Pramod M Gawal

2,3-Butanediol (2,3-BD), known for its various applications and potential microbial production, faces challenges in commercial viability due to the high energy intensity nature of the conventional purification method. This study focuses on recovering and purifying 2,3-BD from glucose-based fermentation broth (FB) using aqueous two-phase extraction-assisted distillation (HATPED). The selected isobutanol/NaCl system studies were optimized with the parameter effect of salt, solvent, and extraction temperature on extraction efficiency of 2,3-BD through central composite design (CCD) and response surface methodology (RSM). Under Optimal conditions (30% (w/v) NaCl, 35% (v/v) isobutanol, and 40°C extraction temperature) yielded the highest partition coefficient (K D) (6.8) and extraction efficiency (87%) of 2,3-BD exceeding the theoretical value of 86.93%, by 0.080%. The extract phase further proceeds in a distillation column to recover the 2,3-BD. In the scale-up study, the extraction and purification were conducted in two cycles, resulting in an overall 2,3-BD extraction and recovery of 97.63% and 95.88% (>99% purity), respectively. NaCl recovery from the aqueous phase reached 86.66% through evaporation. This cost-effective and scalable method provides valuable insights for developing an organic solvent/ inorganic salt ATPS-assisted distillation for 2,3-BD separation and recovery from complex fermentation broth.

Butanediol (2,3-BD) is a valuable chemical used in various industries and as a fuel additive. It can be converted into jet fuel, making it highly sought after. The production of 2,3-BD from renewable sources is important as it reduces reliance on petroleum-based feedstock. However, purifying 2,3-BD from the fermentation broth is a challenging task. A hydrophilic solvent and inorganic salt system have been developed to recover 2,3-Butanediol from the broth. Optimization of process parameters using 1-butanol and NaCl systems has resulted in a maximum recovery efficiency of 81% and a partition coefficient of 1.72. This promising method can potentially be scaled up for pilot-scale production.

Plastics, with their diverse molecular structures, offer a wide range of technical properties that can be tailored through raw material selection, manufacturing processes, and additives. This versatility extends to stress, stiffness, tensile, shear, flexural, compressive, and torsional strengths, as well as characteristics like strain, creep, and impact resistance. However, conventional plastics have limitations, notably in their melting points. High-temperature plastics (HTPs), with permanent operating temperatures exceeding 150°C, address this issue, offering superior properties like sliding friction, weight reduction, and chemical resistance even at elevated temperatures. Through the addition of reinforcing materials and various additives, HTPs like PTFE, PEEK, and others exhibit enhanced performance suitable for diverse applications including aerospace, automotive, medical implants, and industrial uses. The selection of HTPs can be facilitated by tools like the Ashby Diagram. The burgeoning demand for HTPs is driven by technological advancements, particularly in material strength and functional characteristics, and is poised to meet the needs of industries such as aerospace, automotive, and coatings. Despite the potential cost limitations, the substitution of traditional materials with HTPs represents a promising trend for future applications, emphasizing their role as viable alternatives in demanding environments.

Titanium dioxide (TiO2) is a widely studied material known for its diverse properties, including non-toxicity, thermal stability, and photocatalytic performance. Its application in environmental remediation and clean energy production has garnered significant attention. This review focuses on the synthesis methods and modifications of TiO2 nanotubes (TNTs) for enhancing their photocatalytic efficiency under visible light irradiation. Various synthesis techniques, such as hydrothermal treatment, anodic oxidation, and template methods, are discussed alongside modifications like doping, annealing, and surface decoration. The literature survey highlights recent studies on different modifications and their impact on the photocatalytic degradation of organic pollutants. The objective of this work is to explore the visible photocatalytic activity of TiO2 nanotubes and their potential applications, providing a comprehensive overview for further research and development in this field.

Efficient catalysts are essential for various organic reactions, and vanadium complexes have emerged as versatile candidates. This study explores the synthesis and catalytic properties of novel oxidovanadium complexes with Schiff base, hydrazone, hydroxamate ligands, and hemicryptophane supramolecular structures. The complexes exhibit promising catalytic activity in the oxidation of hydrocarbons using environmentally friendly oxidants like hydrogen peroxide. Additionally, encapsulation of these complexes in zeolite-Y enhances their catalytic performance. These findings contribute to the development of efficient and eco-friendly catalysts for industrial applications.

