BIODIESEL PRODUCTION FROM PALM OIL OVER CERIUM OXIDE DOPED TITANIUM DIOXIDE NANOMATERIALS

A brief study was carried out on heterogeneous base catalyst for the transesterification process of oil targeted at effective production of biodiesel. So in order to investigate the catalytic activity and efficiency in improving the production of biodiesel, the characterization and synthesis of Titanium Oxide nanoparticles with ionic liquid to enhance its catalytic effects was carried out. Furthermore, the characterization of Titanium Dioxide was done by using various analytical equipments such as Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Raman Spectra Analysis and so on. So by this, the relation of structure and catalytic activity of the prepared substances can be examined. The catalyst dosage, reaction time and temperature, and the catalyst reusability are the main variables that need to be evaluated. Besides that, the biodiesel is fabricated by using selected feedstock which is palm oil, and then it will be characterized to study the reaction of biodiesel with the catalyst prepared in order to improve the production. The Free Fatty Acid of palm oil is 0.11% and it is below 2%. So this allows for one-step transesterification process. Under the optimized condition the reusability of the catalyst is also tested and it can recycle for about 5 times with some decrease in yield. Generally this shows that heterogeneous catalyst can be recycled and dosage and reaction time can also be manipulated to get better yield. The obtained result proves that with increase of dosage and reaction time we can increase the yield of biodiesel. So overall, there is a very high chance to support biodiesel production by using this method

Synthesis and characterization of titanium dioxide (TiO2) Nanomaterials for biodiesel production

This project studies the optimization for parameters affecting the biodiesel production and synthesized the mixed metal oxides catalyst which is CeO2-TiO2. The feedstock used is crude palm oil which undergone the oil analysis prior the transesterification process. The FFA of crude palm oil is 0.11%, which is readily below 2%. Therefore, one-step transesterification is applicable. Based on the optimization using Response Surface Methodology (RSM), the optimized conditions are reaction temperature is 55oC, methanol to oil ratio is 11.05:1, 1.0 wt% catalyst concentration and reaction time is 60 minutes using NaOH as catalyst. The yield is 53.2%. The transesterification of palm oil is repeated under the same conditions using synthesized catalyst which yield 59.7% biodiesel. The CeO2-TiO2 is characterized using FTIR, SAP, VPFESEM and Raman Spectrometer. The reusability of the catalyst also is tested which shows that it can be recycled for about 5 runs with the decrement of yield not more than 3% for every run. This proves the ability of heterogeneous catalyst to be reused in more than one cycle. Besides, the catalyst dosage and reaction time effect on biodiesel yield are also tested. The results show that as the dosage of catalyst and reaction time increase, the yield also increases. In addition, experimental-simulation comparison is done by using ASPEN HYSYS software which shows slight different of 2.3%

Development of Novel Organic Materials with Stimuli-Responsive Applications

ABSTRACT The research herein describes development of fundamental concepts related to new materials that are designed to be stimuli responsive materials. There are two main avenues explored in this dissertation, a synthetic exploration of a novel aromatization reaction and using single electron reduced 4,4’-bipyridine as sensors for several different inputs. The new synthetic reaction described is based off of an oxidation of a cyclohexane in order to obtain a highly functionalized aromatic ring. The particular functionality that was studied in this abstract is related to the hexaester of cyclohexane. The product of such reactions is shown to be a first generation paddlewheel dendrimer. Since the reaction is not known, mechanistic investigations were performed so that the reaction scope may be generalized for further use beyond hexaester cyclohexanes. The second part of this dissertation shifts away from synthetic methodology into stable organic radical materials. 4,4’-bypridine shows a paramagnetic radical in its monomer form that forms diamagnetic dimers at higher concentrations. Since the dimerization is a fairly weak interaction, we enhance the degree of diamagnetism by tethering units together. Several of these units can be tethered together in a polymeric fashion. We then show the ability to disturb this diamagnetism with stimuli such as non-covalent binding interactions or the addition of heat. These changes in magnetic properties can be followed by electron paramagnetic resonance (EPR) and UV/vis spectroscopy. In addition to affecting the concentration of paramagnetic radicals by tethering units together, we also explore changing the substituents on our molecules to alter the binding constants obtained. Using the knowledge of tethering several units together, modulating our binding constants, and affecting the input by heat and non-covalent binding events, we are able to design molecules that display Boolean logic behavior and can act as sensors for a variety of inputs

Sporopollenin as an efficient green support for covalent immobilization of a lipase

Sporopollenin exine capsules (SECs), derived from the spores of Lycopodium clavatum, have been functionalised with 1,n-diamines and the resulting aminoalkyl microcapsules used to immobilize Candida antarctica lipase B (Cal B) via a glutaradehyde-based diimine covalent linker. The supported enzyme efficiently catalyzes the esterification of oleic acid with ethanol. Initial rates using the SEC-CalBs were comparable to the commercial enzyme Novozym 435, but displayed up to 20-fold higher specific activity. The supported enzymes could also be recycled and after four cycles displayed only a modest decrease in conversions. In a kinetic resolution the SEC-CalBs efficiently acetylated rac-1-phenylethanol, with conversions up to 37% after 5 hours and product enantiomeric excesses of >99%. Related to this, the dynamic resolution of rac-1-phenylethylamine, in the presence of Pd-BaSO₄ and ammonium formate, led to the acetylated amine with a 94% conversion and >99% ee

