Дисертації з теми "Liquid Fuel Production"
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Anders, Mark. "Technoeconomic modelling of coal conversion processes for liquid fuel production." Thesis, Aston University, 1991. http://publications.aston.ac.uk/10240/.
Повний текст джерелаPastore, Andrea. "Syngas production from heavy liquid fuel reforming in inert porous media." Thesis, University of Cambridge, 2010. https://www.repository.cam.ac.uk/handle/1810/237704.
Повний текст джерелаLott, Tawney. "A political economy analysis of liquid fuel production incentives in South Africa." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27233.
Повний текст джерелаComidy, Liam Jacob Frank First Lieutenant. "Technical, economic, and environmental assessment of liquid jet fuel production on aircraft carriers." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122407.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 50-54).
This work is a first order assessment of the technical feasibility and characteristics of technologies to produce fuel onboard aircraft carriers, which is of interested to the United States Navy. They are interested because the logistical burden and supply chain required for delivering fuel at sea is dangerous, expensive, and subject to changes in markets price for liquid fuels. This work is a first order assessment of the technical feasibility and characteristics of technologies to produce fuel onboard aircraft carriers. The plant is evaluated for three technology pathways: Alkaline electrolysis and the reverse water gas shift (AE+RWGS), solid oxide electrolysis and RWGS (SOEC+RWGS), and co-electrolysis of steam and CO₂. They are evaluated within two scenarios: a small infrequently operating plant leveraging excess nuclear power (Scenario A) and a large frequently operating plant with dedicated nuclear capacity.
In addition, a parameter sweep of fuel production capacity and capacity factor is conducted to assess impacts on fuel production costs. In Scenario A, the energy requirements ranged from 152-22OMWe and fuel production cost ranged from 1.91-4.49$/L. In Scenario B, the energy requirements ranged in 1380-2066MWe and fuel production costs ranged from 3.25-4.23$/L. In both scenarios, AE+RWGS was the most cost effective and co-electrolysis was the most energy efficient. The fuel produced reduced lifecycle CO₂ equivalent emissions by 85.3-90.2%. The plant volume and weight were 50-67% and 432% of a current aircraft carrier design at large scales. The results of the parameter sweep indicate that generally a larger more frequently operating plant is more cost effective, but dedicated nuclear capacity requirements diminishes this benefit.
The overall results indicate that a fuel production plant on an aircraft carrier is technically feasible and has the potential to be cost effective, though research into cost, weight, and volume reduction are still necessary.
by Liam Jacob Frank Comidy.
S.M.
S.M. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics
Zhang, Yusheng. "Development of a bench scale single batch biomass to liquid fuel facility." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/811.
Повний текст джерелаChetty, Thamaraveni. "Factors influencing the success of ethanol production for use in liquid transport fuels in South Africa." Diss., University of Pretoria, 2007. http://hdl.handle.net/2263/23815.
Повний текст джерелаDissertation (MBA)--University of Pretoria, 2007.
Gordon Institute of Business Science (GIBS)
unrestricted
Al-Harrasi, Wail Saif Salim. "Novel plasma catalytic systems for Fischer-Tropsch reactions : intensified gas-to-liquid fuel production." Thesis, University of Newcastle Upon Tyne, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578549.
Повний текст джерелаChang, Ai-Fu. "Process Modeling of Next-Generation Liquid Fuel Production - Commercial Hydrocracking Process and Biodiesel Manufacturing." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/58043.
Повний текст джерелаPh. D.
Loegel, Thomas N. "High Performance Liquid Chromatography of Petroleum Asphaltenes and Capillary Electrophoresis of Glycosaminoglycan Carbohydrates." Miami University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=miami1354241855.
Повний текст джерелаDuangsuwan, Wiriya. "Experimental studies of the mixing of alcohols with vegetable oil using gas-liquid compound drops for applications in bio-fuel production." Thesis, University of Surrey, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521716.
Повний текст джерелаWalker, Devin Mason. "Catalytic Tri-reforming of Biomass-Derived Syngas to Produce Desired H2:CO Ratios for Fuel Applications." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4250.
Повний текст джерелаKababji, Ala'a Hamed. "Effects of Diluent Addition and Metal Support Interactions in Heterogeneous Catalysis: SiC/VPO Catalysts for Maleic Anhydride Production and Co/Silica Supported Catalysts for FTS." Scholar Commons, 2009. https://scholarcommons.usf.edu/etd/2035.
Повний текст джерелаCaux, Marine. "Metal-loaded graphitic carbon nitride for photocatalytic hydrogen production and the development of an innovative photo-thermal reactor." Thesis, University of St Andrews, 2018. http://hdl.handle.net/10023/15873.
Повний текст джерелаMarepally, Bhanu Chandra. "Production of Solar Fuels using CO2." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1062.
