scholarly journals Study of Carbohydrate Hydrolysis From Arracacha Roots (Arracacia Xanthorriza Bancroft) to Produce Fermentable Sugars

2021 ◽  
Vol 41 (2) ◽  
pp. e87365
Author(s):  
Darwin Carranza Saavedra ◽  
Jorge Andrés Alvarado Nuñez ◽  
José Fernando Solanilla Duque ◽  
Claudia Patricia Valenzuela Real

In Colombia, approximately 855 840 tons of arracacha are produced each year. The unsalable postharvest arracacha root (Arracacia xanthorriza Bancroft) is not commercialized, mainly due to mechanical damage or small and misshapen roots. In this work, dry samples were characterized and subjected to two treatments: one using thermal hydrolysis, applying saturated steam at pressures of 0,1034 MPa, 0,2068 MPa, and 0,4137 MPa; and another one using hydrolysis with sulfuric acid in concentrations between 0,252,00 M. Then, the cake resulting from the hydrolysis and filtration process was enzymatically hydrolyzed (Liquozyme SC DS, Novozymes) at 1,5, 5 and 10 KNU/g (pH 6, 80 _C, 2 h). Fermentation inhibitors (acetic acid and furfural) were evaluated in the best pretreatment. The results showed that the treatment with sulfuric acid at 1,00 M (2 h) has high yields in reducing sugars added to enzymatic hydrolysis. The maximum level of fermentable carbohydrates per gram of dry sample (1,04 g/g) was also reached. Regarding the fermentation inhibitors of the reducing sugar, a higher concentration of acetic acid was found with a lower furfural content. Therefore, arracacha discards are a promising raw material to increase the supply of bioethanol.

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 956
Author(s):  
Stefan Beisl ◽  
Julian Quehenberger ◽  
Donya Kamravamanesh ◽  
Oliver Spadiut ◽  
Anton Friedl

Lignocellulosic agricultural side products, like wheat straw, are widely seen as an important contribution to a future sustainable economy. However, optimization of biorefinery processes and exploitation of all side streams are crucial for an economically viable biorefinery. Pretreatment of lignocellulosic raw material, which is necessary for further processing steps, can generate low-value side streams. In this feasibility study, side streams from a liquid hot water (LHW) pretreatment of wheat straw were utilized for the production of polyhydroxybutyrate (PHB) and highly valuable tetraether lipids (TELs). Additional value created by these products can benefit the biorefinery’s economic operation. The utilized wheat straw was pretreated at 120 °C and 170 °C for up to two hours in laboratory and lab scale. The resulting side stream consists mainly of carbohydrates from hemicelluloses and fermentation inhibitors such as acetic acid. In order to achieve a successful production of both products, an acetic acid separation via distillation was necessary. Subsequently, the acetic acid fraction was utilized for the PHB production using cyanobacteria. The carbohydrate-rich fraction was applied in the cultivation of Sulfolobus acidocaldarius and resulted in the successful production of TELs. Both fractions achieved better fermentation yields compared to their corresponding reference media.


2021 ◽  
Vol 11 (4) ◽  
pp. 246-254
Author(s):  
Jabosar Ronggur Hamonangan Panjaitan ◽  
Misri Gozan

Nitrocellulose is a cellulose derivative that has many potential applications. Nitrocellulose can bemade through nitration reactions by reacting cellulose and nitric acid at low temperatures. Cellulose can be obtained from lignocellulose biomass such as palm oil empty fruit bunches (POEFBs). In this study, techno-economic evaluation of nitrocellulose production from POEFBs was investigated with various types of alkaline and acid pretreatments. Pretreatment of POEFBs with alkaline and acid was used to purify cellulose fraction as raw material for nitrocellulose. The combination process of POEFBs pretreatment with alkaline and acid can be classified into 4 process routes such as ammonium hydroxide and sulfuric acid pretreatment (Route-1), ammonium hydroxide and acetic acid pretreatment (Route-2), sodium hydroxide and sulfuric acid pretreatment (Route-3), and sodium hydroxide and acetic acid pretreatment (Route-4). The results showed that ammonium hydroxide and sulfuric acid pretreatment (Route-1) was the most profitable route to produce nitrocellulose. Economic parameter values such as return of investment (ROI), payback period (PBP), net present value (NPV) and internal rate of return (IRR) from ammonium hydroxide and sulfuric acid pretreatment (Route-1) were 11.49%, 5.85 years, US$ 442,427 and 13.35%.


2021 ◽  
Vol 104 (4) ◽  
pp. 149-162
Author(s):  
Y.B. Raiymbekov ◽  
◽  
U. Besterekov ◽  
P.A. Abdurazova ◽  
U.B. Nazarbek ◽  
...  

