High Value-added Products Research Articles

Hollow AMn2O4-δ (A = Co, Zn, Ni) nanotube for direct photo-oxidation of methane to C1 and C2 alcohols at atmospheric pressure and room temperature

Methane (CH4) conversion is brought into research hotspot in the field of environment, and direct photo-oxidation of methane into C1 and C2 alcohols under moderate conditions remains a huge challenge. Herein, we report a series of hollow AMn2O4-δ (A = Co, Zn, Ni) spinel nanotubes (HNTs) for the direct photo-oxidation of methane (DPOM) reaction. The results of catalytic performance demonstrated that the CH4 conversion and the yields of high value-added liquid products arrange in order of ZnMn2O4-δ HNTs > CoMn2O4-δ HNTs > NiMn2O4-δ HNTs. The ZnMn2O4-δ HNTs exhibited a superior CH4 conversion of 53.9 %, a liquid product yield of 241.7 μmol g−1h−1 (CH3OH 40.1 μmol g−1h−1, CH3CH2OH 200.9 μmol g−1h−1) and a selectivity of 100 % under light irradiation at atmospheric pressure and room temperature conditions. Xray photoelectron spectroscopy (XPS) and low-temperature electron paramagnetic resonance (EPR) analysis showed that the substitution of Zn ion at the A-site of manganate spinel significantly improved surface chemisorbed oxygen (Oα) and oxygen vacancy activity, which were beneficial to the formation of •CH3. Multi-technology photocatalytic activity characterizations results showed that ZnMn2O4-δ HNTs possessed a narrower band gap and greatly favored the separation of photogenerated carriers. Moreover, the DPOM reaction mechanism involving the formation and dehydrogenation of alkyl and alkoxy intermediates was proposed over AMn2O4-δ (A = Zn, Co, Ni) HNTs, which was investigated through temperature-programmed desorption of CH4 (CH4-TPD), in situ EPR, in situ Fourier transform infrared spectroscopy (FT-IR) and density functional theoretical (DFT) calculations. It emphasized that CH3OH was formed via the combination of •CH3 and •OH. And it was more inclined to generate CH3CH2OH through the intermediates *CH2CH3/*CH3O. This study could broaden the avenue toward the application of manganese-based spinel in the direct photo-oxidation of methane into alcohols and offer a disparate perspective on the role of the substitution of metal ion at the A-site in enhancing the photocatalytic performance.

Valorisation of waste activated sludge for protease production by Bacillus licheniformis

Waste activated sludge (WAS) is the main by-product of wastewater treatment plants. Its management is considered one of the major environmental challenges worldwide, due to the large volume generated, along with the presence of pathogens and hazardous substances. Nevertheless, the biopolymers present in its structure can make it a promising source of nutrients to obtain high value-added products. Therefore, this study is focused on the use of WAS as a renewable feedstock to produce proteases by Bacillus licheniformis. To this end, both thermal hydrolysis (TH) and wet oxidation (WO) were evaluated as strategies for the solubilization of the valuable compounds. The results revealed that an operation time of 90 min (at 140 °C) was optimal for both pretreatments, which allowed obtaining concentrations of carbohydrates, proteins and humic acids up to 2.7 ± 0.1 g/L, 5.3 ± 0.1 g/L and 5.1 ± 0.1 g/L, respectively. Regarding bioconversion processes, the initial pH of the medium significantly influenced the assimilation of the biopolymers, bacterial growth and enzyme biosynthesis. In this sense, a pH of 5.5 for the WAS pretreated by TH (WAS-TH) and 7.5 for the WAS pretreated by WO (WAS-WO) allowed maximizing the proteolytic activities, reaching values of 767 ± 2 U/mL and 838 ± 6 U/mL, respectively. Additionally, higher initial inoculation levels positively influenced the performance of the fermentative process. Consequently, a 30 % inoculum resulted in enzymatic activities of 828 ± 11 U/mL for WAS-TH and 903 ± 4 U/mL for WAS-WO. Partial purification of the medium with ammonium sulphate increased the enzymatic activity by 7 times for WAS-TH and 3 times for WAS-WO.

Rhodium-Catalyzed One-Carbon Ring Expansion of Aziridines with Vinyl-N-triftosylhydrazones for the Synthesis of 2-Vinyl Azetidines.

