Chemical conversion
Niloufar Davodi; Esmaeil Rasooly Garmaroody; Omid Ramezani; Sepideh Haamedi
Abstract
In this study, in order to control the inhibitory compounds in the bio-refinery, bagasse pith was pretreated under acidic hydrolysis with dilute sulfuric acid 8%, 90 minutes at 120 ° C. Then, by using de-depleting methods of overliming, activated carbon and combining of both, removal of deterrent ...
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In this study, in order to control the inhibitory compounds in the bio-refinery, bagasse pith was pretreated under acidic hydrolysis with dilute sulfuric acid 8%, 90 minutes at 120 ° C. Then, by using de-depleting methods of overliming, activated carbon and combining of both, removal of deterrent compounds from the above pretreatment hydrolyzates was performed. In the overliming, calcium hydroxide and sulfuric acid, in activated carbon method, activated carbon was used at three levels (0.5, 1.5 and 2.5%) and in the combined method of the combination of materials in the two previous methods became after acid treatments and each of the methods of insemination, the amount of recovered sugars and the values of the inhibitory compounds of furfural and hydroxymethylfurfural in the hydrolyzate were measured as two important indicators. The results showed that application of the above methods on hydrolyzate increased the yield of reduced sugars, so that the highest sugar yield (˃32%) was obtained after the independent method of overliming. In addition, active and combined carbon autonomous methods (overlimming and activated carbon) have an optimum activated carbon consumption of 2.5 and 1.5%, respectively. The qualitative study of the presence of inhibitory agents in hydrolyzates showed that furfural and hydroxymethylfurfural have maximum absorption at wavelengths of 276 and 282 nm. Also, an overliming with 2.5% activated carbon as the best method could eliminate up to 100% of inhibitory compounds. On the other hand, the autonomous method of overliming, with the removal of ˃90% of the inhibitory compounds, also has the highest sugar yield. Therefore, taking into account simultaneously the rate of sugar yield and the elimination of deterrent compounds, two independent alternatives of Overliming and Overliming with 2.5% active carbon could be proposed for the production of bioassays, such as bioethanol, xylitol, ... from the pith of bagasse.
Management and Economics wood
Azar Haghighi Poshtiri; Mehdi Jonoobi; Ali Naghi Karimi
Abstract
Cellulose nanocrystals (CNC) are new class of cellulose materials that find wide applications in various research areas over the past two decades. These nanoparticles are usually made by acid hydrolysis of cellulose substances such as wood, cotton, Starch etc. The main aim of this study is to find the ...
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Cellulose nanocrystals (CNC) are new class of cellulose materials that find wide applications in various research areas over the past two decades. These nanoparticles are usually made by acid hydrolysis of cellulose substances such as wood, cotton, Starch etc. The main aim of this study is to find the optimal conditions for obtaining an aqueous stable colloid suspension of cellulose nanocrystal (CNC) from α-cellulose with a high-yield procedure. Therefore various conditions of acid hydrolysis were evaluated as reaction temperature and reaction time. The percentage of yield was calculated for all suspensions. The morphology of the prepared CNC was characterized by Transmission Electron Microscopy (TEM), Environmental Scanning Electron Microscopy (ESEM) and the crystallinity was measured by X-ray diffraction (XRD). The results showed that highest yield of CNC (88%), was achieved from the reaction condition of 60 minutes at 60 °C. Generally, rod-like shape crystals achieved from α-cellulose with an average size of 35-50 nm and high crystallinity (92%) can be make it to a convenient and competitive source for the production of cellulose nanocrystal for various industries.
Pulp and paper
alireza shakeri; monireh imani; farshad miraki
Abstract
Cellulose is one of the most abundant natural biopolymer on earth is renewable, biodegradable and non-toxic. Micro and Nano-scale cellulose fibers and their applications in composite materials due to their high strength and stiffness combined with low weight, biodegradability and renewability has attracted ...
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Cellulose is one of the most abundant natural biopolymer on earth is renewable, biodegradable and non-toxic. Micro and Nano-scale cellulose fibers and their applications in composite materials due to their high strength and stiffness combined with low weight, biodegradability and renewability has attracted considerable attention. In this study, Micro-crystalline cellulose (MCC) of the skin of the cotton plant by acid hydrolysis in 2N hydrochloric acid to acid ratio of dough the Nano-crystalline (NCC) were prepared by chemical methods. Effect of hydrolysis conditions on properties such as the crystallinity and crystal size Micro and Nanocrystals cellulose with measurement range into the infra-red February (FT-IR), X-ray diffraction (XRD) were reviewed and The shape and size of the samples by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were studied. Fiber analysis using x-ray showed that increasing the amount of acid in the crystallinity of cotton cellulose Micro- crystalline increase the crystal size does not change Lower moisture uptake. Cotton cellulose Nanocrystals and crystal size greater than Micro- crystalline size were reported.