Повний текст джерелаIn view of the recent alarming rate of depletion of fossil fuel reserves and the drastic rise in the CO2 levels in the atmosphere leading to global warming and severe climate changes, tapping into all kinds of renewable energy sources has been among the top priorities in the research fields across the globe. One of the many such pathways is CO2 reduction to fuels using renewable energies, more commonly referred as photo-electro-catalytic (PEC) cells. Experimental tests were carried out on various types of catalysts in both the gas and liquid phase cells (lab-designed) to understand the different selectivity, productivity and the reaction products obtained. For the studies on the EC reduction of CO2 in gas phase cell, a series of electrodes (based on Cu, Fe, Pt and Cu/Fe metal nanoparticles – NPs - deposited on carbon nanotubes – CNTs - or carbon black and then placed at the interface between a Nafion membrane and a gas-diffusion-layer) were prepared. Under gas phase, the formation of ≥C1 products (such as ethanol, acetone and isopropanol) were observed, the highest being for Fe and closely followed by Pt, evidencing that also non-noble metals can be used as efficient catalysts under these conditions. To enhance the net fuels, a different set of electrodes were also prepared based on substituted Zeolitic Imidazolate (SIM-1) type MOF coatings (MOF-based Fe-CNTs, Pt-CNTs and Cu/Fe-CNTs) and Pt-MOF showed improved fuels. Moving to the studies on the EC reduction of CO2 in liquid phase cell, a similar set of electrodes were prepared (metal NPs of Cu, Fe, Pt, Ru and Co deposited on CNTs or carbon black). For liquid phase conditions, in terms of net C-products, catalytic electrodes based on Pt topped the class, closely followed by Ru and Cu, while Fe got the lowest position. The probable underlying reaction mechanism was also provided. In order to improve further the performances, varied sized metal NPs (Ru, Fe, Pt and Cu) have been synthesized using different techniques: (i) impregnation (ImR) route to achieve NPs in the size range of 10-50 nm; (ii) organometallic (OM) approach to synthesize uniform and ultrafine NPs in the size range of 1-5 nm (i.e., Fe NPs were synthesized through a novel synthesis route to attain 1-3 nm NPs); (iii) Nanowire (NW) top-down approach to obtain ultrafine copper metal NPs in the size range of 2-3.8 nm. The enhancements in the fuel productivity were found to be 5-30 times higher for the smaller metal NPs over the larger metal NPs and moreover, with reduced metal loading from 10 to 1-2 wt %. A different set of electrodes based on nano-foams (Cu NF and Fe NF on Cu foil, Fe foil, Al foil, Inconel foil and Al grid/mesh) prepared via electro-deposition were also investigated, to further improve CO2 to fuels conversion. After, optimization of deposition and voltage using cyclic voltammetry, the fuels improved by 2-10 times over the highest net fuels achieved using metal NPs doped CNT electrodes
Muhammad, Chika. "Pyrolysis-catalysis of plastic wastes for production of liquid fuels and chemicals." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/12142/.
Повний текст джерелаTrivedi, Parthsarathi. "Environmental and economic tradeoffs of feedstock usage for liquid fuels and power production." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90805.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 55-63).
The thesis is divided into two parts - 1) assessing the energy return on investment for alternative jet fuels, and 2) quantifying the tradeoffs associated with the aviation and non-aviation use of agricultural residues. We quantify energy return on energy investment (EROI) as one metric for the sustainability of alternative jet fuel production. Lifecycle energy requirements are calculated and subsequently used for calculating three EROI variants. EROI₁ is defined as the ratio of the lower heating value (LHV) of the liquid fuel produced, to lifecycle (direct and indirect) process fossil fuel energy inputs and fossil feedstock losses during conversion. EROI₂ is defined as the ratio of fuel LHV to total fossil fuel energy input, inclusive of the fossil energy embedded in the fuel. EROI₃ is defined as the ratio of fuel LHV to the sum of renewable and non-renewable process fuel energy required and feedstock energy losses during conversion. We also define an approximation for EROI₁ using lifecycle CO₂ emissions. This approach agrees to within 20% of the actual EROI₁ and can be used as an alternative when necessary. Feedstock-to-fuel pathways considered include jet fuel from conventional crude oil; jet fuel production from Fischer-Tropsch (FT) processes using natural gas, coal and/or switchgrass; HEFA (hydroprocessed esters and fatty acids) jet fuel from soybean, palm, rapeseed and jatropha; and advanced fermentation jet (AF-J) fuel from sugarcane, corn grain and switchgrass. We find that ERO₁ 1 for conventional jet fuel from conventional crude oil ranges between 4.9-14.0. Among the alternative fuel pathways considered, FT-J fuel from switchgrass has the highest baseline EROI₁ of 9.8, followed by AF-J fuel from sugarcane at 6.7. Jet fuel from oily feedstocks has an EROI₁ between 1.6 (rapeseed) and 2.9 (palm). EROI₂ differs from EROI₁ only in the case of fossil-based jet fuels. Conventional jet from crude oil has a baseline EROI₂ of 0.9, and FT-J fuel from NG and coal have values of 0.6 and 0.5, respectively. EROI 3 values are on average 36% less than EROI₁ for HEFA pathways. EROI₃ for AF-J and FT-J fuels considered is 50% less than EROI₁ on average. All alternative fuels considered have a lower baseline EROI₃ than conventional jet fuel. Using corn stover, an abundant agricultural residue, as