A modelling and optimization system for fluidized bed power plants

The energy production has nowadays several challenges. For example, new environmental legislation sets needs to reduce process emissions. However, emission reduction may also be a part of business in power plants arose from emission trading schemes, like The European Union Emissions Trading Scheme. In this paper we demonstrate an optimization and modelling system for fluidized bed power plants, which can be used in this new service business. The software contains four parts: (1) pre-processing, (2) variable selection and process lags, (3) modelling and (4) post-processing. In the post-processing part there are three applications, i.e. process state determination, process optimization and emission reporting. The modelling part is based on the self-organizing maps (SOM) with retrain properties. The software is programmed into standalone software built up in the Matlab platform. The results show that the software can offer an efficient tool to process optimization and also to a new type of service business.     

Ion exchange behaviour and charge compensation mechanism of polypyrrole in electrolytes containing mono-, di- and trivalent metal ions

The electrochemical quartz crystal microbalance technique was used to examine the ion exchange behaviour and charge compensation mechanism of polypyrrole (PPy) doped with polystyrene sulfonate (PSS) immersed in electrolytes containing singly, doubly and triply charged metal ions. New insights were obtained concerning the mechanism of charge compensation and ion exchange behaviour of PPy/PSS films in electrolytes with triply and doubly charged transition metal ions. Understanding the ion exchange behaviour of conducting polymers immersed in these types of aqueous media could play a pivotal part in the development of methods for removing toxic metals from water supplies. Charge compensation occurred predominantly by means of cation movement for PPy/PSS films when the electrolyte was KNO₃, Ca(NO₃)₂, Mn(NO₃)₂ or Co(NO₃)₂. After prolonged redox cycling the electroactivity of the polymer decreases slightly, and the charge compensation mechanism becomes complex owing to movement of ions and neutral species in opposite directions. The charge compensation mechanism for PPy/PSS films immersed in aqueous Cr(NO₃)₃ and Al(NO₃)₃ solutions was also complex, with the ion exchange behaviour shifting towards anion movement to and from the polymer.     

Hierarchically Ordered Supramolecular Protein-Polymer Composites with Thermoresponsive Properties

Synthetic macromolecules that can bind and co-assemble with proteins are important for the future development of biohybrid materials. Active systems are further required to create materials that can respond and change their behavior in response to external stimuli. Here we report that stimuli-responsive linear-branched diblock copolymers consisting of a cationic multivalent dendron with a linear thermoresponsive polymer tail at the focal point, can bind and complex Pyrococcus furiosus ferritin protein cages into crystalline arrays. The multivalent dendron structure utilizes cationic spermine units to bind electrostatically on the surface of the negatively charged ferritin cage and the in situ polymerized poly(di(ethylene glycol) methyl ether methacrylate) linear block enables control with temperature. Cloud point of the final product was determined with dynamic light scattering (DLS), and it was shown to be approximately 31 °C at a concentration of 150 mg/L. Complexation of the polymer binder and apoferritin was studied with DLS, small-angle X-ray scattering, and transmission electron microscopy, which showed the presence of crystalline arrays of ferritin cages with a face-centered cubic (fcc Fm3¯m) Bravais lattice where lattice parameter a = 18.6 nm. The complexation process was not temperature dependent but the final complexes had thermoresponsive characteristics with negative thermal expansion.     

Adsorption characteristics of clay adsorbents – sepiolite,kaolin and synthetic talc – for removal of Reactive Yellow 138:1

Adsorption characteristics of three clay adsorbents – sepiolite, kaolin and synthetic talc – were investigated to determine their applicability to remove an anionic reactive dye – Reactive Yellow 138:1 – from a water stream. Results showed that synthetic talc had the highest maximum monolayer adsorption capacity of 10.07 mg/g, followed by kaolin (3.73 mg/g) and sepiolite (3.23 mg/g), for the removal of Reactive Yellow 138:1. Synthetic talc and sepiolite removed dyes from aqueous solutions mainly through physical adsorption depending on the surface area. By contrast, the adsorption mechanism of kaolin was strongly influenced by the anion exchange mechanism. Zeta potential analysis revealed that the adsorption capacity of clay adsorbents increased under acidic rather than alkaline conditions, owing to protonation of the clay surface. Moreover, synthetic talc was successfully regenerated by heating at more than 400°C, effectively restoring its original adsorption capacity.