Enhanced Process Sustainability in Polymerization and Devolatilization Technologies

More stringent regulations have made of process intensification and sustainability critical topics when developing new processes or revamping existing assets. This has translated into efforts to lower VOC emissions, optimize energy consumption, increase capacity and improve efficiency of the polymerization process and downstream equipment. Since several decades Sulzer is active in the development and supply of process solutions for reaction, devolatilization and upgrading of polymers. [1] The technology is successfully implemented in industrial polymerization and devolatilization plants to enhance the process sustainability. In the first part of this work, the use of static mixers and Sulzer Mixer Reactor (SMR) in different polymerization processes is presented. The equipment is characterized by high mixing and heat transfer efficiency, which avoid concentration and temperature gradients. These aspects are fundamental for the production of thermo-sensitive polymers and for highly exothermic processes. A key aspect of this equipment is that it has a heat transfer capacity which is almost independent upon the reactor volume which represents an advantage for process optimization since the process can be reliably scaled down to versatile pilot scale reactors where process parameters and design are optimized. Different reactor configurations are compared in terms of productivity, heat duty and process stability and control. The second part of the work is focused on the devolatilization technology. Devolatilization of monomers, solvents or impurities is a key step in most polymerization processes because it determines polymer quality, applicability and value. Depending on the polymerization process, from a process cost point of view, degassing can account for up to 80% of the energy consumption. [2] In general, the devolatilization processes are classified as static or dynamic processes and are suitable for a wide range of viscosities. For low volatile content, due to the high viscosity of polymer melts, the devolatilization is characterized by diffusion limitation and thus requires an efficient process that enhances the removal performance by increasing the polymer residence time and the transport specific area and by decreasing the partial pressure of the volatile components in the gas phase with the use a suitable stripping agent. A patented static devolatilization technology suitable for high viscous and thermal sensitive material is presented for two main applications named first stage and final stage processes. The different aspects of the polymerization and devolatilization technologies are presented through case studies. Each case is analyzed on the base of process performance improvements, polymer quality and/or process economics. The experimental work carried out on pilot scale and in the laboratory is presented and the process performances are studied as a function of selected process parameters

Synthesis of Hetero-nanoclusters: The Case of Polymer–Magnetite Systems

Nanoclusters (NCs) composed of nanoparticles (NPs) with different functionalities and having final size in the sub-micrometer range are of great interest for biomedical imaging, drug delivery, sensors, etc. Because some of the functionalities cannot be incorporated into a single NP, e.g., high drug loading combined with strong magnetic properties, here, we present a proof of the concept using an alternative way to combine these properties using different NPs. In particular, starting from polymer and magnetite nanoparticles (MNPs), we produce NCs made out of a statistical distribution of the two components through a process based on aggregation and breakup. The effect of all involved operating parameters, i.e., primary NP size and composition, surfactant type and concentration, and applied hydrodynamic stress on the NC size and internal structure, was systematically investigated using dynamic light scattering (DLS), static light scattering (SLS), and transmission electron microscopy (TEM) analyses. It was found that, by properly tuning the balance between attractive and steric repulsive forces on one side and hydrodynamic stress on the other, NCs as small as 100 nm can be produced. In all cases, the produced NCs have a very compact internal structure characterized by fractal dimension around 2.6. The proposed production strategy to synthesize hetero-NCs composed of mixtures of various primary particles is suitable for the production of multifunctional devices of nanometer size (i.e., approximately 100 nm) for material and biomedical applications

The roof wing opening system of the UAE pavilion at EXPO 2020

The UAE Pavilion will be a major attraction at Expo 2020 in Dubai. The roof of the building consists of 28 operable wings made of carbon and glass fiber, having masses ranging from 5 to 18 tons and total lengths in the range of 30 to 65 m that have to be actuated by a dedicated mechanism. In this paper we present the turn-key project for the design, manufacturing, installation, test and commissioning of the Roof Wing Opening System, which represents a unique system world-wide for operating the wings. It consists of one Hydraulic Power Unit with approximately 1 MW of installed power, 2 km of piping working at the nominal pressure of 210 bar, 46 hydraulic cylinders with 1.5 tons of mass each and the complete automation and control subsystem that includes 9 separate PLCs, dedicated software, 2.000 sensors and control points, and over 20 km of harness. One major challenge is the control of the wings. Part of them, due to their huge dimensions and masses, are actuated using two or three hydraulic cylinders that have to be properly synchronized during the movement, preventing unwanted displacements in order to avoid stresses on the wing mechanical structure and ultimately permanent damages. Due to the nature of the project, a final validation of the control algorithms can be done only at system level during the commissioning phase. Therefore, particular care has to be devoted to the verification strategy, anticipating the behavior of the system in the early validation stages and following a V-model approach, in order to identify critical situations and reduce the overall risk. After a brief system description, we will explain how the verification has been approached by using system level simulations and dedicated testing activities on specific subsystems. In particular, we will detail the verification of the control algorithms that has been performed on a dedicated Hardware-Inthe- Loop system first, followed then by dedicated tests on a reduced wing mock-up, allowing the study of the system behavior under the most critical conditions. These include the application of external forces with specified profiles. Finally, we will provide the actual status of the system installation, testing and commissioning activities that have been running in Dubai since January 2019