Browsing by Author "Dr. Muhammad Yasin"

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Fabrication of Mixed Matrix Membranes and their Performance Evaluation for Elimination of Metals from Industrial Waste Water
(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-26) Ameena Kiran; FA21-R06-019; Dr. Muhammad Yasin; LHR TP 8449
Water is the vital source of life which is being contaminated by industrialization. Industrial wastewater contains large number of pollutants which have very toxic effects on human-beings and ecosystem, therefore it is very necessary to remove these pollutants from industrial wastewater prior to their discharge in freshwater sources. In this groundbreaking study, using zirconium-based metal-organic frameworks (MOFs) embedded in mixed matrix membranes (MMMs), we have created a novel method for purifying water. MOF, which is a highly porous and crystalline material, was modified with mercaptosuccinic acid to increase its hydrophilicity and enhance its ability to remove pollutants from water. This modification helped in increasing the water adsorption capacity of the MOF. The modified MOF was subsequently used to create MMMs with various loadings (0.25wt%, 0.5wt%, 0.75wt%, 1wt%, 1.5wt %) by embedding it in a polyether sulfone (PES) matrix. The influence of the embedded MOF on the morphology and functionality of the manufactured membranes was examined in terms of pure water flux, salts and dyes removal, and antifouling characteristics. The produced MOF and subsequent membranes were characterized using the following techniques: FTIR, TGA, BET, SEM, EDX, and XRD. The 0.75wt% membranes delivered exceptional water permeability of 161.71 L.m-2.h-1bar-1 and salts rejection of 80% and 74% for MgSO4 and NaCl, respectively. Dye rejection was also highly imp
Fabrication of PET (polyethylene terephthalate) based Thin Film Composite Membranes from Waste Plastic Bottles
(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Rimsha Yasin; SP20-R06-027; Dr. Muhammad Yasin; LHR TP 7581
Fresh water scarcity and pollution are the major issues all over the world and millions of people do not have access to clean water. Plastic waste is also a major pollutant of fresh water. In this study, PET is recycled and extracted from waste PET bottles. Forward osmosis (FO) is an efficient technique employed to treat water pollution by converting wastewater into clean water. The TFC membranes have shown great potential for high performance water purification, while the FO process has proved to be an energy efficient process compared with the RO process. This study employed a unique approach where the support layer of the TFC membranes was prepared using waste PET bottles. The support was optimized to give additional separation efficiency by incorporating MOF, i.e., MIL-100, into the support layer. MM supports with different loadings of MIL-100 (0wt%, 1wt%, 3wt%, 6wt% and 12wt%) were fabricated. Then TFC membranes were fabricated via Interfacial polymerization to produce top active polyamide layer. Finally, the performance of TFC membranes for desalination was assessed in the FO process. It was estimated that TFC membrane with 3wt% loading of MIL-100 showed high water flux and rejection as compared to other TFC membranes
Green & Sustainable Membranes for Efficient Bioethanol Purification via Pervaporation
(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Abeera Naeem; SP22-RNE-002; Dr. Muhammad Yasin; LHR TP 8636
Traditional membrane technologies, typically reliant on fossil-based polymers and hazardous solvents, pose significant environmental threats. To address these challenges, this study introduces an innovative approach: the development of hydrophobic mixed matrix membranes utilizing waste polyvinyl chloride (PVC) pipes and deep eutectic solvents (DES) based on thymol: urea as green additives. The research focuses on synthesizing two types of membranes: dense and asymmetrical. Each type is evaluated for its efficiency in terms of flux and selectivity. The asymmetric membranes undergo optimization processes, involving adjustments in polymer concentration, co-solvent use, and evaporation time, to enhance pervaporation performance. This optimization aims to achieve maximum ethanol flux and high separation factor. In contrast, the dense recycled PVC membranes exhibit comparable results to conventional polymeric membranes in terms of flux (1.98 kg/m2) and separation factor (16). Significantly, the incorporation of DES into the membrane matrix results in substantial performance improvements. The separation factor enhanced by approximately 125%, alongside a 36% increase in ethanol sorption capacity. Asymmetric membranes particularly demonstrate a higher potential in flux performance, reaching 5.12 kg/m2.hr, in contrast to dense membranes with a flux of 1.98 kg/m2.hr. These findings highlight the effectiveness of using recycled waste materials and DES in membrane fabrication. This approach not only enhances pervaporation performance but also aligns with the goals of green and sustainable membrane technology, offering a promising solution to environmental concerns in the field of membrane separation.
Liquid Metal Organic Frameworks Based Mixed Matrix Membranes For Efficient Bioethanol Separation
(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) SP22-RNE-001; Amna Kasuri; Dr. Muhammad Yasin; LHR TP 8635
Liquid Metal Organic Frameworks Based Mixed Matrix Membranes For Efficient Bioethanol Separation By Amna Kasuri This dissertation investigates the enhancement of ethanol-water separation using novel mixed matrix membranes (MMMs) incorporating metal-organic frameworks (MOFs). ZIF-90, a well-known MOF, is utilized for its exceptional pore properties, and its outer surface is innovatively functionalized with carbenes to create a porous liquid (PL) form. This functionalization aims to prevent particle agglomeration, a common challenge in MOFs' application in MMMs, thus facilitating higher selectivity and efficiency. The research is structured in two main parts. Initially, the MMMs are synthesized by embedding the carbene-functionalized ZIF-90 PL into a polydimethylsiloxane (PDMS) matrix. This composite membrane is then applied in the pervaporation process for ethanol-water separation. The novel use of ZIF-90 in a PL state is proposed to enable defect-free membrane synthesis with high filler loading, enhancing the process's efficiency. In the second part, a composite of ZIF-90 with Deep Eutectic Solvents (DESs) is developed through in-situ formation within the MOF pores. The resultant ZIF-90-DES composite is incorporated into PDMS to form another set of MMMs. These membranes are expected to further improve the pervaporation performance due to the synergetic effect of MOF pores and DES properties. Extensive characterization of the prepared membranes highlights their effectiveness in ethanol dehydration via pervaporation. The PL-based MMMs demonstrate a significant performance with a total flux of 3.86 kg/m2.hr and a separation factor of 29.3 at 60 °C, with a filler loading of up to 45 wt.%. The ZIF-90-DES composite MMMs also show promising results, achieving a flux of 2.83 kg/m2.h and a separation factor of 24.3. These findings underscore the potential of using MOF-based composites in MMMs for efficient ethanol-water separation, paving the way for advanced applications in catalysis and gas separation.
