42 resultados para robust and stochastic optimization


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The decreasing fossil fuel resources combined with an increasing world energy demand has raised an interest in renewable energy sources. The alternatives can be solar, wind and geothermal energies, but only biomass can be a substitute for the carbon–based feedstock, which is suitable for the production of transportation fuels and chemicals. However, a high oxygen content of the biomass creates challenges for the future chemical industry, forcing the development of new processes which allow a complete or selective oxygen removal without any significant carbon loss. Therefore, understanding and optimization of biomass deoxygenation processes are crucial for the future bio–based chemical industry. In this work, deoxygenation of fatty acids and their derivatives was studied over Pd/C and TiO2 supported noble metal catalysts (Pt, Pt–Re, Re and Ru) to obtain future fuel components. The 5 % Pd/C catalyst was investigated in semibatch and fixed bed reactors at 300 °C and 1.7–2 MPa of inert and hydrogen–containing atmospheres. Based on extensive kinetic studies, plausible reaction mechanisms and pathways were proposed. The influence of the unsaturation in the deoxygenation of model compounds and industrial feedstock – tall oil fatty acids – over a Pd/C catalyst was demonstrated. The optimization of the reaction conditions suppressed the formation of by–products, hence high yields and selectivities towards linear hydrocarbons and catalyst stability were achieved. Experiments in a fixed bed reactor filled with a 2 % Pd/C catalyst were performed with stearic acid as a model compound at different hydrogen–containing gas atmospheres to understand the catalyst stability under various conditions. Moreover, prolonged experiments were carried out with concentrated model compounds to reveal the catalyst deactivation. New materials were proposed for the selective deoxygenation process at lower temperatures (~200 °C) with a tunable selectivity to hydrodeoxygenation by using 4 % Pt/TiO2 or decarboxylation/decarbonylation over 4 % Ru/TiO2 catalysts. A new method for selective hydrogenation of fatty acids to fatty alcohols was demonstrated with a 4 % Re/TiO2 catalyst. A reaction pathway and mechanism for TiO2 supported metal catalysts was proposed and an optimization of the process conditions led to an increase in the formation of the desired products.

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Antiviral nucleosides are compounds that are used against viruses, such as human immunodeficiency virus (HIV) and hepatitis C virus (HCV). To act as therapeutic agent, the antiviral nucleoside needs to be phosphorylated to nucleotide in the body in three consecutive phosphorylation steps by cellular or viral enzymes. The first phosphorylation to the nucleoside monophosphate is often inefficient and leads to poor antiviral activity. The antiviral efficacy can be improved by applying a prodrug strategy and delivering the antiviral nucleoside directly as its monophosphate. In prodrug strategies of antiviral nucleotides, the negative charges on the phosphate moiety are temporarily masked with protecting groups. Once inside the cell, the protecting groups are removed by enzymatic or chemical processes. Many prodrug strategies apply biodegradable protecting groups, the removal of which is triggered by esterase enzymes. Several studies have, however, demonstrated that the removal rate of the second and subsequent esterase labile protecting groups significantly slows down after the first protecting group is removed due to the negative charge on the phosphodiester intermediate, which disturbs the catalytic site of the enzyme. In this thesis, esterase labile protecting group strategies where the issue of retardation could be avoided were studied. Prodrug candidates of antiviral nucleotides were synthesized and kinetic studies on the chemical and enzymatic stability were carried out. In the synthesized compounds, the second protecting group is cleaved from the monophosphate some other mechanism than esterase triggered activation or the structure of prodrug requires only one protecting group. In addition, esterase labile protecting group which is additionally thermally removable was studied. This protecting group was cleaved from oligomeric phosphodiesters both enzymatically and thermally and seems most attractive of the studied phosphate protecting groups. However, the rate of the thermal removal still is too slow to allow efficient protection of longer oligonucleotides and needs optimization. Key words: antiviral, nucleotide, prodrug, protecting group, biodegradable

