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Economically viable process designs should be, in addition to other criteria, profitable over their entire process lifetimes not only at the present time. An improved process design can be achieved by establishing an appropriate trade-off between product income, raw material, operating costs, and investment. The full lifetime of the processes and future prices have to be considered rather than optimising them on a yearly basis using current prices. Single-period optimisation and synthesis models for processes reflects current prices only. The prices can fluctuate rather quickly and the optimal solution may be very different from one year to the another. Therefore, the traditional superstructural synthesis approach applying a mixed-integer nonlinear programming model was upgraded: i) over time, by considering an entire lifetime, which can be described by a multi-period model and ii) the whole field of variation regarding uncertain future prices. A stochastic approach considering the statistical distribution of price projections over an entire lifetime was used on different case studies instead of the traditional deterministic approach accounting for nominal future price projection. The objective was the maximisation of the expected net present value of a process or the expected incremental net present value of different process subsystem. The heat exchanger network has been one of the subsystem, which can significantly contribute to operating costs due to savings of external utility consumption. For this subsystem a deterministic and stochastic multi-period mixed-integer nonlinear programming (MINLP) synthesis models have been developed in order to account for future price projections. Considering higher energy prices gives rise to larger initial investments compared to solutions obtained with current prices. However, due to the uncertainties of utility prices' forecasts, retrofitting using an extension of HEN during future years of the lifespan might be a better strategy. The objective is to identify a design that is the most suitable for effective future extensions and preferably with the lowest sensitivity to energy price fluctuations, as there can be various designs featuring similar initial investment. The results supports that it is economically beneficial to consider future utility prices as the incremental investment is not only paid-off but additional savings are achieved. Process-to-process Heat Integration can also significantly affect the trade-off between investment and operating cost. The aim of Total Site (TS) HEN synthesis was to develop a model synthesis for the TS that, besides many other important features, would also consider future utility prices. Two strategies for TS synthesis have been developed: i) sequential, when HI is performed within a process during the first step and then after a process-to-process HI has been performed, and ii) simultaneous, where the HI is performed within and between processes simultaneously. The second strategy can reveal additional opportunities for heat recovery that might not be identified when applying the first strategy. Comparison of the results obtained at consideration of current utility prices and forecasted utility prices indicates that is worth to account for future utility prices. The separation processes also consume a significant amount of energy. The synthesis of a distillation column sequence integrated within its heat exchanger network was used as a case study for the separation of a multi-component stream into pure component products by considering future utility prices. This analysis has been performed in order to evaluate the magnitude of the influence of forecasted utility prices. It can be concluded that forecasted utility prices can be beneficial, however, the technical limits of the systems should be carefully observed. The price fluctuation can also be observed for other prices not only utility prices, e.g. raw material cost, product price, etc Ekonomično upravičeni načrti morajo biti, poleg ostalih kriterijev, tudi dobičkonosni skozi celotno življenjsko dobo procesa, ne samo v sedanjem času. Z vzpostavitvijo primernega trženja med prihodki produkta, stroški surovin, obratovalnimi stroški in investicijo v celotni življenski dobi lahko dosegamo izboljšan načrt procesa. Zato je optimizacija za celotno življenjsko dobo procesa z upoštevanjem napovedanih cen primernejša od optimizacije na letni osnovi. Enoperiodno optimiranje in sinteza za procese odraža le sedanje cene. Optimalna rešitev, dosežena za eno leto, se lahko znatno razlikuje od rešitve za drugo leto, saj se cene spreminjajo precej hitro. Običajni superstrukturni sintezni pristop z uporabo mešano-celoštevilskega nelinearnega programiranja smo zato nadgradili 1) z upoštevanjem celotne življenjske dobe, kar lahko opišemo z večperiodnim modelom in 2) z območjem spreminjanja negotovih prihodnjih cen. Namesto običajnega determinističnega pristopa pri nominalnih projekcijah prihodnjih cen smo uporabili stohastični pristop z upoštevanjem statistične porazdelitve napovedovanja cen za celotno življenjsko dobo. Namen je bil maksimiranje pričakovane neto sedanje vrednosti procesa oz. pričakovane inkrementalne neto sedanje vrednosti izboljšave različnih procesnih podsistemov. Podsistem, ki znatno prispeva k obratovalnim stroškom zaradi prihrankov pri porabi zunanjih pogonskih sredstev, je omrežje toplotnih prenosnikov. Za sintezo tega podsistema smo razvili tako deterministični kot stohastični večperiodni celoštevilski nelinearni programirni (MINLP) model ob upoštevanju prihodnjih cenovnih projekcij. Z upoštevanjem višjih cen energentov se povečajo začetne investicije v primerjavi z rešitvami, ki jim dosežemo pri sedanjih cenah. Zaradi negotovosti napovedovanja cen se je smiselno povečanju začetne investicije izogniti z načrtovanjem možnosti razširitve omrežja toplotnih prenosnikov v kasnejšem obdobju. Namen je doseči načrt, ki je kar najbolj primeren za učinkovito razširitev v prihodnosti, po možnosti z najmanjšo občutljivostjo na