Recent Innovations in Chemical Engineering - Volume 14, Issue 5, 2021

A large amount of sludge produced in the processing of crude oil has brought great harm. In this paper, common flocculants are summarized. According to the treatment process of crude oil, flocculants are divided into organic flocculants, inorganic flocculants, microbial flocculants, composite flocculants, and magnetic flocculants. The mechanism and limitation of each flocculation on crude oil sludge were analyzed. Finally, it is pointed out that the flocculation process of sludge is complex, and the development of new flocculant with high efficiency, safety, and economy is the main trend of flocculant development in the future.

In recent years, the effective use of CO2 has become one of the research hotspots worldwide to solve environmental pollution and energy shortage, whose excessive emission led to increasingly serious global environmental problems. Metal-organic frameworks (MOFs), with extraordinary specific surface areas, tunable surface chemistry, fast electron migration rate, large CO2 adsorption capacity, etc#142; are a new class of functional materials composed of metal ions/clusters and organic ligands, which have broad application potential in CO2 photocatalytic reduction. This paper systematically generalized the composition of the structure, discussed the methods of synthetics and expounded the photocatalytic properties and photocatalytic mechanism of MOFs. In addition, the application and research progress of MOFs functional materials in recent research are reviewed. The article also summarized challenges and prospects for the large-scale photocatalytic applications of MOFs catalysts. It guides the preparation of novel modified MOFs photocatalysts for high-efficiency applications in the field of CO2 reduction and photocatalytic degradation of dyes.

Background: In the growing environmental concerns, use of of natural products, efficient processes and devices are necessary. Solid-Liquid extraction of active ingredients from plant materials is one of the important unit operations in Chemical Engineering and needs to be enhanced. Objectives: These active ingredients are firmly bound to the plant cell wall membrane, which poses mass-transfer resistance and needs to get detached by using suitable process intensification tools such as ultrasound and suitable devices. Therefore, detailed analysis and review are essential for development made in this area through Publications and Patents. Hence, the present paper illustrates the development of an ultrasound-assisted device for solid-liquid extraction. Methods: Advantages such as percentage yield, reduction in extraction time, use of ambient conditions, better process control and avoidance or minimizing multi-stage extraction could be achieved due to the use of ultrasound in extraction compared to conventional processes. Conclusions: The use of ultrasound to provide significant improvements in the extraction of Vegetable tannins and natural dyes for application in leather processing has been demonstrated and reported earlier. These enhancements could be possible through various effects of ultrasound such as the better flow of solvents through micro-jet formation, mass transfer enhancement due to rupture of plant cell wall membranes through acoustic cavitation, better leaching due to micro-mixing and acoustic streaming effects. This approach would minimize material wastage; thereby, leading to eco-conservation of plant materials, which is very much essential for a better environment. Hence, various methods and designs for the application of ultrasound-assisted solid-liquid extractor devices are necessary.

THIS ARTICLE WAS WITHDRAWN BY THE PUBLISHER IN NOVEMBER 2022

Background: Nanocarbon hybrids have been a topic of interest in recent years because of their important role in energy storage and conversion device fabrication. Objective: To get low-cost graphene/N-doped carbon composites (G-NC) for supercapacitor applications. Method: G-NC samples were prepared with a two-step hydrothermal method and characterized with field emission scanning electron microscopy, 77K nitrogen adsorption, and X-ray photoelectron spectroscopy. The electrochemical performance of samples was investigated with cyclic voltammetry and charge-discharge measurements in threeelectrode configurations. Results: Samples showed a sheet-type morphology and nanoporous structure. The nanohybrids had a specific surface area of 350 m²g^-1, delivered maximum specific capacitance of 103 F g^-1 at 0.5A g^-1 in 6 M KOH with good cycle stability. Conclusion: Low-cost G-NC nanohybrids with good electrochemical performance are promising for supercapacitor applications.