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Imagine the potential implications of an organization whose business and IT processes are well aligned and are capable of reactively and proactively responding to the external and internal changes. The Philips IT Infrastructure and Operations department (I&O) is undergoing a series of transformation activities to help Philips business keeping up with the changes. I&O would serve a critical function in any business sectors; given that the I&O’s strategy switched from “design, build and run” to “specify, acquire and performance manage”, that function is amplified. In 2013, I&O’s biggest transforming programme I&O Futures engaged multiple interdisciplinary departments and programs on decommissioning legacy processes and restructuring new processes with respect to the Information Technology Internet Library (ITIL), helping I&O to achieve a common infrastructure and operating platform (CI&OP). The author joined I&O Futures in the early 2014 and contributed to the CI&OP release 1, during which a designed model Bing Box and its evaluations were conducted through the lens of six sigma’s structured define-measure-analyze-improve-control (DMAIC) improvement approach. This Bing Box model was intended to firstly combine business and IT principles, namely Lean IT, Agile, ITIL best practices, and Aspect-oriented programming (AOP) into a framework. Secondly, the author implemented the modularized optimization cycles according to the defined framework into Philips’ ITIL-based processes and, subsequently, to enhance business process performance as well as to increase efficiency of the optimization cycles. The unique of this thesis is that the Bing Box model not only provided comprehensive optimization approaches and principles for business process performance, but also integrated and standardized optimization modules for the optimization process itself. The research followed a design research guideline that seek to extend the boundaries of human and organizational capabilities by creating new and innovative artifacts. The Chapter 2 firstly reviewed the current research on Lean Six Sigma, Agile, AOP and ITIL, aiming at identifying the broad conceptual bases for this study. In Chapter 3, we included the process of constructing the Bing Box model. The Chapter 4 described the adoption of Bing Box model: two-implementation case validated by stakeholders through observations and interviews. Chapter 5 contained the concluding remarks, the limitation of this research work and the future research areas. Chapter 6 provided the references used in this thesis.

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The recent rapid development of biotechnological approaches has enabled the production of large whole genome level biological data sets. In order to handle thesedata sets, reliable and efficient automated tools and methods for data processingand result interpretation are required. Bioinformatics, as the field of studying andprocessing biological data, tries to answer this need by combining methods and approaches across computer science, statistics, mathematics and engineering to studyand process biological data. The need is also increasing for tools that can be used by the biological researchers themselves who may not have a strong statistical or computational background, which requires creating tools and pipelines with intuitive user interfaces, robust analysis workflows and strong emphasis on result reportingand visualization. Within this thesis, several data analysis tools and methods have been developed for analyzing high-throughput biological data sets. These approaches, coveringseveral aspects of high-throughput data analysis, are specifically aimed for gene expression and genotyping data although in principle they are suitable for analyzing other data types as well. Coherent handling of the data across the various data analysis steps is highly important in order to ensure robust and reliable results. Thus,robust data analysis workflows are also described, putting the developed tools andmethods into a wider context. The choice of the correct analysis method may also depend on the properties of the specific data setandthereforeguidelinesforchoosing an optimal method are given. The data analysis tools, methods and workflows developed within this thesis have been applied to several research studies, of which two representative examplesare included in the thesis. The first study focuses on spermatogenesis in murinetestis and the second one examines cell lineage specification in mouse embryonicstem cells.

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Finnish design and consulting companies are delivering robust and cost-efficient steel structures solutions to a large number of manufacturing companies worldwide. Recently introduced EN 1090-2 standard obliges these companies to specify the execution class of steel structures for their customers. This however, requires clarifying, understanding and interpreting the sophisticated procedure of execution class assignment. The objective of this research is to provide a clear explanation and guidance through the process of execution class assignment for a given steel structure and to support the implementation of EN 1090-2 standard in Rejlers Oy, one of Finnish design and consulting companies. This objective is accomplished by creating a guideline for designers that elaborates on the four-step process of the execution class assignment for a steel structure or its part. Steps one to three define the consequence class (projected consequences of structure failure), the service category (hazards associated with the service use exploitation of steel structure) and the production category (manufacturing process peculiarities), based on the ductility class (capacity of structure to withstand deformations) and the behaviour factor (corresponds to structure seismic behaviour). The final step is the execution class assignment taking into account results of previous steps. Main research method is indepth literature review of European standards family for steel structures. Other research approach is a series of interviews of Rejlers Oy representatives and its clients, results of which have been used to evaluate the level of EN 1090-2 awareness. Rejlers Oy will use the developed novel coherent standard implementation guideline to improve its services and to obtain greater customer satisfaction.

