Xylose production has become one of the most studied process over the year due to the significant application as a raw material for the production of a variety of specialty chemicals, mainly xylitol. The most promising raw material is lignocellulosic biomass because of its widely available and cheap. There are several type of pretreatment process has been studied to depolymerized the lignocellulosic compounds into fermentable sugars. Among all, dilute acid hydrolysis is the most promising process to produce high xylose. However, disadvantage of this pretreatment process is production of byproduct that can slowdown the fermentation step. Understanding the effect of pretreatment processing parameters on lignocellulosic depolymerization could possibly result in minimization of degradation compounds. Therefore, the aim of this work is to carry out the sensitivity analysis of the acid hydrolysis process used for the production of fermentable sugars with the aid of Aspen Plus by considering the concentration of xylose, glucose, furfural and acetic acid obtained at the outlet of reactor as the output variable. Sensitivity analysis were apply at temperature (160 °C, 170 °C and 180 °C) and residence time (0-160 min). The results indicate that the developed process model is possible to improve lignocellulosic conversion efficiency while minimizing degradation product generation with the highest xylose produce is 18.26 g/L at 180 °C during 20 min reaction time.

Dividing wall column (DWC) offers higher degree of freedom in comparison with the conventional column. Furthermore, the different sections configurations within the column are highly interacting with several recycle loops. Facing with such complex unit operation, describing its behaviour encourages the focal point on the resolution of ideal modelling approaches. Equation oriented (EO) modelling of DWC has been studied by several researchers involving complex algorithm and methodology. In this work, a new approach for modelling of DWC is presented. The modelling methodology involves variables connectivity based on ports and streams that is admissible to equation-oriented flow sheet. To verify the functionality of the proposed method, the modelled DWC is validated with two case studies depicted from experimental literature data to separate alcohol mixture and fatty acid fractionation. The model development was performed in MOSAIC, a web-based modelling tool and run in gPROMS. The model shows good convergence and has less than 10% error when compared to the above mentioned case studies. To furthermore extend the model capability, relative gain array (RGA) analysis was conducted for the fatty acid fractionation to determine the best control configuration in DWC. Result shows that L-S-V and L-S-B configurations are the best control configurations. Our analysis also shows that reflux flowrate, side flowrate and vapor boilup are best to control distillate product, side product and bottom product, respectively.

No abstract

No abstract