The name is absent

Chapter 2

demulsifiers do not aggregate to a significant extent and remain surface active.
Aromatic hydrocarbons such as toluene and xylene and water-miscible
hydroxycompounds such as n-butanol, isopropanol and monoethylene glycols are
often used as solvents for demulsifiers ^[21].

All the demulsifiers should be surface active to aggregate at water∕oil
interface. Thus the demulsifier needs to participate in both oil and water phase.
HLB (hydrophilic-lipophilic balance) values are used to characterize such
properties ^[31]. For nonionic surfactant, HLB ranges from 0 (completely lipophilic)
to 20 (completely hydrophilic)^[31]. Abdel-Azim et al.^[32] found demulsification was
favored by an increase in the number of polar groups and in aromaticity with HLB
values from 6 to 14. The authors claimed that such changes in the structure of the
demulsifiers favor their adsorption at the water-oil interfaces and therefore the
displacement/ solubilization of asphaltenes clustered in this region.

For the emulsions of water in diluted bitumen from Athabasca, the
flocculation of water droplets is significant, which will be discussed in chapter 3.
But the emulsion is very stable due to the asphaltenes and clay solids. Thus the
first step is to choose an appropriate coalescer with solvents for the coalescence
and chemicals to change the wettability of the clay solids.

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