Johan Wärnå

Heterogeneously catalyzed conversion of nordic pulp to levulinic and formic acids

Herein, one-pot conversion of cellulose to platform chemicals, formic and levulinic acids was demonstrated. The catalyst selected was an affordable, acidic ion-exchange resin, Amberlyst 70, whereas the cellulose used was sulfite cellulose delivered by a Swedish pulp mill. Furthermore, in an attempt to better understand the complex hydrolysis network of the polysaccharide, kinetic experiments were carried out to pinpoint the optimal reaction conditions with an initial substrate concentration of 0.7–6.0 wt% and a temperature range of 180–200xa0°C. Higher temperatures could not be used due to the limitations in the thermal stability of the catalyst. Overall, maximum theoretical yields of 59xa0and 68xa0mol% were obtained for formic and levulinic acid, respectively. The parameters allowing for the best performance were reaction temperature of 180xa0°C and initial cellulose concentration of 0.7 wt%. After studying the behavior of the system, a simplified reaction network in line with a mechanistic approach was developed and found to follow first order reaction kinetics. A satisfactory fit of the model to the experimental data was achieved (97.8xa0% degree of explanation). The catalyst chosen exhibited good mechanical strength under the experimental conditions and thus, a route providing green platform chemicals from soft wood pulp from coniferous trees (mixture of Scots Pine and Norway Spruce) was demonstrated.

Direct Synthesis of 1-Butanol from Ethanol in a Plug Flow Reactor: Reactor and Reaction Kinetics Modeling

Bio-ethanol is well known for its use as a gasoline additive. However, it can be blended in low portions to traditional gasoline although it has a corrosive nature. By taking advantage of modern continuous reactor technology and heterogeneous alumina catalysts, ethanol can be upgraded to 1-butanol in fixed beds. Butanol has more feasible properties as fuel component in comparison to ethanol. Mathematical modeling of reaction kinetics revealed a simple kinetic model could be used to describe the complex reaction process on a Cu/alumina catalyst. The reaction kinetics model is based on five parallel reactions in which ethanol reacts to 1-butanol, acetealdehyde, ethyl acetate, diethyl ether and diethoxyethane, respectively.