Sustainable Chemistry for Climate Action最新文献

Valorisation of industrial biomass wastes, such as oil palm empty fruit bunch (EFB) generated by the palm oil industry, could promote its sustainable use while minimising the adverse impacts on the environment. To this end, the present study attempted to synthesize lignin from EFB. A simple yet environmentally friendly technique, ultrasonication, has been employed to convert the isolated lignin to lignin nanoparticles (LNPs). The transmission electron microscopy results and dynamic light scattering measurements have confirmed the mean particle size of LNPs at 220 nm. Also, LNPs showed better thermal performance compared to lignin, as indicated by a higher glass transition and maximum degradation temperature. LNPs were stable in the pH range of 4.5 - 9.0 and sodium chloride concentration below 100 mM over a week of storage. At pH 7, the LNP suspension remains stable without precipitation for up to three months of storage under ambient conditions. In addition, the LNPs were incorporated into the starch matrix to form biocomposites and then compared against lignin biocomposites and neat starch film for their thermal, mechanical, and hydrophobic performance. The biocomposites with LNPs are anticipatedly possessing better performance than the neat starch film and lignin biocomposites in all aspects.

Bio-based fertilisers (BBFs) aim to reduce the European Union's (EU) dependence on imported mineral fertilisers by recycling and reusing nutrient-rich by-streams. However, implementation can be very complex, and the right policies must be delivered to optimize BBFs' production-consumption flows. This study seeks a new perspective for policymakers by understanding current policies and reviewing previous studies on BBFs' implementation. Data collection from the researchers' database plus additional information from the "EU-Lex" platform and Member States' Government websites were obtained to fulfil the critical analysis. Our reviews indicate that policies related to BBFs are still under development to comply with some appropriate laws and regulations for their implementation. The current policies, implemented among others by the new EU Fertilising Products Regulation (FPR), are structured by component material categories (CMC) and product function categories (PFC) that govern the specific function of the product and the raw material utilization. For farmers and Small and Medium Enterprises (SMEs), compliance with the FPR may be challenging. Yet, for regional use, farmers and producers can still rely on BBFs in compliance with national regulations. In addition, attention from policymakers is needed to increase the level of public acceptance, farmer's adoption, and availability of BBF with acceptable prices. Finally, this study provides prospective research opportunities to help the development of BBFs.

The increase of man-made greenhouse gas (GHG) emissions is a serious global problem. Hence the 2015 Paris Agreement and the COP meetings, which show the willingness of governments to reduce emissions and fight climate change. Their main goals are keeping average temperatures to max 2 °C above pre-industrial times, and reaching net-zero emissions by 2050. But how realistic are these goals? GHG emissions may be everyone's long-term problem, but they are nobody's short-term problem. The huge benefits we all reap from the free energy provided by fossil fuels, and the way that governments, companies and people handle risk, create enormous barriers. I will show here, using simple back-of-the-envelope calculations, that we will not reach the Paris Agreement goals. Moreover, I will explain the reasons why much excellent research in sustainable chemistry will not make a sizable dent in CO₂ emissions. This doesn't mean we should give up. We must keep on developing and implementing sustainable technologies. But we should also prepare to adapt to living in a world with average temperatures 3–4 °C higher than pre-industrial times. Optimistic scenarios make people complacent. Wake up. It is later than you think.

CO₂ capture from flue gas is one of the global urgent tasks. Adsorption separation of CO₂ is an energy-efficient way as compared to the absorption method. The central issue is to devise efficient adsorbents that work well under flue gas conditions with temperatures of 323–348 K and low CO₂ concentrations of 15%. In this work, we targeted this issue and proposed a well-controlled diffusion strategy, which is achieved over a series of poly(furfuryl alcohol)-derived carbons (PFCs) with dense and abundant ultra-micropores. As the adsorption temperature increased from 298 to 348 K, the CO₂ capture capacity is 54% kept for PFC-800, which is 1.2 times higher than that for samples without diffusion limitation. The capture of CO₂ is kinetics control at ambient temperature, however, at 348 K CO₂ with higher kinetic energy can overcome the restriction of the narrow pore entrance and the CO₂/N₂ selectivity for simulated flue gas composition increases from 20 to 40. Furthermore, the PFCs exhibit a high CO₂ volumetric adsorption capacity of 97 cm³ cm⁻³ at 298 K and 1 bar, benefiting the practical application deployed with an integrated adsorption column. The diffusion kinetics can be further tuned when altering the bulk phase into nanocoating, which would inspire their application in different scenarios.

