scholarly journals Scaling up a Gas-Phase Process for Converting Glycerol to Propane

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1007
Author(s):  
Christian Hulteberg ◽  
Andreas Leveau
Keyword(s):  
Catalyst Deactivation ◽  
Scale Up ◽  
Laboratory Data ◽  
Carbonaceous Material ◽  
Operating Mode ◽  
Water Mixture ◽  
Glycerol Water ◽  
Excess Hydrogen ◽  
Hydrogenation Reactions ◽  
Design Calculations

It is of interest to study not only the fundamental behavior of catalysts and reactors but also to ensure that they can be scaled up in size. This paper investigates the scale-up of a glycerol-to-propane process starting from fundamental laboratory data from micro-reactor testing to the kilogram scale. The process is described in detail and consist of the use of design documents and computer simulations for determining the sizes of the unit operations involved. The final design included a vaporizer section for a glycerol/water mixture, four reactors in tandem with subsequent dehydration and hydrogenation reactions, a flash vessel to separate the excess hydrogen used, and a compressor for recycling the excess hydrogen with additional light components. The system was commissioned in a linear fashion, which is described, and operated for more than 3000 h and more than 1000 h in the final operating mode including recycle. The major results were that no catalyst deactivation was apparent aside from the slow build-up of carbonaceous material in the first dehydration reactor. That the system design calculations proved to be quite close to the results achieved and that the data generated is believed to be sufficient for up-scaling the process into the 1000 to 10,000 tonnes-per-annum range.

Development and Validation of a Design Tool for an Improved Pitot-Tube Jet-Pump Allowing Continuous Fluid-Fluid Separation

2021 ◽  
Author(s):  
Jan Deylen ◽  
Jessica Köpplin ◽  
Dominique Thevenin
Keyword(s):  
Oil Spills ◽  
Separation Efficiency ◽  
Scale Up ◽  
Design Tool ◽  
Pitot Tube ◽  
Polluted Water ◽  
Small Scale ◽  
Water Mixture ◽  
Jet Pump ◽  
Operation Conditions

Abstract A Pitot-tube Jet-Pump (PTJ pump) has been considerably modified and extended in order to continuously separate and transport liquids of different densities. As a first application, an oil-water mixture is considered in this work. The modified PTJ pump could be used as a primary separator for oil-polluted water (e.g., around off-shore platforms, after oil spills from ships), while additionally being able to transport the resulting fluid to further heaters, exchangers, centrifuges, distillation columns, etc., without necessitating additional machinery. The performance behavior of the separating PTJ pump (abbreviated SPP in what follows) has been first investigated with computational fluid dynamics (CFD), and then validated by comparison with experimental data acquired on a small-scale prototype. Based on these observations, a design tool has been developed to (i) predict performance and (ii) support proper device scaling. This tool is based on dimensionless parameters that are already employed for classical turbomachinery, similar to the Cordier chart. However, since the SPP works at an extremely low specific speed, its operating points lie outside the standard Cordier chart. To verify the accuracy of the design tool, a scale-up test has been conducted and validated by CFD, delivering a good agreement. A separation efficiency better than 99% has been obtained in the experiments for suitable operation conditions, while the numerical scale-up test reveals a head of 15.1 m and an oil content below 0.2% in the purified water at the High-Pressure Outlet.

HYDROTHERMAL SYNTHESIS OF CALCIUM HYDROSILICATES

1934 ◽  
Vol 11 (4) ◽  
pp. 520-529 ◽  
Author(s):  
V. A. Vigfusson ◽  
G. N. Bates ◽  
T. Thorvaldson
Keyword(s):  
Hydrothermal Synthesis ◽  
Silica Gel ◽  
Fused Silica ◽  
Steam Treatment ◽  
Crystalline Substance ◽  
Water Mixture ◽  
Glycerol Water ◽  
X Ray ◽  
Lime Water ◽  
Calcium Hydrosilicate

A crystalline substance which appears in steam-cured Portland cement mortar has been shown to be a calcium hydrosilicate and has been prepared by hydrothermal synthesis from mixtures of silica sand with lime, dicalcium silicate and tricalcium silicate, silica gel and lime (after preliminary steam treatment and ignition) and by the action of saturated lime water on quartz crystals or fused silica plates. The crystals appear not to be acted on by solutions of sodium sulphate, calcium sulphate or alkali hydroxides, but they are slowly decomposed by solutions of magnesium sulphate and alkali carbonates and rapidly by dilute acids and ammonium salts. The crystals were obtained free from amorphous matter by growing them on quartz or silica plates in saturated lime water. When the compound was prepared in this way, the lime-silica-water ratio was found to be 2:1:1, the formula being therefore 2CaO∙SiO2∙H2O or H2Ca2SiO5. This product usually appears as thin lath-like prisms showing parallel extinction, positive elongation and moderate birefringence. The crystals are optically positive with a fairly large optic angle. 2V = 68°. The indices of refraction are αNa = 1.614 ±.002, βNa = 1.620 ±.002, γNa = 1.633 ±.002. The optical plane is parallel to the macropinacoid (100) and the acute bisectrix Z is parallel to the direction of elongation which is taken as the crystallographic axis C. The optical properties and X-ray pattern are distinctive and entirely different from those of hillebrandite or foshagite, which have the same composition.Another crystalline calcium hydrosilicate was obtained by hydrothermal synthesis from excess lime and silica gel. This appeared as very small needle-like prisms, observable only when magnified about 200 times. The crystals show parallel extinction, positive elongation and very low birefringence with an index of refraction of 1.597 ±.003. Analysis of this product, extracted with a glycerol-water mixture to remove excess lime, gave a lime-silica ratio of 2 to 1 with an uncertain amount of water of at least one mole. The X-ray pattern is distinctive and shows only slight similarity to the hillebrandite pattern.

