Green hydrogen produced through electrolysis of excess renewable energy is a promising seasonal energy storage solution with the potential to decarbonize the energy sector. However, it has physical properties that make it difficult to store and transport on a large scale for grid scale storage applications. An alternative to storing excess renewable energy in hydrogen is converting the hydrogen to synthetic fuel that has an industrially mature production process and an established transportation, storage and distribution infrastructure. This study aims to conduct a feasibility analysis to compare the cost and compatibility of green hydrogen, ammonia, methane and methanol as seasonal energy storage. The production of each fuel and the barriers to their commercialization as energy vectors is discussed. The hydrogen storage technologies holding the most potential are identified as salt cavern and lined rock cavern storage however type I-IV pressure vessel storage is also included in the analysis due to its prevalence within the industry The outcome of the study is a conceptual model calculating the levelized cost of storage of each fuel considering the storage system size, compression energy required and annualized CAPEX and OPEX of compression and storage. Three cases are developed to analyse the storage system, A- seasonal discharging, B-weekly discharging and C- daily discharging. The results identify that the most feasible seasonal storage option for hydrogen is utilizing a salt cavern. If building a salt cavern is infeasible due to geographical constraints, a lined rock cavern is more cost-effective as compared to utilizing pressure vessel storage. For shorter storage periods or smaller scale applications it is more beneficial to employ low pressure (200-300 bar) pressure vessel storage since geological storage becomes expensive as compared to the seasonal case. Low pressure storage is better suited for smaller applications as compression costs account for a significant share of the total annual cost of each storage system in the weekly and daily cases. The most suitable hydrogen storage option is highly dependent on the end use application. Overall, methanol storage provided the lowest levelized cost of storage in all scenarios. / Grönt väte som produceras genom elektrolys av överskott av förnybar energi är en lovande säsongsbaserad energilagringslösning med potential att koldioxidutlösa energisektorn. Det har dock fysiska egenskaper som gör det svårt att lagra och transportera i stor skala för lagringsapplikationer i nätskala. Ett alternativ till att lagra överskott av förnybar energi i väte är att omvandla vätgas till syntetiskt bränsle som har en industriellt mogen produktionsprocess och en etablerad transport-, lagrings- och distributionsinfrastruktur. Denna studie syftar till att genomföra en genomförbarhetsanalys för att jämföra kostnaden och kompatibiliteten för grönt väte, ammoniak, metan och metanol som säsongsbetonad energilagring. Produktionen av varje bränsle och hindren för deras kommersialisering som energivektorer diskuteras. De tekniker för lagring av väte som har störst potential identifieras som lagring av saltrum och fodrad bergrum, men lagring av tryckkärl av typ I-IV ingår också i analysen på grund av dess förekomst inom industrin Resultatet av studien är en konceptuell modell som beräknar den utjämnade kostnaden för lagring av varje bränsle med hänsyn till lagringssystemets storlek, kompressionsenergi som krävs och årlig CAPEX och OPEX för kompression och lagring. Tre fall är utvecklade för att analysera lagringssystemet, A-säsongsurladdning, B-veckotursning och C-daglig urladdning. Resultaten visar att det mest möjliga säsongsbetonade lagringsalternativet för väte är att använda en saltgrotta. Om det är omöjligt att bygga en salthåla på grund av geografiska begränsningar, är en fodrad berghåla mer kostnadseffektiv jämfört med att använda tryckkärlslagring. För kortare lagringsperioder eller tillämpningar i mindre skala är det mer fördelaktigt att använda lågtrycks (200-300 bar) tryckkärllagring eftersom geologisk lagring blir dyr jämfört med säsongsfallet. Lågtryckslagring är bättre lämpad för mindre applikationer eftersom kompressionskostnaderna står för en betydande del av den totala årliga kostnaden för varje lagringssystem i vecko- och dagliga fall. Det mest lämpliga vätgaslagringsalternativet är starkt beroende av slutanvändningsapplikationen. Sammantaget gav metanollagring den lägsta utjämnade kostnaden för lagring i alla scenarier.

