Flocculation and dewatering of oil sands tailings with hyperbranched functional polyolefins

超支化功能聚烯烃对油砂尾矿的絮凝脱水

• 批准号: 490535-2015
• 负责人: Soares, Joao
• 金额: $ 6.64万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=618954
• 关键词: Flocculation; dewatering; oil; sands; tailings

The oil sands reserves in Alberta are a major Canadian natural resource. They are the third largest source of crude oil in the world, only surpassed by those of Saudi Arabia and Venezuela. Unfortunately, Canadians pay a high environmental price to use this valuable natural resource. The extraction process adopted by the oil sands industry produces about 1.5 barrels of fluid fine tailings for every barrel of bitumen processed. Tailings are a mixture of water, sand, clays, and residual bitumen. The tailings are transferred to ponds where the sand settles fast, but the fine clays remain suspended for a long time before significant settling takes place. After many years, a stable suspension containing about 30 wt% of fine clays, called mature fine tailings, is formed. Mature fine tailings have the consistency of yogurt. It is not possible to walk or drive on top of these ponds. Consequently, the area they occupy becomes a wasteland that cannot be recovered. It has been estimated that the accumulated volume of mature fine tailings will exceed one billion cubic meters by 2020. The continuing collection of tailings has created a severe environmental problem in Alberta because the current treatment technologies cannot significantly reduce the volumes of legacy and fresh tailings. In this project, we will make novel polymer flocculants to treat tailing ponds by flocculation and dewatering. The recovered water will be sent back to the oil sands extraction process, while the dewatered ponds will become solid enough so that it becomes trafficable, allowing for vegetation to be planted on them, thus reclaiming the land wasted by the former tailing ponds. The proposed hyperbranched functional polyethylenes have never been used before to treat oil sands tailings, but our preliminary results show they can potentially solve many of the limitations faced by existing tailings treatment technologies. We will determine which properties of these polymers control tailings flocculation and dewatering, and will transfer this knowledge to the oil sands industry. The proposed research project has great value because of the significant contribution of the oil sands industry to the Canadian economy and the magnitude of the tailings problem.

艾伯塔省的油砂储量是加拿大的主要自然资源。它们是世界第三大原油来源，仅次于沙特阿拉伯和委内瑞拉。不幸的是，加拿大人为使用这种宝贵的自然资源付出了高昂的环境代价。油砂行业采用的提炼工艺，每加工一桶沥青，就会产生约1.5桶液体细粒尾矿。尾矿是水、沙、粘土和残留沥青的混合物。尾矿被转移到沙子快速沉降的池塘中，但细小的粘土在发生显著沉降之前保持悬浮很长一段时间。经过多年，形成了含有30wt%左右细粒粘土的稳定悬浮液，称为成熟细粒尾矿。成熟的细粒尾矿具有酸奶的稠度。在这些池塘上行走或开车是不可能的。结果，他们占领的地区变成了一片无法恢复的荒地。据测算，到2020年，我国成熟细粒尾矿堆积量将超过10亿立方米。尾矿的持续收集在艾伯塔省造成了严重的环境问题，因为目前的处理技术无法显著减少遗留尾矿和新鲜尾矿的数量。在本项目中，我们将通过絮凝和脱水来制备新型聚合物絮凝剂来处理尾矿库。回收的水将被送回油砂开采过程，而脱水后的池塘将变得足够坚固，可以通行，允许在上面种植植物，从而开垦以前尾矿库浪费的土地。建议的超支化功能聚乙烯以前从未被用于处理油砂尾矿，但我们的初步结果表明，它们有可能解决现有尾矿处理技术面临的许多限制。我们将确定这些聚合物的哪些特性控制尾矿的絮凝和脱水，并将这一知识传授给油砂行业。由于油砂行业对加拿大经济的巨大贡献以及尾矿问题的严重性，拟议的研究项目具有很大的价值。