Separation Processes
Facts at your Fingertips: Random Tower Packing
Packed Columns [1] A packed column is a vertical, cylindrical pressure vessel containing one or more sections of a packing material over whose surface the liquid flows downward by gravity, as a film or as droplets, between packing elements. Vapor…
Facts at Your Fingertips: Membranes
Separation by a membrane is achieved by creating a boundary between different bulk gas or liquid mixtures. As different solvents and solutes flow through a membrane at different rates, separation is achieved. Here, we will focus on three filtration techniques:…
Chementator: A promising nanosieve for dehydrating solvents and biofuels
Although nanoporous silica membranes are promising systems for the molecular separation of gases and liquids, they lack microstructural stability in the presence of water at temperatures as low as 60°C. Prolonged exposure to water causes hydrolysis, resulting in the formation…
Chementator: New ceramic-membrane system doubles rate and slashes cost for dehydrating ethanol
Hitachi Zosen Corp. (Hitz; Tokyo, Japan; edlinks.chemengonline.com/7369-531) is commercializing a new membrane for a hybrid-distillation system (HDS) that is especially suitable for dehydrating ethanol and isopropanol. The HDS can produce 99.7 vol.% ethanol from ethanol-water mixtures with 10 vol.% H2O…
Facts at Your Fingertips: Sedimentation Centrifuging
Centrifugation is the method of choice in the chemical process industries (CPI) for separating solids from liquids. It relies on the G-forces generated by high-speed rotation to recover solids or liquids from slurries, as well as clarify liquids or classify…
Chementator: Purification of Single-walled Nanotubes Using Froth Flotation
A method for the purification of single-walled carbon nanotubes (SWNTs) in four sequential steps — oxidative pretreatment, acid treatment, silica dissolution, and froth flotation — has been proposed by a team from the Petroleum and Petrochemical College, Chulalongkorn University (Bangkok,…
Chementator: Membrane Cuts the Cost of Ethanol Dehydration
Ethanol production is an energy-intensive process in which about 50% of the cost is for distillation and dehydration of the ethanol. A membrane system that does the same job, but reduces the energy consumption by up to 50%, has been…
Slash downstream processing costs for producing biologicals with this new chromatography technology
Last month at the BioProcess International Conference (Boston, Mass.; October 1–3), Novasep Process (Boothwyn, Pa.; edlinks.chemengonline.com/6901-533) launched a new technology for downstream processing of biologicals. BioSC (Biopharmaceutical Sequential Chromatography) uses a process known as sequential multi-column continuous chromatography (SMCC), which…
Fabric filters
The world’s power plants, industrial companies and mines will spend $6.1 billion in 2007 for fabric filter equipment, systems and elements to clean up stack gases, according to a report by McIlvaine Co. (Northfield, Ill.; edlinks.chemengonline.com/6900-546). Further, revenues for the…
O2-permeable ceramic
Hollow-fiber membrane tubes that are selectively permeable to oxygen have been constructed by researchers from the School of Chemical Engineering and Advanced Materials at Newcastle University (edlinks.chemengonline.com/6899-542), in collaboration with the Chemical Engineering Dept. at Imperial College London (both U.K.).…