scholarly journals HETEROGENEOUS CATALYTIC FRACTIONATION OF BIRCH-WOOD BIOMASS INTO MICROCRYSTALLINE CELLULOSE, XYLOSE AND ENTEROSORBENTS

2021 ◽  
pp. 105-118
Author(s):  
Boris Nikolayevich Kuznetsov ◽  
Natal'ya Viktorovna Garyntseva ◽  
Irina Gennad'yevna Sudakova ◽  
Andrey Mikhaylovich Skripnikov ◽  
Andrey Vladimirovich Pestunov

For the first time, it was proposed to fractionate the main components of birch wood into microcrystalline cellulose, xylose and enterosorbents by integrating heterogeneous catalytic processes of acid hydrolysis and peroxide delignification of wood biomass. The hydrolysis of wood hemicelluloses into xylose is carried out at a temperature of 150 °C in the presence of a solid acid catalyst Amberlyst® 15. Then the lignocellulosic product undergoes peroxide delignification in a "formic acid – water" medium in the presence of a solid TiO2 catalyst to obtain microcrystalline cellulose (MCC) and soluble lignin. Under the determined optimal conditions (100 °С, Н2О2 – 7.2 wt.%, НСООН – 37.8 wt.%, LWR 15, time 4 h), the yield of MCC reaches 64.5 wt.% and of organosolvent lignin 11.5 wt% from the weight of prehydrolyzed wood. By the treatment of organosolvent lignin with a solution of 0.4% NaHCO3 or hot water the enterosorbents were obtained, whose sorption capacity for methylene blue (97.7 mg/g) and gelatin (236.7 mg/g) is significantly higher than that of the commercial enterosorbent Polyphepan (44 mg/g and 115 mg/g, respectively). The products of catalytic fractionation of birch wood are characterized by physicochemical (FTIR, XRD, SEM, GC) and chemical methods.

Author(s):  
Charishma Venkata Sai Anne ◽  
Karthikeyan S. ◽  
Arun C.

Background: Waste biomass derived reusable heterogeneous acid based catalysts are more suitable to overcome the problems associated with homogeneous catalysts. The use of agricultural biomass as catalyst for transesterification process is more economical and it reduces the overall production cost of biodiesel. The identification of an appropriate suitable catalyst for effective transesterification will be a landmark in biofuel sector Objective: In the present investigation, waste wood biomass was used to prepare a low cost sulfonated solid acid catalyst for the production of biodiesel using waste cooking oil. Methods: The pretreated wood biomass was first calcined then sulfonated with H2SO4. The catalyst was characterized by various analyses such as, Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray diffraction (XRD). The central composite design (CCD) based response surface methodology (RSM) was applied to study the influence of individual process variables such as temperature, catalyst load, methanol to oil molar ration and reaction time on biodiesel yield. Results: The obtained optimized conditions are as follows: temperature (165 ˚C), catalyst loading (1.625 wt%), methanol to oil molar ratio (15:1) and reaction time (143 min) with a maximum biodiesel yield of 95 %. The Gas chromatographymass spectrometry (GC-MS) analysis of biodiesel produced from waste cooking oil was showed that it has a mixture of both monounsaturated and saturated methyl esters. Conclusion: Thus the waste wood biomass derived heterogeneous catalyst for the transesterification process of waste cooking oil can be applied for sustainable biodiesel production by adding an additional value for the waste materials and also eliminating the disposable problem of waste oils.


2021 ◽  
Author(s):  
Manickam Selvaraj ◽  
Mohammed A. Assiri ◽  
Hari Singh ◽  
Jimmy Nelson Appaturi ◽  
Subrahmanyam Ch ◽  
...  

Prins cyclization of styrene (SE) with paraformaldehyde (PFCHO) was conducted with mesoporous ZnAlMCM-41 catalysts for synthesis of 4-phenyl-1,3-dioxane (4-PDO) under a liquid phase heterogeneous catalytic method. For comparison study, the...


2021 ◽  
Vol 14 (1) ◽  
pp. 120-132
Author(s):  
Natalya V. Garyntseva ◽  
◽  
Irina G. Sudakova ◽  
Anna I. Chudina ◽  
Boris N. Kuznetsov

The possibility of isolation of high-quality cellulose by peroxide delignification of birch wood in an acetic acid-water medium in the presence of a TiO2 catalyst at a temperature of 100 °C was shown. The influence of the process conditions (concentration of hydrogen peroxide and acetic acid, liquid/wood ratio (LWR)) on the yield and composition of cellulose products was established. Numerical optimization of the process was carried out using a full factorial experiment. The optimal conditions for isolation from birch wood a cellulose product with residual lignin content of ≤ 1 wt.% are: СН3СООН concentration 23.8 wt.%, Н2О2 concentration 4.9 wt.%, LWR14.9, temperature 100 °C, time 4 h. Under these optimal conditions, the yield of a cellulose product with a cellulose content of 92.5 wt.% was 49.9 wt.%


