FCC process is an interesting alternative, which may increase the yield of propylene by 50% if proper processing is carried out. Furthermore, olefins content of FCC gasoline may be significantly reduced.
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different process schemes for converting light straight run and fluid catalytic cracking Naphthas in a fcc unit for maximum propylene production
Applied Catalysis A-general, 2004Co-Authors: Avelino Corma, Francisco V Melo, Laurent Sauvanaud, Francisco OrtegaAbstract:Light straight run (LSR) and fluid catalytic cracking (FCCN) Naphthas were cracked in a transported bed reactor (MicroDowner) and in a fixed bed reactor (MAT) over a commercial Y zeolite based catalyst, over a commercial ZSM-5 zeolite based additive, and over a mixture of both at selected conditions. Based on the mechanisms through which naphtha hydrocarbons are converted, we evaluated the best alternatives for processing these streams to produce light olefins and/or to reduce olefins content in commercial gasoline. The experimental set-up allowed us to simulate the cracking behaviour of the different naphtha streams in a fluid catalytic cracking (FCC) unit by different processing schemes. Results indicate that LSR only cracks at high severity, yielding large amounts of dry gas. Despite its high olefins content, FCCN practically does not crack when it is fed together with gas oil feed. When cracking FCCN alone at typical gas oil cracking conditions, olefins are transformed preferentially into naphtha-range isoparaffins and aromatics, and when cracking FCCN at high severity, olefins are transformed preferentially into propylene and butylenes. Finally, cracking naphtha in the stripper produces some propylene and increases the aromatics in the remaining gasoline.
Avelino Corma - One of the best experts on this subject based on the ideXlab platform.
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light cracked naphtha processing controlling chemistry for maximum propylene production
Catalysis Today, 2005Co-Authors: Avelino Corma, Francisco V Melo, Laurent Sauvanaud, Francisco OrtegaAbstract:As propylene market is expanding, new production paths have to be found. The cracking of light olefins contained in several Naphthas seems to be a good alternative for responding to this demand. Results of light FCC naphtha cracking have shown that selectivity towards propylene is governed by hydrogen-transfer reactions. Thus, the selectivity to propylene may be increased by minimizing these reactions. This can be achieved by cracking the naphtha at high temperature, by using shape-selective catalysts or by working with coked catalysts. Recycling light naphtha in the FCC process is an interesting alternative, which may increase the yield of propylene by 50% if proper processing is carried out. Furthermore, olefins content of FCC gasoline may be significantly reduced.
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different process schemes for converting light straight run and fluid catalytic cracking Naphthas in a fcc unit for maximum propylene production
Applied Catalysis A-general, 2004Co-Authors: Avelino Corma, Francisco V Melo, Laurent Sauvanaud, Francisco OrtegaAbstract:Light straight run (LSR) and fluid catalytic cracking (FCCN) Naphthas were cracked in a transported bed reactor (MicroDowner) and in a fixed bed reactor (MAT) over a commercial Y zeolite based catalyst, over a commercial ZSM-5 zeolite based additive, and over a mixture of both at selected conditions. Based on the mechanisms through which naphtha hydrocarbons are converted, we evaluated the best alternatives for processing these streams to produce light olefins and/or to reduce olefins content in commercial gasoline. The experimental set-up allowed us to simulate the cracking behaviour of the different naphtha streams in a fluid catalytic cracking (FCC) unit by different processing schemes. Results indicate that LSR only cracks at high severity, yielding large amounts of dry gas. Despite its high olefins content, FCCN practically does not crack when it is fed together with gas oil feed. When cracking FCCN alone at typical gas oil cracking conditions, olefins are transformed preferentially into naphtha-range isoparaffins and aromatics, and when cracking FCCN at high severity, olefins are transformed preferentially into propylene and butylenes. Finally, cracking naphtha in the stripper produces some propylene and increases the aromatics in the remaining gasoline.
Yongwang Li - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation and modeling of steam cracking of fischer tropsch naphtha for light olefins
Chemical Engineering and Processing, 2010Co-Authors: Feng Wang, Yuanyuan Xu, Yongwang LiAbstract:Abstract The characteristics of product distribution and the kinetic model for predicting the yields of the major products from steam cracking of Fischer–Tropsch (F–T) naphtha have been investigated in a pilot plant under various conditions. An analysis of the experimental data suggests that the naphtha produced via the low-temperature slurry-phase F–T process is an excellent feedstock for the production of light olefins, especially ethylene. For steam cracking of two F–T Naphthas studied, ethylene is the primary product varying from 36.89 to 41.83 wt%, and the total yield of valuable light olefins (C 2 H 4 , C 3 H 6 and 1,3-C 4 H 6 ) is not less than 60.34 wt% under the conditions estimated. The experimental product distributions could be satisfactorily predicted by use of a detailed molecular reaction scheme which consists of a first-order primary reaction and 37 secondary reactions.
