Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to b...Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to be controlled. However, there are few studies about how pressure affects the dynamic behavior of distillation columns and most research on distillation column control involve direct manipulation of cooling fluid through the condenser. Nevertheless, such an approach demands constant changes in cooling fluid flowrates that are commonly by the order of tons per hour, which can be difficult to work or even unfeasible in a real plant. Furthermore, this strategy is usually avoided, as it can cause fouling and corrosion acceleration. The hot-vapor bypass strategy fits well as a solution for these issues, eliminating the need to dynamically manipulate cooling fluid flowrates in the condensation unit. This work presents the modeling and simulation of a conventional distillation column for the separation of water and ethanol, in which a comparative study between a conventional pressure control and a control using hot-vapor bypass was performed. The main results were obtained through dynamic simulations which considered various disturbances in the feed stream, and demonstrated superior performance by the hot-vapor bypass system over the usual scheme proposed in literature, while evaluating the lntegral Absolute Error （IAE） norm as the control performance index.展开更多
The Birds Point-New Madrid Floodway（BP-NMF） and the Yolo Bypass, located on the Mississippi and Sacramento rivers, respectively, are agriculture areas that were once each part of vast wetlands but are now intermitte...The Birds Point-New Madrid Floodway（BP-NMF） and the Yolo Bypass, located on the Mississippi and Sacramento rivers, respectively, are agriculture areas that were once each part of vast wetlands but are now intermittently used for flood control. Here the similarity stops, the BP-NMF has been used to convey floodwaters only twice in nearly 80 years, while the Yolo Bypass is used for this purpose on average every other year. The consequences are greatly different. In 2011, the BP-NMF was activated through the explosive detonation of the ＇fuse plug＂ portion of its levees, resulting in elevated property and economic damages, crop losses, and litigation. High-energy flows following the opening of the BP-NMF scour coarse sediment in the vicinity of the opening of the BP-NMF and deposit this material within the floodway, including on agricultural fields. In general the environment of much of the BP-NMF provides poor wildlife habitat. In contrast, the routine operation of Yolo Bypass is expected, avoids damage and litigation, supplies organic-rich sediment to fields, and provides good wildlife habitat. The difference between the two systems is attributed to a better approximation of natural conditions on the Yolo Bypass.展开更多
基金the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)for financial support for this work
文摘Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to be controlled. However, there are few studies about how pressure affects the dynamic behavior of distillation columns and most research on distillation column control involve direct manipulation of cooling fluid through the condenser. Nevertheless, such an approach demands constant changes in cooling fluid flowrates that are commonly by the order of tons per hour, which can be difficult to work or even unfeasible in a real plant. Furthermore, this strategy is usually avoided, as it can cause fouling and corrosion acceleration. The hot-vapor bypass strategy fits well as a solution for these issues, eliminating the need to dynamically manipulate cooling fluid flowrates in the condensation unit. This work presents the modeling and simulation of a conventional distillation column for the separation of water and ethanol, in which a comparative study between a conventional pressure control and a control using hot-vapor bypass was performed. The main results were obtained through dynamic simulations which considered various disturbances in the feed stream, and demonstrated superior performance by the hot-vapor bypass system over the usual scheme proposed in literature, while evaluating the lntegral Absolute Error （IAE） norm as the control performance index.
文摘The Birds Point-New Madrid Floodway（BP-NMF） and the Yolo Bypass, located on the Mississippi and Sacramento rivers, respectively, are agriculture areas that were once each part of vast wetlands but are now intermittently used for flood control. Here the similarity stops, the BP-NMF has been used to convey floodwaters only twice in nearly 80 years, while the Yolo Bypass is used for this purpose on average every other year. The consequences are greatly different. In 2011, the BP-NMF was activated through the explosive detonation of the ＇fuse plug＂ portion of its levees, resulting in elevated property and economic damages, crop losses, and litigation. High-energy flows following the opening of the BP-NMF scour coarse sediment in the vicinity of the opening of the BP-NMF and deposit this material within the floodway, including on agricultural fields. In general the environment of much of the BP-NMF provides poor wildlife habitat. In contrast, the routine operation of Yolo Bypass is expected, avoids damage and litigation, supplies organic-rich sediment to fields, and provides good wildlife habitat. The difference between the two systems is attributed to a better approximation of natural conditions on the Yolo Bypass.