Butanediol is a valuable specialty chemical used in various industries and as a fuel additive. The bio-based production is significant as it's renewable and not reliant on petroleum feedstock. However, purifying 2,3-butanediol from complex fermentation broth is challenging. An integrated hybrid extraction distillation (HED) approach was developed to address this. The process was optimized using butyl acetate solvent, resulting in a maximum recovery efficiency of 91.39 % and purity of 99.99 % for 2,3-butanediol. Simultaneously, 92.22 % ethanol was recovered with 99.11 % purity. The solvent, 96 % of which was recovered, had a purity of 98.38 % and could be successfully recycled. This promising process has the potential for scaling up on a pilot scale.

Bio-based 2,3-butanediol (2,3-BD) is gaining prominence as an alternative to costly petroleum production. It finds diverse applications in chemicals, food, cosmetics, and more, notably as a polybutadiene rubber component. Recent advancements in 2,3-BD purification and increased concentration in fermentation solutions (exceeding 150 g/L) resulted from identifying 2,3-BD-producing bacteria and understanding productivity factors. Nevertheless, challenges arise from its high boiling point, hydrophilicity, complex fermentation broth composition, and costly separation from the broth (accounting for 50-70 % of production costs). The development of a cost-effective and effective separation method for 2,3-BD is essential. Recent developments in separation techniques, such as solvent extraction, pervaporation, and others, have been comprehensively reviewed for their insitu and ex-situ applications. A techno-economic evaluation of these innovative approaches demonstrates significant reductions in energy consumption (up to 54.8 %) and downstream separation expenses (ranging from 25.8 % to 61.2 %), highlighting their potential to enhance the industrial production of 2,3-BD.

This study presents a simulation approach for multicomponent distillation, focusing on the complexities inherent in quaternary systems. The research employs a comprehensive analysis, utilizing simulation software to model the separation processes involved. Through a case study approach, the effectiveness of various distillation configurations and operational parameters are evaluated, providing valuable insights into optimizing separation efficiency and resource utilization in quaternary systems.

Mo-doped, Cr-doped and Ni-doped TiO2 photocatalyst were synthesized by facile sol-gel method. The photocatalyst were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), BET surface area analyzer, ultraviolet visible spectroscopy (UV-Vis), and Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The photocatalytic activity of the synthesized photocatalyst was evaluated by studying the degradation of methylene blue under irradiation of 125W high pressure mercury lamp (UV) and natural solar light outdoor. Metal doping decreased band gap of TiO2 to 2.83 eV for Mo-doped TiO2 and Ni-doped TiO2. 1.5% Mo/TiO2 and 0.9% Mo/TiO2 catalyst achieved 98% degradation under UV light and Solar light within 60 and 120 min respectively.The effects of operating parameters, on MB degradation, including the catalysts loading, pH and concentration of Methylene blue were thoroughly examined. Degradation by-products were analyzed on HR-LCMS and a mechanism is proposed.