a feedstock for liquid fuel or power production has the potential to offset anthropogenic climate impacts associated with conventional utilities and transportation fuels. We quantify the environmental and economic opportunity costs associated with the usage of corn stover for different applications, of which we consider combined heat and power, ethanol, Fischer-Tropsch (FT) middle distillate (MD) fuels, and advanced fermentation (AF) MD. Societal costs comprise of the monetized attributional lifecycle greenhouse gas (GHG) footprint and supply costs valued at the shadow price of resources. The sum of supply costs and monetized GHG footprint then provides the societal cost of production and use of corn stover for a certain application. The societal costs of conventional commodities, assumed to be displaced by renewable alternatives, are also calculated. We calculate the net societal cost or benefit of different corn stover usages by taking the difference in societal costs between corn stover derived fuels and their conventional counterparts, and normalize the results on a feedstock mass basis. Uncertainty associated with the analysis is captured using Monte-Carlo simulation. We find that corn stover derived electricity and fuels reduce GHG emissions compared to conventional fuels by 21-92%. The mean reduction is 89% for electricity in a CHP plant, displacing the U.S. grid-average, 70% for corn stover ethanol displacing U.S. gasoline and 85% and 55% for FT MD and AF MD displacing conventional U.S. MD, respectively. Using corn stover for power and CHP generation yields a net mean societal benefit of $48.79/t and $131.23/t of corn stover, respectively, while FT MD production presents a mean societal benefit of $27.70/t of corn stover. Ethanol and AF MD production from corn stover result in a mean societal cost of $24.86/t and $121.81/t of corn stover use, respectively, driven by higher supply costs than their conventional fuel counterparts. Finally, we note that for ethanol production, the societal cost of CO₂ that would need to be assumed to achieve a 50% likelihood of net zero societal cost of corn stover usage amounts to approximately -$100/tCO₂, and for AF MD production to ~$600/tCO₂.
by Parthsarathi Trivedi.
S.M.
Kantarelis, Efthymios. "Catalytic Steam Pyrolysis of Biomass for Production of Liquid Feedstock." Doctoral thesis, KTH, Energi- och ugnsteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-142412.
Повний текст джерелаDet nuvarande samhällets behov av bränslen och kemiska produkter är starkt knutet till fossila resurser. Detta beroende kan leda till ekonomisk instabilititet, politiska svårigheter och osäker leveranssäkerhet. Dessutom riskeras allvarliga skador i framtiden på grund av global uppvärmning, vilket är relaterat till det ökande och massiva användandet av fossila bränslen. Biomassa är en förnybar resurs som är tillgänglig idag, möjlig att utnyttja för produktion av diverse flytande, gasformiga och fasta produkter. Dessa produkter, beroende på biogeniskt ursprung, betraktas som koldioxidneutrala och kan därför generera koldioxidkrediter. Processande av biomassa kan möta utmaningen av minskad fossilbränsleanvändning, genom produktion av flytande råvara som kan reducera beroendet och/eller möta ökad efterfrågan, via en snabbt expanderande termokemisk teknik - pyrolys. Det slutgiltiga målet med en sådan process är att producera en flytande produkt med förbättrade egenskaper som direkt skulle kunna användas som flytande bränslen, bränsleadditiv och/eller som råmaterial i moderna oljeraffinaderier och petrokemiska komplex. Vätskor som utvinns från termiska processer är problematiska med avseende på hantering och slutanvändningen i olika applikationer, därmed behövs olika spår för produktion av avancerade flytande råvaror. Heterogena katalysen har länge tjänat raffinaderi- och petrokemisk industri, som producerar ett brett utbud av bränslen och produkter, lämpliga för säker användning. Kombinationen av biomassapyrolys och heterogen katalys (genom att bringa pyrolysångorna i kontakt med en lämplig katalysator) är ett väldigt lovande spår. I denna avhandling undersöks användningen av biomassa för produktion av flytande råvara, via pyrolys över en flerfunktionel katalysator i ångatmosfär. Ångpyrolys i en fastbäddsreaktor visade att ånga kan betraktas som ett reaktivt medium, även vid låga temperaturer, som påverkar utbyten och sammansättning av alla produkter. Avgasningen sker snabbare och den slutliga flykthalten i kolresterna blir lägren vid användning av ånga. Snabbpyrolys i ångatmosfär resulterar i förbättrad och mer kontrollerad termisk nedbrytning av biomassa, vilket ger ett högre vätskeutbyte och en något deoxygenerad flytande produkten. ångpyrolys i kombination med bimetalliska NiV-katalysatorer, ger upphov till en flytande råvara med förbättrad kvalitet och selektiv deoxygenering. Dock med ett minskande utbyte som följd. Kombinationen av metall och en sur katalysator (Ni-V/HZSM5) visade förstärkt deoxygenering med bibehållen vätehalt i den flytande produkten. Den slutliga syrehalten i vätskan var 12.83 vikt% vid en zeolithalt (HZSM5) på 75 vikt%, dock med ett kraftigt minskande vätskeutbyte. Dessutom noterades ökad koksbildning på katalysatormaterialet med den högsta zeolithalten. Ökad rymd-tid för katalysatorn (τ) ger ett lägre vätskeutbyte med reducerad syrehalt (7.79 vikt% vid τ=2h) och ökad aromathalt. Koksbildning på ytan, per massenhet katalysatormaterial, minskade vid längre rymd-tider medan utbytet av kolrester förblev opåverkat. Undersökningen av stabiliteten hos hybridkatalysatorn visade inga strukturella defekter och ingen signifikant minskad aktivitet efter regenerering vid låg temperatur (550οC).