2018 ◽  
pp. 63-71 ◽  
Author(s):  
Ирина (Irina) Геннадьевна (Gennad'yevna) Судакова (Sudakova) ◽  
Наталья (Natal'ya) Викторовна (Viktorovna) Гарынцева (Garyntseva) ◽  
Анна (Anna) Ильинична (Il’inichna) Чудина (Chudina) ◽  
Борис (Boris) Николаевич (Nikolaevich) Кузнецов (Kuznetsov)

The known methods to obtain microcrystalline cellulose (MCC) from wood raw material is multi-stage and it is based on the integration of environmentally hazardous processes of pulping, bleaching and acid hydrolysis of cellulose amorphous part. The paper describes a one-stage catalytic method to obtain microcrystalline cellulose from pine wood based on peroxide delignification in acetic acid-water in the presence of a catalyst H2SO4. The optimal parameters of the process of pine wood peroxide delignification in the presence of 2% H2SO4 catalyst were determined by experimental and numerical methods: temperature – 100 °C, concentration H2O2 – 5 wt.%, CH3COOH – 25 wt.%, LWR 15, duration – 4 h. They provide a high yield of cellulose (45.2 wt.%) with a low content of residual lignin (1.0 wt%).The kinetic study of pine wood peroxide delignification at the temperature range 70-100 ºC was accomplished. The delignification process is described satisfactory by the first order equation in all temperature range. The rate constants vary between 0.08·10-4 and 2.15·10-4 s-1 and the activation energy is 90 kJmol-1. It was established by FTIR and XRD methods, that the cellulose, obtained from pine wood has the composition and structure similar to the commercial microcrystalline cellulose.


RSC Advances ◽  
2015 ◽  
Vol 5 (74) ◽  
pp. 60264-60272 ◽  
Author(s):  
Aojie Deng ◽  
Junli Ren ◽  
Huiling Li ◽  
Feng Peng ◽  
Runcang Sun

In this paper, an environmentally-friendly two-step process for furfural production was developed by the hydrothermal pretreatment of corncob and the heterogeneous catalysis of the hydrolysate using a solid acid catalyst.


RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 14071-14078
Author(s):  
Xi-Que Wu ◽  
Pan-Dao Liu ◽  
Qun Liu ◽  
Shu-Ying Xu ◽  
Yu-Cang Zhang ◽  
...  

A new strategy was developed to produce cellulose nanofibrils and films from elephant grass using deep eutectic solvents and a recyclable solid acid catalyst with assistance of ultrasonic disintegration and a suction filtration film forming method.


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Davide Rigo ◽  
Nadia Alessandra Carmo Dos Santos ◽  
Alvise Perosa ◽  
Maurizio Selva

An unprecedented two-step sequence was designed by combining batch and continuous flow (CF) protocols for the upgrading of two aminodiol regioisomers derived from glycerol, i.e., 3-amino-1,2-propanediol and 2-amino-1,3-propanediol (serinol). Under batch conditions, at 80–90 °C, both substrates were quantitatively converted into the corresponding amides through a catalyst-free N-acetylation reaction mediated by an innocuous enol ester as isopropenyl acetate (iPAc). Thereafter, at 30–100 °C and 1–10 atm, the amide derivatives underwent a selective CF-acetalisation in the presence of acetone and a solid acid catalyst, to afford the double-functionalized (amide-acetal) products.


2020 ◽  
Vol 5 (11) ◽  
Author(s):  
Lindsey A Welch

AbstractGreen chemistry and sustainability are important concepts to incorporate into the undergraduate chemistry curriculum. Through the development of innovative undergraduate chemistry research projects in these areas, retention of students in the physical sciences can be improved. This paper describes two projects in undergraduate catalysis research: hydrogenation of furfural and the esterification of biooil from pyrolyzed wood. Catalytic transfer hydrogenation (CTH) of furfural with Pd/C led to the production of furfuryl alcohol, furfuryl isopropyl ether, 2-methylfuran, and tetrahydrofurfuryl alcohol. The metal chloride additives improved selectivity for furfuryl alcohol and furfuryl isopropyl ether. Catalytic conversion of pyrolyzed wood biooil in ethanol with a solid acid catalyst yielded ethyl esters, including ethyl acetate and ethyl propionate, as characterized by GC/MS These projects are described in the context of engaging undergraduate students in hands-on research for the purpose of improving retention and persistence, as well as preparing young scientists to enter graduate programs and the STEM workforce.


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