Mass transfer in bioreactors and reactors

这项研究计划的目的是了解化学反应和分子扩散之间的耦合作用从几纳米到几微米的长度范围。这项研究将调查与能源和环境有关的两个重要反应：油砂沥青的热裂化，以及碳氢化合物在产甲烷联合体中的细菌向细胞内和细菌之间的传输。在高温裂解和碳氢化合物的生物转化中，反应都受到反应分子短距离运动的深刻影响。例如，当油砂沥青中的大分子在高温下破裂时，我们希望破裂的碎片逃逸到汽相中释放出有价值的产品。如果裂解的碎片不能足够快地扩散出液体，那么它们可能会发生反应，形成低价值的焦炭。在碳氢化合物的细菌转化中，细胞壁在决定哪些化合物进入细胞方面起着关键作用。细胞壁中的蛋白质泵可以从细胞中去除抗生素和碳氢化合物等化合物。了解和控制化合物在细胞壁上的移动是利用细菌作为有效的生物反应器进行环境清理和将碳氢化合物转化为有用产品的关键步骤。

The objective of this research program is to understand the role of coupling between chemical reactions and diffusion of molecules length scales from a few nanometers to a few microns. The research will investigate two important reactions relevant to energy and the environment; thermal cracking of oil sands bitumen, and the bacterial transport of hydrocarbons into cells and between bacteria in methanogenic consortia. In both high-temperature cracking and in biological conversion of hydrocarbons, the reactions are profoundly affected by the movements of the reacting molecules over short distances. For example, when large molecules in oil sands bitumen break apart at high temperature, we want the cracked fragments to escape to the vapor phase to release valuable products. If the cracked fragments cannot diffuse out of the liquid phase fast enough, then they can react to form low-value coke instead. In bacterial conversion of hydrocarbons, the cell wall plays the key role in determining which compounds enter the cell. Protein pumps within the cell wall can remove compounds such as antibiotics and hydrocarbons from the cell. Understanding and controlling the movement of compounds across the cell wall is a crucial step to using bacteria as effective bioreactors for environmental cleanup and for conversion of hydrocarbons to useful products.