Οι σύγχρονες ανάγκες της κοινωνίας για παραγωγή υγρών καυσίμων και χημικών προϊόντων εξαρτώνται από τους ορυκτούς πόρους. Αυτή η εξάρτηση μπορεί να οδηγήσει σε οικονομικά προβλήματα, πολιτκή αστάθεια, όπως επίσης και αβεβαιότητα στις προμήθειες της ενεργειακής εφοδιαστικής αλυσίδας. Επιπροσθέτως, μια δραματική «παράπλευρη απώλεια» η οποία θέτει σε κίνδυνο το μέλλον του πλανήτη είναι η υπερθέρμανσή του, η οποία έχει συσχετισθεί με την εκτεταμένη χρήση ορυκτών πόρων. Σήμερα, η βιομάζα είναι η μόνη ανανεώσιμη πηγή από την οποία μπορούν να παραχθούν υγρά, αέρια και στερεά προϊόντα, που λόγω της λιγνοκυταρρινικής τους προελεύσεως, η συνεισφορά τους στις εκομπές CO2 θεώρειται μηδενική. Η θερμοχημική επεξεργασία της βιομάζας συνεισφέρει στον περιορισμό της χρήσης ορυκτών πόρων, με την παραγωγή υγρών προϊόντων, τα οποία μπορούν να μειώσουν την εξάρτηση ή /και την αυξημένη ζήτηση μέσω μιας ταχέως αναπτυσόμενης τεχνολογίας, της πυρόλυσης. Στόχος της διεργασίας είναι η παραγωγή υγρών προϊόντων με ιδιότητες, που επιτρέπουν την απευθείας χρήση τους ως υγρά καύσιμα ή ως πρώτη ύλη, για την παραγώγη χημικών προϊόντων σε συγχρονες μονάδες διύλισης πετρελαίου και σε πετροχημικά συγκτροτήματα. Εν τούτοις, τα υγρά προϊόντα της θερμικής διάσπασης (πυρόλυση) είναι προβληματικά στη διαχείρηση και στις τελικές τους εφαρμογές, λόγω της σύστασής τους. Ως εκ τούτου, απαιτούνται νέες τεχνικές για παραγωγή προηγμένων υγρών προοϊόντων. Η ετερογενής κατάλυση έχει επιτυχώς εφαρμοσθεί στην πετρελαϊκή και χημική βιομηχανία, παράγοντας ένα μεγάλο εύρος προϊόντων. Ο συνδυασμός της με την πυρόλυση (φέρνοντας σε επαφη τα υγρά/ατμούς με κατάλληλο καταλύτη) αποτελεί μια πολλά υποσχόμενη ενναλακτική. Στην παρούσα διατριβή μελετάται η αξιοποίηση βιομάζας για παραγωγή υγρών προϊόντων μέσω καταλυτικής πυρόλυσης, με χρήση πολυλειτουρικού καταλύτη (multi-functional catalyst) υπό την παρουσία ατμού. Η χρήση ατμου κατά τη διαρκειά πυρόλυσης βιομαζας σε αντιδραστήρα σταθερής κλίνης, μεταβάλει τη σύσταση των επιμέρους προϊόντων. Η παρουσία ατμού έχει ως αποτέλεσμα την ταχύτερη αποπτητικοποίηση του υλικού, ενώ παράλληλα η περιεκτικότητα του υπολειπόμενου εξανθρακώματος σε πτητικά είναι μικρότερη. Τα πειραματικά αποτελέσματα ταχείας πυρόλυσης σε αντιδραστήρα ρευστοστερεάς κλίνης δείχνουν ό,τι η χρήση ατμού βελτιώνει την θερμική διάσπαση της βιομαζας, αυξάνοντας την απόδοση σε υγρά προϊοντά, ενώ παράλληλα βοηθάει στην αποξυγόνωσή τους. Ο συνδυασμός της πυρόλυσης υπό την παρουσία ατμού και διμεταλλικού καταλύτη νικελίου–βαναδίου μπορεί να βελτιώσει την ποιότητα των παραγόμενων υγρών (αποξυγόνωση) με παραλλήλη μείωση της απόδοσής τους, ενώ μπορεί να παράγει προϊόντα εκλεκτικής αποξυγόνωσης. Συνδυασμός μεταλλικών και ζεολιθικών καταλυτών (Ni-V/HZSM5) εμφανίζει βελτιωμένη δραστικότητα στις αντιδράσεις αποξυγόνωσης, με παράλληλη συγκράτηση υδρογόνου (Η) στα υγρά προϊόντα. Η τελική περιεκτικότητα των υγρών προϊόντων σε οξυγόνου (Ο) μετά από 90 min αντίδρασης είναι 12.83 wt%, με περιεκτικότητα ζεόλιθου (ΗZSΜ5) ~75 wt% στον καταλύτη. Ωστόσο, η αυξηση της περεικτικότητας σε ζεόλιθο έχει ως αποτέλεσμα την αύξηση των επικαθήσεων άνθρακα επάνω στον κατάλυτη, καθώς και την σημαντική μειώση της απόδοσης των υγρών προϊόντων (24.35wt% επι ξηρής βιομάζας). Η αύξηση του χώρου χρόνου του καταλύτη (τ) έχει ως αποτέλεσμα: τη μείωση των υγρών προϊόντων, τη μείωση του περιεχόμενου Ο στα υγρά προϊόντα (7.79 wt% at τ =2h), την αύξηση των αρωματικών υδρογονανθράκων και τη μείωση του επικαθήμενου κωκ ανά μονάδα μάζας καταλύτη. Η απόδοση του εξανθρακώματος παρέμεινε πρακτικά αμετάβλητη. Η αναγέννηση του υβριδικού καταλύτη σε χαμηλές θερμοκρασιές (550οC) δεν επέφερε σημαντικές δομικές αλλαγές και απώλεια δραστικότητας.
