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A novel alternative methodology (direct crystallisation) to the traditional calcium precipitation to obtain succinic acid (SA) from defined and wheat-based fermentation broths is reported. SA crystals were successfully recovered from fermentation broths (FB) using this method. A higher SA crystal purity (95%) and yield (70%) were obtained in the direct crystallisation method compared to a slightly modified traditional calcium precipitation method (90% and 24%, respectively). Chemical transformations (e.g. esterifications) to high-added value derivatives of both recovered SA crystals were then investigated using a range of solid acids including our acidic tunable mesoporous carbonaceous materials denoted as Starbon® acids. Results showed that SA crystals could be successfully converted into mono- and diesters in high yields and selectivities employing solid acids regardless of the reaction conditions. The order of reactivity was found to be: pure SA crystals > SA crystals from defined FB > FB SA crystals. Results demonstrate that SA can be effectively purified from actual fermentation broths, showing the importance of integrating the fermentation and downstream processing to optimise the fermentative production of SA and its chemical transformations to produce high-added value derivatives. © 2009 The Royal Society of Chemistry.

The interest in adsorbing toxic gases nowadays is primarily due to their short- and long-term adverse health effects. It is generally accepted that the pore morphology and the surface nature play key roles in the adsorption mechanism of any molecules. The interactions between the adsorbate and adsorbent are affected by their polarity, where nonpolar surfaces would be attracted to a non-polar adsorbate, while polar surfaces have a higher affinity for polar molecules. The primary issue is access to a controllable set of materials with multiple functionalities that provide both polar and nonpolar surfaces for adsorption, which would present an advantage over single-phase adsorbents. Recently this has become available thanks to a novel class of bio-based carbonaceous materials (Starbon®). The functionality of these materials can be easily controlled by their temperature of preparation. The present work studies the nature of the surface chemistry and porosity of bio-based mesoporous materials Starbon and the role this plays in the adsorption of toxic volatile molecules such as ammonia, as a basic adsorptive and two acidic gasses (hydrogen sulphide and sulphur dioxide) using an InfraSorp optical calorimeter. Both hydrogen sulphide and sulphur dioxide adsorb better onto a hydrophobic surface, while ammonia adsorbs best onto a hydrophilic surface. The results showed that in both cases, Starbon significantly outperformed the industrially available powdered Norit® activated carbon (AC) and reacted chemically with the gasses to some extent.