Facts At Your Fingertips
Facts At Your Fingertips: Control-Valve Emissions and Packing
Fugitive emissions — defined as unintended releases of volatile organic compounds (VOCs) from process equipment to the atmosphere — have been a long-standing issue in the chemical process industries (CPI). Valves and pumps are two of the leading sources. With…
Facts At Your Fingertips: Conceptualizing Fluid Viscosity
Viscosity is an important property for understanding the flow behavior of liquids, mixtures, emulsions, slurries and other materials in industrial processes. This one-page reference provides a refresher on conceptualizing viscosity. Intermolecular forces Viscosity is a measure of a material’s resistance…
Facts at your Fingertips: Mixing Intensity in Stirred Tanks
The ability to quantify liquid motion in a stirred tank is a basic step toward understanding how mixing influences process results. Quantifying mixing according to a mixing index (MI) can evaluate and predict mixing intensity related to fluid velocities in…
Facts At Your Fingertips: Fractional Solvent-Free Melt Crystallization
Fractional crystallization is a stage-wise separation technique that relies upon the liquid-solid phase change and enables the purification of multi-component mixtures, as long as none of the constituents can act as a solvent to the others. Thanks to the level…
Facts At Your Fingertips: Stainless Steels and Corrosion
Stainless steels are common materials for process equipment and components in the chemical process industries in large part because of their corrosion resistance. This one-page reference reviews the properties of stainless steels with regard to corrosion resistance. Passive layer Stainless…
Facts at your Fingertips: Air-Moving Equipment for Pneumatic Conveying
In a typical bulk-solids pneumatic-conveying system, an air mover is used to generate the necessary air flowrate and pressure required to transport a solid material through a pipeline at a given rate. This one-page reference discusses the operating mechanisms and…
Facts At Your Fingertips: Liquid-Liquid Extraction Basics
Liquid-liquid extraction (LLE) is a separation technique that exploits differences in the relative solubility of compounds of interest (the solute) in two immiscible liquids — most often an aqueous phase and an organic solvent. This one-page reference reviews basic information…
Facts At Your Fingertips: Crossflow Membrane Filtration Module Types
In crossflow membrane filtration (CMF), feed flow is parallel to the filtration surface (rather than perpendicular to it, as in conventional filtration). During a given pass, a portion of the feed permeates the membrane, while a larger portion is retained…
Facts At Your Fingertips: Lifecycle Cost Analysis Basics
When evaluating capital projects in the chemical process industries (CPI), there are many scenarios in which there are important differences between the alternatives in terms of capital, operations and maintenance and decommissioning costs. In these cases, decisions must be made…
Facts At Your Fingertips: Gas Dispersion in Liquids
Injecting gases through a diffuser into a liquid is an important aspect of many operations in the chemical process industries (CPI). Important applications include dissolving reactant gases into a liquid phase for further reaction (such as in hydrogenation, oxidation, ozonation),…