Carbon dioxide assisted paraffinic froth treatment

在石蜡泡沫处理(PFT)中，为了保持沥青产品的质量，需要使用大量的石蜡溶剂来诱导沥青质的析出。溶剂利用率高对尾矿溶剂回收装置的处理能力提出了更高的要求，大大增加了生产成本。此外，沥青质沉淀还会造成油气损失。因此，在不使用大量石蜡溶剂的情况下改进PFT工艺并实现高沥青回收率是可取的。*在这种情况下，我们建议在PFT处理中使用二氧化碳(CO2)作为过程助剂。在PFT操作温度和压力下，将CO2引入到溶剂稀释沥青泡沫中。处理效果将通过沥青质沉淀开始时的溶剂/沥青比、沥青质/水/固体集合体的沉降率和沥青性质(粘度、密度、总酸值、沥青质含量、焦炭指数)进行评估。将研究二氧化碳与沥青组分、水、溶剂中的矿物固体之间的相互作用。我们预计，开发的工艺将减少石蜡溶剂的使用，在保持沥青质量的同时提高沥青回收率。**

In paraffinic froth treatment (PFT), large amount of paraffinic solvent is used to induce asphaltene precipitation in order to maintain the quality of bitumen product. The high solvent usage demands more capacity in tailings solvent recovery unit, increasing operation cost dramatically. In addition, asphaltene precipitation results in hydrocarbon loss. It is therefore desirable to improve the PFT process without using large volume of paraffinic solvent and to achieve high bitumen recovery. ****In this context, we propose to use carbon dioxide (CO2) as a process aid in PFT treatment. CO2 will be introduced to the solvent-diluted bitumen froth at PFT operation temperature and pressure. The performance of treatment will be evaluated by solvent/bitumen ratio at onset of asphaltene precipitation, settling rate of asphaltene/water/solids aggregates, and bitumen properties (viscosity, density, total acid number, asphaltene content, coke index). The interactions between CO2 and bitumen components, water, mineral solids in solvent will be investigated. We anticipate the process developed will reduce the use of paraffinic solvent and improve bitumen recovery while maintain bitumen quality. **