QC 20140306
Puladian, Nargess. "Development of an integrated system model for production of fischer-tropsch liquid fuels from woody biomass." Thesis, University of Canterbury. Chemical and Process Engineering, 2015. http://hdl.handle.net/10092/10582.
Повний текст джерелаBatista, Marta Luísa Salsas. "A computational study of ionic liquids used in the production of fuels and biofuels." Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/14855.
Повний текст джерелаFor the past decades it has been a worldwide concern to reduce the emission of harmful gases released during the combustion of fossil fuels. This goal has been addressed through the reduction of sulfur-containing compounds, and the replacement of fossil fuels by biofuels, such as bioethanol, produced in large scale from biomass. For this purpose, a new class of solvents, the Ionic Liquids (ILs), has been applied, aiming at developing new processes and replacing common organic solvents in the current processes. ILs can be composed by a large number of different combinations of cations and anions, which confer unique but desired properties to ILs. The ability of fine-tuning the properties of ILs to meet the requirements of a specific application range by mixing different cations and anions arises as the most relevant aspect for rendering ILs so attractive to researchers. Nonetheless, due to the huge number of possible combinations between the ions it is required the use of cheap predictive approaches for anticipating how they will act in a given situation. Molecular dynamics (MD) simulation is a statistical mechanics computational approach, based on Newton’s equations of motion, which can be used to study macroscopic systems at the atomic level, through the prediction of their properties, and other structural information. In the case of ILs, MD simulations have been extensively applied. The slow dynamics associated to ILs constitutes a challenge for their correct description that requires improvements and developments of existent force fields, as well as larger computational efforts (longer times of simulation). The present document reports studies based on MD simulations devoted to disclose the mechanisms of interaction established by ILs in systems representative of fuel and biofuels streams, and at biomass pre-treatment process. Hence, MD simulations were used to evaluate different systems composed of ILs and thiophene, benzene, water, ethanol and also glucose molecules. For the latter molecules, it was carried out a study aiming to ascertain the performance of a recently proposed force field (GROMOS 56ACARBO) to reproduce the dynamic behavior of such molecules in aqueous solution. The results here reported reveal that the interactions established by ILs are dependent on the individual characteristics of each IL. Generally, the polar character of ILs is deterministic in their propensity to interact with the other molecules. Although it is unquestionable the advantage of using MD simulations, it is necessary to recognize the need for improvements and developments of force fields, not only for a successful description of ILs, but also for other relevant compounds such as the carbohydrates.