Simulation-Based Development of Deep Eutectic Solvent-Driven Extractive Distillation for Butanol Separation
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Shazam Ali; CUI/FA23-RCH-006/LHR; Dr. Muhammad Yasin; LHR TP 9671
Overreliance on fossil fuels such as coal, oil, and natural gas has led to severe environmental and human health concerns due to greenhouse gas (GHG) emissions and resource depletion. These issues have triggered the world to find renewable and environmentally friendly energy resources. Among these biofuels, biobutanol is the most promising fuel, primarily produced through the microbial fermentation process, and is a key component of the acetone-butanol-ethanol (ABE) fermentation process. However, the industrial scalability of biobutanol production is constrained by its low concentration in fermentation broths and the challenges of separating it from water due to azeotrope formation. Conventional separation processes, such as distillation, are energy-intensive and economically unviable for biobutanol recovery. Hybrid extractive distillation using ionic liquids (ILs) as an entrainer has shown potential as an alternative, with notable success in the dehydration of biobutanol. However, the limitations of ILs, such as toxicity, non- biodegradability, and high costs, pose significant barriers to their widespread adoption. To address these issues, deep eutectic solvents (DES) have emerged as a promising alternative. DES offers superior advantages over ILs, such as biodegradability, lower costs, and simple preparation. Recent research highlights their potential for separating lower alcohol, including biobutanol. However, the selection of optimal DES and the development of an efficient dehydration process for biobutanol remain unexplored. In this study, three new ideal hydrophobic deep eutectic solvents (DESs) were used for the effective extraction of butanol from aqueous mixtures: Thymol: Octanol (1:1), Thymol: Diphenyl (1:1), and Thymol: Octadecanol (3:1) in Aspen Plus V14. The DESs were used as selective entrainers to improve butanol recovery in the extractive distillation process, especially in cases in which the presence of azeotropes makes conventional separation energy intensive. At the distillate outlet, the Thymol: Octadecanol (3:1) mixture produced the highest 87% butanol purity among the evaluated DESs, demonstrating better performance. A thorough exergy analysis was carried out to assess the (DL-Menthol: Decanoic acid) and (Thymol: Octadecanol) DES-based configuration's sustainability and thermodynamic efficiency in further detail. The Thymol: Octadecanol (3:1) system had the best exergy efficiency, extractor column (99.96%), pump (99.99%), distillation column (5.03%), and cooler (99.99%), with the least amount of exergy destruction, according to the data, showing its capability as a highly efficient and energy-efficient solvent for sustainable butanol recovery. This work enhances the advancement of more environmentally friendly options for the purification of biofuels by offering a systematic method to choosing and evaluating the use of DESs in extractive distillation processes.
Synthesis of Polymeric Membranes to Achieve High Gas-Liquid Mass Transfer
(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Muhammad Tayyab Khalid; FA19-R06-021; Dr. Muhammad Yasin; LHR TP 7555
The world is meeting its energy requirements through fossil fuels. However, the environmental consequences caused by the utilization of fossil fuels and their expected depletion are the big concerns. These issues can be resolved by environmentally friendly utilization of coal and by exploring renewable alternatives to fossil fuels. One option is to produce biofuels such as bioethanol, biobutanol and biohydrogen by the biological conversion of syngas produced by the gasification of coal and biomass. Syngas is a mixture of CO, CO2, and H2 and can be converted into biofuels by using microorganisms. The scale up of syngas fermentation is limited by several issues, mainly the gas-liquid mass transfer (GL-MT). The GL-MT in syngas fermentation can be assessed by measuring the overall volumetric mass transfer coefficient (kLa). One of the potential ways to achieve high GL-MT in syngas fermentation is by employing membrane-bioreactors (MBRs). All the published studies on MBRs have used membranes that were synthesized for water purification. Hence, there was a need to synthesize membranes targeted for high GL-MT applications. In this study, the polyimide (P84) membranes were synthesized by varying the concentration of polymer, adding different concentrations of polyvinyl pyrrolidone (PVP), and impregnating the metal-organic framework (MOF) ZIF8 to get low pore size, high porosity, and high hydrophobicity. The highest values of porosity were achieved for membranes M-8 having 12% polyimide and 2% PVP. The GL-MT of O2 was investigated in a bubble column reactor (BCR) employing membrane spargers made of pure PI (P84), additive incorporated PI, and MOF incorporated mixed matrix membrane (MMM). The average values of the obtained kLa were 136.8 h-1 (for pure PI), 212.4 h-1 (for additive incorporated membrane), and 241.2 h-1 (for MMM). For the MOF-based membranes, 78% saturation was achieved in 60 seconds with the highest kLa at a low value of AS/VL (10.7 m-1).