Intense inorganic fertilization practices exponentially detriment upon the soil health and enhance input costs of production. Henceforth, organic bio-fertilizers such as Jeevamrutha being developed with rurally available low cost nitrogen and carbon sources are necessary to serve as alternate fertilization systems for soil nutritional enrichment and plant growth. Associated mechanism with respect to the interaction of precursors such as jaggery and gram flour in Jeevamrutha bio-fertilizer have not been vividly explored in the prior art. Considering this lacunae, the article addresses the optimization of these precursors for the affirming of their fundamental role in the nutrient characteristics of the Jeevamrutha bio-fertilizer. Thereby, the article targets the optimization of Jeevamrutha bio-fertilizer formulations using the Central Composite Design (CCD)-based statistical tool for summer and winter seasons. The corresponding Total Kjehdahl Nitrogen (TKN), Ammonium Nitrogen (AN) and Phosphate (P) during the summer (0.67%, 427.56 mgL⁻¹ and 1405.78 mgL⁻¹) and the winter (0.28%, 135.86 mgL⁻¹ and 1046.75 mgL⁻¹) seasons were achieved in North-East India. This study provides critical insights for waste-to-value added product development through the utilization of rurally available substrates for nutrient enhancement of soil that will aid waste management approach. Also, in comparison with the control group (0%) and various treated samples for the optimized formulation (25%, 50%, 75% and 100% v/v), the highest Germination Index (GI) of 87.87% was obtained for the 50% (v/v) treated sample (mung bean) indicating its efficacy towards phytotoxic effects. Thereby, the methodology and results aim to revolutionize agricultural systems and improve soil health due to reduced cost and preparation time and wider utility of land and waste precursors in comparison to other organic fertilizer preparation techniques.

Globally expanding plastic use has created environmental issues related to the disposal of plastic waste. One of the possible alternative techniques for turning waste plastics into high-quality liquid oils is thermal and catalytic pyrolysis. The research focused on high-density polyethylene (HDPE) thermal and catalytic slow pyrolysis employing waste fluid catalytic cracking (FCC) catalyst at various temperatures and catalyst-to-plastic ratios in a batch reactor. The ASTM methods and Gas Chromatography-Mass Spectrometry (GC-MS) were used to analyze the physical and chemical characteristics of the produced liquid oil fraction. The results indicate that a pyrolysis temperature of 500°C and a catalyst to plastic ratio of 0.2 were the ideal operating conditions. The BET surface area, pore volume, and average pore size of the spent FCC catalyst were 0.103 cm²/g, 7.02 nm, and 63.24 m²/g, respectively. Waste HDPE plastic was thermally pyrolyzed, yielding 73.9 wt% liquid oil, 23.1 wt% gas, and 3 wt% char as the end products.

Furthermore, the catalytic pyrolysis produced a higher yield of liquid oil (88.8 wt%) but less gas (9.9 wt%) and char (1.3 wt%). The kinematic viscosity, density, flash point, pour point, and calorific value of liquid oil produced by catalytic pyrolysis were 2.48 cSt, 0.85 g/cm³, 34.5 °C, -6 °C, and 41.6 MJ/kg, respectively. According to the GC-MS data, the liquid oil's chemical composition contains 38 hydrocarbons between C₆ and C₂₄. Because of this, the liquid oils made from waste HDPE have characteristics similar to those of conventional fuels and can be used as alternative renewable energy sources.

