Enhancing Water Purification by Integrating Titanium Dioxide Nanotubes into Polyethersulfone Membranes for Improved Hydrophilicity and Anti-Fouling Performance.

Water pollution remains a critical concern, one necessitated by rapidly increasing industrialization and urbanization. Among the various strategies for water purification, membrane technology stands out, with polyethersulfone (PES) often being the material of choice due to its robust mechanical properties, thermal stability, and chemical resistance. However, PES-based membranes tend to exhibit low hydrophilicity, leading to reduced flux and poor anti-fouling performance. This study addresses these limitations by incorporating titanium dioxide nanotubes (TiO2NTs) into PES nanofiltration membranes to enhance their hydrophilic properties. The TiO2NTs, characterized through FTIR, XRD, BET, and SEM, were embedded in PES at varying concentrations using a non-solvent induced phase inversion (NIPS) method. The fabricated mixed matrix membranes (MMMs) were subjected to testing for water permeability and solute rejection capabilities. Remarkably, membranes with a 1 wt% TiO2NT loading displayed a significant increase in pure water flux, from 36 to 72 L m2 h-1 bar-1, a 300-fold increase in selectivity compared to the pristine sample, and a dye rejection of 99%. Furthermore, long-term stability tests showed only a slight reduction in permeate flux over a time of 36 h, while dye removal efficiency was maintained, thus confirming the membrane's stability. Anti-fouling tests revealed a 93% flux recovery ratio, indicating excellent resistance to fouling. These results suggest that the inclusion of TiO2 NTs offers a promising avenue for the development of efficient and stable anti-fouling PES-based membranes for water purification.

Sequential Esterification-Diels-Alder Reactions for Improving Pine Rosin Durability within Road Marking Paint.

Pine rosin, which is derived from Pinus merkusii resin, a natural product, has demonstrated potential as a road marking binder. Although pine rosin has an excellent shinning property, it has some limitations, such as instability and color change. To tackle these issues, modified rosin has been developed through sequential esterification and Diels-Alder reactions, and it has shown better properties than untreated rosin. In this study, from the evaluation of untreated and treated rosins, the treated rosin showed some improvements, such as a lower acid value and higher stability, as shown by the color consistency during the oxidation test at 150 °C for 24 h in open-air conditions. Additionally, as road marking paint, the modified rosin is blended with blending materials in the range of 18-28 wt.%. The modified rosin has a softening point of 170-210 °C, a hardness of 50-71 HD, and a weight loss of 1.33-5.12 mg during the wearing test. These results are comparable to or better than those of commercially available road marking products.

Catalytic co-pyrolysis of oil palm trunk and polypropylene with Ni-Mo/TiO2 and Ni/Al2O3: Oil composition and mechanism.

Pyrolysis oil from oil palm biomass can be a sustainable alternative to fossil fuels and the precursor for synthesizing petrochemical products due to its carbon-neutral properties and low sulfur and nitrogen content. This work investigated the effect of applying mesoporous acidic catalysts, Ni-Mo/TiO2 and Ni/Al2O3, in a catalytic co-pyrolysis of oil palm trunk (OPT) and polypropylene (PP) from 500 to 700 °C. The obtained oil yields varied between 12.67 and 19.50 wt.% and 12.33-17.17 wt.% for Ni-Mo/TiO2 and Ni/Al2O3, respectively. The hydrocarbon content in oil significantly increased up to 54.07-58.18% and 37.28-68.77% after adding Ni-Mo/TiO2 and Ni/Al2O3, respectively. The phenolic compounds content was substantially reduced to 8.46-20.16% for Ni-Mo/TiO2 and 2.93-14.56% for Ni/Al2O3. Minor reduction in oxygenated compounds was noticed from catalytic co-pyrolysis, though the parametric effects of temperature and catalyst type remain unclear. The enhanced deoxygenation and cracking of phenolic and oxygenated compounds and the PP decomposition resulted in increased hydrocarbon production in oil during catalytic co-pyrolysis. Catalyst addition also promoted the isomerization and oligomerization reactions, enhancing the formation of cyclic relative to aliphatic hydrocarbon.

Investigation on the Redox Properties of a Novel Cu-Based Pr-Modified Oxygen Carrier for Chemical Looping Combustion.

CO2 levels in the atmosphere are growing as a result of the burning of fossil fuels to meet energy demands. The introduction of chemical looping combustion (CLC) as an alternative to traditional combustion by transporting oxygen emphasizes the need to develop greener and more economical energy systems. Metal oxide, also defined as an oxygen carrier (OC), transports oxygen from the air to the fuel. Several attempts are being made to develop an OC with a reasonable material cost for superior fuel conversion and high oxygen transport capacity (OTC). This study aims to synthesize a potential OC using the wet impregnation method for the CLC process. Thermogravimetric analysis (TGA) was used to determine the cyclic redox properties using 5% CH4/N2 and air as reducing and oxidizing gases, respectively. The 10CuPA-based OC retained a high OTC of about 0.0267 mg O2/mg of OC for 10 cycles that was higher than 10CuA-based OC. Furthermore, the oxygen transfer rate for 10CuPA-based OC was relatively higher compared to 10CuA-based OC over 10 cycles. In comparison to 10CuA-based OC, the 10CuPA-based OC presented a steady X-ray diffraction (XRD) pattern after 10 redox cycles, implying that the phase was stably restored due to praseodymium-modified γ alumina support.

Catalytic reforming of oxygenated hydrocarbons for the hydrogen production: an outlook.

