Sasithorn Sunphorka

Evaluation of biomass component effect on kinetic values for biomass pyrolysis using simplex lattice design

We evaluated the correlation between the biomass constituents and their kinetic values. To simplify the models and indicate the effect of each constituent, pure biomass components and their mixtures were used as biomass model. The experiments were set up based on simplex-lattice design. The pyrolysis of synthesized biomass was performed by non-isothermal thermogravimetric analyzer. Several kinetic models in the literature, including Kissinger-Akahira-Sunose, Ozawa-Flynn-Wall and analytical method were used to determine kinetic values for each experiment. The generated regression models and predicted kinetic values from those methods were compared. The results obtained from analytical model (for n≠1) showed a good agreement (R2>0.95) with those obtained from experiments. This study also provide contour plots for all cases in order to observe the behavior of biomass pyrolysis at different component ratio.

Biocrude oil production and nutrient recovery from algae by two-step hydrothermal liquefaction using a semi-continuous reactor

We evaluated two-step hydrothermal liquefaction in a semi-continuous reactor for recovery of both nutrients and biocrude from the alga Coelastrum sp. in direct comparison with a one-step process. The influence of the operating temperature, pressure and water flow rate was investigated by means of a 2k factorial experimental design and response surface methodology. The two-step process gave a higher total biocrude yield (~36 wt% (daf. basis)) and nutrient recovery level in terms of nitrogen containing compounds (~60 wt% of the protein content in the original algae as ammonium and nitrate ions and protein/polypeptides) than the single-step process. The highest biocrude yield was achieved at first-step temperature of 473 K, second-step temperature of 593 K, pressure of 200 bar and water flow rate of 0.5 mL/min.

Protein and Sugar Extraction from Rice Bran and De-Oiled Rice Bran using Subcritical Water in a Semi-Continuous Reactor: Optimization by Response Surface Methodology

Abstract The extraction of protein and sugar from rice bran and de-oiled rice bran using subcritical water was evaluated in a 30-ml semi-continuous reactor. The effects of the three main factors, operating temperature, time and pressure, on the total sugar and protein yields obtained were investigated using analysis of variance and response surface methodology. A central composite design was performed in order to determine the most likely optimum conditions for the extraction process for both substrates individually and together. The developed models had a very high regression coefficient (R2) value (0.94 – 0.98), and demonstrated that the three main factors investigated had a significant effect on the sugar yield, whilst only time and its interaction with temperature were significant factors controlling the extracted protein yield. Based on the response surface and contour plots, the optimum conditions were evaluated for maximal extracted sugar and protein yields, which reached 100% for protein, from the two materials.

Effect of Biomass Compositions on Combustion Kinetic Parameters using Response Surface Methodology

Abstract The aim of this research is to find the correlation between chemical compositions of biomass, including cellulose, hemicelluloses and lignin, and kinetic rates of biomass combustion. The combustion behavior of biomass constituent was studied by thermogravimetric analyzer. The correlations were generated by means of using Response Surface Methodology based on Simplex-Lattice experimental design. The results obtained from statistical analysis can be used to generate mathematical models and also contour plots which exhibited the relationship between biomass composition and its combustion kinetic. From the observation, the models and contour plots indicated the complexity of combustion mechanism. The correlations proposed by this research were expected to be potentially used to predict combustion behavior in case of real biomass.

Pretreatment of rice straw by hot-compressed water for enzymatic saccharification

The primary objective of this work was to measure the maximum amount of glucose that can be produced from Thai rice straw using hot-compressed water (HCW)-pretreatment before enzymatic saccharification. The optimal HCW-pretreatment temperature and time were found to be 180 °C/2MPa for 20–30 min. However, the concentrations of the yeast inhibitors were strongly dependent on the HCW-pretreatment temperature and time. At temperatures over 180 °C/2MPa or for more than 30 min at 180 °C/2MPa in the HCW-pretreatment the combined concentration of these two inhibitors (Furfural and 5-Hydroxymethylfurfural) increased exponentially, while the glucose levels were near the maximal asymptote. At the more optimal HCW-pretreatment condition of 180 °C/2MPa for 20 min, 25±3 kg of glucose could be produced from a 100 kg of rice straw, which is potentially economically competitive with other sources