With the increasing stringency on sulfur content in petrodiesel, there is a growing tendency of broader usage of ultra low sulfur diesel (ULSD) with sulfur content of 15 ppm. Refineries around the world should develop cost-effective and sustainable strategies to meet these requirements. The primary objective of this work is to analyze alternatives for producing ULSD. In addition to the conventional approach of revamping existing hydrotreating facilities, the option of blending petrodiesel with biodiesel is investigated. Blending petrodiesel with biodiesel is a potentially attractive option because it is naturally low in sulfur, enhances the lubricity of petrodiesel, and is a sustainable energy resource. In order to investigate alternatives for producing ULSD, several research tasks were undertaken in this work. Firstly, base-case designs of petrodiesel and biodiesel production processes were developed using computer-aided tools ASPEN Plus. The simulations were adjusted until the technical criteria and specifications of petrodiesel and biodiesel production were met. Next, process integration techniques were employed to optimize the synthesized processes. Heat integration for petrodiesel and biodiesel was carried out using algebraic, graphical and optimization methods to maximize the integrated heat exchange and minimize the heating and cooling utilities. Additionally, mass integration was applied to conserve material resources. Cost estimation was carried out for both processes. The capital investments were obtained from ASPEN ICARUS Process Evaluator, while operating costs were calculated based on the updated chemical market prices. The total operating costs before and after process integration were calculated and compared. Next, blending optimization was performed for three blending options with the optimum blend for each option identified. Economic comparison (total annualized cost, breakeven analysis, return on investment, and payback period) of the three options indicated that the blending of ULSD with chemical additives was the most profitable. However, the subsequent life-cycle greenhouse gas (GHG) emission and safety comparisons demonstrated that the blending of ULSD with biodiesel was superior.

Climate Change is fast becoming a reality that is gripping the developed and developing world, its economies and people. Erratic weather conditions, rising temperatures and monsoon like weather has scientists asking questions and some countries moving swiftly to ensure that their economies remain stable whilst trying to deal with climate change. South Africa has begun to play an influential role, as a developing country, in international negotiations on climate change. South Africa is not under legal obligation to reduce greenhouse gas emissions but as a large contributor of greenhouse gases in Africa and globally, South Africa has a moral obligation to reduce its emissions. Although not obliged to make commitments to reduce emissions, government has seen the importance of considering long term mitigating actions to play its part to reduce emissions. It can be argued that the policies and strategies being considered are not enough to hold large industries in South Africa more accountable for their own historic responsibility. The “culprits”, the large industries should be more accountable. A tax on greenhouse gas emissions (Carbon Emissions Tax) based on the amount of emissions a corporation produces, should be weighed up as this may be the way towards accountability. South Africa is faced with the task of juggling development (which is largely based on fossil fuels), the eradication of poverty and climate change. There should be an economic policy in place to address and balance these three aspects, in a positive way. According to this study an appropriate tax on emissions may help South Africa in its mitigating actions of reducing greenhouse gas emissions, whilst allowing the country to continue on its path of social and economic development. AFRIKAANS : Klimaatsverandering word vinnig ‘n realiteit wat die ontwikkelde en ontwikkelende wêreld, hul ekonomiese welsyn en bevolking in sy greep het. Wisselvallige weersomstandighede, stygende temperature en reënseisoenagtige weer word deur wetenskaplikes bevraagteken en sommige lande neem voorbehoedende stappe om te verseker dat die ekonomie standvastig bly terwyl hul klimaatsverandering hanteer. Suid-Afrika begin ‘n invloedryke rol speel as ontwikkelende land in internasionale verhandelings oor klimaatsverandering. Suid-Afrika verkeer nie onder enige wetlike verpligting om die vrylating van kweekhuisgasse te verminder maar omdat dit grootliks bydra tot die vrylating van kweekhuisgasse in Afrika en wêreldwyd, het Suid-Afrika ‘n morele verpligting om sy vrylating te beheer. Hoewel nie verplig om enige onderneming te maak om vrylatings te beheer, het die regering die belangrikheid van langtermyn behoedende aksie gesien, en te oorweeg sodat die regering ‘n rol speel om vrylatings te verminder. Dit kan gesê word dat beleid en strategieë wat tans oorweeg word nie voldoende is om die groot nywerhede in Suid-Afrika meer aanspreeklik te maak vir hul historiese verantwoordelikheid. Die “skuldiges”, die groot nywerhede behoort meer toerekeningsvatbaar te wees. Belasting op die vrylating van kweekhuisgas (Koolstof Vrylatingsbelasting), gegrond op die hoeveelheid vrylating wat ‘n korporasie vervaardig, moet opgeweeg word aangesien dit dalk die weg is tot aanspreeklikheid. Suid-Afrika het die taak om ontwikkeling op te weeg (grootliks gebasseer op fossielbrandstof), die uitwissing van armoede en klimaatsverandering. Daar behoort ‘n ekonomiese beleid te wees om hierdie drie aspekte op positiewe wyse te balanseer. Volgens dié studie sou ‘n toepaslike belasting op vrylatings dalk bydra daartoe om Suid-Afrika by te staan om behoedende aksie te neem om kweekhuisgas vrylating te verminder, terwyl die land sy sosiale en ekonomiese ontwikkeling voortsit. Copyright 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Karrappan, A 2011 A carbon emissions tax as a mitigating strategy for reducing greenhouse gas emissions in South Africa, MCom dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-03052012-165638 / > F12/4/144/gm / Dissertation (MCom)--University of Pretoria, 2011. / Taxation / unrestricted

