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Abstract: Trajnostno načrtovanje sistemov postaja vedno bolj pomembno za nadaljnji razvoj sodobne družbe. Da bi dosegli cilje trajnostnega razvoja (SDG) v naslednjem desetletju, je treba obravnavati različne cilje, vključno z gospodarskimi, okoljskimi in socialnimi vprašanji. V magistrski nalogi smo obravnavali problem rekonstruiranja obstoječega procesa proizvodnje sladkorja v Ormožu, ki je sestavljen iz več procesov. Naša naloga je bila v kemijskem procesu integrirati sušilnik z uparjalnikom. Vodna para je kot stranski produkt izhajala v ozračje, saj obrati v preteklosti niso bili povsem energijsko, ekonomsko in učinkovito zgrajeni. Proces smo želeli izboljšati s tako, da bi nam para služila kot vir dohodka. V prvem delu smo primerjali dejanski in integriran kemijski proces. Prikazali smo realni proces proizvodnje ter našo idejno integracijo. Pri tem smo dejanske podatke poskušali preveriti s programsko opremo Aspen Plus. Obstoječi uparjalnik se segreva z nizko-tlačno paro, pridobljeno iz peči. Dejanski sistem segrevanja uparjalnika bi lahko nadomestili z integracijo sušilnika z uparjalnikom, da zvišamo vhodno temperaturo zraka v sušilnik za 40 °C, s tem se tudi zviša segrevanje za 40 °C v peči, ki segreva zrak pred vtokom v sušilnik. V drugem delu smo naredili še ekonomični izračun, da smo lahko potrdili, ali bi se nam simulacija dejanskega procesa izplačala. Izračuni so nam podali rezultate, da bi integriran proces ustvaril višje prihodke kot odhodke. Kot končni rezultat smo ugotovili, da bi dejanski proces proizvodnje sladkorja lahko izboljšali z integracijo obstoječega procesa.
Keywords: integracija, rekonstrukcija, optimiranje, Aspen Plus, sladkor
Published in DKUM: 03.02.2025; Views: 0; Downloads: 23
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Abstract: Anaerobic digestion (AD) is a promising and yet a complex waste-to-energy technology. To optimize such a process, precise modeling is essential. Developing complex, mechanistically inspired AD models can result in an overwhelming number of parameters that require calibration. This study presents a novel approach that considers the role of trace metals (Ca, K, Mg, Na, Co, Cr, Cu, Fe, Ni, Pb, and Zn) in the modeling, numerical simulation, and optimization of the AD process in a batch bioreactor. In this context, BioModel is enhanced by incorporating the influence of metal activities on chemical, biochemical, and physicochemical processes. Trace metal-related parameters are also included in the calibration of all model parameters. The model’s reliability is rigorously validated by comparing simulation results with experimental data. The study reveals that perturbations of 5% in model parameter values significantly increase the discrepancy between simulated and experimental results up to threefold. Additionally, the study highlights how precise optimization of metal additives can enhance both the quantity and quality of biogas production. The optimal concentrations of trace metals increased biogas and CH4 production by 5.4% and 13.5%, respectively, while H2, H2S, and NH3 decreased by 28.2%, 43.6%, and 42.5%, respectively.
Keywords: anaerobic digestion, batch bioreactor, methane production, model parameters calibration, active set optimization method, perturbation of model parameter, gradient based optimization, trace metals
Published in DKUM: 30.01.2025; Views: 0; Downloads: 3
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Abstract: V zadnjem času se pospešeno raziskujejo možnosti pridobivanja energije, goriv in raznih kemikalij iz bioplina. Bioplin, ki je sestavljen predvsem iz CH4 in CO2, lahko uporabimo za proizvodnjo sinteznega plina, iz katerega pa lahko pridobivamo etanol. Etanol se lahko uporablja kot alternativno gorivo za motorna vozila in za ogrevanje stanovanj. V hrani in pijači deluje kot konzervans ali sredstvo za aromatiziranje. Prav tako pa se pogosto uporablja kot surovina v kemijski in farmacevtski industriji. V okviru magistrske naloge smo obravnavali proizvodnjo etanola iz bioplina. Osnovni cilj magistrske naloge je bil določiti optimalne pogoje za proizvodnjo etanola iz bioplina s pomočjo programa Aspen Plus. V ta namen smo izvedli numerično simulacijo proizvodnje etanola pri različnih obratovalnih pogojih (temperatura, tlak) in pri različnih sestavah vhodne surovine (količina dodanega CO2 in vodne pare). Z analizo teh vplivnih parametrov smo določili optimalne pogoje za proizvodnjo etanola. Dobljeni rezultati kažejo, da največjo količino nastalega etanola dosežemo pri temperaturi 200 °C, tlaku 50 bar, količini dodanega CO2 300 kmol/h in pri količini dodane vodne pare 400 kmol/h. Pri teh optimalnih vrednostih vplivnih faktorjev se lahko količina proizvedenega etanola poveča tudi do 15 %.
Keywords: bioplin, sintezni plin, proizvodnja etanola, simulacija z Aspen Plus, optimiranje
Published in DKUM: 25.09.2024; Views: 0; Downloads: 25
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Abstract: In order to ensure efficient wastewater treatment and seawater desalination, adequate modeling and optimization of the forward osmosis (FO) process has the potential to be very helpful. This paper deals with the FO model parameters calibration and FO process optimization by a gradient-based optimization method. For this purpose, an upgraded FO model, which involves temperature- and agent-dependent parameters, was developed. The FO model calibration was done using NaCl as agents in draw solution, while MgCl2 was used for model validation. The agreements between simulated and measured FO performance were satisfactory; relative index of agreement are higher than 0.99. By using the proposed FO model, the optimization of FO process conditions was performed with various definitions of the objective and constraint functions. In case of maximizing the water flux, minimizing reverse solute flux, and fulfilling the required constraints, the ratio of water flux and reverse solute flux increased up to 40 % for NaCl and up to 20 % for MgCl2; meanwhile the effective osmotic pressure difference was improved 2-times for NaCl and up to 3.8-times for MgCl2. The optimization process proved to be stable and efficient and can easily be adapted or upgraded for more complex dynamic FO modeling.
Keywords: forward osmosis, modeling, model and process parameters, calibration procedure, gadient-based optimization
Published in DKUM: 23.08.2024; Views: 67; Downloads: 26
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Abstract: : Anaerobic digestion (AD) is a promising technology for renewable energy production from organic waste. In order to maximize the produced biogas quantity and quality, this paper deals with the optimization of the AD process in a CSTR bioreactor of a full-scale biogas plant. For this purpose, a novel approach was adopted coupling, a highly complex BioModel for AD simulation, and a gradient-based optimization method. In order to improve AD performance, the dosages of various types of biological additives, the dosages of inorganic additives, and the temperature in the bioreactor were optimized in three different scenarios. The best biogas quality was obtained using multi-objective optimization, where the objective function involves the following two conflicting objectives: the maximization of biogas production and minimization of the needed heating energy. The obtained results show that, potentially, the content of CH4 can be increased by 11%, while the contents of H2, H2S, and NH3 can be reduced by 30%, 20%, and 81% when comparing the simulation results with the experimental data. The obtained results confirm the usefulness of the proposed approach, which can easily be adapted or upgraded for other bioreactor types.
Keywords: additives, anaerobic digestion, approximation method, BioModel, complex substrate, gradient-based optimization, process conditions
Published in DKUM: 12.03.2024; Views: 298; Downloads: 30
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