Today, the overall occurrence of re-emerging and rising illnesses has been a serious load on economies as well as public health. Here, we describe a simple, nontoxic and eco-friendly method for the synthesis of milk protein (MP)-stabilized silver nanoparticles (MP-s-AgNPs) using ultrahigh-temperature full cream milk. Highly stable AgNPs were prepared with a fair control over their size, without using any reducing or stabilizing agent, and their formation was attributed to the presence of the MP casein. Ag⁺ ion reduction was possibly caused by the MPs. The synthesized MP-s-AgNPs were characterized in detail by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and dynamic light scattering. MP-s-AgNPs showed inhibitory activity against both Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative microorganisms (Salmonella typhi and Escherichia coli). Moreover, MP-s-AgNPs were found to be more toxic to bacteria than to fungi (Aspergillus fumigatus, Aspergillus ochraceus and Penicillium chrysogenum).

Synthetic natural gas (SNG) using syngas from coal and biomass has attracted much attention as a potential substitute for fossil fuels because of environmental advantages. However, heating value of SNG is below the standard heating value for power generation (especially in South Korea and Japan). In this study, bimetallic Co-Fe catalyst was developed for the production of light paraffin hydrocarbons (C₂–C₄ as well as CH₄) for usage as mixing gases to improve the heating value of SNG. The catalytic performance was monitored by varying space velocity, reaction pressure and temperature. The CO conversion increases with decrease in space velocities, and with an increase in reaction pressure and temperature. CH₄ yield increases and C₂₊ yield decreases with increasing reaction temperature at all reaction pressure and space velocities. In addition, improved CH₄ yield at higher reaction pressure (20 bar) implies that higher reaction pressure is a favorable condition for secondary CO₂ methanation reaction. The bimetallic Co-Fe catalyst showed the best results with 99.7% CO conversion, 36.1% C₂–C₄ yield and 0.90 paraffin ratio at H₂/CO of 3.0, space velocity of 4000 mL/g/h, reaction pressure of 20 bar, and temperature of 350 °C.

Fe-Ni and Co-Fe-Ni catalysts were prepared by the wet impregnation method for the production of high-calorific synthetic natural gas. The influence of Ni addition to Fe and Co-Fe catalyst structure and catalytic performance was investigated. The results show that the increasing of Ni amount in Fe-Ni and Co-Fe-Ni catalysts increased the formation of Ni-Fe alloy. In addition, the addition of nickel to the Fe and Co-Fe catalysts could promote the dispersion of metal and decrease the reduction temperature. Consequently, the Fe-Ni and Co-Fe-Ni catalysts exhibited higher CO conversion compared to Fe and Co-Fe catalysts. A higher Ni amount in the catalysts could increase C₁–C₄ hydrocarbon production and reduce the byproducts (C₅₊ and CO₂). Among the catalysts, the 5Co-15Fe-5Ni/γ-Al₂O₃ catalyst affords a high light hydrocarbon yield (51.7% CH₄ and 21.8% C₂–C₄) with a low byproduct yield (14.1% C₅₊ and 12.1% CO₂).

This study presents the synthesis and characterization of non-isocyanate polyurethanes (NIPU) derived from the copolymerization of cyclic-carbonated soybean oil (CSBO) and cyclic carbonate (CC)-terminated poly(ether carbonate) (RCC). Using a double-metal cyanide catalyst, poly(ether carbonate) polyol was first synthesized through the copolymerization of carbon dioxide and propylene oxide. The terminal hydroxyl group was then subjected to a substitution reaction with a five-membered CC group using glycerol-1,2-carbonate and oxalyl chloride, yielding RCC. Attempts to prepare NIPU solely using RCC and diamine were unsuccessful, possibly due to the low CC functionality and the aminolysis of RCC’s linear carbonate repeating units. However, when combined with CSBO, solid NIPUs were successfully obtained, exhibiting good thermal stability along with enhanced mechanical properties compared to conventional CSBO-based NIPU formulations. Overall, this study underscores the potential of leveraging renewable resources and carbon capture technologies to develop sustainable NIPUs with tailored properties, thereby expanding their range of applications.

We have developed a facile and sustainable method to produce a novel θ-Al₂O₃-supported CuCl adsorbent through impregnation methods using CuCl₂ as the precursor. In an easy two-step process, θ-Al₂O₃ was impregnated with a known concentration of CuCl₂ solutions, and the precursor was calcined to prepare CuCl oversupport. The developed novel θ-Al₂O₃-supported CuCl adsorbent was compared with an adsorbent prepared through the conventional method using CuCl salt. The adsorbents were characterized via X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and temperature-programmed reduction (H₂-TPR). Overall, the adsorbent indicates a high CO adsorption capacity, high CO/CO₂ and CO/N₂ selectivity, and remarkable reusability performance. This process is operated at ambient temperature, which minimizes operation costs in CO separation processes. In addition, these results indicate that the systematic evaluation of alumina-supported CuCl adsorbent can provide significant insight for designing a realistic PSA process for selective CO separation processes.

In this study, hydrogen was recovered and purified by using a membrane contactor unit from CO₂-rich gas without the use of any basic chemicals such as amines. The membrane operational parameters were adjusted to achieve high CO₂ removal and H₂ recovery. The effects of gas flow rate, pressure, gas composition (CO₂/H₂ ratio), pressure difference between liquid and gas, and gas/liquid ratio on CO₂ removal and H₂ recovery were investigated. Depending on the gas flow rate, the contact time between gas and liquid could be controlled, changing the absorption amounts of CO₂ and H₂. Regarding gas composition, an increase in the CO₂/H₂ ratio from 0.25 to 1 boosted H₂ recovery. Furthermore, increasing the CO₂/H₂ ratio above 1 (from 1 to 3) generally reduced H₂ recovery from 98.7% to 83%. Additionally, supplementation with the optimal amount of additive enhanced CO₂ removal and H₂ recovery. Thus, using a membrane contactor system results in high CO₂ removal (82.7–93.5%) and H₂ recovery (91.5–98.7%). Moreover, H₂ production and separation can be performed in one system, implying that CO₂ removal can be performed more efficiently by the membrane contactor. This study offers a new and promising route for producing high-purity H₂ while removing CO₂.