Studying Dispersed Phase Holdup in a Pilot Plant Agitated Liquid–liquid Mixer by Developing Online Expanded Laser Beam based Technique

Expanded Laser Transmission Technique (E-LTT), where a laser beam is used in conjunction with a beam expander large enough to cover the average drop size up to a few millimeters in the path of the laser in a liquid–liquid dispersion mixture, has been applied for online continuous measurement and investigation in a non-invasive manner of the drop phase volume fraction in an agitated flow mixer of a pilot plant scale. The limitations of beam scattering by the drops through the dispersion path were overcome by having liquids of matching refractive indices enabled by the temperature control system. This study reports for the first time the continuous measurements of the line averaged dispersed phase holdup for a pilot plant scale liquid–liquid mixer equipped with a commercial design mixer, where the measurements have no limitations to the geometrical aspects. Experimental results from a cubic mixing tank with a dispersion depth of 30cm were discussed. Online measurements were carried out in the presence of a revolving impeller and transmission of the expanded laser beam. The net volume of the mixer was 20.42liter, and the dispersed phase holdup that was successfully measured ranged between 0.15 and 0.75. In this work, arrangement of the laser setup was made to scan and measure continuously the line average dispersed phase holdup along the height of the pilot plant scale of the flow agitated liquid–liquid mixer. The E-LTT measurements were validated by comparing their results with those obtained from the mixer by shut-down procedure

Tracking the Heavy Metal Contaminants Entrained with the Flow into a Trickle Bed Hydrotreating Reactor Packed with Different Catalyst Shapes using Newly Developed Noninvasive Dynamic Radioactive Particle Tracking

A newly developed modified Dynamic Radioactive Particle Tracking system (DRPT) was used to investigate the heavy metal contaminants deposition locations in different catalyst beds, sphere, cylinder, trilobe, and quadrilobed in Trickle Bed Reactors. In the present paper, Kernel Density Estimator (KDE) was used to estimate the probability density distributions of heavy metal contaminants depositions in terms of bed radius height. The result shows that the four cases have similar probability density distribution in terms of radius, while the spherical catalyst has the larger distribution range in terms of bed height. The heavy metal deposition is directly related to the pressure drops along the bed height which indicate the bed porosity and intricate bed structure in catalyst packed beds. Heavy metals have more chance to deposit at higher levels of packed beds with higher pressure drops

Studying Dispersed Phase Holdup in a Pilot Plant Agitated Liquid-liquid Mixer by Developing Online Expanded Laser Beam based Technique

Expanded Laser Transmission Technique (E-LTT), where a laser beam is used in conjunction with a beam expander large enough to cover the average drop size up to a few millimeters in the path of the laser in a liquid-liquid dispersion mixture, has been applied for online continuous measurement and investigation in a non-invasive manner of the drop phase volume fraction in an agitated flow mixer of a pilot plant scale. The limitations of beam scattering by the drops through the dispersion path were overcome by having liquids of matching refractive indices enabled by the temperature control system. This study reports for the first time the continuous measurements of the line averaged dispersed phase holdup for a pilot plant scale liquid-liquid mixer equipped with a commercial design mixer, where the measurements have no limitations to the geometrical aspects. Experimental results from a cubic mixing tank with a dispersion depth of 30cm were discussed. Online measurements were carried out in the presence of a revolving impeller and transmission of the expanded laser beam. The net volume of the mixer was 20.42liter, and the dispersed phase holdup that was successfully measured ranged between 0.15 and 0.75. In this work, arrangement of the laser setup was made to scan and measure continuously the line average dispersed phase holdup along the height of the pilot plant scale of the flow agitated liquid-liquid mixer. The E-LTT measurements were validated by comparing their results with those obtained from the mixer by shut-down procedure

Separation of phosphoric acid sludge: effect of flocculation on settling and P2O5 recovery rates