Azetidines, being four-membered N-heterocycles, possess significant potential in contemporary medicinal chemistry owing to their favorable pharmacokinetic properties. Regrettably, the incorporation of functionalized azetidines into pharmaceutical lead structures has been impeded by the absence of efficient synthetic methods for their synthesis. In this study, a Rh-catalyzed one-carbon ring expansion of aziridines with vinyl-N-triftosylhydrazones is presented, which facilitates the synthesis of high value-added 2-alkenyl azetidine products. This research represents the first example of ring expansion of aziridines enabled by vinyl carbenes. Additionally, a one-pot two-step protocol, initiated from cinnamaldehyde, was successfully achieved, offering a step-economical and facile approach for the synthesis of these compounds. The pivotal aspect of this successful transformation lies in the in situ formation of an alkenyl aziridinium ylide intermediate. Experimental investigations, coupled with computational studies, suggest that a diradical pathway is involved in the reaction mechanism.

Valorization of waste paper sludge as a sustainable source for packaging applications

Paper sludge consists mainly of wet short cellulose fibers that are lost during papermaking and of residual chemicals used in the manufacturing process that remain dissolved in the water. Each ton of paper generates about 40–50 kg of dry sludge, of which 70% is primary sludge. Paper production, which exceeded 400 million tons globally in 2020, generates vast volumes of solid waste. Primary sludge is usually fiber-rich and hence suitable to be recycled back into the papermaking process. However, if the sludge is to be disposed of in landfills, sustainable practices must be developed in order to recover the fibers as they are valuable source for manufacturing high value-added products. This study investigates the valorization of paper sludge discarded by a filter paper manufacturer, with the purpose of producing cellulose acetate films for food packaging. The process involves recovering cellulose fibers from the sludge, purifying them and through acetylation reaction produce cellulose acetate films. FTIR spectra confirmed successful acetylation of fibers and also that acetyl groups reduced the hydrophilicity of cellulose—the contact angle was increased to over 80° from 50° in native cellulose. The films exhibited very good water barrier properties at both 50% and 90% relative humidity (RH).Graphical abstract

Production and Characterization of Bio-Oil from Cassava Peel

Agroindustrial residues are biomass of interest as they are energy sources and bioproducts with lower environmental impacts than traditional fossil fuels. Pyrolysis has been used to convert residual biomass into higher value-added products such as bio-oil. This work aimed to pyrolyze cassava peels to produce bio-oil and characterization using chromatographic techniques to obtain essential compounds for the chemical industry, adding value to this residue. The pyrolytic process generated 17.5% of bio-oil, with a high concentration of phenols and alcohols. Thus, this residual biomass has potential for industrial use, reducing the environmental impact of its deposit in landfills and offering industrial and economic benefits.

Exploring the potential of chitin and chitosan extracted from shrimp shell waste in enhancing urea-formaldehyde wood adhesives

This work aims to investigate the properties of both chitin (CT), and chitosan (CS) extracted from shrimp shell waste (SSW) and its potential use for the improvement of urea-formaldehyde (UF) based adhesives in particleboards manufacturing. For this purpose, characterization techniques (SEM, ATR-FTIR, XRD, and TGA/DTG) were used to confirm the successful extraction of CT and CS. The effect of different ratios of 4, 6, 8, and 10 wt% of CT and CS, on the ultimate particleboard’s mechanical properties (dry internal bond (IB), modulus of rupture (MOR), modulus of elasticity (MOE) and surface soundness (SS)) was investigated, and compared to the European Standards. It was evidenced that the optimal formulation of adhesives is (92:8; w:w) for both UF:CT and UF:CS leading to higher mechanical performance. For instance, MOE was uplifted to 3478 and 3568 MPa, and MOR was uplifted to 21 and 22 MPa, with the loading of CT and CS respectively, compared to MOE = 2579 MPa and MOR = 16 MPa for the particleboard glued with only UF adhesive. Moreover, when 8 wt% of CT and CS are formulated with UF adhesive, the formaldehyde emission from particleboard was reduced significantly about 36.11 and 37.18%, respectively. The addition of 8 wt% CT and CS exhibited a decrease in the values Thickness Swelling (TS) and Water Adsorption (WA) of the particleboards, highlighting the improvement of the physical properties of the final products. This study aims to promote the use of shrimp shell waste in the development of high added value products in wood urea-formaldehyde based adhesives.