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Experimental investigation and modeling of steam cracking of Fischer–Tropsch naphtha for light olefins
Chemical Engineering and Processing, 2010Co-Authors: Feng Wang, Yuanyuan Xu, Yongwang LiAbstract:Abstract The characteristics of product distribution and the kinetic model for predicting the yields of the major products from steam cracking of Fischer–Tropsch (F–T) naphtha have been investigated in a pilot plant under various conditions. An analysis of the experimental data suggests that the naphtha produced via the low-temperature slurry-phase F–T process is an excellent feedstock for the production of light olefins, especially ethylene. For steam cracking of two F–T Naphthas studied, ethylene is the primary product varying from 36.89 to 41.83 wt%, and the total yield of valuable light olefins (C 2 H 4 , C 3 H 6 and 1,3-C 4 H 6 ) is not less than 60.34 wt% under the conditions estimated. The experimental product distributions could be satisfactorily predicted by use of a detailed molecular reaction scheme which consists of a first-order primary reaction and 37 secondary reactions.
Shiv N Rastogi - One of the best experts on this subject based on the ideXlab platform.
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stability of cracked Naphthas from thermal and catalytic processes and their additive response part ii composition and effect of olefinic structures
Fuel, 1995Co-Authors: Jag M Nagpal, G C Joshi, Shiv N RastogiAbstract:Abstract Olefinic concentrates were separated from two Naphthas, one from fluid catalytic cracking (FCC) and one thermal crackate, using column chromatography. The composition and structure of the olefins were determined by a combination of analytical techniques. FCC Naphthas contain relatively higher levels of conjugated dienes. The monoolefins are highly branched. The thermal crackates have higher levels of α-olefins and abound in mono-, di-, tri- and conjugated cyclic olefins. Stability tests on these olefinic concentrates blended in low-S,N straight-run naphtha showed that cyclic olefins are very active gum formers. Representative commercial antioxidants (hindered phenols and phenylenediamines) both gave good responses to different olefin concentrate test blends. Hindered phenols had a marginally better effect.
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stability of cracked Naphthas from thermal and catalytic processes and their additive response part i evaluation of stability and additive response
Fuel, 1995Co-Authors: Jag M Nagpal, G C Joshi, Shiv N RastogiAbstract:Abstract Olefinic Naphthas derived from fluid catalytic cracking (FCC) or thermal cracking units are increasingly being used in high-octane motor gasoline with growing concern for resulting fuel quality. Hindered phenols and substituted arylamines are the two classes of antioxidants generally used for improving the stability of gasoline. The olefin types in cracked Naphthas depend strongly on the process from which they are derived and hence are expected to show different responses with different antioxidants. However, systematic information on this aspect of antioxidant action is non-existent in the literature. Using two representative commercial antioxidants from each class with representative Naphthas (FCC, visbreaking and coker), it was found that phenolic antioxidants gave a better response with thermally cracked Naphthas. With amine-type antioxidants no clear preference could be observed.
Xiaojun Bao - One of the best experts on this subject based on the ideXlab platform.
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Simple Model for Predicting the Cutting Temperature between Light and Heavy Fractions in Fluid Catalytic Cracking Naphtha Selective Hydrodesulfurization Processes
2015Co-Authors: Lei Wang, Gang Shi, Yu Fan, Xiaojun BaoAbstract:In selective hydrodesulfurization processes for hydro-upgrading fluid catalytic cracking (FCC) naphtha with high olefin and sulfur contents, it is a common practice to split the feeding full-range FCC naphtha into a light fraction and a heavy fraction. This operation can effectively alleviate olefin saturation and thereby octane loss. Thus, the determination of a suitable cutting temperature plays a vital role in guaranteeing the success of the operation. Starting by fractionating two FCC Naphthas into nine narrow cuts, this paper shows that, despite the great differences in the properties of the two FCC Naphthas, both hydrocarbons and sulfides have almost the same distributions in the nine cuts. More importantly, it was observed that the distribution of sulfides in the narrow cuts is irrelevant to their true boiling points because of the formation of azeotropes between sulfides and hydrocarbons. On the basis of these findings, a simple model for estimating thiophene content in light FCC naphtha and, thereby, determining the cutting temperature was deduced and its applicability was verified using three other FCC Naphthas sampled from different refineries. The salient feature of the model lies in that it only uses the total thiophene content of the feeding FCC naphtha to perform the estimation without the necessity to carry out time-consuming and cost-expensive pre-hydrogenation and fractionation tests. Thus, it can provide in-prior estimation for the design and operation optimization of FCC naphtha hydro-upgrading processes
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simple model for predicting the cutting temperature between light and heavy fractions in fluid catalytic cracking naphtha selective hydrodesulfurization processes
Energy & Fuels, 2014Co-Authors: Lei Wang, Gang Shi, Yu Fan, Xiaojun BaoAbstract:In selective hydrodesulfurization processes for hydro-upgrading fluid catalytic cracking (FCC) naphtha with high olefin and sulfur contents, it is a common practice to split the feeding full-range FCC naphtha into a light fraction and a heavy fraction. This operation can effectively alleviate olefin saturation and thereby octane loss. Thus, the determination of a suitable cutting temperature plays a vital role in guaranteeing the success of the operation. Starting by fractionating two FCC Naphthas into nine narrow cuts, this paper shows that, despite the great differences in the properties of the two FCC Naphthas, both hydrocarbons and sulfides have almost the same distributions in the nine cuts. More importantly, it was observed that the distribution of sulfides in the narrow cuts is irrelevant to their true boiling points because of the formation of azeotropes between sulfides and hydrocarbons. On the basis of these findings, a simple model for estimating thiophene content in light FCC naphtha and, ther...