Through the historic usage of fossil fuel, climate impacts have been severe and threaten to disrupt global economies and biological diversity. Hydrogen has emerged as a technology which can enable the productionand storage of renewable energy with no carbon emissions. However, energy transitions are complex as the sector is characterized by lock-in and path dependency due to co-evolution with infrastructure, policy and geography. The purpose of this study is to explore how hydrogen energy can overcome the lock-in and path dependency of fossil fuels. To achieve this, a qualitative single-case study of Sweden was conducted. The theoretical foundation consists of the Multi-Level Perspective and lock-in. The results indicate that in order for hydrogen technology to become large-scale and overcome lock-in, four criteria need to be fulfilled; hydrogen technology needs to be more cost-efficient, investments in infrastructure for hydrogen is required, a market needs to be established for the production of hydrogen and governments/institutions need to support hydrogen through regulation and investments. / Under decennier av fossil användning har klimatpåverkan blivit mer allvarlig och hotar att negativt påverka globala ekonomier och den biologiska mångfalden. Vätgas har framkommit som en teknik som möjliggör produktion och lagring av förnybar energi utan koldioxidutsläpp. Övergångar till nya energilösningar är dock svåra eftersom sektorn kännetecknas av “lock-in” och “path dependency”på grund av samutveckling med infrastruktur, politik och geografi. Syftet med denna studie är att undersöka hur vätgas kan övervinna “lock-in” och “path dependency” av fossila bränslen. För att uppnå detta genomfördes en kvalitativ fallstudie av Sverige. Den teoretiska grunden för studien består av Multi-Level Perspective och lock-in. Resultaten visar att fyra kriterier måste uppfyllas för att vätgas ska gå från en nisch innovation till att vara en del av dagens sociotekniska system. Vätgas måste bli mer kostnadseffektiv, investeringar i infrastruktur för vätgas krävs, en marknad måste skapas för produktion av vätgas och regeringar/institutioner behöver stödja vätgas genom föreskrifter.

<p dir="ltr">Hypergolic propellants contain a fuel and an oxidizer that ignite on contact without the need for an external ignition source. Hydrazines are often used as the fuel, despite health and environmental safely concerns. Monomethylhydrazine (MMH) is a commonly used fuel in conjunction with dinitrogen tetroxide as the oxidizer for in-space maneuvering, although the mechanisms for the reactions of these two compounds are not fully understood. Based on the spontaneous generation of product ions in liquid phase experiments, quantum chemical calculations using the SMD model of implicit solvation were used to probe proposed reaction mechanisms. The reactions of hydrazine and MMH with the nitrosonium cation and the nitronium cation, which included the formation of the corresponding fuel radical cation, were explored. The reactions of hydrazines with the nitronium cation in model solvents were found to be highly exergonic, by as much as 70 kcal mol^-1. Further reactions of the MMH radical cation were also explored, including the formation of tetrazanes. Developing a complete mechanism to explain the formation of the most abundant product ions can further the understanding of hypergolicity and aid in the development of safer fuels.</p><p dir="ltr">The ASTM D2425 method was originally developed in 1965 and updated in 2019 for analyzing aviation fuels. However, a method using two dimensional gas chromatography coupled to a flame ionization detector (GCxGC/FID) was previously developed at Purdue University for the analysis of aviation fuels, including those derived from traditional sources and those derived from sustainable feedstocks. The established ASTM D2425 method was compared to the GCxGC/FID method for the analysis of Jet A-1, a sustainable aviation fuel, and a model compound mixture. The peak areas of eleven compound classes were compared across the three different samples by using a Pearson coefficient to determine skewness, an Anderson-Darling test for normality, Levene’s test and F-test for equal variances (depending on the normality of the data), and a 2-sample t-test. The results of these statistical analyses were somewhat vague and further studies should be done to fully compare the ASTM D2425 method with the GCxGC/FID method.</p>

<h4>This thesis explores the feasibility of <b>injecting waste plastic particles</b> and two compositions of <b>hot syngas</b>, produced from a gasification reactor utilizing waste plastics and natural gas, as alternative fuel sources in <b>ironmaking blast furnace</b><b>s.</b> Computational fluid dynamics <b>(CFD) analysis</b> is employed to assess the viability of these fuels. The study investigates impacts of these novel alternative injected fuels on flame temperature, quenching impact, hot metal temperature, coke replacement ratio, and furnace stability</h4><p></p>

