Pillared Sn-MWW Prepared by a Solid-State-Exchange Method and its Use as a Lewis Acid Catalyst

Pillared Sn-MWW (Sn-MWW(SP)-SSE) was prepared through a solid-state-exchange (SSE) route. The pillared structure was inherited from pillared B-MWW, and Sn was inserted in the framework by boron leaching and solid-state-exchange with tin tetrachloride pentahydrate. The Sn-MWW(SP)-SSE with framework Sn sites exhibits Lewis acidity and good catalytic performance for the Baeyer–Villiger oxidation, and mono- and disaccharide isomerizations

Pillared Sn-MWW Prepared by a Solid-State-Exchange Method and its Use as a Lewis Acid Catalyst

Pillared Sn-MWW (Sn-MWW(SP)-SSE) was prepared through a solid-state-exchange (SSE) route. The pillared structure was inherited from pillared B-MWW, and Sn was inserted in the framework by boron leaching and solid-state-exchange with tin tetrachloride pentahydrate. The Sn-MWW(SP)-SSE with framework Sn sites exhibits Lewis acidity and good catalytic performance for the Baeyer–Villiger oxidation, and mono- and disaccharide isomerizations

Composition of an innovative low-cost adsorbent for industrial scale substitution of activated carbon

In this PhD dissertation, the ability to synthesize innovative adsorbent material as a substitute for active carbon (trade) on an industrial scale is being studied.The adsorption method is of great research and practical interest since the removal of pigments and heavy metals is done by using appropriately selected biomass in a more environmentally friendly manner, with greater economic benefit for the processing plant (construction-operation-maintenance) And greater ease in handling the processing method.More specifically, the possibility of producing adsorbent materials from modified biomass was studied. These adsorbents were used to remove dyestuffs (such as Methylene Blue - Methyl Blue, MW) and heavy metals (such as hexavalent chromium, Cr (VI)) from industrial waste liquors.Στην παρούσα διδακτορική διατριβή μελετάται η δυνατότητα σύνθεσης καινοτόμου προσροφητικού υλικού ως υποκατάστατο του ενεργού άνθρακα (εμπορίου) σε βιομηχανική κλίμακα. Η μέθοδος της προσρόφησης παρουσιάζει μεγάλο ερευνητικό και πρακτικό ενδιαφέρον, εφόσον η απομάκρυνση των χρωστικών και των βαρέων μετάλλων γίνεται με τη χρήση κατάλληλα επιλεγμένης βιομάζας με τρόπο περισσότερο φιλικό προς το περιβάλλον, με μεγαλύτερο οικονομικό όφελος για τη μονάδα επεξεργασίας (κατασκευή-λειτουργία-συντήρηση) και μεγαλύτερη ευκολία στο χειρισμό της μεθόδου επεξεργασίας.Πιο συγκεκριμένα, μελετήθηκε η δυνατότητα παραγωγής προσροφητικών υλικών από τροποποιημένη βιομάζα. Αυτά τα προσροφητικά υλικά χρησιμοποιήθηκαν για την απομάκρυνση χρωστικών (όπως το Μπλέ του Μεθυλενίου - Μethylene Βlue, ΜΒ) και βαρέων μετάλλων (όπως το εξασθενές χρώμιο, Cr(VI)) από υγρά βιομηχανικού απόβλητα

Medical Waste Treatment Technologies for Energy, Fuels, and Materials Production: A Review

The importance of medical waste management has grown during the COVID-19 pandemic because of the increase in medical waste quantity and the significant dangers of these highly infected wastes for human health and the environment. This innovative review focuses on the possibility of materials, gas/liquid/solid fuels, thermal energy, and electric power production from medical waste fractions. Appropriate and promising treatment/disposal technologies, such as (i) acid hydrolysis, (ii) acid/enzymatic hydrolysis, (iii) anaerobic digestion, (vi) autoclaving, (v) enzymatic oxidation, (vi) hydrothermal carbonization/treatment, (vii) incineration/steam heat recovery system, (viii) pyrolysis/Rankine cycle, (ix) rotary kiln treatment, (x) microwave/steam sterilization, (xi) plasma gasification/melting, (xii) sulfonation, (xiii) batch reactor thermal cracking, and (xiv) torrefaction, were investigated. The medical waste generation data were collected according to numerous researchers from various countries, and divided into gross medical waste and hazardous medical waste. Moreover, the medical wastes were separated into categories and types according to the international literature and the medical waste fractions’ percentages were estimated. The capability of the examined medical waste treatment technologies to produce energy, fuels, and materials, and eliminate the medical waste management problem, was very promising with regard to the near future

Simulation and Optimization of Lignocellulosic Biomass Wet- and Dry-Torrefaction Process for Energy, Fuels and Materials Production: A Review

This review deals with the simulation and optimization of the dry- and wet-torrefaction processes of lignocellulosic biomass. The torrefaction pretreatment regards the production of enhanced biofuels and other materials. Dry torrefaction is a mild pyrolytic treatment method under an oxidative or non-oxidative atmosphere and can improve lignocellulosic biomass solid residue heating properties by reducing its oxygen content. Wet torrefaction usually uses pure water in an autoclave and is also known as hydrothermal carbonization, hydrothermal torrefaction, hot water extraction, autohydrolysis, hydrothermolysis, hot compressed water treatment, water hydrolysis, aqueous fractionation, aqueous liquefaction or solvolysis/aquasolv, or pressure cooking. In the case of treatment with acid aquatic solutions, wet torrefaction is called acid-catalyzed wet torrefaction. Wet torrefaction produces fermentable monosaccharides and oligosaccharides as well as solid residue with enhanced higher heating value. The simulation and optimization of dry- and wet-torrefaction processes are usually achieved using kinetic/thermodynamic/thermochemical models, severity factors, response surface methodology models, artificial neural networks, multilayer perceptron neural networks, multivariate adaptive regression splines, mixed integer linear programming, Taguchi experimental design, particle swarm optimization, a model-free isoconversional approach, dynamic simulation modeling, and commercial simulation software. Simulation of the torrefaction process facilitates the optimization of the pretreatment conditions

Simulating the Effect of Torrefaction on the Heating Value of Barley Straw

Many recent studies focused on the research of thermal treated biomass in order to replace fossil fuels. These studies improved the knowledge about pretreated lignocellulosics contribution to achieve the goal of renewable energy sources, reducing CO2 emissions and limiting climate change. They participate in renewable energy production so that sustainable consumption and production patterns can by ensured by meeting Goals 7 and 12 of the 2030 Agenda for Sustainable Development. To this end, the subject of the present study relates to the enhancement of the thermal energy content of barley straw through torrefaction. At the same time, the impact of the torrefaction process parameters, i.e., time and temperature, was investigated and kinetic models were applied in order to fit the experimental data using the severity factor, R0, which combines the effect of the temperature and the time of the torrefaction process into a single reaction ordinate. According to the results presented herein, the maximum heating value was achieved at the most severe torrefaction conditions. Consequently, torrefied barley straw could be an alternative renewable energy source as a coal substitute or an activated carbon low cost substitute (with/without activation treatment) within the biorefinery and the circular economy concept