This master’s thesis is aimed at process of enzymatic hydrolysis of lignocellulosic material – waste paper as a source of raw material for production of liquid biofuels. In the theoretical part of this work are summarized previously used methods of hydrolysis and lignocellulosic materials used for the process of hydrolysis as a source of fermentable sugars for fermentation technology. The different types of waste paper are evaluated from the composition and usability with consideration to the papermaking process in order to select the appropriate type of waste paper for the enzymatic hydrolysis process. In the next part of this work are suggested technological premises and procedures for the preparation of raw materials and the subsequent enzymatic hydrolysis of these pre–treated materials. In the experimental part were optimized parameters of enzymatic hydrolysis using the Novozymes company enzyme package. Enzymatic degradation of cellulose to reducing sugars was observed using Somogyi – Nelson method. For the verification of hydrolysis conditions were used model materials with high cellulose content – pulp and filter paper. Conditions, which seems to be the best after testing on the model materials, were verified on specific waste paper materials – offset cardboard, recycled paper, matte MYsol paper and for comparison again on model materials – pulp and filter paper. The highest yields was achieved with the use of cardboard, which was further tested using various combinations of pretreatment to material for purpose of increase the yields of hydrolysis.

Lignocellulosic biomass is under extensive investigation as a bioethanol and bio-based materials feedstock. However, the complex structural and chemical mechanisms of lignocellulosic plant, which cause resistance to deconstruction during saccharification, require a pretreatment process. In this study, raw materials (corn bran, wheat bran and wheat straw) were selected because of their production and consumption in Turkey and also their accessibilities to be used as bioethanol source. Microfluidization pretreatment (high-pressure fluidization), which stands as a new approach for nano-cellulosic fibers production, was studied at 500 bar and 2000 bar to observe the qualitative and quantitative modifications in enzymatic hydrolysis depending on its effects on lignocellulosic structure. Optimum cellulase concentrations were determined for microfluidized samples as 4.5 U/g dry biomass for wheat bran, corn bran and 6.0 U/g dry biomass for wheat straw samples for the first 150 min interval. Effective usage of solid loads were found as 5.0 %, 2.5 %, and 7.5 % (dw/v) for wheat bran, wheat straw and corn bran, respectively. X-ray diffraction and SEM results of the microfluidized samples have indicated that the pretreatment has increased crystallinity index of all the samples and resulted in a scattered structure. Comparisons with other methods (softening, dilute-acid and lime pretreatments) have shown that microfluidization is advantageous over others by reducing the time required for enzymatic hydrolysis and thus can be a promising alternative pretreatment.

In diploma thesis the process of enzymatic hydrolysis of waste paper as a source for the production of liquid biofuels is discused. It follows directly the homonymous diploma thesis from Ing. Brummer, and it is based on the findings, which were solved and decided in previous work. In the theoretical part there is a summarization of basic information on the enzymatic hydrolysis of waste paper and the associated influences of various factors of the rate and degree of hydrolysis. Higher attention is paid to a waste cardboard and its pretreatment methods due to the maximalization of the yield of hydrolysis. The next part summarizes options of the fermentative production of biofuels, focusing on the method of simultaneous saccharification and fermentation, where the further appropriate organism for ethanol fermentation is discussed. The last part is about the technological process from the raw material input to the separation of ethanol. In the experimental section the pre-treatment of waste paper in order to maximize the efficiency of hydrolysis was examined. The best results were achieved using a vibratory mill. In addition, various parameters for simultaneous saccharification and fermentation were optimized using enzymes from Novozymes® company and the yeast Saccharomyces cerevisiae. The conversion rate of waste paper cellulose to reducing sugars was observed by spectrophotometric method by Somogyi - Nelson and the amount of produced ethanol was quantified using HPLC / RI. As a part of this thesis some conditions (amount of enzyme, substrate, nutrients, yeasts, temperature, pH, type of buffer) were optimized to maximize the effectiveness of the overall process. All experiments were carried out on corrugated cardboard, which was chosen as the most promising material for hydrolysis that was among the waste paper pulp in diploma thesis by Ing. Brummer.