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R. S. Kalb
applications come for ionic liquids? The answer is: Commercial applications already
exist, they increase every year, and they are here to stay!
Table 11.1 shows a list of carefully selected, industrially implemented ionic liquid
applications. By nature of the means by which this information was collected [20], the
list cannot be complete, and there are thus additional unpublished and/or confidential applications. It is beyond the scope of this chapter to describe the chemical and
technical details of each of these applications, and for more information, the reader
is referred to relevant literature [21–32], Web pages, and electronic documents of the
cited companies, as well as other chapters of this book. The listed implementations
are summarized by the general role the ionic liquid plays in each application and have
proven successful within the processing limits of technical effectiveness, robustness,
life cycle, safety, and environmental impact. In spite of the rather high prices of
ionic liquids, the ionic liquid/application pairs have proven competitive within capital expense (CAPEX) and operating expense (OPEX) budgets and remain clearly
attractive to management and investors.
The unusual solvation properties of several ionic liquids are used as activating
solvents, for example, to highly activate hydrochloric acid and replace phosgene for
chlorination of alcohols at BASF (“nucleophilic HCl”) and for the dimerization of
butenes to octanes, that are ultimately used to manufacture plasticizers at Axens (the
“Difasol™” process).
Implemented uses of ionic liquids as catalysts include petroleum refinery alkylations with strong Lewis-acidic, chloroaluminate-based ionic liquids, applied by
Chevron Honeywell UOP (see Chap. 2) and PetroChina.
Since 2002, BASF has used ionic liquids at the commercial scale as auxiliaries to
operate the well-known BASIL™ process; the ionic liquids act as acid-scavenging
agents during the production of alkoxyphenylphosphines. In contrast to the conventional use of triethylamine to synthesize alkoxyphenylphosphines, which results in
the formation of solids, an ionic liquid phase is formed that can be more easily separated. Additionally, BASF is currently using ionic liquids as entrainer components
for azeotropic distillation at the pilot scale.
Ionic liquids are also used as performance additives in commercial products.
For example, polymers made by BASF, Evonik, and 3M exploit the antistatic properties of the ionic liquids. Antistatic fluids are used to clean sensitive and high-value
surfaces and also to prevent the formation of solid residues in process spray nozzles
(IoLiTec/Wandres). Clariant utilizes a SCILL catalyst (supported catalyst with ionic
liquid layer) for the selective hydrogenation of downstream commercial products,
such as 1,3-butadiene, propyne, and acetylene [33–35]. Here, the ionic liquid layer
modifies the catalytic sites of a heterogeneous solid-supported catalyst in a ligandlike manner. The specific solubility of localized feedstocks and products in the ionic
liquid film adjusts their concentrations at the active center causing a crucial modification to the reaction path. Additional performance additives are used for diverse
applications at IoLiTec, including ionic liquids for CO 2 separation and protein stabilization at pilot scale. In the latter application, the solvent’s unique properties allow
for higher temperatures to be tolerated by the proteins, and thus, better crystallization can be achieved. IoLiTec also utilizes ionic liquids as chemical dispersants at
R. S. Kalb
applications come for ionic liquids? The answer is: Commercial applications already
exist, they increase every year, and they are here to stay!
Table 11.1 shows a list of carefully selected, industrially implemented ionic liquid
applications. By nature of the means by which this information was collected [20], the
list cannot be complete, and there are thus additional unpublished and/or confidential applications. It is beyond the scope of this chapter to describe the chemical and
technical details of each of these applications, and for more information, the reader
is referred to relevant literature [21–32], Web pages, and electronic documents of the
cited companies, as well as other chapters of this book. The listed implementations
are summarized by the general role the ionic liquid plays in each application and have
proven successful within the processing limits of technical effectiveness, robustness,
life cycle, safety, and environmental impact. In spite of the rather high prices of
ionic liquids, the ionic liquid/application pairs have proven competitive within capital expense (CAPEX) and operating expense (OPEX) budgets and remain clearly
attractive to management and investors.
The unusual solvation properties of several ionic liquids are used as activating
solvents, for example, to highly activate hydrochloric acid and replace phosgene for
chlorination of alcohols at BASF (“nucleophilic HCl”) and for the dimerization of
butenes to octanes, that are ultimately used to manufacture plasticizers at Axens (the
“Difasol™” process).
Implemented uses of ionic liquids as catalysts include petroleum refinery alkylations with strong Lewis-acidic, chloroaluminate-based ionic liquids, applied by
Chevron Honeywell UOP (see Chap. 2) and PetroChina.
Since 2002, BASF has used ionic liquids at the commercial scale as auxiliaries to
operate the well-known BASIL™ process; the ionic liquids act as acid-scavenging
agents during the production of alkoxyphenylphosphines. In contrast to the conventional use of triethylamine to synthesize alkoxyphenylphosphines, which results in
the formation of solids, an ionic liquid phase is formed that can be more easily separated. Additionally, BASF is currently using ionic liquids as entrainer components
for azeotropic distillation at the pilot scale.
Ionic liquids are also used as performance additives in commercial products.
For example, polymers made by BASF, Evonik, and 3M exploit the antistatic properties of the ionic liquids. Antistatic fluids are used to clean sensitive and high-value
surfaces and also to prevent the formation of solid residues in process spray nozzles
(IoLiTec/Wandres). Clariant utilizes a SCILL catalyst (supported catalyst with ionic
liquid layer) for the selective hydrogenation of downstream commercial products,
such as 1,3-butadiene, propyne, and acetylene [33–35]. Here, the ionic liquid layer
modifies the catalytic sites of a heterogeneous solid-supported catalyst in a ligandlike manner. The specific solubility of localized feedstocks and products in the ionic
liquid film adjusts their concentrations at the active center causing a crucial modification to the reaction path. Additional performance additives are used for diverse
applications at IoLiTec, including ionic liquids for CO 2 separation and protein stabilization at pilot scale. In the latter application, the solvent’s unique properties allow
for higher temperatures to be tolerated by the proteins, and thus, better crystallization can be achieved. IoLiTec also utilizes ionic liquids as chemical dispersants at