Investigation of agglomeration in fluid coking

这项拟议的研究针对的是用于加工加拿大油砂沥青的流体焦化过程中的结块形成。沥青通过大量喷嘴喷洒到反应堆中，这些喷嘴使用蒸汽来辅助雾化。液体在灼热的焦炭颗粒表面发生反应，产生馏分产品、气体和焦炭。该工艺的效率取决于许多参数，其中焦炭颗粒的包膜和颗粒间的相互作用起着重要作用。当注入沥青时，它起到液体粘结剂的作用，形成凝聚体。其中一些破裂，而另一些幸存下来，导致稳定的团聚，这是破坏性的，因为它们导致较低的理想产品产量和反应堆内部的结垢。它还可能导致脱流。因此，了解导致减少结块形成的工艺对工艺效率至关重要。这项研究的目的是建立全面的数学模型来描述团聚体的形成和破裂。它将使用计算流体动力学和粒子数平衡方法来表示多个固体、液体和气相的多相流。它将使用反应堆中相的欧拉/欧拉表示和离散元方法(DEM)来发展表示现象和粒子水平所需的关联。工业合作伙伴辛克鲁德使用流体焦化将沥青升级为有价值的产品。它运营着世界上最大的三个流体焦化工艺装置，每天生产约35万桶合成原油。这些流体焦化工艺装置与帝国石油公司在萨尼亚的流体焦化工艺装置一起，加工了加拿大15%至20%的原油产量。辛克鲁德的业务位于加拿大艾伯塔省的麦克默里堡，拥有约5200名员工。液体产量每增加1%，就相当于每年约5000万美元的奖金。由于效率的提高，需要的沥青将更少，从而减少对环境的影响。油砂对加拿大经济非常重要，因为它对GDP的贡献很大，并创造了大量就业机会。

The proposed research addresses agglomerate formation in fluid coking used to process bitumen from Canadian oil sands. Bitumen is sprayed into the reactor through a large number of nozzles that use steam to assist atomization. The liquid reacts on the surface of hot coke particles resulting in distillate products, gases, and coke. The efficiency of the process depends on many parameters with film coating of the coke particle and the interaction between particles playing an important role. When bitumen is injected, it acts as a liquid binder and forms agglomerates. Some of those break up while others survive, leading to stable agglomerates that are damaging because they cause lower desirable product yield and fouling of the reactor internals. It can also cause defluidization. Therefore understanding the process that leads to reducing agglomerate formation is critical for process efficiency. The objective of this research is to develop comprehensive mathematical models to represent the aggregate formation and breaking. It will use computational fluid dynamics with population balance methods to represent the multiphase flow of multiple solid, liquid, and gaseous phases. It will use Eulerlian/Eulerian representation of the phases in the reactor and Discrete Element Methods (DEM) to develop the correlations needed for the representation of phenomena and the particle level. The industrial partner, Syncrude, uses fluid coking to upgrade the bitumen to valuable products. It operates three of the world's largest fluid coking process units producing about 350 000 barrels of synthetic crude per day. These fluid coking process units, together with Imperial Oil's fluid coking process unit in Sarnia, process between 15 and 20% of Canada's crude oil production. Syncrude's operation is located in Fort McMurray, Alberta, Canada, and employs approximately 5200 people. A 1% increase in liquid volume yields corresponds to a prize of approximately $50 million per year. Because of the increased efficiency, less bitumen would be needed resulting in less environmental impact. The oil sands are very important to the Canadian economy because of the significant contribution to the GDP and the large number of jobs created.