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Title:Ekstrakcija hmelja (Humulus lupulus L.) s sub- in superkritičnimi fluidi : doktorska disertacija
Authors:ID Bizaj, Katja (Author)
ID Knez, Željko (Mentor) More about this mentor... New window
ID Škerget, Mojca (Comentor)
Files:.pdf DOK_Bizaj_Katja_2023.pdf (5,88 MB)
MD5: 59F615280513B7B6792CAEDE35692148
 
Language:Slovenian
Work type:Doctoral dissertation
Typology:2.08 - Doctoral Dissertation
Organization:FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:Glavni namen raziskav v okviru doktorske disertacije je bil opraviti preliminarne raziskave ekstrakcij z različnimi topili in pridobiti podatke za potrebe načrtovanja industrijske postavitve superkritične ekstrakcije hmelja. Delo sestoji iz treh delov. Prvi del se osredotoča na preučitev hmeljnih kultivarjev v Sloveniji in na značilnosti svetovnega trga. Drugi del disertacije preučuje učinkovitost ekstrakcije hmelja z različnimi topili pod sub- in superkritičnimi pogoji delovanja. Topila so bila izbrana glede na njihovo različno polarnost. CO2, propan in SF6 so bili uporabljeni kot nepolarna topila, DME pa kot polarno topilo. Še posebej sta nas zanimala DME in SF6, saj še nobena študija ni preučevala postopka ekstrakcije hmelja z uporabo teh dveh topil. Pri enakih pogojih delovanja so bila topila v različnih stanjih. Delovni parametri so bili 50 bar, 100 bar in 150 bar ter 20 °C, 40 °C, 60 °C in 80 °C za vsa topila. Za postopek ekstrakcije smo uporabili semi-kontinuirni ekstrakcijski postopek, kjer smo raziskovali vpliv ekstrakcijskih parametrov na izkoristek ekstrakcije ter kvaliteto dobljenega ekstrakta. Matematični model, ki temelji na drugem Fickovem zakonu, je dobro opisal eksperimentalne rezultate ekstrakcij. V vseh 27 vzorcih ekstraktov smo določili vsebnost α- in β-kislin z uporabo tekočinske kromatografije visoke ločljivosti (HPLC). Na koncentracijo mehkih kislin v hmeljnih ekstraktih so v veliki meri vplivali vrsta topila ter temperatura in tlak, uporabljena med ekstrakcijo. Rezultati kažejo, da sta bila CO2 in propan po topnosti približno enakovredna DME, medtem ko je bil SF6 pri enakih pogojih zelo slabo topilo za ekstrakcijo hmeljevih smol. V nadaljevanju smo ocenili vsebnost eteričnih olj in fenilnega flavonoida ksantohumola (XN) v ekstraktih hmelja. Za določanje vsebnosti XN v ekstraktih je bila uporabljena HPLC metoda. Dobljeni rezultati so pokazali, da je bila najvišja koncentracija XN ugotovljena v ekstraktih, pridobljenih z DME. Za analizo eteričnih olj v ekstraktih, povezanih z izrazitim vonjem, je bila izvedena parna destilacija ekstraktov in uporabljena GC analiza. Hmeljno olje, pridobljeno z ekstrakti CO2 pri specifičnih pogojih, je imelo najvišjo relativno koncentracijo linalola, β-kariofilena in α-humulena, olje, pridobljeno z ekstrakti propana, pa je imelo najvišjo vsebnost vseh drugih petih izbranih sestavin (mircena, geraniola, farnezena, α-selinena in δ-kadinena). Relativna vsebnost preiskovanih sestavin eteričnega olja v izvlečkih DME je bila podobna kot v izvlečkih iz propana. S pospešenim testom staranja ekstraktov smo proučili vpliv zraka (oksidacije) in temperature na njihovo skladiščno obstojnost ter ugotavljali razliko vsebnosti α- in β-kislin, XN in EO pri specifičnih pogojih ekstrakcij. Zadnji del doktorske disertacije predlaga načrtovanje procesa CO2 ekstrakcije in ekonomsko analizo investicije. V ta namen smo naredili zasnovo »scale-up« postopka in optimizirali postopek CO2 ekstrakcije. Za separacijske procese smo razvili model prenosa snovi med trdno in tekočo fazo, obogateno z znanjem termodinamike, transportnih pojavov in masno bilanco. Z ozirom, da postaja produktno inženirstvo izredno aktualno za tehnološki razvoj, potrebuje vso zahtevno znanstveno in strokovno podlago. Določili smo karakteristike posameznih procesnih enot in ocenili vrednosti investicije. Ovrednotili smo obratovalne stroške in stroške pogonskih sredstev, kamor spada časovni delež obratovanja, stroške električne energije, stroške pare in stroške hladilne vode. Glede na situacijo v hmeljarstvu smo določili stroške hmelja. Na trgu se stekajo informacije o ponudbi in povpraševanju in tu se - glede na splet tržnih dogajanj - oblikuje tudi cena hmelja. Glede na sam proces ekstrakcije smo določili tudi stroške dela ter ovrednotili prihodke od prodaje ekstrakta. Naredili smo finančno analizo s kriteriji za odločanje o sprejemljivosti investicije.
Keywords:hmelj (Humulus lupulus L.), sub- in superkritična ekstrakcija, ogljikov dioksid, propan, dimetil eter, žveplov heksafluorid, eterično olje hmelja, CO2 ekstrakcija, finančna analiza
Place of publishing:Maribor
Place of performance:Maribor
Publisher:[K. Bizaj]
Year of publishing:2023
Number of pages:XV, 123 str.
PID:20.500.12556/DKUM-81873 New window
UDC:[66.061.3:54-139]:633.791(043.3)
COBISS.SI-ID:144297731 New window
Publication date in DKUM:06.03.2023
Views:724
Downloads:222
Metadata:XML RDF-CHPDL DC-XML DC-RDF
Categories:KTFMB - FKKT
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Licences

License:CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Link:http://creativecommons.org/licenses/by-nc-nd/4.0/
Description:The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
Licensing start date:13.06.2022

Secondary language

Language:English
Title:Sub- and Supercritical extraction of Hops (Humulus lupulus L.)
Abstract:The main objective of the PhD research was to conduct preliminary studies on extractions with different solvents and to obtain data for the design of an industrial scale-up for supercritical extraction of hops. The work consists of three parts. The first part focuses on the study of hop varieties in Slovenia and on the characteristics of the world market. The second part of the work investigates the extraction efficiency of hops with different solvents under sub- and supercritical operating conditions. The solvents were selected according to their different polarity. CO2, propane and SF6 were used as non-polar solvents and DME as polar solvent. We were particularly interested in DME and SF6 because no previous study has investigated the extraction process of hops using these two solvents. Under the same operating conditions, the solvents were in different states. The extractions were carried out in a temperature range of 20 °C to 80 °C and a pressure range of 50 bar to 150 bar for all solvents. A semi-continuous operating mode was used for the extraction process, and the influence of the process parameters on the total extraction yield and the content of bitter acids in the extract was studied. The mathematical model based on Fick's second law described well the experimental extraction results. In addition, high-performance liquid chromatography (HPLC) was used to determine the content of α- and β-acids in all 27 extract samples. The yield of bitter compounds in the hop extracts was highly influenced by the type of solvent, temperature, and pressure applied during extraction. The results show that CO2 and propane were approximately equivalent to DME in terms of solvating power, while SF6 was a poor solvent under the same conditions. The essential oil and the content of the prenylated flavonoid xanthohumol (XN) in the hop extracts were also evaluated. The content of XN in the extracts was determined by high-performance liquid chromatography. The highest concentration of XN was obtained in the extracts derived by DME. For the analysis of the essential oil components in the extracts associated with a distinct odour, steam distillation of the extracts was carried out and GC analysis was performed. Hop oil obtained from CO2 extracts under certain conditions had the highest relative concentrations of linalool, β-caryophyllene, and α-humulene, and oil obtained from propane extracts had the highest content of all other five selected components (myrcene, geraniol, farnesene, α-selinene, and δ-cadinene). The influence of oxidation and temperature on the shelf life of the extracts was studied with an accelerated ageing test, and the difference in the content of α- and β-acids, XN, and EO was determined at specific extraction conditions. The last part of the thesis proposes the design of a CO2 extraction process and an economic analysis of the investment. For this purpose, a "scale-up" process design and optimization of the CO2 extraction process were performed. For the separation processes, we developed a model for mass transfer between solid and liquid phases, enriched with knowledge of thermodynamics, transport phenomena and mass balance. The characteristics of each process unit were determined and the investment values were estimated. We evaluated the operating costs and determined the costs of propellants, which includes the time portion of operation, electricity costs, steam costs, and cooling water costs. In the light of the situation in hop growing sector, the cost of hops was also determined. The market is the place where information about supply and demand is available and where the price of hops is formed - within the framework of a market flow. With regard to the extraction process itself, we also determined the cost of labour and evaluated the income from the sale of the extract. A financial analysis was carried out with criteria for deciding whether the investment is acceptable.
Keywords:hops (Humulus lupulus L.), sub- and supercritical extraction, carbon dioxide, propane, dimethyl ether, sulphur hexafluoride, hops essential oil, CO2 extraction, financial analysis


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