Sharif Digital Repository

In recent two decades, with developments in micro and nano scale fabricating techniques, use of microfluidic systems is increasing in different fields. How to drive fluid is a hard question because of high pressure drop in micro scale. Different methods has been suggested to solve this problem, among which, electroosmotic pump is preferred because of its advantages. One of the main applications of microsystems is in biomechanical devices like microreactors which are usually working with non-Newtonian fluids. The cross section of these devices are most often close to rectangular shape.Therefor, in this study,Hydrodynamic charactristics and mass transport of non-Newtonian fluids under... 

Nowadays, technology has facilitate the miniaturization of laboratory systems, medical and drug delivery tools. As a result, researchers are interested to miniaturize these tools. The extensive research in this field led to invention of lab-on-a-chips, which with the size of a few µm to a few mm, can do multiple tasks in human body. One of most important components of these devices, is microreactor. A wide range of measurements and reactions in microreactors, need to bind with the receptors at the surface of the cylindrical microchannels. For this purpose, this study, investigates the effects of surface heterogeneity on microreactors performance. In this Thesis, the governing equations were... 

The purpose of this research is the synthesis of nanoparticles using micro fluid glass.The microfluidic glassy building is studied. Glass microfluidic microchannels making hydrophobic the continuing experiments carried out so that the water droplets in the organic phase and at the end of nanoparticles should be synthesized. Tests hydrophobic microchannels and water droplets in the organic phase was formed. In order to ensure an escape water contact angle and FTIR micro-channel test is taken and to avoid the droplets merged with each of surfactant SDS was used. In the end, DLS and FESEM nanoparticles synthesized using the tests have been evaluated and the concentrations of reactants and flow... 

Consumption of oil and gas as energy carrier leads to irreversible environmental effects related to greenhouse gases emission. Hence, for the reduction in greenhouse gas emission, a shift to renewable resources for energy supply is recommended. However, in recent years, hydrogen has emerged as the most promising clean energy carrier for generating electrical power through fuel cells. Nevertheless, production of renewable hydrogen is the main barrier to the development of hydrogen as an energy carrier. Aqueous phase reforming of oxygenated hydrocarbon is developed by Dumesic for producing renewable hydrogen-rich gas with low CO. Since it is expected that, use of new technology such as the... 

The purpose of this study is to study heterogeneous nanocatalysts for the production of biofuels by the method of exchange of styrene using oil and methanol as a fossil fuel alternative. Preparation of nanocatalysts, performing characteristic tests and investigating the reaction in different operating conditions in the batch reactor has already been studied. Therefore, in this study, the production of biodiesel fuel using the trans-esterification of canola oil with nanocatalysts in the micro-reactor reactor will be discussed. Previously, a heterogeneous catalyst (lithium based on calcium-lanthanum) was constructed using a co-incineration method and a wet inoculum, and as active and stable... 

Due to high efficiency and modular production ability of fuel cells, they have been used extensively in the power plants, especially in portable devices such as fuel cell vehicles. The commercialization of the equipment is dependent on ensuring the safety of their operations. Many of these platforms employ steam reforming reactions at very high temperature in order to produce the hydrogen, which is implemented as the fuel in the PEM fuel cell. The technique of miniaturization is a promising approach to design a chemical process in which the rate of transport phenomena such as the mass and heat transfer are intensified by reducing the size of the reactor and allowing the process to be run... 

Microfluidic devices carry fluids in channels with the diameter in the scale of micrometers. Low consumption of raw materials, higher selectivity, enhancement of heat and mass transfer, and improved safety considerations are benefits of the application of microfluidic devices. In this venue, catalytic microreactors get high potential in the filed of the catalytic reaction. In recent years due to strict international environmental regulations, the sulfur content in fossil fuels should be at the minimum content. MEROX process is to most common route to remove mercaptan from the LPG dreams in the material gas refineries. However, in this process, the production of DiSulfid Oil (DSO) is a... 

Hand in hand with the flourish of the biodiesel industries, glycerol has turned into an abundant waste chemical posing obstacles to their large-scale implementation. Devising measures for efficient transformation of glycerol into value added products is a promising alternative to its large-scale disposal into the nature that would also increase the competitiveness of biodiesel fuels. In this study, production of lactic acid (LA) as a valuable chemical with wide applicability is studied in a continuous process with glycerol as a cheap and convenient feedstock. In this regard, the state-of-the-art approaches in catalytic conversion of glycerol to LA are reviewed. A catalytic method using... 

Sulfur compounds are largely an impurity in fossil fuels such as natural gas, crude oil and coal. In natural gas, the main sulfur compounds are hydrogen sulfide (H2S), carbonyl sulfide (COS),and C1-C3 mercaptans.Commercial methods for removing these compounds require the introduction of additional reactive substances (O2, H2, Olefins, NaOH, etc.), which often results in the production of other pollutants. Microfluid is a branch of science and technology that involves studying the behavior of fluid, the use of fluid and the manufacture of equipment or systems that are carried out in micro-channels.The dimensions of these canals are about ten to several hundred micrometers, and high of... 

Today, with the development of micro-technology in chemical reactions, the use of appropriate systems for the separation and purification of synthesized chemicals seems to be necessary. In this study, the continuous synthesis of bromide-lithium exchange reaction and the separation of organic and aqueous phase products in micro systems was investigated.The method used to construct micro-separator and micro reactor, a laser engraving technique, and thermal bonding of glass to glass.In the first step, the factors affecting the separation of organic and aqueous phase in the capillary micro-separator, such as the width of the capillary, the length of the capillary, the number of capillaries and... 