Nas últimas décadas a redução de emissões de gases poluentes resultantes da combustão de combustíveis fósseis tem sido uma preocupação mundial. Para tal, a redução de compostos à base de enxofre e a sua substituição por biocombustíveis (como o bioetanol, produzido em elevadas quantidades a partir de sacarose, amido ou compostos lenhocelulósicos) tem sido estudada e aplicada. Visando este propósito, uma nova classe de solventes denominada de líquidos iónicos (LIs) têm sido estudada visando o desenvolvimento de novos processos de separação para a substituição dos solventes orgânicos atualmente utilizados. Os LIs podem ser constituídos por diferentes combinações de catiões e aniões, conferindo propriedades únicas a estes solventes. A capacidade de ajustar estas propriedades para um determinado fim ou aplicação é um dos aspetos mais relevantes dos LIs. Dado o número elevado de combinações possíveis para os iões constituintes dos LIs, é necessário recorrer a abordagens preditivas que permitam avaliar, a priori, o potencial dos LIs para uma dada aplicação. Uma abordagem possível consiste em técnicas de simulação de dinâmica molecular, baseadas em mecânica estatística e nas leis de movimento de Netwon, que permitem a reprodução e caracterização de sistemas macroscópicos, pela previsão de propriedades e organização estrutural dos átomos nos sistemas em questão. No caso dos LIs, a aplicação da dinâmica molecular tem sido amplamente usada, com um desafio adicional dada a dinâmica (lenta) característica dos LIs, o que requer melhorias nos campos de força atualmente usados, como também um acrescido esforço computacional. Esta tese aborda diferentes estudos realizados em sistemas representativos de linhas de produção dos combustíveis e biocombustíveis, onde são estudados os mecanismos de interação estabelecidos pelos LIs, através de simulações de dinâmica molecular. Desta forma, sistemas compostos por LIs e tiofeno, benzeno, água, etanol, e moléculas de glucose, serão caracterizados e avaliados. No caso das moléculas de glucose, será também estudado um campo de força recentemente publicado, de forma a avaliar a sua capacidade para reproduzir o comportamento dinâmico do sistema em solução aquosa. Os resultados obtidos mostram que as interações estabelecidas pelos LIs estão relacionadas com as características individuais de cada LI. Em geral, a polaridade dos LIs estudados é determinante nas interações estabelecidas. Embora seja inquestionável as vantagens de usar simulação de dinâmica molecular nestes sistemas, é preciso reconhecer a necessidade de melhorias nos campos de força atuais, não só para uma correta descrição dos sistemas contendo LIs, mas também para os hidratos de carbono.
Chiuta, Steven. "The potential utilization of nuclear hydrogen for synthetic fuels production at a coal–to–liquid facility / Steven Chiuta." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4840.
Повний текст джерелаThesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.
Hague, Robert A. "Pre-treatment and pyrolysis of biomass for the production of liquids for fuels and speciality chemicals." Thesis, Aston University, 1998. http://publications.aston.ac.uk/10064/.
Повний текст джерелаBérubé, Esther. "The production of phenol oxidases by white-rot fungi in submerged liquid culture /." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79999.
Повний текст джерелаWan, Mohtar Wan Abd A. Q. I. "Production and bioactivity of Ganoderma lucidum BCCM 31549 exopolysaccharide using submerged liquid fermentation." Thesis, University of Strathclyde, 2016. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=26556.
Повний текст джерелаKacelenga, Evans. "Towards an optimal product portfolio of liquid fuels for the Malawi energy market : development of a strategic framework for enhancing pathways of ethanol production and use." Thesis, University of Bolton, 2017. http://ubir.bolton.ac.uk/2001/.
Повний текст джерелаMin, Zhenhua. "Catalytic steam reforming of biomass tar using iron catalysts." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/184.
Повний текст джерелаMolaudzi, Vusani. "The production of synthetic liquid hydrocarbons from waste-derived syngas for use as fuel." Thesis, 2016. http://hdl.handle.net/10539/21160.
Повний текст джерелаMT2016
Bridgiliah, Mampuru Madinoge. "Production of biogasoline from waste cooking oil as an environmentally friendly alternative liquid fuel." Thesis, 2017. https://hdl.handle.net/10539/25769.
