Role of Ethyl Cellulose in Bitumen Extraction from Oil Sands Ores Using an Aqueous–Nonaqueous Hybrid Process

Abstract

A major drawback associated with current hot or warm water-based bitumen extraction processes is the high consumption of energy. To address this issue, an aqueous–nonaqueous hybrid bitumen extraction process (HBEP), in which a portion of the diluent (solvent) was added upfront to soak mined oil sands prior to its water-based extraction, was proposed and demonstrated to be feasible to process mineable oil sands at ambient temperatures. This study investigates the effect of adding ethyl cellulose (EC) as a promising demulsifier to the solvent on bitumen recovery and froth quality in the ambient HBEP. The laboratory flotation results clearly showed a significant improvement in froth quality with a negligible setback on bitumen recovery by 100–200 ppm EC addition to the HBEP. Determined by an online visualization method, the addition of EC in solvent to the HBEP was found to further enhance separation kinetics of bitumen from sand grains of real oil sands ores. The addition of EC in solvent also increased the probability of bitumen droplet coalescence determined with a micropipette technique, but hindered the attachment of air bubbles to solvent-soaked bitumen, in particular at high EC dosages as evaluated by increased induction time of air bubble-bitumen attachment.

Impact of a novel bitumen extraction process on mined oil sands tailings behavior

“…Heating water to higher temperature in the WBE process requires large energy consumption and creates high GHG emission concerns. To address these challenges, a novel HBE process was developed in previous studies . A key advantage of HBE is that it can be operated at 20°C while yielding comparable or higher bitumen recoveries and froth qualities compared to higher‐temperature WBE …”

“…The commercial CWHE‐based processes that utilize hot or warm water and sometimes caustic, consume large amounts of thermal energy and produce stable FFT. Recently, both bench and pilot scale studies have demonstrated that an aqueous/nonaqueous hybrid bitumen extraction (HBE) process is a potential alternative to commercial CHWE . In HBE, a fraction of solvent already applied in froth treatment is distributed upstream to soak the mined ore before slurry conditioning, following which the water‐based process is applied as usual, but at ambient operating conditions and without caustic addition .…”

“…Recently, both bench and pilot scale studies have demonstrated that an aqueous/nonaqueous hybrid bitumen extraction (HBE) process is a potential alternative to commercial CHWE . In HBE, a fraction of solvent already applied in froth treatment is distributed upstream to soak the mined ore before slurry conditioning, following which the water‐based process is applied as usual, but at ambient operating conditions and without caustic addition . It was reported that HBE is a robust process for obtaining high bitumen recovery, although its effectiveness depends on the amount and type of solvent used to presoak the ore. Bitumen recoveries from ambient‐temperature HBE are comparable or higher than those achieved using standard Clark hot water extraction.…”

“…It was reported that HBE is a robust process for obtaining high bitumen recovery, although its effectiveness depends on the amount and type of solvent used to presoak the ore. Bitumen recoveries from ambient‐temperature HBE are comparable or higher than those achieved using standard Clark hot water extraction. As well, ambient HBE can produce bitumen froth with lower fines contents and/or water contents . For good‐processing ores, for which over 90% bitumen recoveries are achieved using minimal initial solvent addition, the amount of solvent lost to the HBE tailings can be held below the regulatory limit even without the use of a tailings solvent recovery unit .…”

MPEG grafted quaternized carboxymethyl chitosan for demulsification of crude oil emulsions

“…Recently, Lin et al . found that ethylcellulose (EC) is an effective demulsifier which can get rid of more than 90% of water from water‐in‐bitumen emulsions at an optimal dosage, and systematically studied the demulsification mechanisms . EC was shown to demulsify water‐in‐bitumen emulsions through flocculation‐promoted coalescence of water droplets, displacement, and disruption of the interfacial films and destabilize the emulsions .…”