Investigation of agglomeration in fluid coking

拟议的研究解决了用于从加拿大油砂中加工沥青的流体焦化过程中的团块形成。沥青通过大量使用蒸汽辅助雾化的喷嘴喷射到反应器中。液体在热焦炭颗粒表面发生反应，产生馏出物、气体和焦炭。焦炭颗粒的膜包覆和颗粒间的相互作用是影响焦炭工艺效率的重要因素。当沥青被注入时，它就像液体粘合剂一样形成团块。其中一些破裂，而另一些幸存下来，导致稳定的团聚体，这是有害的，因为它们会降低理想的产物产量，并污染反应堆内部。它也能引起脱流。因此，了解导致减少团块形成的过程对工艺效率至关重要。本研究的目的是建立综合的数学模型来表示骨料的形成和破碎。它将使用计算流体动力学与人口平衡方法来表示多个固体，液体和气体相的多相流。它将使用欧拉/欧拉表示反应器中的相和离散元素方法（DEM）来开发表征现象和粒子水平所需的相关性。工业合作伙伴Syncrude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装置，每天生产约35万桶合成原油。这些流体焦化处理装置，加上帝国石油公司在萨尼亚的流体焦化处理装置，处理了加拿大原油产量的15%至20%。Syncrude公司位于加拿大阿尔伯塔省Fort McMurray，拥有约5200名员工。液体体积产量每增加1%就相当于每年约5000万美元的奖金。由于效率的提高，需要更少的沥青，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做出了重大贡献，并创造了大量的就业机会。

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.