scholarly journals Numerical Optimization of the Abies Ethanol Lignin Sulfation Process with Sulfamic Acid in 1,4-Dioxane Medium in the Presence of Urea

Author(s):  
Aleksandr S. Kazachenko ◽  
Natalya Yu. Vasilyeva ◽  
Irina G. Sudakova ◽  
Vladimir A. Levdansky ◽  
Maxim A. Lutoshkin ◽  
...  

The process of abies ethanol lignin sulfation with sulfamic acid in 1,4-dioxane medium in the presence of urea was optimized by calculation methods. The influence of such factors, as the ratio of lignin/sulfating complex (L/SC), temperature and time of the sulfation process on the sulfur content in the resulting sulfated ethanol lignin and its yield, has been established. The variance analysis of the obtained mathematical models testifies their good predictive properties. The optimal conditions of abies ethanol lignin sulfation process, which provide the formation of water-soluble sulfated lignin with a high yield (to 100 % wt.) and sulfur content (up to 7.9 % wt.), have been established. They are: temperature of 95-100 °C, the ratio L/SC 1:2,3-1:2:9 and the time of the process 119-137 minutes

2021 ◽  
pp. 87-94
Author(s):  
Aleksandr Sergeyevich Kazachenko ◽  
Vladimir Aleksandrovich Levdansky ◽  
Aleksandr Vladimirovich Levdansky ◽  
Boris Nikolayevich Kuznetsov

The effect of temperature and duration of sulfation of birch wood xylan by sulfamic acid in N, N-dimethylformamide (DMF) medium in the presence of urea on the yield of sulfated xylan and on the sulphur content was studied. By mathematical optimization, the sulfation conditions have been established allowing to achieve a high yield of the obtained xylan sulfates with a high sulphur content. Under optimal sulfation conditions: temperature 100±3 °C, duration 1.5 hours, the yield of sulfated xylan reaches to 63% mas. and the content of sulfur – 17.6% mas. The presence of sulfate groups in sulfated xylan samples obtained under optimal conditions was confirmed by elemental analysis and FTIR and 13C NMR spectroscopy.


2019 ◽  
Vol 2 (1) ◽  
pp. 52-59 ◽  
Author(s):  
A G Jiya ◽  
U J Ijah ◽  
M Galadima ◽  
U G Akpan

A response surface methodology (RSM) was utilized in this study for optimisation of biogas production process. The optimal values of process parameter capable of giving a high yield of biogas were established. A biodigester of 20 liters capacity capable of producing biogas from rural household domestic waste was designed, constructed and used in the study. Its major units are the anaerobic and gas collecting units. The process parameters investigated are the pH of the substrate, detention time and ratio of substrate to water while the yield of biogas was used as performance characteristics. The experiment was based on a central composite rotatable design (CCRD). The results revealed that the highest yield of biogas was obtained from a combination of detention time of 30 days, ratio of substrate to water of 1:1 and pH of 7, while the least yield of biogas of 11 cm3 was obtained from combination of detention time of 30 days, ratio of substrate to water of 1:3 and pH of 2. Numerical optimization carried out with the goal of maximizing the biogas yield revealed optimum values of detention time of 40 days, the ratio of substrate and water used; 1:2 and pH of 6.71 for biogas of 771.77 cm3 with the desirability of 0.9850. The detention time had the highest significant effects on the yield of biogas. The results of this study provided standard input process variables capable of yielding the optimum yield of biogas for the rural community.


2021 ◽  
Author(s):  
Yuting Zhu ◽  
Yuhe Liao ◽  
Luying Lu ◽  
Wei Lv ◽  
Jing Liu ◽  
...  