Electrospun polymeric nanohybrids with outstanding pollutants adsorption and electroactivity for water treatment and sensing devices

Graphene oxide (GO) and carbon nanotubes (CNTs) were loaded at different mutual ratios into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) matrix and electrospun to construct mats that were assessed as smart sorbents for decontaminating water from methylene blue (MB) pollutant, while ensuring the additional possibility of detecting the dye amounts. The results revealed that sorption capacity enhances upon increasing GO content, which is beneficial to wettability and active area. Equilibrium adsorption of these materials is precisely predicted by the Langmuir isotherm model and the maximum capacities herein achieved, ranging from 120 to 555 mg/g depending on the formulation, are higher than those reported for similar systems. The evolution of the structure and properties of such materials as a function of dye adsorption was studied. The results reveal that MB molecules prompted the increase of electrical conductivity of the samples in a dose-dependent manner. Mats containing solely CNTs, while displaying the worst sorption performance, showed the highest electrical performances, displaying interesting changes in their electrical response as a function of the dye amount adsorbed, with a linear response and high sensitivity (309.4 µS cm−1 mg−1) in the range 0–235 µg of dye adsorbed. Beyond the possibility to monitor the presence of small amounts of MB in contaminated water and the saturation state of sorbents, this feature could even be exploited to transform waste sorbents into high-added value products, including flexible sensors for detecting low values of pressure, human motion, and so on.Graphical Multifunctional materials for dye absorption and detection, pressure sensing, fabricated by integrating GO and CNTs into PVDF-HFP matrix via electrospinning.

Assessing the application of marine microalgae Dunaliella salina in a biorefinery context: production of value‐added biobased products

AbstractMicroalgae are a rich source of bioactive compounds such as pigments, carbohydrates, lipids, proteins, and other substances of interest. Thus, given the possible variety of products that can be obtained from them, it is important to determine their biochemical composition, taking into consideration the species and cultivation conditions, so that they can be used as feedstock in biorefineries, with the aim of using all the biomass in the biorefining processes and increasing its economic viability. This work aimed to characterize the biochemical composition of the microalgae Dunalliela salina in a multi‐product biorefinery context, focusing on the production of high value‐added compounds such as pigments and biofuels. The biomass concentration obtained was 1.15 g·L−1 and the volumetric productivity was 164.28 mg·L−1·day−1, providing fractions of 23.86 ± 0.24% of lipids, 10.80 ± 0.86% of carbohydrates, and 5.71 ± 0.50% of proteins. The microalgal biomass contained pigment concentrations of 0.896 and 0.5380 mg·g−1of chlorophylls a and b, and 0.2043 mg·g−1 of total carotenoids. Thus, the data suggest that D. salina has biotechnological potential for application in integrated multi‐product biorefineries, focused on obtaining energy and high added value products simultaneously.

Exploiting High Voltage Fragmentation to Enable Demand-Driven Recycling of End-of-Life Wind Blades

In recent years, the number of installations of wind turbines significantly increased, driven by the necessity for a transition to a sustainable economy to achieve EU goals of carbon neutrality. However, considering their life of 20-25 years, it is urgent to fnd innovative solutions for End-of-Life (EoL) treatment. Among their components, one of the most critical elements is the blade, made in composites, particularly glass fiber reinforced plastics (GFRP). Currently, EoL wind blades are going to disposal (where possible), incineration, or they are used in low-value applications, mainly due to uncontrolled mechanical recycling processes, which result in the reduction of their mechanical properties, limiting their reuse in high-added value products. High-Voltage Fragmentation (HVF) is an innovative technology that creates localized shockwaves at the interface between two different materials through the generation of electric discharges within a product. This study focuses on the application of HVF to EoL wind blades. Experimental results demonstrate that this technology can act as a feasible recycling solution, both to remove impurities and to recycle GFRP, as a highly-controlled shredding process. This opens up interesting prospects for the reuse of the material itself in high-quality, high-added value products, following a demand-driven approach.

Photo-, electro-, and photoelectro-catalytic conversion of glucose into high value-added products

Recent advances in photo-, electro-, and photoelectro-catalytic conversion of glucose to high value-added products are highlighted.

