Chemical Engineering

Heat exchangers move heat from one fluid to another. Shell and tube exchangers and plate exchangers are two common types. In a shell and tube exchanger, one fluid flows through a set of tubes while a second fluid flows around them to cool or heat the first stream. In a plate heat exchanger, fluids move between closely joined plates with a small gap between each plate. Because plate exchangers have a large surface area, they are usually more efficient.

This experiment studies a finned-tube heat...

Tray dryers are used in many industrial processes to remove water from solids. They do this by moving heat through the material. Dryers can use different heat transfer methods. Adiabatic dryers rely on convection, which is heat transfer by moving gas, and direct contact with gases. Non-adiabatic dryers use other methods, including conduction, radiation, and radio frequency drying.

Dryers may also run as batch processes or as continuous systems. In a batch process, a set amount of material is...

In this experiment, a Cannon-Fenske viscometer measures the viscosities of several propylene glycol solutions. The goal is to determine the relationship between viscosity and composition.

Nitrogen adsorption and desorption are used to measure the surface area and pore size distribution of a porous solid. These two properties help show how well a material can adsorb molecules or support catalytic activity.

For adsorbent and catalyst manufacturers, surface area and pore size distribution are important quality control measures. They also help identify when a product is reaching the end of its useful life. In a porous solid, the surface area is closely tied to how much material it...

Polymer extrusion turns heated thermoplastic material into simple shapes such as pellets, sheets, or pipe. An extruder melts the solid feed, moves it forward, and builds pressure as the material flows through the die. Polyolefins are among the most common polymers used for this process.

This experiment uses a simple lab extruder to test how operating conditions affect polymer output and pressure drop. The feed may also include non-polymeric materials. The same setup can be used to study...

Gas absorbers remove contaminants from gas streams, and this page focuses on how a packed counter-flow column works. In this setup, the gas and liquid move in opposite directions. The column is filled with random packing that helps the two phases make efficient contact.

Packed bed absorbers can use loose packing made from ceramics, metals, or plastics. Structured packing can also be used. The large surface area from the packing supports high mass transfer rates, and these systems are low...

Vapor-liquid equilibrium helps explain how liquid mixtures separate in distillation. Distillation is a process that separates liquids by their boiling point. A liquid mixture is fed into a distillation unit or column and then boiled.

As the mixture heats, the component with the lower boiling point forms vapor more easily. That vapor rises through the column, while the other liquid stays behind and drains through the unit. Vapor-liquid equilibrium data helps predict this split and shows how a...

Tray distillation is used to separate liquid mixtures with a column that contains trays or packed sections. This experiment focuses on a sieve tray column, which uses trays with holes in a support plate to create a large contact area between liquid and vapor. The mixture being separated contains methanol, isopropanol, and water.

The Tray Distillation Unit starts in total reflux mode. After a steady reflux drum level is reached, the system is switched to finite reflux mode. The bottoms,...

Liquid-liquid extraction uses two immiscible or partly miscible liquids to separate a solute by solubility differences. The feed and solvent are mixed, then separated so the solute moves from the feed into the solvent. The solvent-rich stream leaving the unit is the extract, and the solute-poor stream is the raffinate.

This separation is often used instead of distillation when the compounds have very similar relative volatility. It is also useful when one or more mixture components are...

Packed bed reactors can be used to study the kinetics of sucrose inversion. In this liquid-phase reaction, sucrose is converted into glucose (dextrose) and fructose while a solid catalyst helps drive the process.

Batch and continuous flow reactors are both used in catalytic chemistry. Packed beds use a solid catalyst with continuous flow, and they are the most common reactor setup. Without a large recycle stream, packed bed reactors are usually modeled as plug flow. The other common continuous...

Salicylic acid crystal growth by pH swing uses a chemical change to make solid salicylic acid form from solution. This crystallization method is common in biochemical processing, where scientists separate solids from liquids or large molecules from small ones. Crystallization is especially important in pharmaceutical, chemical, and food processing industries because it handles large amounts of material.

Crystal shape and crystal size matter in process economics. They can affect later steps...

Packed bed reactors can show uneven flow patterns in both single-phase and two-phase systems. This experiment examines that maldistribution and how it changes pressure drop across the bed. It also uses tracers to connect residence time distribution and dispersion to the way fluid moves through the packing.

In single-phase flow, channeling can develop along the walls or through a larger part of the bed cross-section. In two-phase flow, channeling can arise from more complex causes. Simple...

Polymers are long molecules made of repeating monomer units that are chemically bonded together. Their properties depend on chemical structure, molecular weight, and degree of polymerization. The polymer industry makes many raw materials that are used in commercial products.

This experiment uses an addition polymerization reaction to make polydimethylsiloxane. The product is then evaluated to show how viscosity can help determine polymer molecular weight. It also examines how molecular weight...

Ethylene hydrogenation is a catalyst kinetics experiment that converts ethylene (C2H4) into ethane (C2H6). It is often used as a model reduction reaction for testing new metal catalysts. In this study, supported nickel is used. It is not the most active catalyst for this reaction, but it works well enough for the reaction to occur below 200°C.

The reaction happens on a metal surface. Hydrogen gas first dissociates, which means it splits into hydrogen atoms. Ethylene also adsorbs, or sticks, to...

The Spin-and-Chill experiment tests how fast a soft drink cools when a can or bottle is spun at high speed. It uses heat transfer and fluid flow ideas to study why rotation can chill a beverage from room temperature to 38 °F in as little as 2 min.

The setup can cool much faster than a refrigerator, which takes about 240 min for the same temperature change. It is also faster than an ice chest, which takes about 40 min. Spinning the container at up to 500 rpm creates little or no foaming, so the...