Chemical Kinetics

Chemical Kinetics relates to the rates of chemical reactions and factors such as concentration and temperature, which affects the rates of chemical reactions. Such studies are important in providing essential evidence as to the mechanisms of chemical processes. The book is designed to help the reader, particularly students and researchers of physical science, understand the chemical kinetics mechanics and chemical reactions. The selection of topics addressed and the examples, tables and graphs used to illustrate them are governed, to a large extent, by the fact that this book is aimed primarily at physical science (mainly chemistry) technologists. Undoubtedly, this book contains "must read" materials for students, engineers, and researchers working in the chemistry and chemical kinetics area. This book provides valuable insight into the mechanisms and chemical reactions. It is written in concise, self-explanatory and informative manner by a world class scientists in the field

Hydrothermally stable heterogeneous catalysts for biorenewable-derived molecule conversions to chemicals

The biorenewables filed seeks to emulate the petroleum model for chemical production; from a select few chemicals a plethora of products are produced. This emulation of the modern petroleum refinery-henceforth called the biorefinery-would allow greater penetration of biorenewable feedstocks into the typically petroleum based chemicals industry. Of great important to this idea is the development of catalysts capable of handling the conditions inherent to biorenewable feedstocks. Water presents a significant challenge to today\u27s catalysis. Using biorenewables, especially sugars, forces the processing to be in the condensed phase as they have little to no volatility. Water is the solvent of choice with most bio-based systems. In addition, the reactions desired to create the chemicals (like esterification) will also create water. This work sought to overcome this difficulty by developing new catalysts with a hydrothermally stable scaffold and active group. From this work the development of the carbon catalyst is shown. First, I investigated of the hydrothermal stability of the current carbon catalysts in literature. Second, some model compound work showed which active site configurations, if possible, would increase the hydrothermal stability of the acid catalyst. The last two are papers developing the first and second generation of hydrothermally stable acid catalysts. This work increases the possibility of chemicals derived from biorenewables. Hydrothermal stability of carbon based acid catalysts synthesized by sulfonating carbohydrates pyrolyzed at moderate temperatures (300-600°C) has been reported previously. To test the effect of carbon structure on hydrothermal stability, we produced catalysts by dry pyrolysis at 350ºC and 450ºC or by hydrothermal carbonization, followed by sulfonation with fuming sulfuric acid, as well as by direct sulfonation of glucose. The catalysts were characterized by BET, titration, Raman spectroscopy, TGA, XPS, reaction testing, and 13C solid state NMR. Catalysts were hydrothermally treated and then analyzed for sulfur retention and catalytic activity. The lower temperature carbon catalysts showed the best stability, however all showed significant activity loss. Solid state NMR characterized the structural details to attempt to correlate functional groups to hydrothermal stability of catalyst active sites. Structural models generated from NMR data showed that the most stable catalysts contained a significant fraction of furan rings and hardly any polycondensed aromatic rings. Development of heterogeneous catalysts for the biorenewables industry requires catalyst materials that are resistant to hydrothermal degradation. Unlike metal oxides and silica, carbon materials are recalcitrant to hydrothermal conditions. However, for solid-acid sulfonated carbon materials, there are conflicting reports on the stability of the sulfonic-acid groups on the aromatic rings for commercial applications. Currently, incomplete understanding remains about the relationship between hydrothermal stability and the immediate electronic hybridization of the carbon atoms adjacent to the sulfonic-acid active group. To test this relation systematically, model compounds containing sulfonic acid groups linked to aromatic, alkane, or cycloalkane carbon atoms were subjected to hydrothermal conditions (100°, 130°, and 160°C DI water up to 24 h). The structural integrity of the compounds was monitored with solution NMR. While the aromatic-sulfonic compounds degrade readily, the changes in the molecules with alkyl sulfonic acid linkages are negligible. Therefore, a hydrothermally stable sulfonic-acid catalyst needs to contain the sulfur attached via alkyl linkers. We combined research showing typical electrophilic substitution methods for sulfonated carbon catalysts to be inadequate with initial testing of model compounds and a proof of concept of glucose and taurine. This use of the Malliard reaction resulted in a catalyst stable under hydrothermal conditions but initially in colloidal form. Since this is undesireable in industrial processing, we sought to further stabilize the carbon backbone with the addition of more glucose. We found that the ratio of the glucose to the glucose taurine mixture is not as important as the ion used for the precursor. The potassium ion increased the amount of sulfur on the carbon catalyst, thereby increasing the reaction rate on a mass basis. These catalysts suffer from low surface area so we supporting them on SBA-15 and mesoporous carbon nanoparticles. With these two supports, the catalysts showed good activity on a similar sulfur basis. From previous research the Maillard reaction was successfully used to create hydrothermally stable carbon catalysts through pyrolysis synthesis. The Maillard reaction was used to create a new catalyst through a hydrothermal synthesis. The combination of glucose and taurine in a hydrothermal synthesis creates a solid that retains the sulfur-from the active group-even better than through pyrolysis synthesis. The synthesis temperatures ranged from 200-300ºC and it was found that the most stable catalysts were synthesized at 250ºC. The catalytic activity seemed insensitive to differences in the changes of the glucose to taurine ratio from 1:1 to 2:1 at the 250ºC synthesis. At the 200ºC synthesis temperature, the activity is not stable through the hydrothermal testing and at the 300ºC synthesis temperature; the sulfur retention is not as stable as the catalysts synthesized at 250ºC. From this work the development of the carbon catalyst is shown. First, the initial work showed the hydrothermal instability of the current carbon catalysts in literature because of their attachment of the sulfonic acid through an aromatic carbon. Second, model compounds showed an active site configuration connecting the sulfonic acid to the backbone through an aliphatic carbon, if possible, would increase the hydrothermal stability of the acid catalyst. The last two are papers developing the first and second generation of hydrothermally stable acid catalysts whereby glucose and taurine are used to make a catalyst through the Millard reaction. This work increases the possibility of chemicals derived from biorenewables