ПОТЕНЦІАЛ ТА ПЕРСПЕКТИВИ РОЗВИТКУ АГРАРНОГО СЕКТОРУ УКРАЇНИ В УМОВАХ ВОЄННОГО СТАНУ

The article studies the potential and prospects of development of the agricultural sector of Ukraine, taking into account the conditions and consequences of the martial law. It is established that the war has caused a number of crisis phenomena in the Ukrainian economy, negatively affecting the state of the Ukrainian agricultural sector and its export capacity. In 2022, Ukrainian agricultural exports in dollar terms decreased by 16% compared to 2021, and by another 7% in 2023. The war has caused changes in the regional structure of Ukrainian exports. The reason for these changes was the blockade of Black Sea ports and the need to establish alternative shipment routes. Logistics costs have increased by an average of 5 times, while prices for agricultural products in the domestic market have fallen. In addition, the agricultural sector is significantly affected by labour shortages. In 2024, compared to 2021, the number of working-age people in Ukraine decreased by 40% due to extremely complex demographic processes. However, Ukraine's agricultural sector has significant potential for development due to: favourable natural and climatic conditions and fertile soils; favourable geographical location and proximity to major markets; availability of skilled labour and scientific and technical potential; and opportunities for innovation and digitalisation in agriculture. The main promising areas for developing the potential of Ukraine's agricultural sector: 1. Diversification of production – expanding the range of crops and products, including organic and high value-added products. 2. Implementation of innovations and digitalisation – application of the latest technologies, precision farming, and robotics to improve production efficiency. 3. Development of agricultural infrastructure - modernisation of elevators, warehouses, and logistics for storage and transportation of products. 4. Government support and regulation – preferential taxation, access to finance, investment incentives, and the fight against corruption. 5. Greening and sustainable development – implementation of environmentally friendly technologies, rational land use, environmental protection.

Selective electrooxidation of 5-hydroxymethylfurfural to 5-formyl-furan-2-formic acid on non-metallic polyaniline catalysts: structure-function relationships.

The biomass-derived HMF oxidation reaction (HMFOR) holds great promise for sustainable production of fine chemicals. However, selective electrooxidation of HMF to high value-added intermediate product 5-formyl-furan-2-formic acid (FFCA) is still challenging. Herein, we report the electrocatalytic HMFOR to selectively produce FFCA using carbon paper (CP) supported polyaniline (PANI) as a catalyst. The PANI/CP non-metallic hybrid catalyst with moderate oxidation capacity exhibitsoptimized FFCA selectivity up to 76% in alkaline media, which has reached the best performance in reported literature studies. Identification and quantification of active sites for the HMFOR are further realized via linking the activity to structural compositions of PANI; both polaronic-type nitrogen (N3) and positively charged nitrogen (N4) species are proved responsible for adsorption and activation of HMF, and the intrinsic activity of N4 is higher than that of N3. The present work provides new physical-chemical insights into the mechanism of the HMFOR on non-metallic catalysts, paving the way for the establishment of structure-function relations and further development of novel electrochemical synthesis systems.

Investigation on 3D printing of shrimp surimi under different printing parameters and thermal processing conditions

Improving the printing accuracy and stability of shrimp surimi and finding appropriate printing parameters and suitable thermal processing method can help to develop high value-added 3D printing products of shrimp surimi. It was found that in order to make the 3D printing products of shrimp surimi have higher printing adaptability (printing accuracy and printing stability reach more than 97%), by choosing nozzle diameter of 1.20 mm and setting the printing height of the nozzle to 2.00 mm, the layers of the printed products were better fused with each other, and the printing accuracy of the products could be greatly improved; there was no uneven discharge and filament breakage when the nozzle moved at the speed of 30 mm/s; and the products were internally compact and had good stability when the printing filling rate was 80%. In addition, the deformation rates of steamed, boiled and deep-fried shrimp surimi products were significantly higher than those of oven-baked and microwaved shrimp surimi products (P < 0.05). Microwave heating had a greater effect on the deformation and color of shrimp surimi products, and was not favored by the evaluators. In terms of deformation rate, sensory score, and textural characteristic, the oven-baked thermal processing method was selected to obtain higher sensory evaluation scores and lower deformation rates of shrimp surimi 3D printed products. In the future, DIY design can be carried out in 3D printing products of shrimp surimi to meet the needs of different groups of people for modern food.