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Today industries and commerce in Ghana are facing enormous energy challenge. The pressure is on for industries to reduce energy consumption, lower carbon emissions and provide se-cured power supply. Industrial electric motor energy efficiency improvement is one of the most important tools to reduce global warming threat and reduce electricity bills. In order to develop a strategic industrial energy efficiency policy, it is therefore necessary to study the barriers that inhibit the implementation of cost – effective energy efficiency measures and the driving forces that promote the implementation. The aim of this thesis is to analyse the energy consumption pattern of electric motors, study factors that promote or inhibit energy efficiency improvements in EMDS and provide cost – effective solutions that improve energy efficiency to bridge the existing energy efficiency gap in the surveyed industries. The results from this thesis has revealed that, the existence of low energy efficiency in motor-driven systems in the surveyed industries were due to poor maintenance practices, absence of standards, power quality issues, lack of access to capital and limited awareness to the im-portance of energy efficiency improvements in EMDS. However, based on the results pre-sented in this thesis, a policy approach towards industrial SMEs should primarily include dis-counted or free energy audit in providing the industries with the necessary information on potential energy efficiency measures, practice best motor management programmes and estab-lish a minimum energy performance standard (MEPS) for motors imported into the country. The thesis has also shown that education and capacity development programmes, financial incentives and system optimization are effective means to promote energy efficiency in elec-tric motor – driven systems in industrial SMEs in Ghana

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Succinate is a naturally occurring metabolite in organism’s cell and is industrially important chemical with various applications in food and pharmaceutical industry. It is also widely used to produce bio-degradable plastics, surfactants, detergents etc. In last decades, emphasis has been given to bio-based chemical production using industrial biotechnology route rather than fossil-based production considering sustainability and environment friendly economy. In this thesis I am presenting a computational model for silico metabolic engineering of Saccharomyces cerevisiae for large scale production of succinate. For metabolic modelling, I have used OptKnock and OptGene optimization algorithms to identify the reactions to delete from the genome-scale metabolic model of S. cerevisiae to overproduce succinate by coupling with organism’s growth. Both OptKnock and OptGene proposed numerous straightforward and non-intuitive deletion strategies when number of constraints including growth constraint to the model were applied. The most interesting strategy identified by both algorithms was deletion combination of pyruvate decarboxylase and Ubiquinol:ferricytochrome c reductase(respiratory enzyme) reactions thereby also suggesting anaerobic fermentation of the organism in glucose medium. Such strategy was never reported earlier for growth-coupled succinate production in S.cerevisiae.

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Web-palvelut muodostavat keskeisen osan semanttista web:iä. Ne mahdollistavat nykyaikaisen ja tehokkaan välineistön hajautettuun laskentaan ja luovat perustan palveluperustaisille arkkitehtuureille. Verkottunut automatisoitu liiketoiminta edellyttää jatkuvaa aktiivisuutta kaikilta osapuolilta. Lisäksi sitä tukevan järjestelmäntulee olla joustava ja sen tulee tukea monipuolista toiminnallisuutta. Nämä tavoitteet voidaan saavuttamaan yhdistämällä web-palveluita. Yhdistämisprosessi muodostuu joukosta tehtäviä kuten esim. palveluiden mallintaminen, palveluiden koostaminen, palveluiden suorittaminen ja tarkistaminen. Työssä on toteutettu yksinkertainen liiketoimintaprosessi. Toteutuksen osalta tarkasteltiin vaihtoehtoisia standardeja ja toteutustekniikoita. Myös suorituksen optimointiin liittyvät näkökulmat pyrittiin ottamaan huomioon.

