The Experts below are selected from a list of 12555 Experts worldwide ranked by ideXlab platform
Edward C. Little - One of the best experts on this subject based on the ideXlab platform.
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fcc coprocessing oil sands heavy gas oil and canola oil 1 yield structure
Fuel, 2015Co-Authors: Siauw H Ng, Mustafa Alsabawi, Fuchen Ding, Hao Ling, Ying Zheng, Jinsheng Wang, Edward C. LittleAbstract:Abstract Reducing the carbon footprint or GHG emissions is a major challenge during the production and processing of Canadian oil sands bitumen for clean transportation fuels. Co-processing bitumen derived feeds and biomass may provide an alternative solution since the level of GHG emissions for producing renewable biofuels is considered significantly lower than that for fossil fuels. In many developed countries, it is required that biofuels replace from 6% to 10% of petroleum fuels in the near future. Co-processing biomass and bitumen feeds can use existing refining infrastructure and technologies, saving capital and operating costs. In addition, co-processing may generate synergies that improve gasoline and diesel qualities. The current study investigates the catalytic cracking performances of pure heavy gas oil (HGO) derived from oil sands synthetic crude and a mixture of 15 v% canola oil in HGO using a commercial Equilibrium Catalyst under typical FCC conditions. Cracking experiments were performed using a bench-scale Advanced Cracking Evaluation (ACE) unit at fixed weight hourly space velocity (WHSV) of 8 h−1, 490–530 °C, and Catalyst/oil ratios of 4–12 g/g. Higher conversion, dry gas yield, and liquefied petroleum gas (LPG) yield were observed at a given Catalyst/oil ratio when cracking the HGO/canola oil blend compared with pure HGO. The increase in dry gas yield can be attributed to the decarboxylation and decarbonylation reactions in the presence of triglycerides composed of fatty acids in the feed, leading to the formation of CO2 and CO. In general, at a given conversion, the addition of canola oil resulted in lower gasoline yield at the expense of water formation. As well, lower coke yield was observed for the blend. The relatively high nitrogen content in the feeds played an important role in Catalyst activity and selectivity, particularly at low reaction temperatures.
Guy Marin - One of the best experts on this subject based on the ideXlab platform.
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a single event microkinetic analysis of the catalytic cracking of cyclo alkanes on an Equilibrium Catalyst in the absence of coke formation
Chemical Engineering Science, 2007Co-Authors: R Quintanasolorzano, Joris W Thybaut, Guy MarinAbstract:Abstract Single-event microkinetics (SEMK) are applied to model the catalytic cracking of (cyclo)alkanes on an Equilibrium Catalyst in the absence of coke formation. Model kinetic parameters are estimated via regression of cracking data obtained at temperatures relevant for industrial practice, 693–753 K. The obtained parameter values allow quantifying the main reaction pathways. Hydride transfer and protonation favor the formation of more stable, tertiary carbenium ions. β -scission of (cyclo)alkylcarbenium ions is preceded by skeletal isomerization and ring contraction. Small side chain cycloalkanes crack via ring-opening followed by β -scission, while the cracking of long side chain cycloalkanes occurs via dealkylation and only to a lesser extent via ring-opening. Temperature effects, such as the increase of the alkene to alkane ratio with temperature, are adequately simulated.