<a></a><a>Herein, we report the catalytic use of multifunctional CuO nanoparticles (NPs) to oxidatively fractionate lignocellulosic feedstock with dioxygen in aqueous NaOH under mild conditions . In presence of CuO NPs, lignocellulose is fractionated into three parts, overall yielding 90% carbon efficiency. Lignin is converted to up to 45.6 wt% in organic soluble aromatic aldehyde monomers, rich in vanillin and syringaldehyde, the value surpassing the theoretical one based on b-O-4 bond content, indicating significant cleavage of other ether bonds. All hemicellulose is selectively converted into water soluble small (di)acids, mainly to oxalic acid. Up to 81% of cellulose, in contrast, is obtained as a white crystalline residue with high cellulose purity (over 95%), which can readily be transformed into high quality nanocellulose, useful in many applications.</a>


2020 ◽  
Vol 47 (3) ◽  
pp. 298-308
Author(s):  
K. R. Idowu ◽  
A. S. Chaudhry ◽  
J. Dolfing ◽  
V. O. A. Ojo

Fungal improvement of the nutritive content of low-quality forages can be affected by several factors among which loss of water-soluble content (WSC) plays a major role. To achieve this aim, two growth conditions i.e. forage-liquid ratios (1:3 and 1:5) and two inoculation times (14 and 28 days) were used to cultivate the selected fungi i.e. Pleurotus ostreatus (PO) at 30°C and Ceriporiopsis rivulosus (CR) at 20°C on Brachiaria decumbens (BD), Andropogon gayanus (AG), Triticum aestivum (TA) straw, Lolium perenne (LP), respectively with the view of selecting the optimal conditions that facilitate the release of WSC. The impact that losses of WSC have on the ability of fungi to improve the nutritive content (i.e. proximate, fibre, secondary metabolites and total antioxidant content) of the forages were then measured using 2 filtering methods i.e. light pump filtering method (LFM) and free flow filtering method (FFM). The optimal conditions that supported increased th soluble was identified as 28th day for both fungi; forage-liquid ratio of 1:5 for both fungi in most of the forages except BD (CR) and BD & AG (PO). The LFM led to lesser or no improvement in the nutritive quality of the upgraded forages while the opposite was recorded with the LFM. The LFM as against the FFM produced upgraded forages with lesser reduction in NDF; similar or higher ADF and lignin contents; and similar reduction in secondary metabolites and TAC when compared with un-improved forages. It can be concluded that the fungal improvement of the nutritive content of low-quality forages was negatively affected by the loss of WSC. It is therefore recommended that fungal improvement of the nutritive quality of low quality forages should be carried out with methods or techniques that facilitates little or no WSC loss in the upgraded forages.


2016 ◽  
Vol 44 (3) ◽  
pp. 790-795 ◽  
Author(s):  
Andrea E. Rawlings

Membrane proteins play crucial roles in cellular processes and are often important pharmacological drug targets. The hydrophobic properties of these proteins make full structural and functional characterization challenging because of the need to use detergents or other solubilizing agents when extracting them from their native lipid membranes. To aid membrane protein research, new methodologies are required to allow these proteins to be expressed and purified cheaply, easily, in high yield and to provide water soluble proteins for subsequent study. This mini review focuses on the relatively new area of water soluble membrane proteins and in particular two innovative approaches: the redesign of membrane proteins to yield water soluble variants and how adding solubilizing fusion proteins can help to overcome these challenges. This review also looks at naturally occurring membrane proteins, which are able to exist as stable, functional, water soluble assemblies with no alteration to their native sequence.


2018 ◽  
Vol 7 (3.32) ◽  
pp. 59
Author(s):  
Zhylkybaev Oral ◽  
Alimzhanova Mereke ◽  
Ashimuly Kazhybek ◽  
Shoinbekova Sabina ◽  
Tukenova Zulfia

