Asphaltene precipitation kinetics and oil sands processing

油砂开采每天为全球石油供应贡献160万桶石油，是加拿大经济的主要贡献者。到目前为止，开采的沥青是使用水萃取方法回收的，这种方法会产生大量的温室气体，并需要大型尾矿池来处理废水。另一种选择是非水提取，使用溶剂而不是水，这样这个过程就不那么耗能，根本不需要尾矿库。然而，在非水萃取成为一种可行的技术之前，还有许多技术和经济问题需要解决。其中一个问题是，产品沥青可能含有悬浮细小的无机固体，这可能会给炼油商带来问题。这项建议研究了一种通过在沥青质沉淀开始附近促进颗粒聚集来去除这些细固体的方法。沥青质是沥青中最重的成分，在某些溶剂中会以微米级的颗粒形式沉淀。沉淀的颗粒倾向于迅速凝聚成直径数百微米的聚集体。沥青中的无机颗粒通常部分覆盖有沥青质材料，也可能在导致沥青质沉淀的溶剂条件下发生絮凝。在这项建议中，将在一系列条件下研究沥青质(和细粒)的沉淀和絮凝速率，以确定细粒可以在没有大量沥青质沉淀的情况下进行絮凝的条件。将进行沉降实验，以确定是否可以在实际时间框架内去除固体。拟议的研究还将提供相关的背景和必要的经验，为两名研究生在工业、研究机构和学术界从事与油砂有关的职业做准备。

Oil sands mining contributes 1.6 million barrels per day of oil to the global oil supply and is a major contributor to the Canadian economy. To date, mined bitumen is recovered using aqueous extraction methods which produce significant amounts of greenhouse gases and require large tailings ponds for the waste water. An alternative is non-aqueous extraction, where a solvent is used instead of water so that the process is less energy intensive and does not require tailings ponds at all. However, there are a number of technical and economic issues to be resolved before non-aqueous extraction becomes a viable technology. One of these issues it that the product bitumen may contain suspended fine inorganic solids which can be problematic for refiners. This proposal investigates a method to remove these fine solids by promoting particle aggregation near the onset of asphaltene precipitation. Asphaltenes are the heaviest components of the bitumen and can precipitate as micron sized particles in certain solvents. The precipitated particles tend to flocculate rapidly into aggregates which are hundreds of microns in diameter. The inorganic particles in the bitumen are often partially coated with asphaltenic material and may also flocculate at the solvent conditions that cause asphaltene precipitation. In this proposal, asphaltene (and fine solids) precipitation and flocculation rates are to be investigated over a range of conditions to identify the conditions where fine solids can be flocculated without significant asphaltene precipitation. Settling experiments will be performed to determine if the solids can be removed in a practical timeframe. The proposed research will also provide a relevant background and the necessary experience to prepare two graduate students for oil sands related careers in industry, research institutes, and academia.