www.chemengonline.com August 2017 Cover Story 30 Part 1 Reboiler Circuit Debottleneck with No Hardware Changes With a thorough investigation and proper problem diagnosis, an entire gas plant limited by a de-ethanizer reboiler circuit was successfully debottlenecked 38 Part 2 Dry-Tray Pressure Drop of Sieve Trays Revisited Data from literature are refined into a single correlation defining dry-tray pressure drop in sieve trays In the News 7 Chementator New process generates saleable products from Marcellus produced water; A new catalyst for making methane from CO2 and H2; Bio-based xylitol lowers production costs; Vehicle fuel tank for adsorbed natural gas moves toward commercialization; and more 12 Business News Arkema invests in expansion for bio-sourced polyamide 11; Braskem selects Linde for EPC work on new polypropylene plant; AkzoNobel announces a pair of coatings acquisitions; Amec Foster Wheeler completes sale of CFB boiler business; and more 14 Newsfront New CO2-Capture Approaches Push Against Cost Hurdles Despite cost hurdles, CO2-capture technologies continue to advance, driven by the critical role of CO2-capture in achieving emissions-reductions goals 18 Newsfront Bringing Increased Reliability and Safety to Control Valves Hardware improvements and service programs add more value to today's control valves Technical and Practical 28 Facts at your Fingertips Blending This one-page reference provides information on the advantages and disadvantages of continuous versus batch blending operations 29 Technology Profile Diammonium Phosphate Production This process description outlines the manufacture of diammonium phosphate 42 42 Feature Report Mixing: Impeller Performance in Stirred Tanks Characterizing mixer impellers on the basis of power, flow, shear and efficiency 52 Environmental Manager Control Room Design for Chemical Engineers Chemical engineers bring many essential skills to the diverse teams required for successful control room design 18 14 30 Volume 124 | no. 8 CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM AUGUST 2017 1http://www.chemengonline.com http://WWW.CHEMENGONLINE.COM