The green pathway for the synthesis of nanoparticles targeting the photoreduction of CO2 to value-added chemicals is a potential approach to control industrial CO2 emission. In this study, we synthesized bio-based CdS(bio) nanorods using plant-based phytochemicals found in Aegle marmelos and carbon quantum dots (CQDs) using orange peels. CQDs (7 nm) were homogeneously incorporated into CdS(bio) nanorods via simple deposition, forming CQDs/CdS(bio) nanocomposites. The catalysts were thoroughly characterized using diffraction, microscopic, spectroscopic, and electrochemical techniques. CQDs/CdS(bio) composites had a diameter and length of 73 nm and 822 nm with 82.25 m2/g specific surface area. CQDs/CdS(bio) composites showed a fourfold increase in both photocurrent density (0.38 μA/cm2) and CO2 adsorption capacity (0.292 mmol/g) compared to CdS(bio) nanorods alone. The conduction band of the composite (􀀀 0.92 eV) becomes more negative compared to CdS(bio) (􀀀 0.85 eV). Moreover, the composite formation notably improved decay time by 2.35 folds and reduced photoluminescence intensity by 59.23% compared to CdS(bio), indicating enhanced charge separation and reduced charge carrier recombination. Furthermore, the photocatalytic activity of CQDs/CdS(bio) nanocomposites was investigated for CO2 reduction to methanol under visible light (250 W, λ
> 420 nm, 2.2 W/m2, 4.2719 ×1018 photons/m2.s) without any sacrificial reagent. The effect of the mass fraction of CQDs on CdS and catalyst loading on photocatalytic CO2 reduction has been investigated. The optimal CQDs/CdS(bio) loading (0.50% w/w) exhibited the maximum methanol yield of 1060.52 μmol/g⋅h (apparent quantum efficiency 7%) over 5 h. CQDs/CdS(bio) nanocomposites exhibited strong stability (test up to 25 h in five consecutive cycles), retaining the morphological (0.11% variation in size) and structural (4.2% variation in crystallinity index) attributes. This work would provide valuable insights into the development of bio-based CdS-based composites for efficient PCO2RR into valuable chemicals.

Highly active Cr-doped, Ni-doped and Mo-doped TiO 2 photocatalysts were synthesized by a sol-gel method. The synthesized catalysts were characterized by UV-DRS, BET, XRD, FE-SEM-EDS, TEM and XPS. Metal doping decreased the band gap of TiO 2 to 2.83 eV for Mo-doped TiO 2 and Ni-doped TiO 2. The activity of the synthesized photocatalysts was evaluated by studying the degradation of MB as a model pollutant under both UV and solar irradiation. The Mo/TiO 2 catalyst achieved 98% degradation under solar light within 120 min. The activity of the catalysts was in the order Ni-doped TiO 2 \ Cr-doped TiO 2 \ TiO 2 \ Modoped TiO 2. The optimum activity was found at a loading of 1.5 g/L of Mo-doped TiO 2 under both UV and solar irradiation. The degradation was rapid at pH [ 7 and followed pseudo-first order kinetics. Degradation by-products were analyzed on HR-LCMS and a mechanism is proposed. Keywords Mo-doped TiO 2 Á Cr-doped TiO 2 Á Ni-doped TiO 2 Á Dye degradation Á MB Á UV light Á Visible light

Butanediol is a valuable specialty chemical used in various industries and as a fuel additive. The bio-based production is significant as it's renewable and not reliant on petroleum feedstock. However, purifying 2,3-butanediol from complex fermentation broth is challenging. An integrated hybrid extraction distillation (HED) approach was developed to address this. The process was optimized using butyl acetate solvent, resulting in a maximum recovery efficiency of 91.39 % and purity of 99.99 % for 2,3-butanediol. Simultaneously, 92.22 % ethanol was recovered with 99.11 % purity. The solvent, 96 % of which was recovered, had a purity of 98.38 % and could be successfully recycled. This promising process has the potential for scaling up on a pilot scale.

Bio-based 2,3-butanediol (2,3-BD) is gaining prominence as an alternative to costly petroleum production. It finds diverse applications in chemicals, food, cosmetics, and more, notably as a polybutadiene rubber component. Recent advancements in 2,3-BD purification and increased concentration in fermentation solutions (exceeding 150 g/L) resulted from identifying 2,3-BD-producing bacteria and understanding productivity factors. Nevertheless, challenges arise from its high boiling point, hydrophilicity, complex fermentation broth composition, and costly separation from the broth (accounting for 50-70 % of production costs). The development of a cost-effective and effective separation method for 2,3-BD is essential. Recent developments in separation techniques, such as solvent extraction, pervaporation, and others, have been comprehensively reviewed for their insitu and ex-situ applications. A techno-economic evaluation of these innovative approaches demonstrates significant reductions in energy consumption (up to 54.8 %) and downstream separation expenses (ranging from 25.8 % to 61.2 %), highlighting their potential to enhance the industrial production of 2,3-BD.