The catalytic steam reforming of oxygenated hydrocarbons has been holding an interest in scientific societies for the past two decades. The hydrogen production from steam reforming of glycerol, ethanol and other oxygenates such as ethylene glycol and propylene glycol are more suitable choice not just because it can be produced from renewable sources, but it also helps to decrease the transportation fuel price and making it more competitive. In addition, hydrogen itself is a green fuel for the transportation sector. The studies on the production of hydrogen from various reforming technologies revealed a remarkable impact on the environmental and socio-economic issues. Researchers became more focused on glycerol steam reforming (GSR), ethanol steam reforming (ESR) and other oxygenates to investigate the catalyst suitability, their kinetics and challenges for the sustainability of the oil and gas production. In the present work, the authors critically addressed the challenges and strategies for hydrogen production via GSR, ESR and other oxygenates reforming process. This review covers extensively thermodynamic parametric analysis, catalysts developments, kinetics and advancement in the operational process for glycerol, ethanol and few other oxygenates. This detailed investigation only highlights the steam reforming process (SRP) of these oxygenates at the laboratory experimental stage. It was found that from this review, there are many technical issues, which lead to economic challenges. The issues are yet to be addressed and thus, these particular applications require faster accelerations at the pilot scale, taking into the consideration of the current pandemic and economic issues, for a safer and greener environment. Graphical abstract.

Development of Polyvinylidene Fluoride Membrane by Incorporating Bio-Based Ginger Extract as Additive.

Biofouling on the membrane surface leads to performance deficiencies in membrane filtration. In this study, the application of ginger extract as a bio-based additive to enhance membrane antibiofouling properties was investigated. The extract was dispersed in a dimethyl acetamide (DMAc) solvent together with polyvinylidene fluoride (PVDF) to enhance biofouling resistance of the resulting membrane due to its antibiotic property. The concentrations of the ginger extract in the dope solution were varied in the range of 0-0.1 wt %. The antibacterial property of the resulting membranes was assessed using the Kirby Bauer disc diffusion method. The results show an inhibition zone formed around the PVDF/ginger membrane against Escherichia coli and Staphylococcus aureus demonstrating the efficacy of the residual ginger extract in the membrane matrix to impose the antibiofouling property. The addition of the ginger extract also enhanced the hydrophilicity in the membrane surface by lowering the contact angle from 93° to 85°, which was in good agreement with the increase in the pure water flux of up to 62%.

X-ray diffraction and TGA kinetic analyses for chemical looping combustion applications.

Synthesis and characterization of supported metal-based oxygen carriers were carried out to provide information related to the use of oxygen carriers for chemical looping combustion processes. The Cu, Co, Fe, Ni metals supported with Al2O3, CeO2, TiO2, ZrO2 were prepared using the wetness impregnation technique. Then, the X-ray Diffraction (XRD) characterization of oxidized and reduced samples was obtained and presented. The kinetic analysis using Thermogravimetric analyzer (TGA) of the synthesized samples was conducted. The kinetics of reduction reaction of all samples were estimated and explained.

Development of oil-spill sorbent from straw biomass waste: Experiments and modeling studies.

The recovery of oil spilled on land or water has become an important issue due to environmental regulations. Canadian biomasses as fibrous materials are naturally renewable and have the potential to absorb oil-spills at different ranges. In this work, four Canadian biomasses were examined in order to evaluate their oil affinities and study parameters that could affect oil affinity when used as sorbent, such as average particle size, surface coating and reusability. Moreover, one oil sorption model was adopted and coupled with another developed model to approximate and verify the experimental findings of the oil sorbent biomasses. At an average particle size of 150-1000 µm, results showed that barley straw biomass had the highest absorbency value at 6.07 g/g, while flax straw had the lowest value at 3.69 g/g. Wheat and oat straws had oil absorbency values of 5.49 and 5.00 g/g, respectively. An average particle size of 425-600 µm indicated better absorbency values for oat and wheat straws. Furthermore, the thermal stability study revealed major weight recovery for two flame retardant coatings at hemicellulose and lignocellulose degradation temperature ranges. It was also found that oat straw biomass could be regenerated and used for many sorption/desorption cycles, as the reusability experiment showed only a 18.45% reduction in the oil absorbency value after six consecutive cycles. The developed penetration absorbency (PA) model showed oat straw adsorbed oil at the inter-particle level; and, the results of the sorption capacity model coupled with the PA model excellently predicted the oil sorption of raw and coated oat straws.

Characterization, thermochemical conversion studies, and heating value modeling of municipal solid waste.

A study was carried out to examine the characteristics of municipal solid waste (MSW) from the City of Red Deer, Alberta, Canada. Experiments were performed for determining the moisture content, proximate and ultimate compositions, heating value of fourteen wastes in different categories. Their thermal weight loss behaviors under pyrolysis/torrefaction conditions were also investigated in a thermogravimetric analyzer (TGA). An empirical model was developed for the high heating value (HHV) estimation of MSW. A total of 193 experimental data were collected from this study and those in the literature, of which 161 data were used for model derivation; and, 32 additional data were used for model validation. The model was developed using multiple regression analysis and a stepwise regression method: HHV (MJ/kg)=0.350C+1.01H-0.0826O, which is expressed in terms of weight percentages on a dry basis of carbon (C), hydrogen (H) and oxygen (O). The validation results suggest that this model was effective in producing accurate outputs that were close to the experimental values. In addition, it had the lowest error level in comparison with seven other models from the literature.