5 Commercial Aspects of Biomass Deconstruction with Ionic Liquids
117
Both the technology (the use of ILs) and intended application (biomass fractionation)
have an embedded deployment risk. Although many process-related advantages have
been claimed, none is yet proven at scale. Therefore, it is essential to find a currently
under-served niche application where there is a clear unmet customer need that can
be addressed. Niche applications should focus on using very low-cost feedstock and
existing infrastructure and preferably provide an environmental and/or social solution to an existing problem. These considerations can expedite learning by doing at an
industrially relevant level while still minimizing technological and investment risks.
For example, if the process is first developed for the use of an unwanted waste, which
is already collected at centralized locations and typically comes with a gate fee, this
serves to de-risk the processing costs. Once successfully proven at a relatively small
scale, which is viable for very low-cost feedstocks, the process can then be further
scaled-up to a point where relatively more expensive raw materials become viable,
such as sawdust or agricultural residues.
5.7.3 Toxicity and Safety Aspects
For any substance to be sold in the European Union in volumes exceeding one ton
per annum (tpa), Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) is required, and overseas markets will require similar registration.
Therefore, careful design of the IL to reduce toxicity is paramount to facilitate the
registration. However, more information on the health and environmental safety data
of ILs is needed [149]. The sheer number of ionic liquids conceivable, as well as their
very diverse structure, makes it impossible to give generally applicable statements
about their health and safety implications. This is contrary to the popular history of
ILs, as a huge part of their fame from the early 2000s until recently was hailed to the
their “green credentials”, which were largely attributed to their non-volatile nature.
The non-volatility of many ILs can provide some processing advantages, such as
relatively safer handling as no toxic fumes are produced and quantitative recovery
without the need for a solvent condenser.
However, such an exaggerated and non-assessed claim was toned down in many
recent IL studies for two main reasons. First is the increased awareness of the relativity concept as no solvent can be “green” in an absolute sense. The performance
of the new solvent will always have to be assessed for the specifically intended
application and then compared to other solvent options. The application of this relativity concept is imbedded in the life cycle assessment (LCA) approach, the standard
method to evaluate the environmental impact and performance of technologies [150–
152]. Currently, the lack of LCA studies to critically assess IL performance in many
technologies was addressed as one of the main challenges. Second, there has been
evidence that certain ILs have greater (eco)toxicity than molecular solvents [151],
and there is, therefore, concern about the environmental benefits of using ILs over
traditional solvents. The protic ILs used in the ionoSolv pretreatment, for example,
have not been studied for their health and environmental impacts. However, they
117
Both the technology (the use of ILs) and intended application (biomass fractionation)
have an embedded deployment risk. Although many process-related advantages have
been claimed, none is yet proven at scale. Therefore, it is essential to find a currently
under-served niche application where there is a clear unmet customer need that can
be addressed. Niche applications should focus on using very low-cost feedstock and
existing infrastructure and preferably provide an environmental and/or social solution to an existing problem. These considerations can expedite learning by doing at an
industrially relevant level while still minimizing technological and investment risks.
For example, if the process is first developed for the use of an unwanted waste, which
is already collected at centralized locations and typically comes with a gate fee, this
serves to de-risk the processing costs. Once successfully proven at a relatively small
scale, which is viable for very low-cost feedstocks, the process can then be further
scaled-up to a point where relatively more expensive raw materials become viable,
such as sawdust or agricultural residues.
5.7.3 Toxicity and Safety Aspects
For any substance to be sold in the European Union in volumes exceeding one ton
per annum (tpa), Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) is required, and overseas markets will require similar registration.
Therefore, careful design of the IL to reduce toxicity is paramount to facilitate the
registration. However, more information on the health and environmental safety data
of ILs is needed [149]. The sheer number of ionic liquids conceivable, as well as their
very diverse structure, makes it impossible to give generally applicable statements
about their health and safety implications. This is contrary to the popular history of
ILs, as a huge part of their fame from the early 2000s until recently was hailed to the
their “green credentials”, which were largely attributed to their non-volatile nature.
The non-volatility of many ILs can provide some processing advantages, such as
relatively safer handling as no toxic fumes are produced and quantitative recovery
without the need for a solvent condenser.
However, such an exaggerated and non-assessed claim was toned down in many
recent IL studies for two main reasons. First is the increased awareness of the relativity concept as no solvent can be “green” in an absolute sense. The performance
of the new solvent will always have to be assessed for the specifically intended
application and then compared to other solvent options. The application of this relativity concept is imbedded in the life cycle assessment (LCA) approach, the standard
method to evaluate the environmental impact and performance of technologies [150–
152]. Currently, the lack of LCA studies to critically assess IL performance in many
technologies was addressed as one of the main challenges. Second, there has been
evidence that certain ILs have greater (eco)toxicity than molecular solvents [151],
and there is, therefore, concern about the environmental benefits of using ILs over
traditional solvents. The protic ILs used in the ionoSolv pretreatment, for example,
have not been studied for their health and environmental impacts. However, they