This paper critically analyzes the implementation of compressed natural gas and the ways in which it creates discourse in urban Bolivia. The rapidly developing nation is keen on making ubiquitous use of compressed natural gas a reality by issuing subsidies, citing increased mobility, savings, and environmental stewardship as the primary motives. Currently, eight out of every 10 public vehicles in Bolivia are powered by compressed natural gas. Through semi-structured interviews, questionnaires and secondary data collection, this paper elucidates the transitional process of building a natural gas-based transport network through discursive governance. This work draws on the critical discourse analysis literature to dissect disaggregated modal preference data, government documents, and news articles collected in Santa Cruz, Latin America's second fastest growing city. Moreover, this paper identifies and examines the ways in which the counter-discourse impacts the transformation of the country’s energy matrix. Results show that Bolivian automobile owners are reluctant to convert their automobiles, despite reduced transportation costs, stating that minimal compressed natural gas infrastructure exists outside of urban areas, and the conversion damages their vehicles’ motor. Additionally, the research reveals that automobile owners are currently the main beneficiaries, though respondents who do not posses an automobile speak more favorably of natural gas. Finally, this research illustrates that the compressed natural gas-oriented policies encourage personal automobile use that continues to drive socio-spatial segregation of Santa Cruz’s residents. Thus, the compressed natural gas discourse helps shape the urban landscape by persuading the public to consume domestically extracted and manufactured natural gas.

