The NAD glycohydrolase (NADase) from Bungarus fasciatus venom was purified over 1000-fold to electrophoretic homogeneity through a 3-step procedure which included affinity chromatography on Cibacron Blue agarose. The enzyme exhibited a broad pH profile with the optimum range between 7-8. Studies on the substrate specificity of B. fasciatus venom NADase demonstrated that alterations in the purine ring were less pronounced then alterations in the pyridinium moiety of NAD. Product inhibition studies indicated nicotinamide to be a noncompetitive inhibitor with a K_i = 1.4 mM and ADP-ribose to be a competitive inhibitor with a K_i =0.4 mM. The purified enzyme was inactivated by both 2,4-pentane dione and Woodward's Reagent K suggesting the involvement of a lysine and carboxyl group in the catalytic process. In contrast to other known NADases, the snake venom enzyme did not self-inactivate. The purified B. fasciatus venom NADase catalyzed a transglycosidation reaction (ADP-ribose transfer) with a number of acceptor molecules. The functioning of a variety of substituted pyridine bases as acceptor molecules was demonstrated through the formation of the corresponding NAD analogs. The enzyme also catalyzed the transfer of ADP-ribose to aliphatic alcohols (methanol to hexanol, inclusive) and a positive chainlength effect was observed in the functioning of these acceptors. Kinetic studies of transglycosidation reactions were consistent with the partitioning of an enzyme-ADP-ribose intermediate between water and nucleophilic acceptors as has been proposed in earlier studies of mammalian NADases. The partitioning of this intermediate between water and pyridine bases can be correlated with the basicity of the ring nitrogen of the pyridine derivative. The K_i of pyridine bases in the hydrolytic reaction did not equate to the K_m of these bases in the pyridine base exchange reaction suggesting two forms of the NADase with varying affinity for the pyridine bases. This implys the pyridine base exchange reaction to be more complicated than originally proposed. / Master of Science

Recent publications on ethanol production and purification shows optimized energy and water consumptions as low as 22,000 Btu/gal ethanol and 1.54 gal water/gal ethanol respectively using multieffect distillation. Karuppiah, et al use column rating and mathematical optimization methods and shortcut design models to design evaluate and optimize the energy and water consumption. In this work, we compare shortcut design and rigorous simulation models for an ethanol purification distillation system, and we show that distillation systems based on shortcut design underestimate the true energy and water consumption of the distillation system. We then use ASPEN Plus, to design a multieffect distillation system and an extractive distillation system using rigorous simulation and compare the two for energy and water consumptions. We show that the extractive distillation system has lower steam and cooling water consumptions and consequently lower energy and water consumptions than multieffect distillation in corn-to-ethanol production and purification. We also show that the extractive distillation system is cheaper than the multieffect distillation system on a cost per gal ethanol basis. This work gives an energy consumption of 29987 Btu/gal ethanol and water consumptions 2.82 gal/gal ethanol for the multieffect distillation system at a manufacturing cost of $3.03/gal ethanol. For the extractive distillation system, we calculate an energy consumption of 28199 Btu/gal ethanol and a water consumption of 2.79 gal/gal ethanol at a manufacturing cost of $2.88/gal ethanol. / Master of Science

During the past decades, reactive distillation has received intensive attention due to the well known benefits of integrating distillation with reaction in a single unit. Significant capital savings, improved conversion and selectivity, avoidance of azeotropes, together with heat integration are some of the main advantages of using reactive distillation. Many applications have proven to be economically advantageous by using reactive distillation (e.g. MTBE and TAME synthesis, production of methyl-acetate, manufacture of di-isopropyl-ether, oligomerisation of linear butenes and others). Whereas there are many procedures available for the synthesis of non-reactive columns or reactive-separation systems, the synthesis of reactive distillation columns is still a challenge, due to the complexity and the high number of design parameters involved. Available conceptual design methods generally address three (or four) components and fully reactive columns, but there is still a lack of systematic conceptual design methods for more general column configurations and for multi-component systems. The aim of this work is to develop a methodology to identify promising column configurations and to obtain column design parameters (number of reactive and non-reactive stages, reflux and reboil ratios, feed condition) for a given feed mixture and a set of desired products. A new systematic design method for reactive systems reaching equilibrium allows the analysis of the impact of different configurations (fully reactive or hybrid columns) and feed policies (single- or double-feed columns) on column performance. The methodology is extended to account for kinetically-controlled reactions in synthesis and design of reactive distillation columns. Systems with two degrees of freedom (according to the Gibbs phase rule) were considered for equilibrium reactions, and ternary and quaternary systems for kinetically-controlled reactions. Reactive distillation column designs generated by the methodology are presented as illustrative examples. Their predicted performances are shown to be in good agreement with those predicted by rigorous simulation using HYSYS. The approach can easily be automated and typically generates multiple designs, allowing a design engineer to efficiently compare various design options including hybrid and fully reactive columns, single- and double-feed configurations, and different sets of operating parameters for a given column configuration. The new methodology developed in this work facilitates a stepchange in conceptual design practice, offering a systematic and easy to use tool for the synthesis and design of reactive distillation columns.

The reStill is the next generation in home-distillation columns, more commonly referred to as Stills. The advances in design and control make it easier than ever to produce high quality alcohol. The project focussed on producing a proof of concept and conducting market validation for the product as it was in the design/concept stage. This report summarises the planning processes involved in the project, the progression of the venture to date and analyses the lessons learnt during this process.

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