Volume 32, Issue 6

Ionic liquids (ILs) and supercritical CO 2 (scCO 2 ) are two promising types of reaction media for green chemical processes due to their unique properties. They can be integrated into chemical reactions as catalysts and solvents to develop green and environment-friendly processes. This review presents current research trends aiming to solve the major chemical engineering issues in light of a fundamental understanding of these media. Applications of these media in the petrochemical industry, biochemical engineering, and fine chemical production are reviewed, suggesting the challenges and directions of utilizing them for green processes prospectively. These recent explorations and successful examples of applications demonstrate that ILs and scCO 2 offer huge potential for novel and green chemical engineering processes.

Produced water (PW) from the oil/gas field is an important waste stream. Due to its highly pollutant nature and large volume of generation, the management of PW is a significant challenge for the petrochemical industry. The treatment of PW can improve the economic viability of oil and gas exploration, and the treated water can provide a new source of water in the water-scarce region for some beneficial uses. The reverse osmosis (RO) and selective nanofiltration (NF) membrane treatment of PW can reduce the salt and organic contents to acceptable levels for some beneficial uses, such as irrigation, and different industrial reuses. However, membrane fouling is a major obstacle for the membrane-based treatment of PW. In this review, the author discusses the polymeric membrane (mainly RO/NF) fouling during PW treatment. Membrane fouling mechanisms by various types of foulants, such as organic, inorganic, colloidal, and biological matters, are discussed. The review concludes with some of the measures to control fouling by membrane surface modification approaches.

Tissue engineering has evolved into an exciting area of research due to its potential in regenerative medicine. The shortage of organ donors as well as incompatibility between patient and donor pose an alarming concern. This has resulted in an interest in regenerative therapy where the importance of understanding the transport properties of critical nutrients such as glucose in numerous tissue engineering membranes and scaffolds is crucial. This is due to its dependency on successful tissue growth as a measure of potential cure for health issues that cannot be healed using traditional medical treatments. In this regard, the diffusion of glucose in membranes and scaffolds that act as templates to support cell growth must be well grasped. Keeping this in mind, this review paper aims to discuss the glucose diffusivity of these materials. The paper reviews four interconnected issues, namely, (i) the glucose diffusion in tissue engineering materials, (ii) porosity and tortuosity of these materials, (iii) the relationship between microstructure of the material and diffusion, and (iv) estimation of glucose diffusivities in liquids, which determine the effective diffusivities in the porous membranes or scaffolds. It is anticipated that the review paper would help improve the understanding of the transport properties of glucose in membranes and scaffolds used in tissue engineering applications.

Banana peel (BP) is an agrowaste produced in large volumes annually, especially by food-processing industries; however, its disposal is of significant concern. However, recent research suggests that BP is a valuable source of bioactive compounds, which can be converted into value-added products. This article reviews the conversion process of value-added products from BP and provides an outline on the chemical composition of BP and its possible applications. In addition, we also discuss the utilization of BP as a substrate to produce animal feed, biofertilizer, dietary fibers, clean energy, industrial enzymes, as well as its use in the synthesis of nanomaterials. Based on the research conducted so far, it is obvious that BP has a wide variety of applications, and thus, developing a biorefinery approach to adequately utilize BP will help realize its economic benefits to the fullest. Based on the valorization of BP, a scheme for BP biorefinery has been proposed. A material balance for BP biorefinery for 1-ton bone-dry BP is presented and our results show that 432 kg of protein or 170 kg of citric acid, 170 kg of pectin, 325 m 3 of ethanol, and 220 m 3 of methane can be produced.