Carbon dioxide assisted paraffinic froth treatment: Simulating flue gas

我们最近完成了NSERC CRD项目CRDPJ516469-17“二氧化碳辅助石蜡泡沫处理”。在该项目中，我们将正庚烷与沥青以1.08的重量比混合，观察到沥青质开始沉淀。随后，我们将CO2气体注入到正庚烷/沥青混合物中，在此比例下，21℃或90℃，CO2压力高达1.7 Mpa，发现沉淀沥青质的数量显著增加。当向庚烷/沥青混合物中加入水，然后注入二氧化碳时，会有更多的沥青质析出。总体而言，在庚烷/沥青比为1.08时，水和1.7兆帕二氧化碳的联合使用使沉淀沥青质的数量增加了7个百分点。因此，在石蜡泡沫处理中使用气态二氧化碳可以显著减少溶剂用量。目前的建议是对第二阶段研究的继续。在第二阶段，我们建议检查在石蜡泡沫处理中使用烟道气中的二氧化碳促进沥青质沉淀的操作参数。此外，将使用戊烷代替庚烷。烟气中的CO2含量在10%到70%之间，这将在实验室中用CO2/N2混合气体进行模拟。将使用来自Kearl的沥青泡沫样品(已经含有水)。二氧化碳/氮气混合物将在不同的戊烷/沥青比例下注入到总压力高达1.7兆帕的戊烷/科尔沥青泡沫样品的混合物中。将确定沉淀沥青质的数量，并分析沥青产品(DILBIT)和沉淀废物的质量。拟议项目的结果将使二氧化碳辅助石蜡泡沫处理的概念更接近于减少溶剂用量的潜在商业实施。

We recently completed an NSERC CRD project CRDPJ516469-17 "CO2-Assisted Paraffinic Froth Treatment". In the project, we mixed n-heptane with bitumen at a weight ratio of 1.08, and observed that asphaltene started to precipitate. Subsequently, we injected CO2 gas to the heptane/bitumen mixture at this ratio, 21ºC or 90ºC, and CO2 pressures up to 1.7 MPa, and found that the amount of precipitated asphaltene was increased significantly. When water was added to the heptane/bitumen mixture, followed by CO2 injection, even more asphaltene was precipitated. Overall the amount of precipitated asphaltene increased by 7 percentage points by the combined use of water and 1.7 MPa CO2 at heptane/bitumen ratio of 1.08. Therefore, significant reductions in solvent dosages may be achieved by using gaseous CO2 in paraffinic froth treatment. The current proposal is a continuation of the research into Phase 2. In Phase 2, we propose to examine operational parameters of using CO2 in flue gas to promote asphaltene precipitation in paraffinic froth treatment. Also, pentane will be used instead of heptane. CO2 content in flue gas ranges from 10 to 70 vol%, which will be simulated by CO2/N2 gas mixtures in the laboratories. A bitumen froth sample from Kearl will be used (which already contains water). The CO2/N2 mixtures will be injected to the mixtures of pentane/Kearl bitumen froth sample up to 1.7 MPa total pressure at different pentane/bitumen ratios. The amount of precipitated asphaltene will be determined, and the quality of the bitumen product (dilbit) and precipitated wastes will be analyzed. The results of the proposed project will bring the concept of CO2-assisted paraffinic froth treatment a step closer to potential commercial implementation for solvent dosage reduction.