spreminjanje cen. Toplotna integracija med različnimi procesi lahko tudi znatno vpliva na trženje med investicijo in obratovalnimi stroški. Tako je bil eden od ciljev sinteze omrežja toplotnih prenosnikov prav upoštevanje prihodnjih cen pogonskih sredstev. Razvili smo dve strategiji za sintezo celotnega območja (ang. Total Site), in sicer: i) zaporedno, pri kateri toplotno integracijo izvajamo najprej na nivoju procesa in potem na nivoju celotnega območja, in ii) sočasno, pri kateri izvajamo toplotno integracijo na nivoju procesa in na nivoju celotnega območja hkrati. Slednja strategija omogoča dodatne možnosti prihranka toplote, kar potrjuje primerjava rezultatov doseženih pri sedanjih in prihodnjih cenah pogonskih sredstev. Separacijski procesi so lahko veliki porabniki energije. Sintezo zaporedja destilacijskih kolon integriranih z lastnim omrežjem toplotnih prenosnikov smo uporabili kot študijski primer za ločevanje večkomponentnega toka v čiste produkte. Analizo smo izvedli tudi z namenom določitve obsega vpliva napovedanih prihodnjih cen pogonskih sredstev. Zaključimo lahko, da z upoštevanjem napovedanih cen lahko dosegamo ekonomsko učinkovitejše procese ali procesne podsisteme, vendar je pri tem potrebno skrbno upoštevati tehnološke omejitve študiranega sistema. Nihanje cen razen pri pogonskih lahko opazimo tudi pri drugih cenah, npr. pri cenah surovin, in produktov. Pričakujemo lahko, da trženje v postopku optimiranja poskuša kompenzirati ta nihanja cen, npr. višje cene pogonskih sredstev bodo izravnane s povečanjem investicije, s čemer se zmanjšajo prihodnji obratovalni stroški. Vendar, ko upoštevamo vse stroške in prihodke hkrati, so lahko trendi vplivov različni od posameznega vpliva le teh, kar smo pokazali tudi s študijskim primerom.

This paper upgrades the Total Site integration methodology, when accounting for a trade-off between capital and heat recovery by selection of optimal temperature levels for intermediate utilities and therefore, decrease capital cost. Heat transfer area for recuperation in Total Site is a two-fold problem and it depends on the Sink Profile on one side and on the Source Profile on another. The resulting temperature of intermediate utility is a result of a trade-off since the heat transfer area on Source side is decreasing, when temperature of IM is decreasing, however increased on Sink side. In the opposite higher intermediate utility temperature leads to higher area on the Source side and lower on Sink side. The temperature of each intermediate utility may be varied between specified lower and upper bounds subject to serving the Sink and Source Profiles.

V diplomski nalogi smo proučevali anaerobno digestijo mešanic japonskega dresnovca in piščančjega gnoja, ki so bile predhodno obdelane z glivo Pleurotus Ostreatus. Pred nastavitvijo eksperimentov smo določili optimalno razmerje med biomaso dresnovca in inokuluma. Nastavili smo štiri različna razmerja glede na trdne snovi in sicer: 1(D/I) = 85:15, 2(D/I) = 70:30, 3(D/I) = 50:50 in 4(D/I) = 30:70. Med procesom anaerobne digestije smo spremljali količino in sestavo nastajajočega bioplina in merili množinski delež metana, CO2 (glavni komponenti bioplina), N2 in O2 za nadzorovanje anaerobnega procesa. Ocenili smo, da je optimalno razmerje med dresnovcem in inokulumom 80:20, saj smo želeli imeti v vhodni snovi največji možni delež rastlinskih substratov. Nato smo izvedli eksperiment, kjer so bili vhodni substrati mešanice z različnimi razmerji dresnovca in piščančjega gnoja, obdelani z glivo Pleurotus Ostreatus. Namen obdelave teh mešanic z glivo je bil, da gliva z encimi pretvori bakterijam nedostopno lignocelulozo, tako iz dresnovca kot tudi stelje iz gnoja, v substrat, katerega bakterije v procesu anaerobne digestije hitreje in lažje razgradijo, pri tem pa kot produkt nastaja bioplin. Tudi med tem procesom smo merili volumen nastalega bioplina in njegovo sestavo. Pred in po anaerobni digestiji smo določevali vsebnost trdnih snovi in vsebnost hlapnih trdnih snovi. Iz podatkov o volumnu bioplina, njegovi sestavi in vsebnosti trdnih in hlapnih trdnih snovi, smo lahko izračunali različne donose metana. Izkazalo se je, da so glive ob prisotnosti dresnovca prerasle tudi gnoj in da je bil donos bioplina pri anaerobni digestiji obdelanega dresnovca nekoliko višji kot pri neobdelanem dresnovcu. This diploma work deals with the anaerobic digestion of the mixture of Japanese knotweed and chicken manure which had previously been treated with fungus Pleurotus Ostreatus. Before setting the experiments we set the optimal ratio between the biomass of knotweed and inoculum. We set four different ratios with respect to the total solids as follows: 1(D/I) = 85:15, 2(D/I) = 70:30, 3(D/I) = 50:50 in 4(D/I) = 30:70. During the process of anaerobic digestion we monitored the amount and the composition of the created biogas and we measured the amount fractions of methane, CO2 (main components of biogas), N2 and O2 to control the anaerobic conditions. We estimated the optimal ratio between knotweed and inoculum is (D/I) = 80:20, because we wanted to have as high a proportion of plant substrates as possible in the input matter. After obtaining the optimal ratio we set up an experiment, where the inputs were mixtures with different ratios of knotweed and chicken manure, now treated with fungus Pleurotus Ostreatus. The purpose of the treatment was to use enzymes to convert bacteria inaccessible lignocelluloses, both knotweed as well as bedding from manure, into substrates which bacteria degrade with greater ease and faster during the process of anaerobic digestion, where biogas is produced. During the anaerobic digestion we measured the amount and composition of the created biogas. Before and after the anaerobic digestion we measured the content of total solids and volatile total solids. From the measurements we calculated different methane yields. It turned out that fungus can grow on manure in the presence of knotweed and that the biogas yield of anaerobic digestion of treated knotweed is slightly higher than in the case of untreated knotweed.

