This report deals with the mathematical model of the transient behaviour of an existing ethane dehydrogenation furnace which is composed of two main sections: a preheating convection section and a radiant-heated section. The correlation of pressure drop with time has been found from the available data. The fractional carbon deposition and the multiplier coefficient of a pressure drop equation have been determined by the direct search optimization technique of Hooke and Jeeves. An optimal policy for the cyclic operation of the furnace was determined by considering plant temperature profile and hydrocarbon/ steam ration as parameters for maximizing average ethylene produced per day. The effect of temperature profile on the distribution of carbon deposited along the reactor was also predicted and discussed. / Thesis / Master of Engineering (ME)

The reaction barrier and heat of formation of the various dehydrogenation reactions involved in the steam reforming of ethane is a critical concern in the applications and understanding of these reactions. Focusing on Ir-based catalyst, we report a comprehensive reaction network of dehydrogenation of ethane on Ir(100) based on extensive density functional theory calculations performed on 10 C-H bond cleavage reactions, utilizing the Vienna Ab Initio Package codes. The geometric and electronic structures of the adsorption of C2Hx species with corresponding transition-state structures is reported. We found that the C-H bond in CH3C required the most energy to activate, due to the most stable four-fold hollow adsorption site configuration. Ethane can easily dissociate to CH3CH and CH2CH2 on Ir(100) and further investigation of surface temperature dependence will contribute to the research effort in this area. By using the degree of dehydrogenation of the reactant species as a variable to correlate the C-H bond cleavage barrier as well as reaction energy. DFT studies reveal that the surface Ir(100) to a great extent promotes ethane dehydrogenation when compared to other surfaces.

<p>The present work is focused on the synthesis of small-scale (modular processes) to produce olefins from light alkane resources in shale gas.</p> <p>Olefins, which are widely used to produce important chemicals and everyday consumer products, can be produced from light alkanes - ethane, propane, butanes etc. Shale gas is comprised of light alkanes in significant proportion; and is available in abundance. Meanwhile, shale gas wells are small sized in nature and are distributed over many different areas or regions. In this regard, using shale gas as raw material for olefin production would require expensive transportation infrastructure to move the gas from the wells or local gas gathering stations to large central processing facilities. This is because existing technologies for natural gas conversions are particularly suited for large-scale processing. One possible way to take advantage of the abundance of shale resource for olefins production is to place small-sized or modular processing plants at the well sites or local gas gathering stations.</p> <p>In this work, new process concepts are synthesized and studied towards developing simple technologies for on-site and modular processing of light alkane resources in shale gas for olefin production. Replacing steam with methane as diluent in conventional thermal cracking processes is proposed to eliminate front-end separation of methane from the shale gas processing scheme. Results from modeling studies showed that this is a promising approach. To eliminate the huge firebox volume associated with thermal cracking furnaces and allow for a compact cracking reactor system, the use of electricity to supply heat to the cracking reactor is considered. Synthesis efforts led to the development of two electrically powered reactor configurations that have improved energy efficiency and reduced carbon footprints over and compare to conventional thermal cracking furnace configurations.</p> <p>The ideas and results in the present work are radical in nature and could lead to a transformation in the utilization of light alkanes, natural gas and shale resources for the commercial production of fuels and chemicals.</p>