Lipase-Mediated Syntheses of Trimethylolpropane-Based Biolubricant and Cyclic Carbonate

Abstract Biocatalysis is considered as benign and efficient alternative to chemical catalysis for organic syntheses. Lipases are the most versatile biological catalysts implemented so far with great potential for production of different chemicals and materials in non-conventional reaction media. This thesis presents investigations on lipase catalyzed esterification and transesterification reactions in solvent-free media with a polyol (tri-ol), trimethylolpropane (TMP) to form TMP-trioleate and -cyclic carbonate for lubricant and polymer applications, respectively. Conventional lubricants are mineral oil based and lack biodegradability resulting in their accumulation in the environment. Synthetic esters of polyhydric alcohols and fatty acids are biodegradable and possess desirable technical properties for lubricant applications. Synthesis of TMP-trioleate from oleic acid and TMP catalyzed by commercial immobilized Candida antarctica lipase B, Novozym®435 (N435) was studied by varying reaction parameters. The product obtained possesses desirable pour point (-42 °C) for lubricant applications in sub-zero conditions. The biocatalyst was recycled in reactions at 70 °C for 7 batches, 24 h each, with a half-life of 94 h. The biocatalyst half-life was doubled by washing it with 2-propanol between the batches. A simplified kinetic model was developed for the lipase-catalyzed reaction in order to facilitate optimization and design of the process and minimize the amount of resources required for investigations of the process. The methodology used for the kinetic modeling is applicable for similar types of enzymatic reactions involving multi-substrate multi-product systems. Cyclic carbonates are potential monomers for phosgene-/isocyanate-free polycarbonates and polyurethanes that have wide range of applications. Six-membered cyclic carbonates can readily undergo ring-opening polymerization to form aliphatic polycarbonates and polyurethanes and their copolymers. Six-membered cyclic carbonate with hydroxyl functional group was obtained with 75% yield using a chemoenzymatic process involving lipase B catalyzed transesterification of dimethylcarbonate (DMC) with TMP in the presence of molecular sieve to form linear TMP carbonate followed by thermal cyclization. Performing the reaction in a recirculating flow reactor, higher conversion rates were obtained compared to the batch process, the product was recovered easily without extra separation steps, and the biocatalyst and molecular sieve remained intact for reuse. In silico evaluations of the reaction accompanied with empirical investigations confirmed that lipase B prefers DMC as acyl-donor while TMP and its derivatives, formed during the course of the reaction, serve as acyl acceptors. The formation of TMP carbonate oligomers hence found to be non-enzymatic and intensified by heat

Advances in Surface Modification and Treatment of Wood

Biopolymers including natural (e.g., polysaccharides, proteins, gums, natural rubbers, bacterial polymers), synthetic (e.g., aliphatic polyesters and polyphosphoester), and biocomposites are of paramount interest in regenerative medicine, due to their availability, processability, and low toxicity. Moreover, the structuration of biopolymer-based materials at the nano- and microscale along with their chemical properties are crucial in the engineering of advanced carriers for drug products. Finally, combination products including or based on biopolymers for controlled drug release offer a powerful solution to improve the tissue integration and biological response of these materials. Understanding the drug delivery mechanisms, efficiency, and toxicity of such systems may be useful for regenerative medicine and pharmaceutical technology. The main aim of the Special Issue on “Biopolymers in Drug Delivery and Regenerative Medicine” is to gather recent findings and current advances on biopolymer research for biomedical applications, particularly in regenerative medicine, wound healing, and drug delivery. Contributions to this issue can be as original research or review articles and may cover all aspects of biopolymer research, ranging from the chemical synthesis and characterization of modified biopolymers, their processing in different morphologies and hierarchical structures, as well as their assessment for biomedical uses