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The solid-rotor induction motor provides a mechanically and thermally reliable solution for demanding environments where other rotor solutions are prohibited or questionable. Solid rotors, which are manufactured of single pieces of ferromagnetic material, are commonly used in motors in which the rotationspeeds exceed substantially the conventional speeds of laminated rotors with squirrel-cage. During the operation of a solid-rotor electrical machine, the rotor core forms a conductor for both the magnetic flux and the electrical current. This causes an increase in the rotor resistance and rotor leakage inductance, which essentially decreases the power factor and the efficiency of the machine. The electromagnetic problems related to the solid-rotor induction motor are mostly associated with the low performance of the rotor. Therefore, the main emphasis in this thesis is put on the solid steel rotor designs. The rotor designs studied in thisthesis are based on the fact that the rotor construction should be extremely robust and reliable to withstand the high mechanical stresses caused by the rotational velocity of the rotor. In addition, the demanding operation environment sets requirements for the applied materials because of the high temperatures and oxidizing acids, which may be present in the cooling fluid. Therefore, the solid rotors analyzed in this thesis are made of a single piece of ferromagnetic material without any additional parts, such as copper end-rings or a squirrel-cage. A pure solid rotor construction is rigid and able to keep its balance over a large speed range. It also may tolerate other environmental stresses such as corroding substances or abrasive particles. In this thesis, the main target is to improve the performance of an induction motor equipped with a solid steel rotor by traditional methods: by axial slitting of the rotor, by selecting a proper rotor core material and by coating the rotor with a high-resistive stainless ferromagnetic material. In the solid steel rotor calculation, the rotor end-effects have a significant effect on the rotor characteristics. Thus, the emphasis is also put on the comparison of different rotor endfactors. In addition, a corrective slip-dependent end-factor is proposed. The rotor designs covered in this thesis are the smooth solid rotor, the axially slitted solid rotor and the slitted rotor having a uniform ferromagnetic coating cylinder. The thesis aims at design rules for multi-megawatt machines. Typically, mega-watt-size solidrotor machines find their applications mainly in the field of electric-motor-gas-compression systems, in steam-turbine applications, and in various types of largepower pump applications, where high operational speeds are required. In this thesis, a 120 kW, 10 000 rpm solid-rotor induction motor is usedas a small-scale model for such megawatt-range solid-rotor machines. The performance of the 120 kW solid-rotor induction motors is determined by experimental measurements and finite element calculations.

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Diplomityön tavoitteena on määrittää rajahinta Mertaniemen lämmitysvoimalaitoksella tuotetun kaukolämpöenergian korvaamiselle erillishankinnalla Lappeenrannan Energian kannalta tarkasteltuna. Tarkoituksena on muodostaa taulukkolaskentapohjat erilaisille lämmönkorvaustapauksille sekä päivittää kyseisen lämmitysvoimalaitoksen sähköteho/kaukolämpöteho -karakteristikat. Työssä selvitetään myös lämmön erillishankinnan vaikutusta laitoksen ajotapaan. Laadittujen laskentapohjien ja karakteristikoiden avulla arvioitiin erillishankinnan kannattavuutta suunnitellun UPM-Kymmene Oyj:n Kaukaan voimalaitoksen, paikkakunnan teollisuuslaitoksien, Mertaniemen voimalaitoksen kaasukattiloiden sekä Lappeenrannan Energian lämpökeskuksien lämmöntuotannon tapauksissa. Lisäksi työssä tehtiin kustannuslaskelma kiinteälle lämpökeskukselle sekä laadittiin optimointilaskelma lämmöntuotannon polttoaineiden käytölle. Tuloksiksi saatiin, että yhteistuotanto on erillishankintaa paljon edullisempaa kaikissa tapauksissa. Kaukaan voimalaitoshankkeesta Lappeenrannan Energia jättäytyi täten toistaiseksi pois. Paikkakunnan teollisuuslaitoksilta ostetaan lämpöä edelleen, koska se on todettu edulliseksi yhteistuotannon seisokkien aikaan. Lappeenrantaan suunnitellaan uutta kiinteää lämpökeskusta, mutta sen käyttö korvaamaan yhteistuotantoa ei kannata nykyisillä polttoaineen hinnoilla.

