(567a) Biomass Reaction Engineering Driving Genetic Modification

It has been premised that lignocellulosic biomass is the  main renewable energy resources  available here on earth and con be considered as one of few sources that can provide renewable liquid, gaseous and solid fuels. In contrast to fossil fuels, the use of biomass for energy renders significant environmental advantages. Plant growth needed to generate biomass feedstocks removes atmospheric carbon dioxide, which offsets the increase in atmospheric carbon dioxide that results from biomass fuel combustion.

One promising and clean way to acquire bio-oil is by the fast pyrolysis of biomass, which is considered as a network of rich hemicellulose and cellulose bound by lignin. This process is carried out in the absence of oxygen, or when significantly less oxygen is present than required for complete combustion, and at elevated temperatures, thus yielding in gaseous products, liquids (bio-oil and water) and solid charcoal. The bio-oil contains a broad range of organic chemicals; hence they offer the potential to be used as an energy carrier, or as a renewable raw material for the chemical industry for the production of high-value chemicals and liquid biofuels. The valorization of the phenolics as building blocks or new synthetic bioplastics, phenol-formaldehyde resins or epoxy- or polyurethane materials,.. are some of the many possible applications. Another possibility is to use the bio-oil as a refinery feedstock for the production of the much needed biofuels. This requires upgrading via hydrodeoxygenation (HDO) with expensive hydrogen. Major breakthroughs in genetic modification of lignocellulosic biomass have made it possible to change the biomass composition, and hence to optimize the structure for targeted applications. Unfortunately the lack of fundamental understanding of biomass fast pyrolysis makes it quasi impossible to provide guidelines for genetic modification.

Realizing those potential applications requires having the control over the chemical composition of the bio-oil and the biomass. In other wordds the right type of biomass and the pyrolysis conditions should be selected. In short, to understand and to be able to predict/control the pyrolysis behavior, it is essential to understand the kinetics of the thermal reactions that are involved in the decomposition of biomass. Up to now, the goal of the fast pyrolysis process was limited to convert as much biomass as possible to liquid bio-oil, neglecting the effect(s) of the biomass composition and/or the process conditions on the bio-oil composition. Therefore in this presentation classical reaction engineering techniques such as reaction network generation, feed representation, fast detremination of kinetic and thermodynamic datat, model reduction and analysis are assessed. Experimental results that look at the role of feed and process conditions on the bio-oil composition are used to identify where major breakthorighs are still needed. Both pyrolysis GC as well as pilot plant data will be shown that have been obtained with genetically modified biomass feeds. Single gene modifications have been evaluated and the effect of these modifications on the biomass composition and produced bio-oil has been evaluated. This requires a comprehensive set of analytical techniques such as comprehensive 2D GC and LC to unravel the complexity of both feed and product.