National Repository of Grey Literature 60 records found  beginprevious51 - 60  jump to record: Search took 0.01 seconds. 
A bioconversion study of cellulosic waste to ethanol using yeasts systems
Čalová, Iveta ; Vítová, Eva (referee) ; Babák, Libor (advisor)
This diploma thesis deals with the optimization of the production of ethanol from waste paper using yeast. There were used 4 kinds of paper as a substrate - office paper, non-recycled workbook, recycled workbook and newspaper. All papers were pretreated with the following procedures: grinding, microwaves + NaOH, microwave + H2SO4 and microwave + H2SO4 + NaOH. The glucose concentration was determined in enzymatic hydrolysis by HPLC. Saccharomyces cerevisiae were chosen for ethanol production. The production of ethanol was carried out with all the pretreated papers in simultaneous saccharification and fermentation. During hydrolysis, the pretreated papers have reached the highest results in the combination with microwave + H2SO4 + NaOH. Non-recycled workbook was the only exception, where the highest concentration of glucose has been obtained by the pretreatment of microwaves + H2SO4. Following results have been acquired: office paper 24,69 gdm-3, non-recycled workbook 22,47 gdm-3, recycled workbook 16,94 gdm-3 and newspapers 15,36 gdm-3. SSF was carried out again with all the papers and their pretreatments. The highest concentration of ethanol has been achieved in microwave pretreatment + H2SO4 + NaOH. The highest overall concentration has been gained from the office paper, amounted to 16,98 gdm-3. The maximum concentration of ethanol for non-recycled workbook has been 15,25 gdm-3, for recycled workbook 12,2 gdm-3 and for newspapers 12,59 gdm-3.
Use of Kluyveromyces marxianus to bioethanol produce from waste paper
Tomečková, Andrea ; Hrstka, Miroslav (referee) ; Babák, Libor (advisor)
The diploma thesis is focused on production possibilities of bioethanol from waste paper by yeast Kluyveromyces marxianus. Waste cardboard was used as a potential substrate for bioethanol production. Several methods for cardboard preparation were introduced and compared as well as methods of fermentation. Simultaneous sacharification and fermentation and separate hydrolysis and fermentation of preprepared cardboard paper were performed in different pH buffer (4,8-7). Simultaneous sacharification and fermentation was held at a temperature of 45°C. Hydrolysis in separate hydrolysis and fermentation was performed at 50°C and fermentation at 25°C. Procedures outputs were obtained by sampling in specific time intervals and samples were analyzed by HPLC for presence and concentration glucose and ethanol. The results of the analysis have shown that the highest concentration of glucose produced by enzymatic hydrolysis was achieved by using microwaves, 2% H2SO4 and 2% NaOH pretreated paperboard at pH 4,8. The highest yield of ethanol was obtained by separate hydrolysis and fermentation of pulp pretreated by microwaves, 2% H2SO4 and 2% NaOH in pH 5,4 buffer. The method SHF proved to be more effective for the production of ethanol than SSF.
Optimization of bioethanol production by Zymomonas mobilis
Andrlová, Kateřina ; Vítová, Eva (referee) ; Babák, Libor (advisor)
Diploma thesis deals with use of Zymomonas mobilis for the production of bioethanol from waste paper. There were used three kinds of substrate (cardboard, drawing and office paper) to optimize of bioethanol production. Individual papers were subjected to the same pre treatment, namely a milling, a combination of microwave irradiation and NaOH, a combination of microwave irradiation and H2SO4 and combination microwave irradiation, H2SO4 and NaOH. The substrates were decomposed by enzymatic hydrolysis after pre treatment to evaluate the best pre-treatment. Simultaneous saccharification and fermentation was carried out for each substrate (with two of the best pre-treatment). The samples were taken during the hydrolysis and the simultaneous saccharification and fermentation, and were determined by HPLC. Growth curves of Zymomonas mobilis were constructed, as the most appropriate for SSF was chosen temperature of 40 ° C in which the exponential phase took place at the time of 6 15 hours. During hydrolysis was monitored glucose concentration in the solution. The maximum concentration of glucose was in the cardboard (microwaves + H2SO4 + NaOH) 16.46 gdm-3, a drawing (microwaves + H2SO4 + NaOH) 31.78 gdm-3, and office paper (microwaves + H2SO4) 25.04 gdm-3. The concentration of ethanol for SSF was highest in the same cases as in the hydrolysis. The cardboard was the maximum concentration of bio ethanol 9.5 gdm-3, for the drawing 16.1 gdm-3 and for the office paper 12.13 gdm-3.
Pretreatment of polysaccharide waste materials to maximize of hydrolysis products
Myslivcová, Pavla ; Trachtová, Štěpánka (referee) ; Babák, Libor (advisor)
This thesis deals with study of the polysacharidic waste material pretreatment in order to maximize the hydrolysis products. It has been chosen a pastry as a waste material, specifically rolls and bread. Pastry was pretreated by milling and 15% w/v suspension of pastry in the water was prepared. Then several types of hydrolysis were performed with suspensions. Products of hydrolysis were characterized by spectrophotometric method of Somogyi-Nelson and efficiency of hydrolysis was compared. Three acids (H2SO4, HNO3, HCl) and two alkalis (NaOH, KOH) in three various concentration were used for the chemical hydrolysis. Microwave and ultrasound were chosen for the physical hydrolysis.
Application of Zymomonas mobilis for bioethanol production from cellulose materials
Čalová, Iveta ; Zichová, Miroslava (referee) ; Babák, Libor (advisor)
The thesis deals with the use of Zymomonas mobilis to produce bioethanol from waste paper. There were used three types of paper made by various manufacturers to optimize the production of bioethanol. Individual papers were subjected to the same adjustments namely mechanical grinding and subsequent enzymatic hydrolysis. During cultivation of Zymomonas mobilis in different hydrolysates were taken samples for determination of bioethanol production. The analysis was carried out on high-performance liquid chromatography. Production of bioethanol and glucose consumption was evaluated as well as production of lactic acid since it was also noticeable on the chromatograms.
Processing of non-standard products in the production of food phosphates
Hejsek, Michal ; Hrstka, Miroslav (referee) ; Pilátová, Ivana (advisor)
Theoretical part describes production technology and defines sources of nonconforming materials including their hypothetical composition. Chemical processes that take place during reworking were searched for every compound. Practical part focuses on simulation of these processes in laboratory scale. The aim was to explore dependence of whiteness of final product on hydrogen peroxide concentration during reworking.
Hydrolysis of potatoes
VLAČIHOVÁ, Andrea
This work compares acid, alkaline and enzymatic hydrolysis of potato starch with simultaneous application of various pressures (0MPa, 0,3MPa and 1MPa). Acid hydrolysis was made by sulphuric acid of intensity 3, 6, 9 and 12 %, alkaline hydrolysis was made by sodium hydroxide of intensity 3, 6, 9 and 12 % and four enzymatic preparations for starch hydrolysis were used for enzymatic hydrolysis. Hydrolysis effect was measured via GE and added by alcohol yield. There was positive influence of increased pressure 0,3MPa and 1Mpa on hydrolysis process visible in this experiment.
Hydrolysis of corn silage
MÍKA, Václav
Aim work is compare yield GE at acid, alkalic and enzymatic hydrolysis cellulose phytomass at different acidity (H2SO4, 3, 6, 9 and 12%), fundamentals (NaOH, 3, 6, 9 and 12%) and while using different enzymatic preparations (6 preparations to hydrolysis celluloses and hemicelluloses). Further is assessed positive influence compressive extrusion (0,3MPa and 1MPa).

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