Phosphoric acid sludge is one of the prominent problems in the phosphate industry. Its formation is co-occurred by considerable losses of P2O5 that affect the process performance. Management and valorization of this waste is a key issue. This work aimed to deal with this industrial concern by studying the influence of the flocculation on the sludge sedimentation and thus the P2O5 recovery rate. The flocculation tests were conducted in the presence of various types of anionic polymers. The effect of dosage, molecular weight, and type of flocculant were examined. The results indicated that all polymers showed settling performance improvement. And, the flocculant with the highest molecular weight (F1), showed the best settling performance with a pace of 3.3 cm/min and the lowest turbidity value of 40.4 NTU using a dosage of 5 ppm. Due to its high molecular weight, this polymer carries a polyelectrolyte bridging mechanism, which allows the absorbed polymer to move further away from the surface of the particle and then increases the particle radius, the number of collisions, and thus the particle size. However, for the P2O5 recovery rate, the sulfonic polymer (F5) was the best performer allowing recovery of 78.8% of the total mass of the sludge. F5 is weakly amphoteric. Polymers containing sulfonic acid groups are known to be inherently powerful than the carboxylic acid groups as they are stable due to their high energy barrier. According to the results, the flocculation increases the recovery of P2O5, which represents a profit of more than 30 kg of clarified phosphoric acid per 1 tone of sludge

Experimental Investigation Of Residence Time And Axial Velocity Of 6.0 Cm Graphite Pebbles In A Cold-flow Pebble Bed Reactor Using Radioisotope-based Technique

Understanding pebble flow characteristics and residence time distribution is essential for reactor design, fuel burnup estimations, and safety analysis of High-Temperature Gas-Cooled Pebble Bed Reactors. However, due to the complex nature of the dense granular flow, pebble flow remains inadequately understood and challenging to study through experiments. In this work, a three-dimensional experimental pebble-bed setup was developed to investigate pebble flow behavior in pebble-bed reactors. For the first time, 6.0 cm graphite pebbles were utilized, and features such as one pebble at a time discharge mode and continuous pebble recirculation were incorporated. The overall and zonal residence time distributions and the zonal-averaged axial velocity were investigated using a radioisotope-based residence time distribution (RTD) technique. The results showed that the overall residence time increases as the radius of the initial seeding position increases, but with a higher increase rate at the wall compared to the center region. The zonal residence time findings indicated a uniform profile in the upper section of the bed, except near the wall. However, non-uniformity in the radial profile increased in the lower sections, with the greatest variation occurring in the conical section. The axial velocity of the pebbles was found to be small and nearly uniform in the upper section of the bed. In the lower section, however, the velocity increased significantly for the center-region pebbles compared to those at the wall, resulting in a pronounced non-uniform radial profile. Moreover, a consistent hexagonal arrangement of pebbles was observed across the entire container wall after recirculating several bed inventories, which is worth further investigation

Advancement in heavy oil upgrading and sustainable exploration emerging technologies

Upgrading heavy oil is a subject of high importance for fossil fuel industry due to the rapid depletion of light oil reservoirs and the consequent increased demand for upgrading heavy oil. In this review, the advancement made in heavy oil upgrading and the proposed sustainable emerging technologies dedicated to heavy oil processing have been discussed in a comprehensive and informative manner with consideration to the encountered associated with properties of heavy oil including its significant content of undesirable large molecular weight hydrocarbons, its high viscosity, and its elevated impurity level. The shortcomings of conventional crude oil upgrading technologies are outlined, in relation to the upgrading of heavy oil. The various technologies used for the extraction of heavy oil from reservoirs, as well as refinery technologies for improving the quality and marketability of heavy oil products are summarized encompassing modified conventional methods and emerging technologies. Thermal and catalytic processes were compared and evaluated based on the literature for heavy oil processing. Furthermore, emerging technologies for heavy oil processing were listed and discussed comprehensively. The proper selection of the refining technology for heavy oil processing is crucial for the quality of the final products and it is evident from the literature that the selection criteria vary from one heavy oil reservoir to the other depending on the properties of the crude oil

Tracking the Heavy Metal Contaminants Entrained with the Flow into a Trickle Bed Hydrotreating Reactor Packed with Different Catalyst Shapes using Newly Developed Noninvasive Dynamic Radioactive Particle Tracking

A newly developed modified Dynamic Radioactive Particle Tracking system (DRPT) was used to investigate the heavy metal contaminants deposition locations in different catalyst beds, sphere, cylinder, trilobe, and quadrilobed in Trickle Bed Reactors. In the present paper, Kernel Density Estimator (KDE) was used to estimate the probability density distributions of heavy metal contaminants depositions in terms of bed radius height. The result shows that the four cases have similar probability density distribution in terms of radius, while the spherical catalyst has the larger distribution range in terms of bed height. The heavy metal deposition is directly related to the pressure drops along the bed height which indicate the bed porosity and intricate bed structure in catalyst packed beds. Heavy metals have more chance to deposit at higher levels of packed beds with higher pressure drops