Isosaccharinic Acid Mediated Fine Chemicals Production from Cellulose

Abstract

Cellulose (Avicel®) is converted to potentially useful products (formic acid, ethylene glycol, and lactic acid). Isosaccharinic acid is identified as the reaction intermediate. Homogeneous aqueous dispersions of cellulose were obtained with the aid of sonication (1 h.). The degradation of the cellulose dispersion was carried out in an alkaline (NaOH) medium under microwave (domestic) irradiation conditions. With 1, 4 and 10 wt. % cellulose dispersions, conversion values of 44, 58 and 54 wt. %, respectively, were observed upon 5 min. of microwave irradiation. The reaction products in each case have been analyzed by 1 H and 13 C NMR. products in the filtrate were analyzed using NMR ( 1 H, 13 C, DEPT) without further separation. In a large scale production process, based on the wide variation in the boiling point of ethylene glycol relative to formic acid and lactic acid, ethylene glycol could be separated using ordinary distillation whereas fractional distillation to be employed for the separation of formic acid and lactic acid from the product mixture as their boiling points are close. 1 H and 13 C NMR spectra of reaction products obtained from 1 wt. % cellulose (aqueous dispersion in alkaline medium) are shown in Figure 2. Two peaks at 61.1 and 168 ppm in the 13 C NMR spectrum were assigned to ethylene glycol and formic acid, respectively. The presence of formic acid, ethylene glycol and lactic acid, were confirmed by the observation of When the initial concentration of the cellulose (in the aqueous dispersion) is increased from 1 to 4 wt. %, a conversion of 58 wt. % is observed. Isosaccharinic Acid Mediated Fine Chemicals Production from Cellulose Journal of Fundamentals of Renewable Energy and Applications Jo1 H and 13C NMR spectra of reaction products obtained from 4 wt. % cellulose (aqueous dispersion in alkaline medium) are shown in Figure 3. The peaks at 20.2, 61.3 and 168.3 ppm in the 13 C NMR spectrum were assigned to lactic acid, ethylene glycol and formic acid. The formation of the afore mentioned chemicals upon cellulose degradation is also confirmed by the presence of 1 H, doublet at 1.18 and 1.20 ppm (lactic acid), Table 1. For comparison, the 1 H and 13 C NMR spectra of authentic samples of formic acid, ethylene glycol and lactic acid are shown in Figure S1 and S2 respectively. Slight up field shift in the δ values of the reaction product formic acid (8.5 ppm, Figure 2 (a)) relative to the authentic sample (7.5 ppm, Figure S1) is attributed to the alkali under atmospheric pressure in the presence of air. The output of the domestic microwave reactor was 900 W. The microwave oven was modified so as to have provision for a distillation column passing through the MW oven (for enhanced safety of operation) as well as a stirring facility during the reaction [21]. The cellulose decomposition reaction was carried out in a batch mode in a round bottom flask with provision for a reflux condenser. Typically, each batch comprise of 10 mL of the aqueous dispersion of cellulose powder (1, 4 and 10 wt. ...

Evaluation of the Potential of Chlorella vulgaris for Bioethanol Production

“…In addition to microwave irradiation, the hydrolysis process was also carried out by hydrothermal means in a PTFE-lined stainless-steel autoclave at varying temperatures (80, 100, and 120 °C). The hydrolyzate obtained by both techniques was qualitatively analyzed for fermentable sugars using 13 C nuclear magnetic resonance spectroscopy (NMR, Bruker Advance DPX 300 instrument, with D 2 O as a solvent) and quantified using high-performance liquid chromatography (HPLC) analysis. , The residual algae that did not react were dried under vacuum at room temperature overnight. The weight percent conversion of the algae was calculated from the difference in the weight of the initial and final biomasses .…”

“…The hydrolyzate obtained by both techniques was qualitatively analyzed for fermentable sugars using 13 C nuclear magnetic resonance spectroscopy (NMR, Bruker Advance DPX 300 instrument, with D 2 O as a solvent) and quantified using high-performance liquid chromatography (HPLC) analysis. , The residual algae that did not react were dried under vacuum at room temperature overnight. The weight percent conversion of the algae was calculated from the difference in the weight of the initial and final biomasses . The fermentation reaction to convert the fermentable sugars to ethanol was carried out at 30 °C for 28 h in an incubator using S.…”

“…The weight percent conversion of the algae was calculated from the difference in the weight of the initial and final biomasses. 29 The fermentation reaction to convert the fermentable sugars to ethanol was carried out at 30 °C for 28 h in an incubator using S. cerevisiae. Prior to fermentation, the pH of the hydrolyzate was adjusted to 6 using 1 M NaOH.…”

Design of a selective solid acid catalyst for the optimization of glucose production from Oryza sativa straw

“…The wt% conversion of the biomass to products is deduced from the difference in the initial (before exposure to microwave irradiation) and nal (aer exposure to microwave irradiation) weights of the biomass. 31,32 Typical hydrolysis batch in a commercial microwave oven comprise of taking 0.125 g pretreated rice straw, 3 M HCl, 5 mL in the reaction vessel (XP-1500 plus control vessel) and irradiating the contents at 100 C, 300 W for 1-5 min. The rice straw (pretreated) hydrolysis reaction is also evaluated using the designed solid acid catalyst (0.125 g) in the place of the mineral acid with other conditions being the same.…”