Повний текст джерелаEnergy is an important utility to human kind. Since the beginning of human civilization, human beings have become acquainted with travelling and transportation of goods. The use of conventional energy fuels for automobile engines is no longer sustainable due to finite crude oil reserves available in the world, of which many are facing the crisis of being depleted. The use of conventional fuels is a major contributor to environmental concerns such as global warming. Therefore there is an urgent need to explore alternative sources of fuel energy that are sustainable and environmentally friendly. The production of biofuels has been receiving increased academic and industrial attention as practical alternative fuel sources that can partially or completely replace conventional fuels. A study of the production of biogasoline from waste cooking oil as an alternative and re-usable source of liquid fuel was conducted in this project. This work focused on the variety of parameters that would deliver the optimum conversion and yield of biogasoline. The waste cooking oil was converted through catalytic hydrocracking in the presence of an acid activated Ni-Mo/Al2C>3 catalyst and constant hydrogen gas pressure of 0.5 kPa. A number of Ni-Mo/A^Oa catalysts were synthesized with varying Ni-loadings from 5-25 wt. % and calcination temperatures from 300 °C to 700 °C. The catalysts were characterised using ICP-OES, TGA, BET, SEM, FT-IR and Raman spectroscopy. Catalyst characterisation results revealed that the catalyst with 5 wt. % Ni possessed the greatest thermal strength, with the maximum BET surface area of 61.61 m /g and high dispersion of the active species in the catalyst. The optimal calcination temperature range for this catalyst was found from 500 °C to 600 °C. The effects of reaction temperature, reaction time, catalyst: oil ratio, catalyst calcination temperature and Ni-loading (wt. %) were investigated. The highest percentage of produced biogasoline was 59.50 wt. % at a reaction temperature of 250 °C, catalyst: oil ratio of 1:75, reaction time of 1 hr with a catalyst loaded with 5 wt. % Ni and calcinated at 300 °C. The use of stainless steel reactors that can handle higher reaction temperatures and pressure is recommended for future studies that will allow more severe cracking of the raw material into lighter hydrocarbons. The Ni-Mo/AhCT catalyst can also be modified with boron or fluorine to enhance its catalytic activity.
MT 2018
Guo, Peijun. "Assessment of Fischer−Tropsch liquid fuels production via solar hybridized dual fluidized bed gasification of solid fuels." Thesis, 2017. http://hdl.handle.net/2440/119469.
Повний текст джерелаThesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Chemical Engineering, 2017
Simonetti, Dante Adam. "The production of liquid fuels and chemicals from biomass derived polyols by catalytic coupling." 2008. http://www.library.wisc.edu/databases/connect/dissertations.html.
Повний текст джерелаAuYeung, Nicholas J. "Hydrogen production via a sulfur-sulfur thermochemical water-splitting cycle." Thesis, 2011. http://hdl.handle.net/1957/25662.
Повний текст джерела4I₂(l)+4SO₂(l)+8H₂O(l)↔4H₂SO₄(l)+ 8HI(l)
8HI(l)+H₂SO₄(l)↔ H₂S(g)+4H₂O(l)+4I₂(l)
3H₂SO₄(g)↔ 3H₂O(g)+3SO₂(g)+1½O₂(g)
H₂S(g)+2H₂O(g)↔ SO₂(g)+3H₂(g)
The critical step in the Sulfur-Sulfur cycle is the steam reformation of H₂S. This highly endothermic step is shown to successfully occur at temperatures in excess of 800˚C in the presence of a molybdenum catalyst. A parametric study varying the H₂O:H₂S ratio, temperature, and residence time in a simple tubular quartz reactor was carried out and Arrhenius parameters were estimated. All reactive steps of the Sulfur-Sulfur cycle have been either demonstrated previously or demonstrated in this work. A theoretical heat-to-hydrogen thermal efficiency is estimated to be 55% at a hot temperature of 1100 K and 59% at 2000 K. As a highly efficient, all-fluid based thermochemical cycle, the Sulfur-Sulfur cycle has great potential for feasible process implementation for the transformation of high quality heat to chemical energy.
Graduation date: 2012
Naidoo, Simone. "Feasibility study for maize as a feedstock for liquid fuels production based on a simulation developed in Aspen Plus®." Thesis, 2018. https://hdl.handle.net/10539/25034.
