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A major constraint in the microalgal technology is the economics involved in cultivation and harvesting. This work is focussed on the optimization of nutrients for cultivation and harvestin...

Pretreatment and hydrolysis of lignocellulosic biomass are affected by several uncertainties, which must be systematically considered for a robust process design. In this work, stochastic simulations for expected uncertainties in feedstock composition, kinetic parameter values, and operational parameter values for these two steps were performed. The results indicated that these uncertainties significantly impacted the concentration profiles, which could also affect the optimal batch time. Global sensitivity analysis was then used to identify the critical uncertain parameters. In the feedstock components, cellulose and xylan fractions for acid pretreatment and cellulose fraction for enzymatic hydrolysis were important. Temperature was the most sensitive operating parameter for both acid pretreatment and hydrolysis. The activation energies for different reactions were ranked in terms of their impact on process output. The selected parameters were used to develop stochastic process models using Ito process and mean reverting process for feed composition and kinetic parameter uncertainty. (C) 2017 Elsevier Ltd. All rights reserved.

Among the various sources of biomass, the lignocellulosic sources such as agricultural residue, dedicated energy grasses, forestry residue and short rotation woody biomass are expected to satisfy a significant fraction of the total future demand. However, while technologically feasible, the production of biofuels from lignocellulosic biomass is not techno-economically feasible. The presence of various uncertainties creates a number of challenges in overcoming these hurdles. The biomass to biofuel system is impacted by variability, both natural as well as anthropogenic, at almost all stages. This includes variability in feedstock production on a seasonal basis, variability in feedstock composition, variability in process efficiencies and variability in prices of raw material and products. This makes the optimization of the complete system extremely challenging. This article highlights the presence of these uncertainties and their impact on the operations of the biomass to biofuel systems. A detailed classification of uncertainties in biomass to biofuel systems, methods of incorporating uncertainties in process optimization and supply chain design are reviewed and explained. The paper will also review the work done to address these uncertainties using systematic methods.

A major constraint in the microalgal technology is the economics involved in cultivation and harvesting. This work is focussed on the optimization of nutrients for cultivation and harvesting using 'Scenedesmus sp'