The generation of alternative fuels, particularly from non-edible feedstocks such as cellulose has become a topic of great national interest in recent years. The focus of this effort has been primarily on conversion of cellulose to useful products or intermediates. However, for the biorefinery concept to achieve its full potential it will be essential for new separation paradigms/processes to emerge. Decomposition of cellulose typically leads to a complex mixture of highly oxygenated compounds that are not thermally stable and quite hydrophilic. The PI hypothesizes that organic-inorganic nanocomposite membranes offer one route to achieve these separations.
To test this hypothesis the PI will explore key separations that will facilitate processing/conversion of cellulose into usable chemical feedstocks: 1. Selective separation of low molecular weight components (e.g. pentoses/hexoses) from residual solids formed in cellulose hydrolysis via microfiltration. 2. Separations of low molecular weight (e.g. acetic acid) components from model bio-oils obtained from pyrolysis.
Separations of bio-oils and cellulose hydrolysis mixtures have been sparingly studied, yet these types of separations are essential to advancing towards the goal of a biorefinery to reduce the nation's dependency on oil.
Biofuels are one promising route for the nation to reduce its dependency on imported fossil fuel. In this project new materials were developed that will make it easier for industry to develop ways to make high purity biofuel feedstocks. The intellectual merit of the perfomed work was twofold. The work funded by this award let to new materials that could be used to separate mixtures that are important to biofuel production. Second, this work funded in this award developed a base of knowledge on separations that have not previously been studied in detail. The broader impact of the performed work was also twofold. First, separations of bio-oils and cellulose hydrolysis mixtures have been sparingly studied, yet these types of separations are essential to advancing towards the goal of a biorefinery to reduce the nation’s dependency on oil. Second, students involved in the research received cutting edge training in an emerging field. The work performed in this award led to two key findings: 1. It was possible to develop materials that were very stable in the presence of processed biomass. By controlling the chemistry of the surface of these materials it was possible to make stable materials which could selectively remove particles from solutions. This will be important in the processing of biomass such as cellulose. 2. It was also possible to make materials that could selectively remove one compound from a mixture containing many compounds. The work performed here showed it was possible, for instance, to selectively capture sugards from complex mixtures. The ability to do these types of separations will also be very important in the biorefinery of the future.