Varnost v kemijskih procesih postaja vse bolj pomemben vidik že v fazi načrtovanja procesa. V tem magistrskem delu smo upoštevali vidik varnosti v fazi načrtovanja omrežja toplotnih prenosnikov (OTP). Pri tem smo ocenili inherentno varnost s pomočjo mešano celoštevilskega nelinearnega programirnega (MINLP) modela najprej z osnovnim modelom. Nato smo izvedli občutljivostno analizo z različnimi tipi toplotnih prenosnikov, pri čemer smo primerjali ploščine toplotnega prenosa, mase prisotnih snovi, tlačne padce ter razmerja med volumnom in ploščino v toplotnih prenosnikih. Za vsak prenos smo dimenzionirali primeren prenosnik toplote. Izračunane podatke smo nato vstavili v posodobljen model za celotno OTP. Tako dobljene vrednosti ploščin in indikatorjev tveganja smo primerjali z začetnimi vrednostmi. Ugotovili smo, da so bile začetne ploščine vseh toplotnih izmenjevalcev precenjene. Posledično so bili napačno ocenjeni tudi stroški investicije in indikatorji tveganja. Nato smo za izbrane dimenzije toplotnih prenosnikov primerjali indikatorje tveganja za toksičnost, vnetljivost in eksplozivnost med rezultatoma, ko nismo upoštevali natančnih mer toplotnih prenosnikov ter pri upoštevanju natančnih dimenzij toplotnih prenosnikov. Rezultati kažejo, da ima natančno dimenzioniranje prenosnika za posamezne prenose toplote velik vpliv na oceno varnosti v OTP. Z dodatkom natančnega dimenzioniranja prenosnikov toplote smo omogočili natančnejše načrtovanje OTP in realnejše ocenjevanje njihove varnosti. Importance of safety in chemical processes is increasing already in the first phases of design. This master's thesis takes into account the safety aspect of heat exchangers network (HEN) in the design phase. In doing so, inherent safety was assessed using the mixed-integer nonlinear programming (MINLP) model, taking into account the precise dimensions of the heat exchangers. A sensitivity analysis was performed with different types of heat exchangers, where surfaces of heat transfer, mass of substances present, pressure drops and the ratio of volume to surface in heat exchangers were compared. We then compared risk indicators for toxicity, flammability and explosiveness for the selected dimensions of the heat exchangers between the results when the exact dimensions of the heat exchangers were considered and when they were not taken into account. The results show that accurate sizing of exchangers for individual heat transfers has a major impact on safety assessment of the HEN. A suitable heat exchanger was dimensioned for each heat exchange, and the calculated data was then inserted into the updated model for the entire HEN. The surface values and risk indicators obtained in this way were compared to the initial values. The initial surfaces of all heat exchangers were found overestimated. As a result, the costs of the investment and risk indicators were also misjudged. By adding precise dimensioning of heat exchangers to risk assessment in HEN, we have made it possible to plan HENs more accurately and evaluate their safety more realistically.

The steady decline of the Dead Sea’s water level, a high dependence on imported fossil fuels and the increasing gap between water supply and demand are serious problems facing Jordan. A possible solution for all of these problems is the construction of the Red Sea- Dead Sea Canal which would not only help preserve the Dead Sea but would also provide the potential for desalinization plants and pump storage hydroelectric power plants which would enable a higher penetration of renewable energy sources. The goal of this paper is to present the implementation of the Red Sea-Dead Sea Canal and the desalinization plant in Jordan’s energy strategy and to present a number of possible alternatives. The results of the analysis have shown that it might be beneficial to integrate renewable energy sources with desalinization plants. Furthermore, the water produced with this process could be sufficient for the agricultural needs of the country.