www.chemengonline.com August 2019 Cover Story 24 Part 1 Liquid Mixing in Stirred Tanks A method of quantifying mixing according to a mixing index is presented. This index can evaluate and predict mixing intensity related to fluid velocities in stirred tanks 36 Part 2 Beyond Simple Mixing Five different examples are presented in which specialty mixers are used to perform tasks more efficiently than conventional approaches In the News 5 Chementator Microbial electrolysis produces H2 from organic waste; Polydibetoenamines could allow closed-loop plastics recycling; A solvent-extraction approach for desalination of high-salinity brines; Pilot plant slated for an H2-based process to make DRI from iron-ore fines; MOFs that mimic leaves for enhanced performance; and more 12 Business News Orion to expand production capacity for gas blacks; Wacker expands silicone elastomer production in China; Eastman expands capacity for DEHA at Louisiana facililty; Ineos to invest $2 billion in Saudi Arabia; Outotec to merge with Metso Minerals; and more 14 Newsfront Increasing the Reliability of Valves Through Design The latest valves are designed to last in challenging chemical applications, increasing uptime and safety Technical and Practical 20a Facts at your Fingertips Selecting a Heat-Transfer Fluid Supplier This one-page reference provides information on issues operating companies should consider when selecting a heat-transfer fluid supplier 21 Technology Profile Production of Titanium Dioxide This column outlines a production process for titanium dioxide, a molecule widely used in paints, coatings and other areas 42 Feature Report Part 1 Considerations for Industrial Gas Purification Purity profiles and gas properties require different methods in the purification of industrial gases. Provided here are key considerations for selecting gas-purification technologies 47 Feature Report Part 2 Tailgas Considerations for Biogas Upgrading Thermal oxidation is used to destroy tailgas from biogas-upgrading facilities. Presented here are guidelines for selecting the proper method 14 36 24 Volume 126 | no. 8 47 CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM AUGUST 2019 1http://www.chemengonline.com http://WWW.CHEMENGONLINE.COM