Parthenium hysterophorus is a lignocellulosic material with a high potential for fermentable sugar production due to its high availability and adaptability. The current investigation aims at studying the effectiveness of KOH-assisted ultrasonication on the pretreatment of P. hysterophorus biomass. Ultrasonication is a new hydrolysis technology that can provide a higher fermentable sugar yield in less time and at a lower temperature while using less alkali. The combination of KOH and ultrasound has been applied with a detailed study into the effects of various parameters such as sonication time (operating range of 10–50 min), KOH concentration (0.5–2.5%), and temperature (20–50 °C). A higher reducing sugar yield (128.15±0.06 mg/g) was obtained in US-KOH-pretreated biomass as compared with that of the KOH-pretreated biomass. The optimised pretreatment (using a 1:10 bath ratio, 1% (w/v) KOH, and 15-min sonication times) reduced lignin content (delignification) by 58.72% (w/w) and increased the available cellulose content (27.97% w/w) over untreated biomass, which was confirmed by compositional analysis of treated biomass. Further US-KOH-pretreatment was investigated for the liberation of maximum reducing sugar (325.51 mg/g) using the response surface methodology (RSM) approach. Following statistical optimization using response surface methodology, the yield of enzymatic hydrolysis was increased by 3.2-fold compared to the control. According to the investigations, P. hysterophorus can be used as a promising and affordable biomass source for the production of commercial bioethanol.

This bibliometric analysis is a following part that aims to expand the information from our previous study. Direct Air Capture (DAC) technologies are not progressing as fast as expected and time is limited. Research and shared knowledge can accelerate the implementation of DAC and Carbon Capture Utilisation and Storage (CCUS) solutions. Numerous authors publish their findings on different platforms and journals. Thus, this bibliometric analysis is using Web of Science as data base. During this study, two cases of study were performed: one merges concepts such as ``carbon capture,'' CO<sub>2</sub> capture and DAC, and a second one only focused on removing the CO<sub>2</sub> from the atmosphere; being the latter at the principal topic of this analysis. CCUS and DAC + S share the same approach to capture CO<sub>2</sub>, yet the conditions are quite different. Many articles related to DAC were overshadowed by words such as ``CO₂ capture'' and ``carbon capture.'' However, the results showed that in 1999, Professor Lackner was the first scientist who suggested the implement of DAC technologies. After him, a great number of authors followed up and researched on the topic. Based on the outcomes of this study, United States, Europe and China are leading the research. The United States holds the major number of publications and has strong links with the rest of the countries, which implicates that authors from other nations collaborate with the North American country. Yet, it is necessary to increase its social acceptance to accelerate the deployment of these technologies.

After the edible cashew nut's pulp and oil are removed, the shells are considered agricultural waste. A number of by-products and waste produced during the industrial processing of cashew nuts can pose environmental risks. Testa, cashew apple, cashew apple bagasse, and cashew nut shell liquid (CNSL) are a few examples. The reddish-brown covering part of cashew is called Testa, which exists between Kernel and Shell. Academic, industrial, and other practitioners are becoming interested in using agricultural by-products as green raw materials to create a variety of valuable goods. It has been determined that cashew nut shells (CNS) and their liquid extract (CNSL) are agro-waste rich in valuable and functional renewable goods. Cashew Nut Husk (CNH) components distinctive structural characteristics warrant the possibility of various modifications to accommodate different purposes. Numerous previously published articles describe the work done mainly on the potential of cashew nut shell liquid and cashew nut shell. [1] This review focuses on developing Cashew Nut Husk as a green source to create different value-added products. A thorough literature review of the existing situation and attempts undertaken to use Cashew Nut Husk waste for various uses is provided.

Selective hydrogenation of CO₂ to methanol over Pd nanoparticles supported on MgO promoted ZnO oxide catalyst was investigated in a fixed bed continuous downflow reactor at 3 MPa pressure and temperature between 200–280 °C. The synthesized catalyst showed exceptionally high selectivity (>90%) for methanol production via CO₂ hydrogenation at low temperature (220 °C) and pressure (3 MPa). 2wt%Pd loaded on ZnO catalyst showed very less activity but the addition of MgO on the ZnO led to a higher dispersion of Pd, which directly influences catalyst activity and methanol production. The addition of 10 wt% MgO over 2wt%Pd/ZnO catalyst improved the catalyst activity, where we observed ∼ 8.2% CO₂ conversion with ∼ 90.6% methanol selectivity. Density Functional Theory (DFT) calculation shows the addition of MgO at the Pd/ZnO catalyst promotes the adsorption of CO₂, as well as reaction intermediates HCOO and COOH. The long-term stability of MgO-promoted Pd-ZnO was tested, and it was found that catalyst showed no deactivation even after 80 h time-on-stream.