Uporaba encimov v procesu razsivitve

Malalan, Staša (author), Gregor Svetec, Diana (mentor), Sežun, Mija (co-mentor)

Papir za recikliranje predstavlja za papirno industrijo možnost pridobitve sekundarnih vlaken za ponovno uporabo. Želja vsake industrije je pridobiti kvaliteten papir s čim nižjo stopnjo okoljske obremenitve ter nizkimi stroški. Omejitve predstavlja konvencionalna oblika razsivitve papirja s kemikalijami. Encimska obdelava predstavlja okolju prijazno ter ekonomično gledano, ugodnejšo rešitev. V diplomskem delu je bilo željeno doseči - v primerjavi s konvencionalno obliko razsivitve - primerljive rezultate s pomočjo uporabe encimov ter z vnosom manjše količine kemikalij. Teoretični del vključuje razlago ključnih postopkov razsivitve in vključuje opis dosedanjih raziskav na področju encimske obdelave celuloznih vlaken. Za raziskovalni del se je uporabilo vzorce različnih vrst recikliranega papirja, ki so vsebovali 60 – 70% starega časopisnega papirja in revij. Večinski delež vzorcev je bil natisnjen s tiskarskimi barvami ofset tiska (95%), preostanek pa je vključeval barve ostalih oblik tiska. V procesu je bila uporabljena manjša količina kemikalij v kombinaciji z encimi celulaza, lipaza in lakaza. Razsivitveni postopek je vključeval osnovne korake konvencionalne oblike razsivitve: priprava vzorcev, razpuščanje, dodatek kemikalij/encimov, flotacijo, oblikovanje končnih laboratorijskih vzorcev in ovrednotenje mehaničnih ter optičnih lastnosti vzorcev. Encimsko obdelani vzorci so v kombinaciji s kemikalijami dosegli boljše mehanske in optične lastnosti končnega izdelka. Vsi uporabljeni encimi so dosegli boljše rezultate ISO beline, še posebej izstopa belina vzorca, kjer se je uporabilo kombinacijo celulaze in lipaze. Najnižja stopnja beline je bila dosežena pri razsivitvi s pomočjo lipaze v samostojni obliki.

• Language: Slovenian
• Keywords: papir za recikliranje, razsivitev, flotacija, encimi, ISO belina
• Work type: Bachelor thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2018
• PID: 20.500.12556/RUL-101526
• Publication date in RUL: 14.06.2018

Secondary language

• Language: English
• Title: Efficiency of deinking process by enzymes

Abstract

For papermaking industry, paper for recycling represents a possiblility to extract secundary fibers for re-use. Every industry's priority is to obtain high-quality paper with the lowest level of environmental impact and low cost. The convencional deinking using chemicals represents environmentally damaging process. Biodeinking, using enzymes, represents environmentally friendly and better solution from economical point of view. Comparing with convencional deinking process it was aimed to achieve similar results with encymatic deinking, combining lower values of chemicals. Theoretical part includes explanation of key deinking steps and indication of previous researches in the field of encymatic treatment of cellulose fibers. In the practical part of this study various types of recycled paper were used and they contained 60 – 70% of old newspaper and magazines. The majority of samples were printed with offset inks (95%), the rest of samples contained inks of other printing technologies. In the process, there was a combination of low amount of chemicals and encymes like cellulase, lipasse and laccase. Deinking procedure involved basic steps of convencional deinking process – preparation of samples, pulping, enzymatic and chemical treatment, flotation, papermaking and evaluation of mechanical and optical properties. Encymatically threated samples (in combination with chemicals) achieved better mechanical and optical properties. All off the used enzymes fulfilled better results of ISO brightness, especially combination of cellulase and lipasse. The lowest value of ISO brightness was obtained in encymatic deinking with lipasse individually.

• Keywords: paper for recycling, deinking, flotation, enzymes, ISO brightness