Optimization of Xylose Production by Alkaline Hydrolysis of Water Hyacinth Biomass Using Response Surface Methodology and Artificial Neural Network.

This paper entails a comprehensive study on production of xylose by alkali pretreatment of water hyacinth biomass. Artificial Neural Network (ANN) and Response Surface Methodology (RSM) were used for optimization in order to enhance xylose yield by alkali pretreatment using NaOH. In the present study, water hyacinth (Eichhornia crassipes), a fast growing, aquatic lignocellulosic weed was exploited for the production of xylose .The application of RSM in the study for xylose yield by alkali hydrolysis process utilizing optimization and modeling facilitated the analysis of interaction effects of the process variables on the response. Artificial Neural Network modeling was also studied to validate and compare the results obtained from RSM. The optimized experimental result of the influencing parameters are NaOH concentration of 3%, agitation speed of 130 rpm, treatment time of 11 min, treatment temperature of 60 oC and soaking time of 3h which produced a xylose yield of 84.56 mg/g of dried biomass. The yield dropped drastically on increasing the temperature above a certain point which may be due to the degradation of xylose. The analysis was done by Design Expert 9.0.3 software and Matlab, R2009a (The Math Works, Inc., MA, USA) for optimization by Response Surface Methodology and Artificial Neural Networking.

Enzymatic hydrolysis of water hyacinth biomass for the production of ethanol: Optimization of driving parameters.

An efficient conversion of lignocellulose into fermentable sugars is a key step in producing bioethanol in a cost effective and eco-friendly manner. Alternative source like water hyacinth biomass (WHB) (Eichhornia crassipes) may be used as a supplement for the routine feedstocks. The enzyme loading for optimum yield of total reducing sugar was investigated and the enzyme-substrate interaction optimised. The maximal reducing sugar and xylose yield was obtained using cellulase and xylanase loading of 46.12 and 289.98 U/g and 2.26% (w/v) substrate loading. The efficiencies of ethanol production from the WHB hydrolysate are very less and the maximal ethanol yield was 3.4969 g/L when Pichia stiptis was used, followed by 3.4496 and 3.1349 g/L for Candida shehatae and Saccharomyces cerevisiae.