Kazakhstan has a huge phosphate raw material base, where the basis is made up of micro-grained phosphate ores of the Karatau basin. The depletion of reserves of high-quality commercial ores leads to the search for new methods of using the enrichment and sorting of low-grade technogenic ores, one of which is phosphate-siliceous slates. The presented study was carried out in two stages: at the first stage, phosphate-siliceous shales were enriched by the acetic acid method, regime technological parameters, kinetic and thermodynamic regularities of the process were determined. At the second stage of the research a method for recycling used acetic acid during the enrichment of low-grade phosphate-siliceous slates is proposed. In this case, sulfuric acid was chosen as the regenerating agent of acetic acid. The reliability of the performed studies was proved by the use of modern complex research methods: scanning electron microscopy, Energy Dispersive X-Ray and X-Ray difraction analyses. To determine the course of a particular reaction, a thermodynamic analysis was performed using modern HSC 6.0 software. The kinetic data are determined by calculation. The obtained experimental data were subjected to statistical analysis (Chaddock scale, standard deviation, coefficient of determination). The mechanism of interaction of an acetate solution with sulfuric acid is illustratively described. In conclusion, the sulfuric acid method is suitable for the regeneration of applied acetic acid. In this case, a by-product is formed in the form of calcium sulfate. This product can be used as a building binder (confirmed by the protocol of the “National Center of Expertise” of the Republic of Kazakhstan).


2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.


2015 ◽  
Vol 15 (2) ◽  
pp. 289-305 ◽  
Author(s):  
Maja Fijałkowska ◽  
Barbara Pysera ◽  
Krzysztof Lipiński ◽  
Danuta Strusińska

Abstract Losses of crude protein during ensiling of herbages, in contrast to carbohydrates, do not affect the reduction of its content; their form is changed into greater solubility non-protein compounds and also highly degraded forms, which lower the efficiency of the microbial protein synthesis in the rumen. These processes are accompanied by a change of amino acid composition of herbage protein and decrease in intestinal digestibility of protein from feeds as a result of the formation of indigestible complexes with carbohydrates (ADIN). Reduction of protein degradation in silages is achieved by accelerated acidity through addition of acids or dominance of homofermentative bacteria. The positive effects of fermentation inhibitors or sorbents use, as well as the wilting of raw material on the level and rate of protein degradation were demonstrated by many researchers. A greater contribution of protein nitrogen and reduction of deamination in silages can also be obtained by using bacteria inoculants. Increasing the proportion of protein nitrogen is accompanied by the improved efficiency of microbial protein synthesis.


2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Elena Konyushenko ◽  
Miroslava Trchová ◽  
Jaroslav Stejskal ◽  
Irina Sapurina

AbstractConditions of polyaniline (PANI) nanotubes preparation were analyzed. Aniline was oxidized with ammonium peroxydisulfate in 0.4 M acetic acid. There are two subsequent oxidation steps and the products were collected after each of them. At pH > 3, neutral aniline molecules are oxidized to non-conducting aniline oligomers. These produce templates for the subsequent growth of PANI nanotubes, which takes place preferably at pH 2–3. At pH < 2, granular morphology of the conducting PANI is obtained. High final acidity of the medium should be avoided in the preparation of nanotubes, e.g., by reducing the amount of sulfuric acid which is a by-product. Reduction of the peroxydisulfate-to-aniline mole ratio was tested for this purpose in the present study. Lowering of the reaction temperature from 20°C to −4°C had a positive effect on the formation of nanotubes.


1984 ◽  
Vol 62 (9) ◽  
pp. 1840-1844 ◽  
Author(s):  
Karl R. Kopecky ◽  
Alan J. Miller

Treatment of methyl hydrogen decahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a,8a-dicarboxylate with lead tetraacetate in benzene – acetic acid replaces the carboxyl group by an acetoxy group. Hydrolysis of this product with 25% sulfuric acid at 130 °C forms 8a-hydroxydecahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a-carboxylic acid 10. The reaction between 10 and benzenesulfonyl chloride in pyridine containing triethylamine at 95 °C produces anti-sesquinorbornene 1 in 34% yield. In the absence of triethylamine 1 is converted to the hydrochloride. The iodohydroperoxide of 1 is converted by silver acetate at 0 °C to the diketone in a luminescent reaction. The 1,2-dioxetane could not be isolated. Decahydro-1,4:5,8-exo,exo-dimethanonaphthalene-4a,8a-dicarboxylic anhydride is converted slowly by methoxide ion in methanol at 150 °C to the monomethyl ester which then undergoes demethylation. The isomeric exo,endo anhydride undergoes reaction readily with methoxide ion at 80 °C.


Author(s):  
Sebastian Ponce ◽  
Stefanie Wesinger ◽  
Daniela Ona ◽  
Daniela Almeida Streitwieser ◽  
Jakob Albert

AbstractThe selective oxidative conversion of seven representative fully characterized biomasses recovered as secondary feedstocks from the agroindustry is reported. The reaction system, known as the “OxFA process,” involves a homogeneous polyoxometalate catalyst (H8PV5Mo7O40), gaseous oxygen, p-toluene sulfonic acid, and water as solvent. It took place at 20 bar and 90 °C and transformed agro-industrial wastes, such as coffee husks, cocoa husks, palm rachis, fiber and nuts, sugarcane bagasse, and rice husks into biogenic formic acid, acetic acid, and CO2 as sole products. Even though all samples were transformed; remarkably, the reaction obtains up to 64, and 55% combined yield of formic and acetic acid for coffee and cocoa husks as raw material within 24 h, respectively. In addition to the role of the catalysts and additive for promoting the reaction, the influence of biomass components (hemicellulose, cellulose and lignin) into biogenic formic acid formation has been also demonstrated. Thus, these results are of major interest for the application of novel oxidation techniques under real recovered biomass for producing value-added products. Graphical abstract


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