No abstract

No abstract

No abstract

In this paper, the design of a miniaturized methanol reformer is considered that can operate in two different modes to produce sufficient hydrogen for generating a net power of 24 W and 72 W. The reformer is modeled as a radial flow packed bed reactor and the Ergun equation is used to model the pressure drop. Simulation studies are conducted to study the effect of steam to methanol ratio, inlet pressure and reactor temperature on the production of hydrogen. It is shown that a volume of 20 ml is required to produce sufficient hydrogen for generating the necessary power if an inlet pressure of 202 kPa and a steam to methanol ratio of 1.5 is used. A temperature of 500 K is required for the lower power application while a temperature of 550 K is required for the higher power application.

A two stage pretreatment approach for biomass is developed in the current work in which dilute acid (DA) pretreatment is followed by a solvent based pretreatment (N-methyl morpholine N oxide - NMMO). When the combined pretreatment (DAWNT) is applied to sugarcane bagasse and corn stover, the rates of hydrolysis and overall yields (>90%) are seen to dramatically improve and under certain conditions 48h can be taken off the time of hydrolysis with the additional NMMO step to reach similar conversions. DAWNT shows a 2-fold increase in characteristic rates and also fractionates different components of biomass - DA treatment removes the hemicellulose while the remaining cellulose is broken down by enzymatic hydrolysis after NMMO treatment to simple sugars. The remaining residual solid is high purity lignin. Future work will focus on developing a full scale economic analysis of DAWNT for use in biomass fractionation.