Due to the potential risk of sulfur compounds in fossil fuels and according to today’s regulations, sulfur content should be kept as low as possible, e.g., below 5 ppm. Mercaptans are one of the sulfur components in natural gas. Scope of this research defined as catalytic removal of ethyl mercaptan from the gas stream. For this purpose, two microreactor systems placed in series. In the first microreactor, catalytic decomposition of ethyl mercaptan has been investigated. In the first step of this survey, a microreactor with 24 microchannels with a newly designed distributor has been developed with a computational fluid dynamic technique. in comparison to the conventional triangular... 

Artemisinin as a natural peroxide possess a high anti parasite, and antivirus (Covid-19) properties which could be synthesized through the photooxygenation of dihydroartemisinic acid. This production possesses a lot of difficulties, for example, homogeneous catalyst is used for the photooxygenation reaction which makes photocatalyst and solvent non-reusable. In addition, separation of products from solvent and photocatalysts is difficult. Photooxygenation needs high pressure and low temperature which is very costly. Besides, because of several by-products which are producing during photooxygenation and protonation reactions, Artemisinin yield decreases. The aim of this study is to optimize... 

Nowadays, the use of microreactors is receiving a great deal of attention due to the unique characteristics of such systems, such as high surface-to-volume ratio, low material loss, greater safety, and minimizing mass and heat transfer limitations. In this study, the optimization of the continuous-flow synthesis of Plavix by Cu-MOF heterogeneous catalyst utilizing a glass microreactor was investigated. Structural characteristics of the catalyst were investigated using X-ray diffraction spectroscopy (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and BET surface area studies to describe the structure and morphology of the catalyst. In order to build... 

Idiopathic pulmonary fibrosis is the most common type of pulmonary fibrosis that causes ulcers inside the lungs. In addition to Nintedanib, Pirfenidone is currently the only compound approved by the US Food and Drug Administration in 2014 for the treatment of idiopathic pulmonary fibrosis. Meanwhile, in the pharmaceutical industry, drug synthesis is usually done through batch-wise processes, and pirfenidone is currently only produced through batch-wise processes. Hence, this study aims to change the synthesis method of this drug, which is traditionally performed through batch-wise processes, to a continuous flow process. Therefore, a micro-reactor technology can be adopted which offers a... 

In the past decades, the production of various active pharmaceutical ingredients in batch processes was common. But today, the approach of pharmaceutical companies has changed and the use of the equipment and continuous processes such as microreactors has become common for reasons of safety, better mass and heat transfer, reduction of operators, and ease of scale-up. Unlike many top-selling drugs such as Ibuprofen and Artemisinin, Clopidogrel, the world's third best-selling drug needed by cardiac patients, has been manufactured only in batch processes. Due to the increase in the average age of the population, the urgent need for the use of Plavix (clopidogrel) has increased in recent years.... 

Manufacturing in many industries, such as electronics, petrochemical, automotive, and food, has long relied on continuous approaches, while the pharmaceutical industry has traditionally been processed in batch reactors. Since the beginning of the third millennium, continuous drug synthesis has received attention due to its multiple advantages over batch systems, which include process safety, adaptability, controllability, economic efficiency, scale-up, and enhancing performance. In this project, the pharmaceutical intermediate 1,4-benzodiazepine, which is usable as a precursor of diazepam and flurazepam, is continuously synthesized in a 400 microliters integrated micromixer and microreactor... 

Clopidogrel, as an antiplatelet medicine, is currently one of the most widely used medicines to reduce the risk of stroke and prevent the formation of blood clots for heart patients all over the world. This medicine is still produced using the conventional approach of drug production, i.e. batch method. On the other hand, due to the many advantages of flow chemistry, such as increasing the rate of mass and heat transfer, increasing safety, performance, etc., the production of medicines using the flow approach has been highly regarded by large pharmaceutical companies in recent years. In this research, the production of clopidogrel was done using a continuous flow approach and different... 

In recent years, batch systems were often used in the synthesis of pharmaceuticals. Nowadays, due to the possibility of more optimal conditions in flow systems, such as better mixing and optimal performance of heat transfer and mass transfer, process safety, reduction of retention time, and ease in increasing the scale of the process, the use of flow systems has been expanded. B-hydroxysulfone is a pharmaceutical intermediate in the production of bicalutamide, which is used in the treatment of prostate cancer and is used in many organic and biological processes. The reaction time in batch systems is about 17 to 20 hours, and in the flow system, the retention time has reached about 180-90... 

In order to fabricate batch and continuous systems to synthesize Pirfenidone (PFD), Solidwork and COMSOL software were used. Effects of parameters on reaction yield including; microreactors, micromixer, solvents, temperature, reaction time, and catalysts were understudied. Moreover, FTIR, NMR and HPLC analyses used to evaluate the prepared PFD. Its yield in microfluidic (30.5 %) was higher than that of batch (17.1 %) reactor. Besides, reaction yield in the presence of DMSO was higher than DMF in both reactors. It was shown that, adding a micromixer enhanced reaction time. leading to a higher PFD yield. Nonetheless, the yield was reduced by enhancing the temperature when DMF was utilized....