The paper at hand presents the environmental impact analysis of a photovoltaic (PV) power station sited in Stockholm, Sweden, using life cycle assessment (LCA). The LCA considers the primary energy return on investment and global warming potential of the PV-station, including; resource extraction, manufacturing, transportation, operation and maintenance, and decommissioning. Other environmental impact indicators are also presented, such as; the eutrophication, acidification, human toxicity, and ozone depletion potentials. The results show that the most critical phase of the lifecycle is the upgrade from metallurgical to solar grade silicon due to the high consumption of energy. The emissions results are compared to the emissions factors used for calculations in Sweden in accordance with the Swedish Energy agency and the European Commission’s directive for emissions calculations. The results for the other environmental indicators showed inconsistencies compared to existing studies, something that is according to the IEA’s guideline for PV-systems LCA caused by data scarcity and the indicators lacking consensus within the PV LCA-community. The studied PV-station is expected to reach energy neutrality after 2,4 years and offset annual GHG emissions of up to18 ton of CO 2 equivalents. / Studien tillhands presenterar miljöutvärderingen av en fotovoltaisk solcellsanläggning i Stockholm. Detta utfördes med hjälp av livscykelanalysverktyget. Analysen använder energiåterbetalningstiden och den globala uppvärmningspotentialen som indikatorer på anläggningens miljöinverkan. Både återbetalningstiden och den globala uppvärmningspotentialen beräknas för gruvarbetet, transporten, drift och underhåll samt avveckling och bortskaffning av anläggningen. Överföringsförluster beräknas också över anläggningens livscykel. Andra indikatorer som beräknas i denna studie är potentialen för försurning, övergödning, ozonnedbrytning och humantoxicitet. Dessa beräknas endast för modulens tillverkningskedja. Studiens resultat visar att den mest kritiska processen under solcellsanläggningens livscykel är kiselmetallens omvandling till solkisel, detta med avseende på energiförbrukningen och utsläpp av växthusgaser. Anläggningens globala uppvärmningspotential uttrycks i växthusgasutsläpp och jämförs med den nordiska elmixens utsläppsfaktor. Jämförelsen görs enligt dem gällande EU-direktiven. Resultaten för dem andraindikatorerna har visat på väsentliga avvikelser jämfört med tidigare studier. Detta beror enligt det internationella energirådet på databrist och på att dessa indikatorer saknar stöd inomLCA samfundet. Solcellsanläggningen beräknas bli energineutral efter 2,4 år samt eutralisera utsläpp på upp till 18 ton koldioxidekvivalenta per år.

Global climate change is becoming increasingly evident. There has been increased attention paid to the impact of human activity on climate. As a rising power, China’s energy needs to fuel its rapid economic growth with the resulting potential impacts of climate change presents an enormous climate policy dilemma not only for China but also for the entire world. The role of China is an issue of perennial concerns at the international climate change negotiation: its energy saving, emission reduction and clean production reflect China’s dual objectives about sustainable development and efforts on international legal obligations.Education abroad is an integral part of China’s development strategy. The abroad Chinese students who possess the knowledge, technologies skills and ideas, as well as information are playing an important role to assist China retain or increase its competitive advantage. The aim of this paper is to analyze the abroad Chinese students’ opinion on China’s role under the circumstance of global climate change, with main focus on three aspects: Energy consumption and environment situation in China; Several current domestic policies regarding problems of climate change and energy consumption in China; Issues facing the country on its road map to future mitigation action regarding climate change.Alongside the interviews carried out within ten overseas Chinese students, using the social science of Science, Technology and Society (STS) especially its public understanding of Science and Technology as the theoretical perspective, this thesis is exploring the interviewees’ attitudes toward current China’s climate change related issues from a deeper sense of human, culture and public perspective.