Electrochemically synthesized Ce-doped Cu-mesh catalyst with high activity and stability towards HMF to FDCA conversion

The electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to high value-added downstream products is a sustainable and cost-effective strategy.

Coupling electrochemical CO2 reduction with value-added anodic oxidation reactions: progress and challenges

This review presents recent advances and future challenges of emerging and potential alternative anodic reactions with high energy-efficiency and value-added products in overall CO2 electrolysis.

A novel green biorefinery strategy for corn stover by pretreatment with weak alkali-assisted deep eutectic solvents

The strategy using deep eutectic solvent–sodium bicarbonate (DES–SB) has achieved a high delignification efficiency, excellent carbohydrate digestibility (glucose yield, 97.47%; xylose yield, 92.93%), and regenerated lignin with great potential.

Valorisation of food waste with distinct carbon-to-nitrogen ratios by the microalga Isochrysis galbana: laboratory demonstration and techno-economic assessment

Valorization of food waste with varying C/N ratios through microalgal cultivation for the tailored production of high value-added products.

Enhancement of the flavor and functional characteristics of cod protein isolate using an enzyme-microbe system.

Cod protein isolate (CPI), a by-product of the cod processing industry, represents a novel source of high value-added products. However, off-flavors in cod protein such as bitterness and fishy odor reduce its acceptability to consumers. Here, CPI was first debittered using aminopeptidase from Streptomyces canus (ScAPase) and then deodorized through probiotic fermentation. This is the first reported demonstration of complete removal of the bitterness of CPI using ScAPase. Subsequently, Syn3 and Syn4, as aromatic CPI (ACPI), were prepared from debittered CPI (DCPI) via fermentation with Lactobacillus acidophilus and Bifidobacterium longum, respectively. These products, DCPI and ACPI, were characterized by the absence of bitterness and fishy odor, along with a strong aromatic scent and high overall acceptability. Additionally, these products exhibited improved physicochemical properties, including enhanced oil-holding capacity, emulsifying activity, and resistance to digestion, compared to untreated CPI. However, significant differences were observed in their radical scavenging activities. The highest scavenging activity was detected in Syn3 against DPPH˙ (63.5%) and ˙OH (79.2%), in DCPI against O2- (32.0%), and in post-digestion Syn4 against ABTS˙+ (95.2%). Furthermore, after digestion treatment, these products significantly promoted the proliferation of probiotics. Notably post-digestion Syn4 showed the most substantial proliferation effect on Lactobacillus reuteri, Lactobacillus rhamnosus, and Bifidobacterium breve compared to other post-digestion samples. These results indicate that the treated CPI has the potential for applications in health food products.

Engineering Uranyl Sites into MOF for the Efficient and Highly Selective Photocatalytic CO2 Reduction†

Utilizing sunlight for photocatalytic reduction of CO2 to CO and other high value-added products represents a pivotal strategy for the environment protection and energy crisis mitigation. Herein, we have designed...

Стимулювання високотехнологічного експорту як основа стратегії повоєнного відновлення української економіки

The aim of the article is to assess the export activity of Ukraine and determine its role in the conditions of the ongoing war and post-war recovery of the national economy. Economic growth rates are higher in countries that are deeply integrated into global value chains, have a more diversified export structure, and focus on the quality of their own exports. In the pre-war period, Ukrainian exporters had a number of internal (difficulties in accessing financing for the production and sale of export products, low level of production technologies, non-compliance of national products with the technical requirements and standards of the world market, burdensome border crossing procedures, corruption, etc.) and external problems (unstable conditions in foreign markets of raw materials), which negatively affected the results of export activity. A sharp decline in Ukrainian exports during the wartime is caused by restrictions on production, financial, technological, and human resources resulting from the physical destruction of enterprises and logistics infrastructure, the loss of part of the workforce due to an increase in mortality and its outflow abroad, a decrease in income due to an unprecedented decline in business activity and production efficiency, the inability to insure war risks, etc. According to the experience of South Asian countries, which are now leaders in terms of high-tech exports (Hong Kong, Vietnam, Singapore, South Korea), changes in the commodity structure of exports by reducing the volume of raw materials and increasing the share of high-tech goods, as well as IT services, can become the basis for preserving the Ukrainian economy during the war and the post-war recovery, which requires stimulating scientific and technical research and development by increasing investment in innovation areas, the State support for exporters of high value-added products.