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Chemical Industry: The aggregate enterprise of manufacturing and technically producing chemicals. (From Random House Unabridged Dictionary, 2d ed)

Testing the Heat Transfer Efficiency of a Finned-tube Heat Exchanger

JoVE 10437

Source: Michael G. Benton and Kerry M. Dooley, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA

Heat exchangers transfer heat from one fluid to another fluid. Multiple classes of heat exchangers exist to fill different needs. Some of the most common types are shell and tube exchangers and plate exchangers1. Shell and tube heat exchangers use a system of tubes through which fluid flows1. One set of tubes contains the liquid to be cooled or heated, while the second set contains the liquid that will either absorb heat or transmit it1. Plate heat exchangers use a similar concept, in which plates are closely joined together with a small gap between each for liquid to flow1. The fluid flowing between the plates alternates between hot and cold so that heat will move into or out of the necessary streams1. These exchangers have large surface areas, so they are usually more efficient1. The goal for this experiment is to test the heat transfer efficiency of a finned-tube heat exchanger (Figure 1) and compare it to the theoretical efficiency of a heat exchanger without fins. The experimental data will be measured for three diffe

 Chemical Engineering

Single and Two-phase Flow in a Packed Bed Reactor

JoVE 10431

Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA

The goal of this experiment is to determine the magnitude of maldistribution in typical packed bed reactors in both single phase and two-phase (gas-liquid) flow and evaluate the effects of this maldistribution on pressure drop. The concepts of residence time distribution and dispersion are introduced through the use of tracers, and these concepts are related to physical maldistribution. Channeling in a single-phase flow can occur along walls or by preferential flow through a larger portion of the bed cross-section. Channeling in two-phase flow can result from even more complex causes, and simple two-phase flow theories seldom predict pressure drops in packed beds. A design goal is always to minimize the extent of channeling by finding the optimal bed and particle diameters for the design flow rates and by packing a bed in a way to minimize settling. It is always important to quantify how much maldistribution might occur and to over-design the unit to account for its occurrence. The permeameter apparatus measures pressure drop, ΔP, and the concentration of tracer (dye) exiting horizontal packed beds of armored glass for either water,

 Chemical Engineering

Liquid Phase Reactor: Sucrose Inversion

JoVE 10408

Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA

Both batch and continuous flow reactors are used in catalytic reactions. Packed beds, which use solid catalysts and a continuous flow, are the most common configuration. In the absence of an extensive recycle stream, such packed bed reactors are typically modeled as "plug flow". The other most common continuous reactor is a stirred tank, which is assumed to be perfectly mixed.1 One reason for the prevalence of packed bed reactors is that, unlike most stirred tank designs, a large wall area to reactor volume ratio promotes more rapid heat transfer. For almost all reactors, heat must either be added or withdrawn to control the temperature for the desired reaction to take place. The kinetics of catalytic reactions are often more complex than the simple 1st order, 2nd order, etc. kinetics found in textbooks. The reaction rates can also be affected by rates of mass transfer - reaction cannot take place faster than the rate at which reactants are supplied to the surface or the rate at which products are removed - and heat transfer. For these reasons, experimentation is almost always necessary to determine the reaction kine

 Chemical Engineering

Vapor-liquid Equilibrium

JoVE 10425

Source: Michael G. Benton and Kerry M. Dooley, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA

Vapor-liquid equilibrium is paramount in engineering applications such as distillation, environmental modeling, and general process design. Understanding the interactions of components in a mixture is very important in designing, operating and analyzing such separators. The activity coefficient is an excellent tool for relating molecular interactions to mixture composition. Finding the molecular interaction parameters allows future prediction of the activity coefficients for a mixture using a model. Vapor-liquid equilibrium is a critical factor in common processes in the chemical industry, such as distillation. Distillation is the process of separating liquids by their boiling point. A liquid mixture is fed into a distillation unit or column, then boiled. Vapor-liquid equilibrium data is useful for determining how liquid mixtures will separate. Because the liquids have different boiling points, one liquid will boil into a vapor and rise in the column, while the other will stay as a liquid and drain through the unit. The process is very important in a variety of industries. In this experiment, the activity coefficients of mixtures of various com

 Chemical Engineering

Preparation of Giant Vesicles Exhibiting Visible-light-induced Morphological Changes

1Department of Applied Chemistry, School of Applied Science, National Defense Academy of Japan, 2Department of Applied Physics, School of Applied Science, National Defense Academy of Japan, 3Department of Materials Science and Technology, Faculty of Engineering, Niigata University

Video Coming Soon

JoVE 54817

 JoVE In-Press

Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light

1Institute for Complex Molecular Systems (ICMS), Technical University of Eindhoven, 2Department of Chemical Engineering and Chemistry, Laboratory of Macromolecular and Organic Chemistry, Technical University of Eindhoven, 3Department of Chemical Engineering and Chemistry, Laboratory for Functional Organic Materials and Devices (SFD), Technical University of Eindhoven

JoVE 56266


Synthesis of Multi-Walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties

1Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology, 2School of Integrative Engineering, Chung-Ang University, 3Division of Synthetic Biology and Regenerative Medicine, Institute for Quantitative Health Science and Engineering, Michigan State University