Повний текст джерелаSouth Africa’s energy sector is vital to the development of its economy. Instability in the form of disruption in supply affects production costs, investments, and social and economic growth. Domestic sources are no longer able to meet the country’s demands. South Africa must find a local alternative fuel source in order to reclaim stability and encourage social and economic development. Biomass is one of the most abundant renewable energy sources, and has great potential as a fuel source. Currently biomass contributes 12% of the world’s energy supply, while in some developing countries it is responsible for up to 50% of the energy supply. South Africa is the highest maize producer on the African continent. Many studies carried out indicated that maize, and its residue contain valuable materials, and has the highest lower heating value in comparison to other agricultural crops. This indicates that maize can be a potential biomass for renewable energy generation in South Africa. A means for energy conversion for biomass, is the process of gasification. Gasification results in gaseous products H2, CO and CO2. Since the process of biomass gasification involves a series of complex chemical reactions involving a number of parameters, which include flow, heat transfer and mass transfer, it is very difficult to study the process of gasification by relying on experimentation only. Numerical simulation was used to provide further insight on this process, and accelerate development and application of maize gasification in a cost effective and efficient manner. The objective of this study was therefore, to verify and evaluate the feasibility of maize gasification and liquid fuels production in South Africa from an economic and energy perspective. The simulation model was developed in Aspen Plus® based on two thermodynamic models specified as Soave – Redlich – Kwong and the Peng Robinson equation of state. All binary parameters required for this simulation were available in Aspen Plus®. The gasification unit was modelled based on a modified Gibbs free energy minimization model. Gasification of maize and downstream processing in the form of Fischer-Tropsch (FT) synthesis and gas to liquids (GTL) processing for liquid fuels production was modelled in Aspen Plus®. Sensitivity analyses were carried out on the process variables: equivalence ratio (ER), steam to biomass ratio (SBR), temperature and pressure, to obtain the optimum gasification conditions. The optimum reactor conditions, which maximized syngas volume and quality was found to be an ER of 0.22 and SBR of 0.2 at a temperature of 611ºC. An increase in pressure was found to have a negative effect; therefore atmospheric conditions of 101.325 kPa were chosen, in order to maximize CO and H2 molar volumes. Based on these conditions the produced syngas consisted of 35% H2, 16% CO, 24% CO2 and 3%CH4. The results obtained from gasification, based on a modified Gibbs free energy model, show a closer agreement with experimental data, than other simulations based on the assumption that equilibrium is reached and no tar is formed. However, these results were still idealistic as it under predicted the formation of CO and CH4. Although tar was accounted for as 5.5% of the total product from the gasifier (Barman et al., 2012), it may have been an insufficient estimation resulting in the discrepancy in CO and CH4. The feasibility of maize as a feed for gasification was examined based on quality of syngas produced in relation to the requirements for FT synthesis. A H2/CO ratio of 2.20 was found, which is within range of 2.1 – 2.56 found to support greater conversions of CO with deactivation of the FT catalyst (Lillebo et al., 2017). The syngas produced from maize was found to have a higher H2/CO ratio than conventional fossil fuel feeds; implying that maize can result in a syngas feed which is both renewable and richer in CO and H2 molar volumes. Liquid fuels generation was modelled based on experimental production distributions obtained from literature for FT synthesis and hydrocracking. The liquid fuel production for 1000 kg/hr maize feed, was found to be 152 kg/hr LPG, 517 kg/hr petrol and 155 kg/hr diesel. The simulation of liquid fuels production via the Fischer-Tropsch synthesis and hydrocracking process showed fair agreement with literature. Where significant deviations were found, they could be reasonably explained and supported. This simulation was found to be a suitable means to predict liquid fuels production from maize gasification and downstream processing. The feasibility of liquid fuels production from maize in South Africa was examined based on the country’s resource capacity to support additional maize generation. It was found that based on 450 000 hectares of underutilized land found in the Homelands, an additional 1.216 billion litre/annum of synthetic fuels in the form of diesel and petrol could be produced. This has the potential to supplement South African liquid fuels demand by 6% using a renewable fuel source. This fuel generation from maize will not impact food security due to the use of underutilized arable land for maize cultivation, or impact water supply as maize does not require irrigation. In addition, fuel generation in this manner supports the Biofuels Industry Strategy (2007) by targeting the use of underutilized land, ensuring minimal impact on food security, and exceeds its primary objective of achieving a 2% blending rate from renewable sources. The economic feasibility of liquid fuels derived from maize was determined based on current economic conditions in 2016. Based on these conditions of 49 $/bbl Brent Crude, 40 $/MT coal and 6.5 $/mmBTU of natural gas at a R/$ exchange rate of R14.06 per U.S. dollar, it was found that coal, natural gas and oil processing are more economically viable feeds for fuel generation relative to maize. However, based on projected market conditions for South Africa, the R/$ exchange rate is expected to weaken further, the coal supply is expected to diminish and supply of natural gas is expected to be a continued issue for South Africa. Based on this, maize should be considered as a feed for fuel generation to reduce the dependency on non-renewable fossil fuel sources. The energy feasibility of liquid fuels produced from maize was only evaluated from a thermal energy perspective. It was found that maize gasification and FT processing requires 0.91 kg steam/kg feed. This 0.91kg of steam accounts for the raw material feed, distillation and heating required for every 1kg of maize processed. It was found that 2.56 kg steam/kg feed was generated from the reactor units. This was assumed to be in the form of 10 bar steam, as in this form it can be sent to steam turbines for electricity generation to assist with overall energy efficiency for this process. In addition, the amount of CO2 (kg/kg feed) produced, was examined for maize processing in comparison to fossil fuel feeds: natural gas and coal. The CO2 production from liquid fuels processing based on a maize feed, was found to be the highest at 0.66 kg/kg feed. However, a coal feed has higher ash and fix carbon content indicating greater solid waste generation in the gasifer. While dry reforming of natural gas is a net consumer of CO2, but had significantly higher steam requirements in order to achieve the same H2/CO ratio as maize. This indicates that although maize results in more CO2/kg feed, it is 88% more energy efficient than dry methane reforming. Additional experimental work on FT processing using syngas derived from maize is recommended. This will assist in further verification of liquid fuels quantity, quality and process energy requirements.
XL2018