PYROLYSIS OF PINE WOOD SAWDUST IN THE PRESENCE OF NATURAL ALUMINOSILICATE-BASED CATALYSTS

Пиролиз лигноцеллюлозного сырья в ценные продукты является перспективным направлением для переработки отходов деревообрабатывающей промышленности и для получения энергоносителей. Поиск катализаторов, обеспечивающих максимальный выход и теплоценность получаемых продуктов, - это актуальный вопрос в развитии технологии пиролиза. В данной работе были проведены исследования по влиянию катализаторов на основе природных алюмосиликатов на пиролиз сосновых опилок. Было найдено, что катализатор Ni-Red Clay оказывает наибольшее влияние на процесс термодеструкции сосновых опилок, приводя к увеличению выхода жидких и газообразных продуктов пиролиза. Pyrolysis of lignocellulose feedstock into valuable products is a promising direction for processing waste from the woodworking industry and for obtaining energy carriers. The search for catalysts that provide the maximum yield and heat value of the products obtained is an urgent issue in the development of pyrolysis technology. In this paper, studies on the effect of catalysts based on natural aluminosilicates on the pyrolysis of pinewood sawdust were carried out. It was found that the Ni-Red Clay catalyst has the highest influence on the process of thermal degradation of pinewood sawdust, leading to an increase in the yield of liquid and gaseous pyrolysis products.

Visible-Light Enhanced Catalytic Wet Peroxide Oxidation of Natural Organic Matter in the Presence of Al/Fe-Pillared Clay

An Al/Fe-pillared clay catalyst (Al/Fe-PILC) prepared from low cost technical-grade reagents has been investigated in the photocatalytic Wet Peroxide Oxidation (photo-CWPO) of dissolved Natural Organic Matter (NOM) under circumneutral pH. The successful pillaring of the layered clay material was confirmed by X-ray diffraction (XRD), N2 adsorption at −196 °C, cation exchange capacity (CEC) and simultaneous thermal analysis (TGA/DSC). High levels of mineralization of the dissolved organic carbon and color removal of a synthetic NOM surrogate solution were achieved even under natural lab’s lighting and ambient temperature and pressure, whereas the absence of radiation (in dark) was found to strongly affect the performance of the degradation. The photo-CWPO of NOM activated by the Al/Fe-PILC clay catalyst under visible light irradiation (LED lamp, 450 and 550 nm peaks) displayed a DOC mineralization of 72% and color removal of 73% in just 210 min of irradiation at neutral pH, whereas both responses decayed under ultraviolet lightning (λ: 365 nm) to 41% and 58%, respectively. This behavior is ascribed to formation of triplet states of natural organic matter (3NOM*) by absorption of visible light, which seems to synergistically improve the rate-determining step of the heterogeneous Fenton process, namely reduction of Fe3+ into Fe2+ on the surface of the clay catalyst. Interestingly, experiments performed at neutral and pH 3.0 showed very similar efficiencies under visible light irradiation; these findings may really facilitate the application of the photo-CWPO process to assist conventional drinking water treatment plants in the removal of NOM before the typical disinfection by chlorine to produce safer drinking water.

Activation of Nano Kaolin Clay for Bio-Glycerol Conversion to a Valuable Fuel Additive

High production of biodiesel results in a surplus of glycerol as a byproduct that leads to a drastic decline in the glycerol price as well as overall biodiesel production. Alternative methods must be introduced for the economical process for biodiesel production via utilization of crude glycerol into valuable chemicals or fuel additives. This study introduces an ecofriendly process of solketal synthesis from glycerol and acetone in the presence of a novel metakaolin clay catalyst, which is a useful additive in biodiesel or gasoline, in order to enhance the octane number and to control the emissions. Moreover, kaolin clay catalysts are low cost, abundantly available, eco-friendly and one of the more promising applications for solketal synthesis. In this study, raw kaolin clay was activated with an easy acid activation technique, modification in physicochemical and textural properties were determined by using X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) and Field Emission Scanning Electron Microscope. Among all acid-treated catalysts, metakaolin K3 have shown best catalytic properties, high surface area and pore size after acid activation with 3.0 mol/dm3 at 98 °C for 3 h. Acetalization of glycerol with acetone carried out in the presence of an environmentally friendly and inexpensive novel metakaolin K3 catalyst. The maximum yield of solketal obtained was 84% at a temperature of 50 °C, acetone/glycerol molar ratio 6/1 and for 90 min with novel metakaolin clay catalyst. Effect of various parameters (time, temperature, acetone/glycerol molar ratio, catalyst loading) on the solketal yield and glycerol conversion was discussed in detail. This approach offers an effective way to transform glycerol into solketal—a desirable green chemical with future industrial applications.

Direct Synthesis and Characterization of Photo-Crosslinkable Biodegradable PLA-PEG-PLA Ttiblock Copolymer with Methacrylates Functions by Green Montmorillonite Clay Catalyst

Di-methacrylated PLA-PEG-PLA triblock copolymers of polylactide and polyethylene glycol were synthesized in one-step process by bulk cationic polymerization of lactide in the presence of PEG with different average molecular weights, using Maghnite-H+, an acidic montmorillonite clay, as a solid non-toxic catalyst. The obtained di-methacrylated copolymer was analyzed by 1H NMR and DSC. The effect of Maghnite-H+ proportions and PEG average molecular weight on the copolymerization and methacrylation yields and on average molecular weight of the resulting copolymers was studied.