Synthesis of new potential plant growth regulators (analogues of natural phytohormones) is accomplished by mixing an equimolar mixture of aryloxypropin and 1-methylpiperidin-4-one under the conditions of Favorsky's reactions. New derivatives of acetylene aminoalcohols - the ZhOT series - have been obtained. The structure of the synthesized compounds was established by IR and NMR 1H spectroscopy. Screening of their water-soluble forms, on wheat and barley seeds, two preparations (ZhOT-4 and ZhOT-7) were selected, which exceed both the control and standards of known phytohormones, such as heteroauxin (indolyl-3-acetic acid), 6-BAP (6-benzylaminopurine) for further testing. Conducted in-depth laboratory and demonstration field tests on cereals (wheat and barley) showed high efficiency of ZhOT-4 and ZhOT-7, the indicators of which exceeded the well-known reference preparation - Agrostimulin (Ukraine). The growth regulating activity of synthesized compounds was determined. Processing of wheat seeds ZhOT-4 and ZhOT-7 increased the field germination of seeds, plant height, leaf area, the mass of the aerial part and the total area. The conducted studies showed that the biological activity of the tested compounds largely depends on the concentration and the best growth regulator is ZhOT-4. The activity of the synthesized growth regulatory compounds has been determined. Treatment of seeds of with ZhOT-4 and ZhOT-7 increased seed germination, height of plants, leave areas, weight of an elevated part and the total area, weight of an elevated part and the total area. Studies have shown that the biological activity of tested compounds is largely dependent on the concentration and the best growth regulator is ZhОТ-4. Thus, the advanced laboratory and demonstration (small-scale) comparative tests of ZhOT-4 and ZhOT-7 and the well-known reference preparation "Agrostimulin" (Ukraine) for cereals (wheat and barley) showed high efficiency of new synthesized preparations. The use of ZhOT preparations increases the germination and germination energy, the number of spikelets, the mass of grains, the bushiness and the yield of wheat and barley, leads to the accumulation of dry mass in both the ground and underground parts of plants. The advantages of ZhOT-4 and ZhOT-7 are: high efficiency, a wide range of cultures, good solubility in water, low application dose of 0.0001% by active ingredient (1g per 1t of water) or 13-50 mg per hectare, comparable to natural phytohormones, long shelf life, safety, high yield of target products, sequential 3-stage reaction in one reactor. 


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1009
Author(s):  
Suresh Thangudu ◽  
Mu Tzu Lee ◽  
Sami Rtimi

Molybdenum Sulfide nanosheets (MoS2 NSs) have unique properties that allow its use in a wide range of applications. Unfortunately, a lack of green synthesis methods to achieve a high yield remains a challenge after decades. Herein we report a simple, ecofriendly, green and cost-effective approach to synthesize water soluble MoS2 NSs via probe/Tip sonication method. The sequential batch manner pathway allows us to attain a high yield of MoS2 NSs (~100%). The prepared MoS2 NSs were characterized using up-to-date surface science techniques. UV-visible-NIR spectroscopy allowed us to visualize the doublet peaks of pristine MoS2 at 610 and 680 nm concomitant with the inter-band transitions at 394 nm and 460 nm. Using Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS), the crystallites’ sizes were estimated. X-ray diffraction (XRD) and Raman Spectroscopy were performed with respect to the bulk MoS2. The energy difference between the Raman peaks revealed that our NSs are formed of 5–6 layers. Further, we explored enzyme peroxidase mimetic properties of the synthesized MoS2 NSs. Results showed that the present MoS2 NSs offer excellent peroxidase mimicking properties. Most importantly, we observed that the optical properties and characteristics of MoS2 NSs synthesized by the current green method are similar to those of MoS2 NSs synthesized using conventional harsh methods reported in the literature. So that we strongly assume that the present method is a green alternative for the existing low yield and harsh experimental procedures to achieve water soluble MoS2 NSs in high yield. The synthesized soluble NSs are promising catalysts for the detection of toxic chemicals in the environment and/or for following enzymatic chromogenic reactions.


2005 ◽  
Vol 11 (4) ◽  
pp. 243-249 ◽  
Author(s):  
A. Sayaslan ◽  
P. A. Seib ◽  
O. K. Chung

Straight-grade and high-yield flours milled from red, white and low-polyphenol oxidase (PPO) activity white wheats were wet-milled to give gluten, starch, tailings and water-soluble fractions. Wet gluten fractions were either oven-dried or freeze-dried and ground to obtain dry gluten. White wheats yielded slightly more flour with higher lightness ( L*) than the red wheat. The wet-milling properties of all flours were comparable. The wet and oven-dried gluten fractions isolated from the low-PPO flours were the lightest, followed by the gluten fractions from the white and red wheat flours. The L* of the oven-dried gluten fractions from the low-PPO flours were ~ 1-3% higher than those from the white and red wheat flours. As the flour yield increased, the L* of the dry gluten fractions from all flours decreased likewise. However, the high-yield low-PPO white wheat flour gave the dry gluten with almost equal L* to the gluten isolated from the straight-grade red wheat flour, indicating the potential of the low-PPO white wheat flour in manufacturing brighter gluten.


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