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Raaka-aineen hiukkaskoko on lääkekehityksessä keskeinen materiaaliparametri. Lääkeaineen partikkelikoko vaikuttaa moneen lääketuotteen tärkeään ominaisuuteen, esimerkiksi lääkkeen biologiseen hyväksikäytettävyyteen. Tässä diplomityössä keskityttiin jauhemaisten lääkeaineiden hiukkaskoon määrittämiseen laserdiffraktiomenetelmällä. Menetelmä perustuu siihen, että partikkeleista sironneen valon intensiteetin sirontakulmajakauma on riippuvainen partikkelien kokojakaumasta. Työn kirjallisuusosassa esiteltiin laserdiffraktiomenetelmän teoriaa. PIDS (Polarization Intensity Differential Scattering) tekniikka, jota voidaan käyttää laserdiffraktion yhteydessä, on myös kuvattu kirjallisuusosassa. Muihin menetelmiin perustuvista analyysimenetelmistä tutustuttiin mikroskopiaan sekä aerodynaamisen lentoajan määrittämiseen perustuvaan menetelmään. Kirjallisuusosassa esiteltiin myös partikkelikoon yleisimpiä esitystapoja. Työn kokeellisen osan tarkoituksena oli kehittää ja validoida laserdiffraktioon perustuva partikkelikoon määritysmenetelmä tietylle lääkeaineelle. Menetelmäkehitys tehtiin käyttäen Beckman Coulter LS 13 320 laserdiffraktoria. Laite mahdollistaa PIDS-tekniikan käytön laserdiffraktiotekniikan ohella. Menetelmäkehitys aloitettiin arvioimalla, että kyseinen lääkeaine soveltuu parhaiten määritettäväksi nesteeseen dispergoituna. Liukoisuuden perusteella väliaineeksi valittiin tällä lääkeaineella kyllästetty vesiliuos. Dispergointiaineen sekä ultraäänihauteen käyttö havaittiin tarpeelliseksi dispergoidessa kyseistä lääkeainetta kylläiseen vesiliuokseen. Lopuksi sekoitusnopeus näytteensyöttöyksikössä säädettiin sopivaksi. Validointivaiheessa kehitetyn menetelmän todettiin soveltuvan hyvin kyseiselle lääkeaineelle ja tulosten todettiin olevan oikeellisia sekä toistettavia. Menetelmä ei myöskään ollut herkkä pienille häiriöille.

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Recent years have produced great advances in the instrumentation technology. The amount of available data has been increasing due to the simplicity, speed and accuracy of current spectroscopic instruments. Most of these data are, however, meaningless without a proper analysis. This has been one of the reasons for the overgrowing success of multivariate handling of such data. Industrial data is commonly not designed data; in other words, there is no exact experimental design, but rather the data have been collected as a routine procedure during an industrial process. This makes certain demands on the multivariate modeling, as the selection of samples and variables can have an enormous effect. Common approaches in the modeling of industrial data are PCA (principal component analysis) and PLS (projection to latent structures or partial least squares) but there are also other methods that should be considered. The more advanced methods include multi block modeling and nonlinear modeling. In this thesis it is shown that the results of data analysis vary according to the modeling approach used, thus making the selection of the modeling approach dependent on the purpose of the model. If the model is intended to provide accurate predictions, the approach should be different than in the case where the purpose of modeling is mostly to obtain information about the variables and the process. For industrial applicability it is essential that the methods are robust and sufficiently simple to apply. In this way the methods and the results can be compared and an approach selected that is suitable for the intended purpose. Differences in data analysis methods are compared with data from different fields of industry in this thesis. In the first two papers, the multi block method is considered for data originating from the oil and fertilizer industries. The results are compared to those from PLS and priority PLS. The third paper considers applicability of multivariate models to process control for a reactive crystallization process. In the fourth paper, nonlinear modeling is examined with a data set from the oil industry. The response has a nonlinear relation to the descriptor matrix, and the results are compared between linear modeling, polynomial PLS and nonlinear modeling using nonlinear score vectors.

