Sustainable and environmental catalysis

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High-Resolution Ultrasound Spectroscopy for the Determination of Phospholipid Transitions in Liposomal Dispersions

High-resolution ultrasound spectroscopy (HR-US) is a spectroscopic technique using ultrasound waves at high frequencies to investigate the structural properties of dispersed materials. This technique is able to monitor the variation of ultrasound parameters (sound speed and attenuation) due to the interaction of ultrasound waves with samples as a function of temperature and concentration. Despite being employed for the characterization of several colloidal systems, there is a lack in the literature regarding the comparison between the potential of HR-US for the determination of phospholipid thermal transitions and that of other common techniques both for loaded or unloaded liposomes. Thermal transitions of liposomes composed of pure phospholipids (dimyristoylphosphatidylcholine, DMPC; dipalmitoylphosphatidylcholine, DPPC and distearoylphosphatidylcholine, DSPC), cholesterol and their mixtures were investigated by HR-US in comparison to the most commonly employed microcalorimetry (mDSC) and dynamic light scattering (DLS). Moreover, tramadol hydrochloride, caffeine or miconazole nitrate as model drugs were loaded in DPPC liposomes to study the effect of their incorporation on thermal properties of a phospholipid bilayer. HR-US provided the determination of phospholipid sol-gel transition temperatures from both attenuation and sound speed that are comparable to those calculated by mDSC and DLS techniques for all analysed liposomal dispersions, both loaded and unloaded. Therefore, HR-US is proposed here as an alternative technique to determine the transition temperature of phospholipid membrane in liposomes

An overview of natural polymers as reinforcing agents for 3D printing

Three-dimensional (3D) printing, or additive manufacturing, is a group of innovative technologies that are increasingly employed for the production of 3D objects in different fields, including pharmaceutics, engineering, agri-food and medicines. The most processed materials by 3D printing techniques (e.g., fused deposition modelling, FDM; selective laser sintering, SLS; stereolithography, SLA) are polymeric materials since they offer chemical resistance, are low cost and have easy processability. However, one main drawback of using these materials alone (e.g., polylactic acid, PLA) in the manufacturing process is related to the poor mechanical and tensile properties of the final product. To overcome these limitations, fillers can be added to the polymeric matrix during the manufacturing to act as reinforcing agents. These include inorganic or organic materials such as glass, carbon fibers, silicon, ceramic or metals. One emerging approach is the employment of natural polymers (polysaccharides and proteins) as reinforcing agents, which are extracted from plants or obtained from biomasses or agricultural/industrial wastes. The advantages of using these natural materials as fillers for 3D printing are related to their availability together with the possibility of producing printed specimens with a smaller environmental impact and higher biodegradability. Therefore, they represent a “green option” for 3D printing processing, and many studies have been published in the last year to evaluate their ability to improve the mechanical properties of 3D printed objects. The present review provides an overview of the recent literature regarding natural polymers as reinforcing agents for 3D printing

Acetonitrile from Bioethanol Ammoxidation : Process Design from the Grass-Roots and Life Cycle Analysis

The growing interest for new routes to obtain acetonitrile led to the development of catalysts active toward the ammoxidation of various substrates. Among these, a C2 molecule such as ethanol represents a good choice in terms of atom economy and, being renewable, sets the basis for a long-term sustainable process. This paper describes a fully integrated, newly designed process for the production of acetonitrile from bioethanol, currently not present in the literature. The target is the production and purification of 10 kg/h of acetonitrile, unit of production used for calculations, obtained from ethanol, ammonia, and air as raw materials. All the byproducts, mainly ammonium bicarbonate and sodium cyanide, are considered marketable chemicals and represent an added value, instead of a disposal issue. Their optimized recovery is included in this flowsheet as a basis for the future economic assessment of the system. The process consumes CO2 without its direct emission. In principle, all the carbon atoms and 90% of the nitrogen atoms are turned into reaction products, and the main loss is gaseous N2. The process design has been performed by means of the Aspen PLUS process simulator, on the basis of literature data and other experimental results. In addition, for an evaluation of the potential benefits of the innovative biobased route, a life cycle analysis was carried out including all the stages involved in the bioacetonitrile production (from raw materials extraction up to the gate plant). The results were then compared with those achieved for the traditional fossil route (SOHIO process), showing a sensible decrease of the environmental burdens in terms of nonrenewable resources and damage to ecosystems (e.g., toxicity, climate change, etc.). Finally, a simplified sensitivity analysis was carried out by substituting the starting raw material for the production of bioethanol (corn) with other materials conventionally used worldwide, such as sugar cane and wood. The latter option seems to make the system more competitive in terms of carbon neutrality, thanks to the usage of the residual lignocellulosic fraction available on the market

Recycling within the Chemical Industry: The Circular Economy Era

In this present work, we have briefly discussed the importance of recycling within the chemical sector. Recycling is fundamental in promoting a circular economy, which is a new paradigm of sustainability that is able to reduce environmental implications, and in creating new business opportunities. Therefore, to highlight the importance of recycling in the circular economy era, we have reported on some recent examples of strategies helpful to minimize waste by increasing the efficiency of the whole system and promoting a greener/safer chemical industry

Environmental certifications and programs roadmap for a sustainable chemical industry

Meeting public demands for benign chemistry will require companies to develop holistic approaches that manage chemicals from three different perspectives that focus on the organization, its products, or specific chemical materials. A more collaborative approach to chemical management will depend on building trust among a diverse group of stakeholders with often conflicting objectives

Butadiene from biomass, a life cycle perspective to address sustainability in the chemical industry

In the past few decades, innovative approaches such as Green Chemistry and Green Engineering have come out in order to set the basic principles for a more sustainable chemical industry. However, researchers also need a more scientific and quantitative tool to address the sustainability behind the application of those principles. Therefore, a multi-criteria approach based on life cycle thinking was proposed to investigate the production of 1,3-butadiene. Five indicators were selected to address sustainability: the Cumulative Energy Demand, the carbon footprint, the water depletion, a midpoint-oriented analysis method and an economic index. The use of renewable feedstock was evaluated in comparison with the traditional fossil-based route from naphtha. Two alternative pathways which use bio-ethanol were considered - the Lebedev and Ostromisslensky processes - evaluating the possibility to locate the plant in three different regions (the EU, Brazil and the US). Detailed analysis reveals how the use of bio-based feedstock leads to a significantly lower consumption of fossil sources, despite the higher exploitation of renewable resources leading to larger water withdrawals. Moreover, the assessment of the global warming potential reveals how bio-routes are far from able to be considered carbon-neutral. In addition, the ReCiPe single-score was used, showing greater sustainability of the Lebedev process compared with the traditional way. On the other hand, the two-step pathways (Ostromisslensky) result in the worst scores. An economic evaluation was also applied. The index reveals how the direct conversion into 1,3-butadiene seems more suitable than the two-step method, particularly in the case of production in the US