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catalytic cracking and coking of cyclo alkane 1 octene mixtures on an Equilibrium Catalyst
Applied Catalysis A-general, 2006Co-Authors: R Quintanasolorzano, Joris W Thybaut, Guy MarinAbstract:Abstract Catalytic cracking of n -decane and n -butylcyclohexane spiked with 1-octene to promote coke formation has been performed in a temperature range 693–753 K and (cyclo)alkane inlet partial pressure in the range 13.3–26.6 kPa in an oscillating microbalance reactor on a commercial REUSY (rare earth-modified ultrastable Y zeolite) Equilibrium Catalyst. The Catalyst is severely deactivated during the first minutes of the reaction, while the Catalyst activity becomes practically asymptotic at long times on stream. The cracking of n -decane/1-octene mainly yields alkanes and alkenes, while that of n -butylcyclohexane/1-octene leads to alkanes, alkenes, cycloalkanes and aromatics. The coke selectivity increases with (cyclo)alkane conversion but decreases with temperature. It is significantly higher for n -decane/1-octene compared with n -butylcyclohexane/1-octene for a given (cyclo)alkane conversion. When cracking n -decane/1-octene, coke was associated to the formation of bulky oligomers formed via alkylation of (branched) C 8 + alkylcarbenium ions with alkenes. Fed with n -butylcyclohexane, the conversion of 1-octene to coke proceeds via a more complicated mechanism involving alkenylcarbenium ions and ultimately aromatics. At the observed coke levels, coke formation negatively affects the rate of protolysis, hydride transfer and beta-scission as well as coking. At identical (cyclo)alkane conversions, however, the product distributions are not affected by the coke content of the Catalyst except for typical protolysis products. The latter increases with coke content at a given conversion.
Carla Costa - One of the best experts on this subject based on the ideXlab platform.
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durability of an uhpc containing spent Equilibrium Catalyst
Construction and Building Materials, 2021Co-Authors: Ana Mafalda Matos, Sandra Nunes, Carla Costa, Jose Barroso L AguiarAbstract:Abstract UHPC is an advanced cementitious material able to meet the current construction industry challenges regarding structural safety and durability. However, new UHPC formulations with limited shrinkage are still being pursued to reduce residual tensile stresses in the UHPFRC layers, for rehabilitation/strengthening applications. This investigation estimates the durability of a non-proprietary UHPC incorporating a by-product originated by the oil refinery industry (ECat), as an internal curing agent. Direct and indirect transport properties measurements as well as the carbonation assessment and evaluation of dimensional resilience to potential deleterious reactions revealed that the new UHPC possesses an excellent durability performance, typical of these materials. These results combined with its self-compacting ability, low autogenous shrinkage and high compressive strength confirm the belief in the role of this new UHPC towards a high-tech construction.
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spent Equilibrium Catalyst as internal curing agent in uhpfrc
Cement & Concrete Composites, 2019Co-Authors: Ana Mafalda Matos, Sandra Nunes, Carla Costa, Jose L BarrosoaguiarAbstract:Abstract The main goal of the current paper is to optimize ultra-high performance cementitious material (UHPC) mixes incorporating the spent Equilibrium Catalyst (ECat) to mitigate autogenous shrinkage. Design of experiments approach was used to optimize mixtures targeting different engineering properties, namely, self-compactibility, low early-age shrinkage and cracking risk, improved durability and high mechanical performance. The statistical models established indicated that ECat exhibits a strong positive effect on the autogenous shrinkage mitigation of UHPC attributed to the water absorbed in the porous of ECat particles. The proposed optimal UHPC mixture represents the best compromise between low autogenous shrinkage – 32% of reduction – and high resistivity at 28 days without impairing self-compatibility and compressive strength. This optimal UHPC combined with 3% high-strength steel fibres (lf/df = 65) proved to be comparable to other Ultra High-Performance Fibre Reinforced Composites (UHPFRC), in terms of mechanical behaviour, and more eco-friendly and cost-efficient than UHPCs reported in the literature.
