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Organic Chemistry
Published in Steven L. Hoenig, Basic Chemical Concepts and Tables, 2019
There are three main disaccharides of interest, (+)-maltose (malt sugar), (+)-lactose (milk sugar), and (+)-sucrose (cane or beet sugar). Maltose, or malt sugar, is a disaccharide formed by a dehydration reaction between two glucose molecules. Lactose is a disaccharide consisting of the glucose and galactose monomers. It contains a β-1,4-glycosidic bond It is naturally in milk. And the most common disaccharide is sucrose, which is comprised of glucose and fructose monomers. Sucrose contains a α,β-1,2-glycosidic bond. It is our common table sugar, obtained from sugar cane and sugar beets.
Catalytic Conversion of Lignocellulosic Biomass into Fuels and Value-Added Chemicals
Published in Sonil Nanda, Prakash Kumar Sarangi, Dai-Viet N. Vo, Fuel Processing and Energy Utilization, 2019
Shireen Quereshi, Suman Dutta, Tarun Kumar Naiya
Biomass-derived chemicals and fuel have become a necessity of the current society to counter environmental damages as well as the growing demand for chemicals. Interestingly, biomass-derived HMF, EMF, LA, and EL have emerged as the most promising and highly reported building-block platform chemicals. Overall, the production of HMF, EMF, LA, and EL requires acid catalysts, which may be further categorized into Brønsted and Lewis acid catalysts. Furthermore, the requirement of an optimal Brønsted-to-Lewis acid ratio depends upon the starting feedstock material. A reactant may undergo dehydration reaction and not isomerization such as fructose. Therefore, catalysts with high Brønsted acidity will be more effective. On the contrary, the reactants which undergo isomerization reaction such as glucose require both Brønsted and Lewis acidities for efficient production of HMF, EMF, LA, and EL. Furthermore, the operating conditions such as reaction temperature, reaction time, feed concentration, catalysts concentration, solvent volume, and the type of reactor used also affect the overall EL yield. Nevertheless, the type of catalysts and their acidity remain a dominating factor in determining the overall efficiency of the biomass conversion process.
Sustainability Assessment of Biorefineries Based on Indices
Published in Carlos Ariel Cardona Alzate, Jonathan Moncada Botero, Valentina Aristizábal-Marulanda, Biorefineries, 2018
Carlos Ariel Cardona Alzate, Jonathan Moncada Botero, Valentina Aristizábal-Marulanda
The biorefinery from CCSs considers the production of ethanol, furfural, and hydroxymethylfurfural (HMF) [18]. Figure 8.8 indicates the flowsheet of the proposed biorefinery and as can be seen, the biorefinery is composed of 1 feedstock, 2 platforms, 11 processes, and 3 products. The biorefinery is designed taking into account different scales of processing of raw materials such as, 5, 25, 50, and 100 ton/h. The biorefinery comprises four processes. Initially, the lignocellulosic biomass is subjected to a sugar extraction process divided into three stages: (i) size reduction, (ii) dilute-acid pretreatment, and (iii) enzymatic hydrolysis. Then, 50% of glucose-rich liquor is sent to fermentation using Saccharomyces cerevisiae as a microorganism for ethanol production, and distillation and molecular sieves are used for purification. The remaining 50% of glucose is sent to HMF production by dehydration reaction, and a liquid–liquid extraction with dimethyl sulfoxide (DMSO) is used for purification. Finally, the xylose-rich liquor is sent to furfural production by dehydration reaction, and a liquid–liquid extraction with toluene is used for purification. Table 8.3 shows the mass and energy balances of the biorefinery from CCS for all processing scales of the raw material.
Improvement of the bonding performance of sucrose and ammonium dihydrogen phosphate adhesive by addition of dephenolized cottonseed protein
Published in The Journal of Adhesion, 2023
Qiumu Lin, Xue Zhang, Wenqian Cai, Xuanyuan Xia, Chengsheng Gui, Zhongyuan Zhao
ATR FT-IR spectroscopy analysis was conducted investigate the molecular changes in the DCP/SADP-1/3 adhesive during the curing process, and its spectra are shown in Figure 10. The spectra reveal that four adsorption bands disappeared after the curing process. The two peaks at 989 and 925 cm−1 corresponded to the -OH groups derived from the sucrose hydrolysis products and pyranose rings, respectively,[47,48] indicating that sucrose dehydration reaction occurred during curing. The peaks at 1,536 cm−1 was attributed to the N-H bending of amide II and 1,247 cm−1 was due to the C-N stretching of amide III,[49,50] and the disappearance of these chemical bonds indicated that the chemical structure of DCP changed after the curing process. In addition, three new peaks appeared in the spectra of the cured insoluble substance. The peaks at 1,514 and 797 cm−1 are derived from the furan ring,[51] and they indicate that 5-HMF or its derivatives are involved in the curing reaction. Meanwhile, the bonding at 1,213 cm−1 was assigned to a C-O-C stretching vibration,[52] which indicated dimethylene ether bridges were formed in the cured polymer, which were probably attributed to the Maillard reaction and caramelization during curing process.
A review on the co-processing of biomass with other fuels sources
Published in International Journal of Green Energy, 2021
The schematic of the reaction process for the pyrolysis of cellulose is presented in Figure 3. Two reactions schemes for the cellulose feed were proposed which would compete with each other: a chain-cleavage reaction to form a low degree of polymerization product, i.e., the “active cellulose”a dehydration reaction of first-order to form “char” and “water”.The condensed phase “active cellulose” material reacted in three ways: directly cracked to secondary gases;pyrolyzed and volatilized to primary vapors;dehydrated to “char” and “water”.The primary vapors were allowed to react to form secondary gases orsecondary tars (and by-product gases).
A comparative study on the chemo-enzymatic upgrading of renewable biomass to 5-Hydroxymethylfurfural
Published in Journal of the Air & Waste Management Association, 2020
Kongkona Saikia, Abiram Karanam Rathankumar, Krishnakumar Ramachandran, Harshini Sridharan, Pranay Bohra, Nikhil Bharadwaj, Anisha Vyas, Vaidyanathan Vinoth Kumar
The sugars obtained by the hydrolysis of both the biomass were used for the production of HMF by microwave dehydration in a microwave oven (Indian Fine Blanks, IFB, Convection 30SC3). In the system with A. americana hydrolyzates, the dehydration of 10% fructose to HMF using TiO2 nanopowder as the catalyst was achieved by performing the dehydration reaction at a temperature range of 100–150°C for 5–20 min, with catalyst loading of 5–20% based on the fructose concentration (Vandana et al. 2017). Simultaneously, the reducing sugars obtained from C. equisetifolia biomass was also dehydrated using TiO2 nanopowder as the catalyst. In this reaction system, 10% reducing sugar solution was dehydrated at a temperature range of 100–140°C for 5–30 min, with catalyst loading of (5–20) % (based on reducing sugar concentration). The TiO2 utilized in both the dehydration strategies was characterized according to our previous publication (Vandana et al. 2017). The produced HMF was identified by HPLC (Shimadzu Corporation, Japan) consisting of an RP-C18 column (150 mm × 2.5 mm × 5 μm), with a mobile phase of acetonitrile and water in the ratio 9:1 (v/v) with flow rate of 1.2 mL/min (Lee et al. 2014). The yield (%) of HMF was calculated by Equation (1) and the HMF yield from both the reaction systems was compared.