This study investigates the photocatalytic conversion of CO₂ into valuable chemicals in an aqueous solution using nature-inspired CDs/CdS QDs composites. These composites, synthesized from orange peels and Aegle Marmelos phytochemicals via microwave irradiation, are employed under visible light irradiation to facilitate the conversion process.

Contamination of water with hazardous chemicals is a serious concern for the environment as well as human health. These chemical contaminants are non-biodegradable, highly toxic and offer possess complex chemical structure which makes them difficult to remove by conventional water treatment processes [1]. Dye is one of such pollutant majorly found in the industrial effluents of plastic, paper, textile, cosmetic, etc. [2]. In the present study we report that, photocatalytic degradation of Methylene Blue (MB) dye using Mo doped TiO2 by sol gel method (Mo/TiO2). An efficient dye degradation can be achieved within a reasonable short exposure time by using Mo/TiO2 catalyst. The effect of various parameters, such as catalyst loading, initial dye concentration, temperature and pH on the degradation is investigated.

The energy demand has been increasing dramatically due to industrialization and improving the living standard of human society. Global energy consumption has been estimated to rise by 28 % in 2040 . A large amount of energy demand is fulfilled by the burning of non-renewable fossil fuels, and if this trend continues, existing fossil fuels will be depleted in the future. Furthermore, excessive burning of fossil fuels leads to an increasing level of greenhouse gas in the environment. CO2 is the primary driver of the greenhouse emission effect and contributes around 76%. Currently, globally CO2 emission has reached over 36 billion tons per year with an atmospheric concentration of 412.5 ppm (source: International Energy Agency). Therefore, developing sustainable energy resources is highly demanding to provide energy and control the greenhouse gas effect.
Different technologies have been employed to reduce CO2 emissions, such as biological conversion, catalytic conversion, thermochemical conversion, electrocatalytic conversion, photocatalytic conversion, and photoelectrocatalytic conversion . Among them, photocatalytic reduction has been considered one of the most effective techniques due to abundant solar energy and the use of H2O as a reactant in the process. The operation is mainly carried out at ambient temperature and pressure. Furthermore, photoreduction of CO2 with water or other reactants catalyzed by semiconducting materials under solar light or illuminated light transforms it into fuels such as CH4, CO, C2H6, CH3OH, etc. This process could mimic natural photosynthesis in the plant. Therefore, photocatalytic reduction of CO2 is like killing two birds with one stone to solve energy and environmental issues simultaneously.
The chemical synthesis methods of photocatalyst employ costly and environmentally aggressive chemicals. However, the bio-based approach for the synthesis of semiconductor nanoparticles (NPs) has several advantages over chemical methods, such as its eco-friendly nature, cost-effectiveness, one-pot synthesis process, and abundant sources of biomaterials. The development of green pathways for the synthesis of NPs and their application in the photoreduction of CO2 to value-added chemicals could be a potential technique for the control of industrial CO2 emissions. The North-eastern states of India are the hub of several tropical and subtropical plants. These plants could be employed as the potential sources of reducing and capping analytes for the quick and effective formation of semiconductor NPs.
Herein, we report the synthesis of bioinspired CdS nanoparticles using plant-based phytochemicals in Aegle Marmelos [3]. The CdS NPs were further modified to minimize its oxidative corrosion and high recombination of electron/hole pair. The coupling of CdS with carbon quantum dots (CQDs) was carried out in a bioinspired route to enhance the separation and transportation of charge carriers and CO2 adsorption, minimizing electron/hole recombination and photocorrosion .

Global energy demand drives greenhouse gas emissions. Sustainable energy technologies are sought to mitigate this. Photocatalytic CO2 reduction, using solar energy, converts CO2 into valuable fuels. Bio-based synthesis of semiconductor nanoparticles offers advantages like environmental friendliness and cost-effectiveness. Northeastern India's diverse plant life could provide phytochemicals for green nanoparticle synthesis. We synthesized CdS nanoparticles using Aegle Marmelos-derived phytochemicals, enhancing them with In2O3 to improve CO2 reduction efficiency and stability. The catalyst showed promise in reducing CO2 to formic acid and carbon monoxide under visible light, with stability and reusability.