Video Coming Soon

JoVE 57384

 JoVE In-Press

Safe Handling of Mineral Acids

JoVE 10370

Source: Robert M. Rioux & Taslima A. Zaman, Pennsylvania State University, University Park, PA

A mineral acid (or inorganic acid) is defined as a water-soluble acid derived from inorganic minerals by chemical reaction as opposed to organic acids (e.g. acetic acid, formic acid). Examples of mineral acids include: • Boric acid (CAS No.10043-35-3) • Chromic acid (CAS No.1333-82-0) • Hydrochloric acid (CAS No.7647-01-0) • Hydrofluoric acid (CAS No. 7664-39-3) • Nitric acid (CAS No. 7697-37-2) • Perchloric acid (CAS No. 7601-90-3) • Phosphoric acid (CAS No.7664-38-2) • Sulfuric acid (CAS No.7664-93-9) Mineral acids are commonly found in research laboratories and their corrosive nature makes them a significant safety risk. Since they are important reagents in the research laboratory and often do not have substitutes, it is important that they are handled properly and with care. Some acids are even shock sensitive and under certain conditions may cause explosions (i.e., salts of perchloric acid).

 Lab Safety

The Effect of Reflux Ratio on Tray Distillation Efficiency

JoVE 10432

Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA

Tray and packed columns are both commonly used for distillation, absorption, and stripping separation operations.1,2 The goal of this experiment is to distill a mixture of alcohols (methanol, isopropanol) and water in a sieve tray column and examine how closely simple theories of distillation based on equilibrium assumptions are followed. Sieve trays provide maximum interfacial area between the liquid and vapor. A P&ID schematic of the sieve tray (each tray contains holes in a support plate) distillation system can be found in Appendix A. In this demonstration, the Tray Distillation Unit (TDU) is started in total reflux mode. After a steady reflux drum level is attained, a switch to finite reflux mode is made by adjusting the bottoms, distillate and reflux flow rate controllers as necessary to maintain steady levels in the reflux drum and the reboiler, and to maintain a target reflux ratio RD = L/D. Once steady state is achieved (takes at least 90 min), liquid samples will be taken from the reflux drum, reboiler and on each tray and analyzed in a gas chromatograph. A typical protocol is to investigat

 Chemical Engineering

Microfluidic-based Synthesis of Covalent Organic Frameworks (COFs): A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

1Institute of Chemical and Bioengineering, Department of Chemistry and Applied Bioscience, ETH Zurich, 2Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 3Departamento de Química Inorgánica, Universidad de Granada, 4Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), 5School of Chemistry, University of Nottingham, 6Condensed Matter Physics Center (IFMAC), Universidad Autónoma de Madrid, 7Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia)

JoVE 56020


Capillary-based Centrifugal Microfluidic Device for Size-controllable Formation of Monodisperse Microdroplets

1Department of Computational Intelligence and Systems Science, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 2Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 3Department of Mechanical Engineering, Keio University, 4PRESTO, Japan Science and Technology Agency

JoVE 53860


Removal of Branched and Cyclic Compounds by Urea Adduction for Uk'37 Paleothermometry

JoVE 10160

Source: Laboratory of Jeff Salacup - University of Massachusetts Amherst

As mentioned in previous videos, the product of an organic solvent extraction, a total lipid extract (TLE), is often a complex mixture of hundreds, if not thousands, of different compounds. The researcher is often only interested in a handful of compounds. In the case of our two organic paleothermometers (Uk'37 and MBT/CBT), the interest is in only 6 compounds (2 alkenones and 4 isoprenoidal glycerol dialkyl glycerol tetraethers). As discussed in the previous two videos in this series, purification techniques may be applied in order to pare down the number of compounds in an analyzed sample. These techniques may chemically alter the unwanted components (saponification), take advantage of the different compound chemistries (column chromatography), or use the different shapes and sizes of the molecules to include or exclude certain components from the analysis (urea adduction). The atomic structure of different chemicals leads some organic compounds to form long, narrow, straight chains (n-alkanes and alkenones), other organic compounds to form complex cyclic structures, others to form highly-branched structures, and yet others which form both cyclic and branched structures (GDGTs) (Figure 1). The different

 Earth Science

Lewis Acid-Base Interaction in Ph3P-BH3

JoVE 10316

Source: Tamara M. Powers, Department of Chemistry, Texas A&M University 

One of the goals of chemistry is to use models that account for trends and provide insights into the properties of reactants that contribute to reactivity. Substances have been classified as acids and bases since the time of the ancient Greeks, but the definition of acids and bases has been modified and expanded over the years.1 The ancient Greeks would characterize substances by taste, and defined acids as those that were sour-tasting, such as lemon juice and vinegar. The term "acid" is derived from the Latin term for "sour-tasting." Bases were characterized by their ability to counteract or neutralize acids. The first bases characterized were those of ashes from a fire, which were mixed with fats to make soap. In fact, the term "alkaline" is derived from the Arabic word for "roasting." Indeed, it has been known since ancient times that acids and bases can be combined to give a salt and water. The first widely-used description of an acid is that of the Swedish chemist, Svante Arrhenius, who in 1894 defined acids as substances which dissociate in water to give hydronium ions, and bases as substances which dissociate in water to give

 Inorganic Chemistry

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