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numerical optimization of self compacting mortar mixture containing spent Equilibrium Catalyst from oil refinery
Journal of Cleaner Production, 2017Co-Authors: Sandra Nunes, Carla CostaAbstract:Abstract As the oil refining industries continue to grow, the production of waste Catalysts generated in that process is expected to also increase. It would be of great value both economically and ecologically if these wastes could be reused as an addition in self-compacting concrete (SCC). This paper uses statistical factorial design approach, namely a central composite design, to conduct a proper experimental plan to design SCC mortar mixtures incorporating spent Equilibrium Catalyst (ECat), a waste generated by the oil-refinery industry. The mathematical empirical models derived (which were also experimentally validated) revealed the influence of mixture design parameters, and their coupled effects, on the mortars’ properties namely, deformability, viscosity, compressive strength, resistivity and ultrasonic pulse velocity. A numerical optimization technique was applied to the derived models to select the best mixture, which maximizes simultaneously durability and eco-efficiency and minimize cost, while maintaining self-compactability. The current study revealed that ECat can be successfully applied in SCC mortars, as a high volume cement replacement material (up to V E c a t / V p = 19.7%) due to its high pozzolanic activity. Nevertheless, for powder-type SCCs, cement/ECat blends must be combined with other finer additions to complete the powders distribution curve increasing the viscosity and stability of paste phase, in the fresh state.
Fuchen Ding - One of the best experts on this subject based on the ideXlab platform.
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FCC coprocessing oil sands heavy gas oil and canola oil. 3. Some cracking characteristics
KeAi, 2019Co-Authors: Nicole E. Heshka, Ying Zheng, Qiang Wei, Fuchen DingAbstract:Coprocessing of bitumen-derived feeds and biomass through a fluid catalytic cracking (FCC) route has the potential to assist in the reduction of fuel and petroleum product carbon footprints while meeting government regulatory requirements on renewable transportation fuels. This approach is desirable because green house gas (GHG) emissions for producing renewable biofuels are significantly lower than those for fossil fuels, and coprocessing can be executed using existing refining infrastructure to save capital cost. The present study investigates the specific FCC performances of pure heavy gas oil (HGO) derived from oil sands synthetic crude, and a mixture of 15 v% canola oil in HGO using a commercial Equilibrium Catalyst under typical FCC conditions. Cracking experiments were performed using a bench-scale Advanced Cracking Evaluation (ACE) unit at fixed weight hourly space velocity (WHSV) of 8 h−1, 490–530 °C, and Catalyst/oil ratios of 4–12 g/g. This work focuses on some cracking phenomena resulting from the presence of oxygen in the blend—a lower heat requirement for cracking due to the exothermic water formation, which also entails lower hydrogen yield at a given severity. The distribution of feed oxygen in gaseous and liquid products, the mitigation in GHG emissions, and the technological and economical advantages of the coprocessing option are also discussed. Keywords: FCC coprocessing, Microactivity test (MAT) unit, Four-lump kinetic model, Heat of formation of water vapour, Carbon footprint reductio
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fcc coprocessing oil sands heavy gas oil and canola oil 1 yield structure
Fuel, 2015Co-Authors: Siauw H Ng, Mustafa Alsabawi, Fuchen Ding, Hao Ling, Ying Zheng, Jinsheng Wang, Edward C. LittleAbstract:Abstract Reducing the carbon footprint or GHG emissions is a major challenge during the production and processing of Canadian oil sands bitumen for clean transportation fuels. Co-processing bitumen derived feeds and biomass may provide an alternative solution since the level of GHG emissions for producing renewable biofuels is considered significantly lower than that for fossil fuels. In many developed countries, it is required that biofuels replace from 6% to 10% of petroleum fuels in the near future. Co-processing biomass and bitumen feeds can use existing refining infrastructure and technologies, saving capital and operating costs. In addition, co-processing may generate synergies that improve gasoline and diesel qualities. The current study investigates the catalytic cracking performances of pure heavy gas oil (HGO) derived from oil sands synthetic crude and a mixture of 15 v% canola oil in HGO using a commercial Equilibrium Catalyst under typical FCC conditions. Cracking experiments were performed using a bench-scale Advanced Cracking Evaluation (ACE) unit at fixed weight hourly space velocity (WHSV) of 8 h−1, 490–530 °C, and Catalyst/oil ratios of 4–12 g/g. Higher conversion, dry gas yield, and liquefied petroleum gas (LPG) yield were observed at a given Catalyst/oil ratio when cracking the HGO/canola oil blend compared with pure HGO. The increase in dry gas yield can be attributed to the decarboxylation and decarbonylation reactions in the presence of triglycerides composed of fatty acids in the feed, leading to the formation of CO2 and CO. In general, at a given conversion, the addition of canola oil resulted in lower gasoline yield at the expense of water formation. As well, lower coke yield was observed for the blend. The relatively high nitrogen content in the feeds played an important role in Catalyst activity and selectivity, particularly at low reaction temperatures.