Call number: LD2668 .T4 1985 S335 / Master of Science

Thesis (MBA)--Stellenbosch University, 2006. / ENGLISH ABSTRACT: The adoption of the White Paper on the promotion of Renewable Energy and clean fuels in 2003, opened the playing field for participants from other industries than the conventional petroleum, to participate in the fuel industry in South Africa. South Africa is a net importer of crude oil, which accounts for 92% of liquid fuels supply in South Africa. Although the country has significant coal reserves which can supply the country's demand for approximately 200 years, this energy source contributes significantly to CO, emissions. South Africa's participation in the Kyoto Protocol compels it to abide by its commitments to reduce these emissions between 2008 and 2012. The country's dependence on energy to fuel its growing economy, and the infiationary impact that oil imports has had on the country's economy, has prompted government to explore alternative sources of energy to reduce its dependence on fossil fuels and especially importing crude oil. As a result of this, and in an attempt to increase the potential for the successful implementation of ASGISA, government is exploring the feasibility of introducing an E10 fuel blend to the South African petrol blend. In view of th is, government has in it Accelerated and Sustainable Growth Initiative (ASGISA) targeted the development of the bio-fuels industry as an industrial sector that presents opportunities to create opportunities for sustainable growth and development. In view of this, the fiedgling fuel-ethanol industry (which is in its construction phase at the t ime of writing this report), faces lucrative prospects for the agricultural industry, especially maize- and ethanol producers. It is anticipated that the fuel-ethanol industry will create between 8000 and 10000 direct and indirect employment opportunities per plant. This will result in significant investment in rural areas as well. The creation of employment in the rural areas will prevent the large-scale urbanisation that has become a phenomenon in the past decade, as a result of dwindling agricultural industries. The production of ethanol presents the opportunity to earn foreign exchange, especially if the industry embarks on large scale export strategies. In addition to the export market, the local market for ethanol consist of the possible E10 petrol-blend and to supply Eskom with ethanol to fuel its gas turbine electricity generators at Acacia, Port Rex, as well as the anticipated generators at Atlantis and Mossel Bay. This document is a report on the investigation of the economic evaluation of a bio-fuel industry in South Africa. It will explore the current outlook for fossil fuel reserves, supplies and demand, both internationally and locally. It will report on the phenomenon of peak oil production and some opinions thereon . An investigation into the most probable biomass that can be used as feedstock for bio-fuel production will conducted. In this regard, specific investigation into maize, sugar cane (for fuelethanol) and Jatropha eureas (for bio-diesel) will be conducted. The report will explore the most efficient ethanol production processes, for both maize- and sugar-to-ethanol production, with the weight of the document to be attributed to the economic impact that the adoption of the fuel-ethanol programme / AFRIKAANSE OPSOMMING: Die publisering van die Witskrif oor die promosie van hernieubare energiebronne en skoon brandstowwe in 2003, het die speelveld vir deelname aan die brandstof industrie oopgemaak vir rolspelers buiten die konvensionele petroleum maatskappye. Suid-Afrika is 'n netto invoerder van ru-olie en het in 2004 ongeveer 92% van die totale vloeibare brandstowwe ingevoer. Alhoewel die land aansienlike steenkool reserwes het om te voorsien in die aanvraag vir die volgende ongeveer 200 jaar, dra hierdie energiebron aansienlik by tot die koolstofdioksied vrystellings. Suid-Afrika se deelname aan die Kyoto Protokol van 1998, dwing die land om te voldoen aan die ondernemings wat gemaak is om hierdie koolstofdioksied vrystellings te verminder tussen 2008 en 2012. Die land se afhanklikheid van energiebronne om groei te stimuleer, asook die inflasionistiese effek van olie invoere op die ekonomie, het die regering genoop om alternatiewe bronne van energie te ondersoek sodat die afhanklikheid van olie verminder kan word. Uiteenlopend hiervan en om die implementering van ASGISA te stimuleer, ondersoek die regering tans die moontlikheid om 'n E10 petrol vermenging in die petrol formule te spesifiseer. Uit die oogpunt van ASGISA (Accelerated and Sustainable Growth Initiative) van Suid-Afrika, het die regering die ontwikkeling van die bio-brandstowwe industrie geoormerk om geleenthede te skep vir volhoubare ontwikkeling en groei. Met die oog hierop, voorspel die etanol bedryf, wat ten tyde van die skryf van hierdie verslag nog in kontruksie was, winsgewende potensiaal vir die landboubedryf, veral mielie produsente. Dit word verwag dat die etanol bedryf tussen ongeveer 8000 en 10000 direkte en indirekte werksgeleenthede sal skep, veral in die landelike gebiede. Dit sal grotendeels bydra tot die voorkoming van die voortslepende ontvolking van die platteland wat oor die afgelope jare 'n verlammende effek op plattelandse gebiede gehad het. Dit word ook voorsien dat daar aansienlike belegging in die platteland sal plaasvind en al hierdie faktore sal bydra tot die voorkoming van verstedeliking . Die etanol bedryf skep die geleentheid om buitelandse valuta te genereer, veral as die industrie op uitvoere gaan konsentreer. Indien 'n plaaslike mark beoog word , sal die implementering van die E10 vermenging 'n besliste mark skep. 'n Alternatiewe mark wat ondersoek kan word, en wat groot geleentheid skep, is Eskom, wat tans ingevoerde diesel verbruik om hul gas turbine krag opwekkers by Acacia en Port Rex van brandstof te voorsien . Indien die beoogde turbines by Atlantis en Mosselbaai gebou word, sal die mark vir plaaslike etanol verdubbel. Hierdie dokument is 'n verslag oor die ondersoek wat gedoen is na die lewensvatbaarheid van 'n brandstof etanol bedryf in Suid-Afrika. Dit berig oor die huidige uitkyk oor die fossiel brandstof reserwes in die wereld en plaaslik. Dit opper die vraagstuk oor piek olie produksie fenomeen wat uiteenlopende debate ontketen het. Die verslag dek die waarskynlike bronne van biomassa wat aangewend kan word in die produksie van etanol, met spesifieke verwysing na mielies, suikerriet en Jatropha curcas. Die mees effektiewe produksie metodes word verder ondersoek wat van toepassing is op beide mielies en suikerriet. Die mees relevante deeI van die verslag is die ondersoek na die ekonomiese impak wat die industrie op die Suid-Afrikaanse ekonomie mag hê, waarna die nodige gevolgtrekkings en aanbevelings gemaak sal word.

Global CO2 emissions produced by energy-related processes, mainly power plants, have increased rapidly in recent decades; and are widely accepted as the dominant contributor to the greenhouse gas (GHG) effect and consequent climate changes. Among countermeasures against the emissions, CO2 capture and storage (CCS) is receiving much attention. Capture of CO2 is the core step of CCS as it contributes around 75% of the overall cost, and may increase the production costs of electricity by over 50%. The reduction in capture costs is one of the most challenging issues in application of CCS to the energy industry. Using limestone in CaO-looping cycles is a promising capture technology to provide a cost-effective separation process to remove CO2 content from power plants operations. Limestone has the advantage of being relatively abundant and cheap, and that has already been widely used as a sorbent for sulphur capture. However, this technology suffers from a critical challenge caused by the decay in the sorbent capture capacity during cyclic carbonation/calcination, which results in the need for more sorbent make-up; hence a reduction in cost efficiency of the technology. The performance of sorbent influenced by several operating and reaction conditions. Therefore, much research involves investigation of influencing factors and different methods to reduce the sorbent deactivation. Cont/d.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management