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Tämä diplomityö toteutettiin Sammet Dampers Oy:ltä saatuna toimeksiantona. Yritys haluaa yhä parempia tuloksia tuoteryhmien kehitysprojekteista, jolloin se asettaa vaatimuksia kehitysprojekteissa käytettävälle kehitysprosessille. Yrityksen täytyy optimoida ja systematisoida käytettävää menetelmää, jotta näihin parempiin tuloksiin voidaan päästä. Työn ensimmäisenä tavoitteena on optimoida yrityksen käytössä oleva tuoteryhmien kehitysprojekteissa käytettävä prosessimalli. Tavoitteen mukaisesti työssä luodaan uusi optimoitu tuoteryhmien kehitysprosessimalli, joka vastaa yrityksen tarpeisiin. Tämä uusi malli kirjataan osaksi yrityksen toiminnanohjausjärjestelmää. Työn toisena tavoitteena on käyttää uutta optimoitua prosessimallia kellopeltien tuoteryhmän kehitysprojektissa. Tätä kehitysprojektia käytetään samalla uuden prosessimallin sisäänajamiseen osaksi yrityksen toimintoja.Tämän diplomityön puitteissa kellopeltien kehitysprojektista käydään läpi kehitysprojektin ensimmäinen osio eli vaatimustenmäärittelyprosessi ja esitellään sen tuloksena syntynyt toteutussuunnitelma. Työn tuloksena syntyneen uuden tuoteryhmien kehitysprojektin prosessimallin avulla voidaan saavuttaa merkittäviä parannuksia tarkasteltaessa kehitysprojektin tuloksia ajankäytön, laadun ja kustannusten suhteen.

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Tutkielmassa selvitettiin UPM-Kymmene Oyj:n liiketoimintaportfolion muodostamia synergioita julkisiin lähteisiin pohjautuen. Synergioiden määrittämistä varten muodostettiin malli, jonka avulla määritettiin synergiat montaa eri liiketoimintaa harjoittavalle yhtiölle. Synergianäkemystä hyödynnettiin portfolion optimoinnissa uudella lähestymistavalla. Synergian mittausmallissa arvotettavan yhtiön liiketoiminta-alueille valittiin vertailuyhtiöt, joiden taloudellista suoriutumista arvioimalla pystyttiin määrittämään arvio synergian määristä. Tutkielman aihe synergioiden muodostumisesta ja mittaamisesta on tärkeä, sillä montaa liiketoimintaa harjoittavat yhtiöt oikeuttavat olemassa olonsa vetoamalla liiketoimintojen välillä syntyviin hyötyihin ja synergioihin. Synergiat ja portfolion optimointi ovat johdolle tärkeä aihe, sillä portfolion hallinta on yrityksen liiketoiminnan jatkuvuuden, taloudellisen suoriutumisen ja olemassa olon kannalta erittäin keskeistä Tutkielman tulosten perusteella UPM:n liiketoimintaportfoliossa muodostuvien synergioiden voidaan arvioida olevan vuosittain 44 miljoonasta eurosta 117 miljoonaan euroon. Portfolion optimoinnin tuloksena ainoastaan paperin ja vaneriliiketoimintojen suhteellista painoarvoa tulee laskea, mikä johtuu lähinnä näiden liiketoimintojen jatkuvasta huonosta taloudellisesta suoriutumisesta.

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Batch chromatography is a widely used separation technique in a variety of fields meeting difficult separations. Several technologies for improving the performance of chromatography have been studied, including mixed-recycle steady state recycling (MR-SSR) chromatography. Design of MR-SSR has been commonly limited on 100 % purity constraint cases and empirical work. In this study a predictive design method was used to optimize feed pulse size and design a number of experimental MR-SSR separations for a solution of 20 % sulfuric acid and 100 g/L glucose. The design was under target product fraction purities of 98.7 % for H2SO4 and 95 % for glucose. The experiments indicate a maximum of 59 % increase in sulfuric acid productivity and 82 % increase for glucose when compared to corresponding batch separation. Eluent consumption was lowered by approximately 50 % using recycling chromatography. Within this study the target purities and yields set in design were not completely met, and further optimization of the process is deemed necessary.