Sandra Nunes - One of the best experts on this subject based on the ideXlab platform.
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durability of an uhpc containing spent Equilibrium Catalyst
Construction and Building Materials, 2021Co-Authors: Ana Mafalda Matos, Sandra Nunes, Carla Costa, Jose Barroso L AguiarAbstract:Abstract UHPC is an advanced cementitious material able to meet the current construction industry challenges regarding structural safety and durability. However, new UHPC formulations with limited shrinkage are still being pursued to reduce residual tensile stresses in the UHPFRC layers, for rehabilitation/strengthening applications. This investigation estimates the durability of a non-proprietary UHPC incorporating a by-product originated by the oil refinery industry (ECat), as an internal curing agent. Direct and indirect transport properties measurements as well as the carbonation assessment and evaluation of dimensional resilience to potential deleterious reactions revealed that the new UHPC possesses an excellent durability performance, typical of these materials. These results combined with its self-compacting ability, low autogenous shrinkage and high compressive strength confirm the belief in the role of this new UHPC towards a high-tech construction.
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spent Equilibrium Catalyst as internal curing agent in uhpfrc
Cement & Concrete Composites, 2019Co-Authors: Ana Mafalda Matos, Sandra Nunes, Carla Costa, Jose L BarrosoaguiarAbstract:Abstract The main goal of the current paper is to optimize ultra-high performance cementitious material (UHPC) mixes incorporating the spent Equilibrium Catalyst (ECat) to mitigate autogenous shrinkage. Design of experiments approach was used to optimize mixtures targeting different engineering properties, namely, self-compactibility, low early-age shrinkage and cracking risk, improved durability and high mechanical performance. The statistical models established indicated that ECat exhibits a strong positive effect on the autogenous shrinkage mitigation of UHPC attributed to the water absorbed in the porous of ECat particles. The proposed optimal UHPC mixture represents the best compromise between low autogenous shrinkage – 32% of reduction – and high resistivity at 28 days without impairing self-compatibility and compressive strength. This optimal UHPC combined with 3% high-strength steel fibres (lf/df = 65) proved to be comparable to other Ultra High-Performance Fibre Reinforced Composites (UHPFRC), in terms of mechanical behaviour, and more eco-friendly and cost-efficient than UHPCs reported in the literature.
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numerical optimization of self compacting mortar mixture containing spent Equilibrium Catalyst from oil refinery
Journal of Cleaner Production, 2017Co-Authors: Sandra Nunes, Carla CostaAbstract:Abstract As the oil refining industries continue to grow, the production of waste Catalysts generated in that process is expected to also increase. It would be of great value both economically and ecologically if these wastes could be reused as an addition in self-compacting concrete (SCC). This paper uses statistical factorial design approach, namely a central composite design, to conduct a proper experimental plan to design SCC mortar mixtures incorporating spent Equilibrium Catalyst (ECat), a waste generated by the oil-refinery industry. The mathematical empirical models derived (which were also experimentally validated) revealed the influence of mixture design parameters, and their coupled effects, on the mortars’ properties namely, deformability, viscosity, compressive strength, resistivity and ultrasonic pulse velocity. A numerical optimization technique was applied to the derived models to select the best mixture, which maximizes simultaneously durability and eco-efficiency and minimize cost, while maintaining self-compactability. The current study revealed that ECat can be successfully applied in SCC mortars, as a high volume cement replacement material (up to V E c a t / V p = 19.7%) due to its high pozzolanic activity. Nevertheless, for powder-type SCCs, cement/ECat blends must be combined with other finer additions to complete the powders distribution curve increasing the viscosity and stability of paste phase, in the fresh state.