Development of a Modeling-Based Strategy for the Safe and Effective Scale-up of Highly Energetic Hydrogenation Reactions

2014 ◽  
Vol 18 (12) ◽  
pp. 1828-1835 ◽  
Author(s):  
Christopher W. Mitchell ◽  
Josiah D. Strawser ◽  
Alex Gottlieb ◽  
Michael H. Millonig ◽  
Frederick A. Hicks ◽  
...  
Keyword(s):  
Scale Up ◽  
Hydrogenation Reactions

Experimental and CFD Investigations of Heat Transfer in Helical Coils for the Development of Correlations for Newtonian and Non-Newtonian Fluids in Transient State-Space Conditions

2013 ◽  
Author(s):  
Sandipan S. Pawar ◽  
Vivek K. Sunnapwar ◽  
Vivek K. Yakkundi
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Turbulent Flow ◽  
Transfer Coefficient ◽  
Flow Regimes ◽  
Newtonian Fluids ◽  
Water Mixture ◽  
Glycerol Water ◽  
Laminar And Turbulent Flow ◽  
Helical Coils

Experimental studies and CFD investigations were carried out under laminar and turbulent flow regimes in isothermal steady state and non-isothermal unsteady state conditions in helical coils for Newtonian and non-Newtonian fluids. Water and glycerol-water mixture (10 and 20 % glycerol) as Newtonian fluids and dilute aqueous polymer solutions of sodium carboxymethyl cellulose (SCMC), sodium alginate (SA) as non-Newtonian fluids were used in this study. The experiments were performed for three helical coils of coil curvature ratios as 0.0757, 0.064 and 0.055 in laminar and turbulent flow regimes. For the first time, two innovative correlations to calculate Nusselt number (Nu) in terms of new dimensionless ‘M’ number, Prandtl number and coil curvature ratio under different conditions for Newtonian fluids are proposed in this paper. Third correlation of Nu vs. Graetz number (Gz) including the effects of coil curvature on heat transfer coefficient which was not considered by earlier investigators is developed based on tests conducted in laminar flow for Newtonian fluids. All these three innovative correlations developed based on experimental data which were not found in the literature. These correlations were compared with the work of earlier investigators and were found to be in good agreement. The CFD analysis for laminar and turbulent flow was carried out using the CFD package FLUENT 12.0.16. The CFD calculation results (Nui, U) for laminar and turbulent flows were compared with the experimental results, and also the work of earlier investigators was found to be in excellent agreement. Further, the effect of helix diameter on heat transfer for Newtonian and Non-Newtonian fluids are also presented in this paper and it was observed that as helix diameter increases, overall heat transfer coefficient decreases.

Preference for Isolated Water Molecules in a Concentrated Glycerol–Water Mixture

2011 ◽  
Vol 115 (24) ◽  
pp. 7799-7807 ◽  
Author(s):  
J. J. Towey ◽  
A. K. Soper ◽  
L. Dougan
Keyword(s):  
Water Molecules ◽  
Water Mixture ◽  
Glycerol Water

scholarly journals The FMO Complex in a Glycerol–Water Mixture

2013 ◽  
Vol 117 (24) ◽  
pp. 7157-7163 ◽  
Author(s):  
Mortaza Aghtar ◽  
Johan Strümpfer ◽  
Carsten Olbrich ◽  
Klaus Schulten ◽  
Ulrich Kleinekathöfer
Keyword(s):  
Water Mixture ◽  
Glycerol Water

scholarly journals Influence of bubble content on laser-induced cavitation bubble oscillation in glycerol-water mixture

2009 ◽  
Vol 58 (12) ◽  
pp. 8400
Author(s):  
Zhao Rui ◽  
Xu Rong-Qing ◽  
Liang Zhong-Cheng ◽  
Lu Jian ◽  
Ni Xiao-Wu
Keyword(s):  
Cavitation Bubble ◽  
Water Mixture ◽  
Glycerol Water ◽  
Bubble Oscillation
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