A Distillation-type Process for Thermal Decomposition of Complex Hydrocarbons by Film Boiling

复杂烃类薄膜沸腾热分解的蒸馏式工艺

• 批准号: 1336657
• 负责人: Charles Avedisian
• 金额: $ 33万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1336657&HistoricalAwards=false
• 关键词: Distillation; type; Process; Thermal; Decomposition

CBET-1336657PI-AvedisianThe conversion of condensed phase (liquid) organic chemicals to lighter fractions forms the basis of some chemical process industries. The current practice is to vaporize the reactant liquid separately and then transport the gases to the high temperature reaction environment. The overarching objective of this research is to develop the understanding of the thermo/chemical processes that governs operation of a unique chemical reactor concept which closely couples vaporization with decomposition in a reaction space that essentially builds itself. The concept involves establishing film boiling on a heated surface submerged in a pool of the reactant liquid. This heat transfer mode is developed when bubbles cannot transport energy away from a surface at a fast enough rate to avoid coalescence. A vapor film then forms on the surface which insulates it from the surrounding liquid. The resulting temperature drop across the vapor film can be more than a thousand degrees even though the liquid is comparatively cold. Such temperatures are more than sufficient for organic gases to decompose. The reaction occurs in the physical space of the vapor film that is controlled almost entirely by operational variables, most directly temperature of the surface on which film boiling is established. If surface temperature is lowered below the minimum film boiling temperature the reactor literally disappears. This aspect of self-assembly is unique among chemical reactor technologies. This research will investigate the versatility of film boiling to convert organic reactants that form condensable species which are soluble in the reactant liquid, and high boiling point liquids that can stress containment seals for the liquid pool. An all-glass distillation-type design for a reactor will be fabricated and applied to a range of chemicals with a progression of decomposition complexities, including a reactant liquid that will decompose only to noncondensable gases with a known reaction rate constant, a chemical that forms both noncondensable and condensable gases, a liquid hydrocarbon with many conversion steps, and a chemical that is prominent as a waste product in the biodiesel production process. The major outcome of the project will be a greater understanding of how film boiling promotes chemical reaction of organic gases with an experimental design that is applicable to a wide range of organic liquids. Success in this investigation will result in a fundamental understanding of the vaporization and heat transfer processes that govern a new chemical reactor technology based on film boiling for decomposing organic chemicals into more high-valued products. For example, there is currently a world-wide glut of glycerine due to its formation in the biodiesel production process that threatens the viability of the industry. The inherent portability and high gas temperatures of film boiling suggests its feasibility to convert pure glycerine to synthesis gas with potential to create a useful energy source from what is currently a waste product by a simple process that could make more efficient the production of biofuel from bio-based seed oil feedstocks.

CBET-1336657 PI-Avedisian将冷凝相（液体）有机化学品转化为轻质馏分是某些化学加工工业的基础。 目前的做法是将反应物液体单独蒸发，然后将气体输送到高温反应环境中。这项研究的首要目标是发展的热/化学过程，管理一个独特的化学反应器的概念，密切耦合汽化与分解的反应空间，基本上建立自己的操作的理解。 该概念涉及在浸没在反应物液体池中的加热表面上建立膜沸腾。 当气泡无法以足够快的速度将能量从表面传输出去以避免聚结时，就会产生这种传热模式。 然后在表面上形成蒸汽膜，使其与周围的液体绝缘。 即使液体相对较冷，蒸汽膜上的温度下降也可能超过1000度。 这样的温度足以使有机气体分解。 反应发生在蒸汽膜的物理空间中，蒸汽膜几乎完全由操作变量控制，最直接的是膜沸腾建立的表面的温度。如果表面温度低于最低膜沸腾温度，反应器实际上消失了。 自组装的这一方面在化学反应器技术中是独一无二的。 本研究将调查薄膜沸腾的通用性，以转换有机反应物，形成可冷凝的物种，这些物种是可溶于反应物液体，和高沸点液体，可以应力的液体池的安全壳密封。 将制造用于反应器的全玻璃蒸馏型设计，并将其应用于具有分解复杂性进展的一系列化学品，包括仅分解为具有已知反应速率常数的不可冷凝气体的反应物液体，形成不可冷凝气体和可冷凝气体的化学品，具有许多转化步骤的液态烃，以及在生物柴油生产过程中作为废物的化学品。该项目的主要成果将是更好地了解薄膜沸腾如何促进有机气体的化学反应，其实验设计适用于各种有机液体。 这项研究的成功将导致对蒸发和传热过程的基本理解，这些过程控制着基于膜沸腾的新化学反应器技术，用于将有机化学品分解成更高价值的产品。例如，由于甘油在生物柴油生产过程中形成，目前世界范围内甘油过剩，威胁到该行业的生存能力。 膜沸腾的固有便携性和高气体温度表明其将纯甘油转化为合成气的可行性，该合成气具有通过简单的方法从目前的废物产生有用的能源的潜力，该方法可以使从生物基种子油原料生产生物燃料更有效。