Most of the carbon-based compounds currently manufactured by the chemical industry are derived from petroleum. The rising cost and dwindling supply of oil have been focusing attention on possible routes to making chemicals, fuels, and solvents from biomass instead. In this context, many recent studies have assessed the relative merits of applying different dedicated crops to chemical production. Here, we highlight the opportunities for diverting existing residual biomass—the by-products of present agricultural and food-processing streams—to this end.

A novel concept for performing stoichiometric and catalytic chemical transformations has been developed that is based on the limited miscibility of partially or fully fluorinated compounds with nonfluorinated compounds. A fluorous biphase system (FBS) consists of a fluorous phase containing a dissolved reagent or catalyst and another phase, which could be any common organic or nonorganic solvent with limited or no solubility in the fluorous phase. The fluorous phase is defined as the fluorocarbon (mostly perfluorinated alkanes, ethers, and tertiary amines)—rich phase of a biphase system. An FBS compatible reagent or catalyst contains enough fluorous moieties that it will be soluble only or preferentially in the fluorous phase. The most effective fluorous moieties are linear or branched perfluoroalkyl chains with high carbon number; they may also contain heteroatoms. The chemical transformation may occur either in the fluorous phase or at the interface of the two phases. The application of FBS has been demonstrated for the extraction of rhodium from toluene and for the hydroformylation of olefins. The ability to separate a catalyst or a reagent from the products completely at mild conditions could lead to industrial application of homogeneous catalysts or reagents and to the development of more environmentally benign processes.

We propose that γ-valerolactone (GVL), a naturally occurring chemical in fruits and a frequently used food additive, exhibits the most important characteristics of an ideal sustainable liquid, which could be used for the production of both energy and carbon-based consumer products. GVL is renewable, easy and safe to store and move globally in large quantities, has low melting (−31 °C), high boiling (207 °C) and open cup flash (96 °C) points, a definitive but acceptable smell for easy recognition of leaks and spills, and is miscible with water, assisting biodegradation. We have established that its vapor pressure is remarkably low, even at higher temperatures (3.5 kPa at 80 °C). We have also shown by using ¹⁸O-labeled water that GVL does not hydrolyze to gamma-hydroxypentanoic acid under neutral conditions. In contrast, after the addition of acid (HCl) the incorporation of one or two ¹⁸O-isotopes to GVL was observed, as expected. GVL does not form a measurable amount of peroxides in a glass flask under air in weeks, making it a safe material for large scale use. Comparative evaluation of GVL and ethanol as fuel additives, performed on a mixture of 10 v/v% GVL or EtOH and 90 v/v% 95-octane gasoline, shows very similar properties. Since GVL does not form an azeotrope with water, the latter can be readily removed by distillation, resulting in a less energy demanding process for the production of GVL than that of absolute ethanol. Finally, it is also important to recognize that the use of a single chemical entity, such as GVL, as a sustainable liquid instead of a mixture of compounds, could significantly simplify its worldwide monitoring and regulation.