Bio-derived Solvents
As was discussed in the Renewable Resources module, there is a drive towards the manufacture of bio-based chemicals and a number of bio-derived solvents are now readily available. Although bio-derived solvents are not always safe and non-toxic, as they are renewable, they reduce concerns about the use of finite resources such as oil and natural gas.[1] Typical examples of bio-derived solvents include bio-ethanol, limonene and 2-methyl tetrahydrofuran (2-MeTHF). Bio-derived solvents may be renewably derived replacements to established solvents or novel molecules such as dihydrolevoglucosenone, a bio-based alternative for dipolar aprotic solvents. [2] A broad range of bio-derived solvents will be required to reduce dependence upon traditional fossil derived solvents. Figure 1 below shows a range of possible solvents that can be derived from bio-resources such as forestry, agricultural and food wastes.
It cannot be assumed that simply because a solvent is bio-derived, it is automatically green. The CHEM21 project has developed a new solvent selection guide to assess new bio-derivable solvents alongside traditional solvents. [3]
To study this area in more depth, see The CHEM21 Solvent Selection guide.
One consideration to take into account, in the case of some bio-derived solvents, is their greater viscosity and higher boiling points, which can lead to potential issues with recycling and recovery due to higher energy demands. [4] Whether or not this presents an issue obviously depends upon the industrial application of the solvent.
Figure 1: Some examples of bio-derived solvents
Recommended reading:
, Renewable Solvent Selection in Medicinal Chemistry, in Green and Sustainable Medicinal Chemistry: Methods, Tools and Strategies for the 21st Century Pharmaceutical Industry, , Royal Society of Chemistry, Cambridge, UK, 2016, ch. 3, pp. 28-40.
, Biocatalysis in bio-derived solvents: an improved approach for medium optimisation, Green Chem., 2014, 16, 2107–2110.
- , Renewable Solvent Selection in Medicinal Chemistry, in Green and Sustainable Medicinal Chemistry: Methods, Tools and Strategies for the 21st Century Pharmaceutical Industry, , Royal Society of Chemistry, Cambridge, UK, 2016, ch. 3, pp. 28-40.
- , Dihydrolevoglucosenone (Cyrene) as a bio-based alternative for dipolar aprotic solvents, Chem. Commun., 2014, 50, 9650–9652.
- , CHEM21 selection guide of classical- and less classical-solvents, Green Chem., 2016, 18, 288–296.
- , Survey of Solvent Usage in Papers Published in Organic Process Research & Development 1997–2012, Org. Process Res. Dev., 2015, 19, 740–747.
