Biorefinery: Valorisation of pulp and paper industry side - products for bioplastic production

thesis

Sebastjan Huš (Author), Maja Leitgeb (Mentor), Mateja Primožič (Co-mentor)

Abstract

Polihidroksialkanoati so biorazgradljivi polimeri proizvedeni s pomočjo mikroorganizmov ali gensko spremenjenih bakterij. Njihove lastnosti so zelo podobne lostnostim pilietilena in polipropilena, zato predstavljajo dobro zamenjavo za plastiko, ki bazira na prizvodnji fosilnih goriv. Glavni razlog za njihovo omejujočo uporabo je visoka cena, ki je štirikrat višja kot cena za sintetično plastiko. Visoke proizvodnje stroške je možno zmanjšati z uporabo mešanih mikrobioloških kultur in cenenih odpadnih materialov in stranskih industrijskih proizvodov, kot substrat za rast mikroorganizmov. Najboljši rezultati so bili doslej dobljeni v procesu imenovanem aerobno dinamično hranjenje (ADF), ki temelji na menjanju obdobja presežek ogljika in obdobja lakote. Pod pogoji aerobnega dinamičnega hranjenja, mikroorganizmi tekmujejo za preživetje in tako preživijo tisti z največjo sposobnostjo shranjevanja zalog (polihidroksialkanoatov), kar je najbolj pomembno za proizvodnjo polihidroksialkanoatov. Namen te diplomske naloge je bila proizvodnja polihidroksialkanoatov iz odpadne sulfitne tekočine in mešanih mikrobnih kultur. Posredno pa je bil namen tudi odstranitev ocetne kisline iz odpadne sulfitne tekočine, za nadaljno uporabo pri proizvodnji bioetanola s P. stipitis. Kultura je bila izbrana v SBR reaktorju pod ADF pogoji. Sistem je deloval 72 dni in najvišja shranjena koncentracija polihidroksialkanoatov je bila 29% glede na suho težo. Kot vir ogljika so mikroorganizmi porabljali ocetno kislino, prav tako pa so porabljali tudi sladkorje, kar je onemogočilo odstranitev ocetne kisline iz odpadne sulfitne tekočine. Poleg tega je ocetna kislina v sistemu nastajala tudi s fermentacijo, saj je bil sistem kontaminiran z glivami.

Keywords

biochemical engineering;polyhidroxyalkanoates;mixed microbial culture;spent sulfite liquor;acetic acid;

Data

Language:	English
Year of publishing:	2010
Source:	Maribor
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[S. Huš]
UDC:	663.1:66.095.253.094.32(043.2)
COBISS:	14282262
Views:	2809
Downloads:	291
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary title:	Biorafinerija: Valorizacija stranskih produktov industrije celuloze in papirja za proizvodnjo bioplastike
Secondary abstract:	Polyhydroxyalkanoates (PHAs) are biodegradable biopolymers, which have been recognized as a good substitution for petroleum-based polymers. The main reason for slow replacing of the synthetic plastic is the production cost, which can be four times higher than the chemical synthesis. PHA production in activated sludge is a possible technology to decrease production costs, since no sterilization is needed and bacteria can adapt easily to the substrate in low cost feedstock. Until now, best results were obtained in a process called aerobic dynamic feeding (ADF) or also known as feast and famine cycle which is based on alternation of periods of excess carbon (feast) and periods of starvation (famine). Under ADF conditions microorganisms have to compete for survival and only the one with high storage capacity survive. Hardwood spent sulfite liquor (HSSL) is a by-product of paper industry and is rich in carbohydrates and acetic acid. It can be used as a substrate for PHA production, where mainly acetic acid is used, and also for bioethanol production, if acetic acid is removed. The aim of this work was production of polyhydroxyalkanoates from spent sulfite liquor by mixed microbial culture and also removal of acetic acid from SSL for bioethanol production with P. stipitis. The culture was selected in Sequenced batch reactor (SBR) under ADF conditions. The system was operating for 72 days and microorganisms were able to store 29% of PHA per cell dry weight. The microorganisms were able to uptake acetic acid and sugars and convert it to PHAs. The acetic acid was not removed, because microorganisms were fermenting sugars in acetic acid, or fungus present in the system were producing acetic acid.
Secondary keywords:	biokemijska tehnika;bioplastika;biorazgradljiva plastika;polihidroksialkanoati;proizvodnja polihidroksialkanoatov;mešane mikrobiološke kulture;odpadna sulfitna tekočina;ocetna kislina;mikroorganizmi;diplomske naloge;
URN:	URN:SI:UM:
Type (COBISS):	Undergraduate thesis
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	VIII, 52 f.
Keywords (UDC):	applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;chemical technology;chemical and related industries;kemijska tehnologija;kemijske in sorodne industrije;industrial microbiology;industrial mycology;zymurgy;fermentation industry;beverage industry;stimulant industry;industrijska mikrobiologija;industrijska mikologija;pivovarstvo;vrenja;industrija pijač;industrija poživil;microbiological industries;science and technique of applied microbiology;applied mycology;mikrobiološke industrije;mikrobiološka znanost in uporabne tehnike;uporabna mikologija;applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;chemical technology;chemical and related industries;kemijska tehnologija;kemijske in sorodne industrije;
ID:	1012038