Fossil fuels has preserved their importance in gradually increasing production and consumption of both energy and electricity of the world. Asia, especially China and India, has arisen new actors of the sector. Energy and electricity consumption of Turkey has also increased in parallel with her economic development, but due to her limited resources, she has become more and more energy dependent in order to meet her growing demand. Although hard coal is only found around Zonguldak region, with its abundant and widely spread reserves, Turkey ranked world&rsquo / s third place in lignite production in 2008. Having low calorific value together with high ash and moisture content, most of lignites extracted is being consumed in thermic power plants located near those reserves. In the first two chapters of this study, energy in the world and Turkey will be considered seperately, then coal resources in Turkey will be analysed in the next coming chapter. Indirect and direct greenhouse emissions presented to the UNFCCC will be handled in the fifth chapter In the last chapter, first past and present performances of all indigenous coal fired power plants will be analysed, then after projecting their generation and fuel needs, they are evaluated considering with the reserves they are located. Finally, at the end of decomissioning of those power plants, remaining reserves will be re-evaluated and additional new units will be proposed accordingly.

The objective of this study is to restrict the emission of greenhouse gasses by investigating if this objective would be reached by the implementation of a tax. Global warming is caused by the emission of greenhouse gasses into the atmosphere. In order to restrict global warming it is necessary for individuals and entities to act in a more environmentally friendly manner and to emit less greenhouse gasses. A further objective of this study is to investigate various measures that can be used as an incentive to restrict the emission of greenhouse gasses. This study found that the main emitters of greenhouse gasses are power stations, industries and the transport sector. This study will therefore focus on the reduction of greenhouse gasses in these areas. The way to identify methods used to reduce greenhouse gas emissions, is to investigate the techniques that first world countries use to reduce greenhouse gas emissions, to judge the level of success they achieved and to compare their methods to the definition of a “good tax”. It was found that “cap-and-trade” is a better model than carbon tax for the reduction of greenhouse gas emissions by power stations and industries. It was also found that a combination between a tax on fuel and a tax calculated on greenhouse gas emissions per kilometre for each individual vehicle will result in the greatest reduction in the emission of greenhouse gasses produced by the transportation sector. AFRIKAANS : Die doelwit van hierdie studie is om die vrystelling van groenhuis uitlaatgasse te beperk deur ondersoek in te stel of die doelwit bereik kan word deur die implementering van 'n belasting. Globale aardverwarming word veroorsaak deur 'n oormaat vrystelling van groenhuisgasse in die atmosfeer. Om globale aardverwarming te beperk, sal individue, sowel as entiteite, meer omgewingsvriendelik moet optree deur minder groenhuisgasse vry te stel. 'n Verdere doelwit van hierdie studie is om verskeie metodes, insluitende belasting, te ondersoek waardeur die vrystelling van groenhuisgasse verminder kan word. In die studie is vasgestel dat kragstasies, industrieë en vervoerstelsels die hoofvrystellers van groenhuisgasse is. Die fokus van die studie is dus gerig op die vermindering van groenhuisgasvrystelling spesifiek in hierdie areas. Die wyse om metodes, wat gebruik word om groenhuisgasvrystellings te verminder, te identifiseer, is om die tegnieke wat in eerste wêreldlande gebruik word te ondersoek, om die vlak van sukses wat daarmee bereik word, te bepaal en om daardie metodes teen die definisie van 'n “goeie belasting” te toets. Daar is gevind dat “uitlaatgas handel” 'n beter model is as koolstofdioksiedbelasting ten einde 'n vermindering van groenhuisgasvrystellings deur kragstasies en industrieë te bewerkstellig. Daar is ook gevind dat ‘n kombinasie van ‘n belasting op brandstof en ‘n belasting bereken op groenhuisgasvrystellings per kilometer van elke individuele voertuig die grootste vermindering in groenhuisgasvrystellings in die vervoerstelsel sal meebring. Copyright / Dissertation (MCom)--University of Pretoria, 2010. / Taxation / unrestricted

Transitioning from the conventional steel process to a direct hydrogen reduction process in the steel industry is a significant step towards reducing carbon dioxide emissions and achieving greater sustainability. The process involves using hydrogen gas as a reducing agent instead of carbon to remove oxygen from the iron ore. This study aimed to investigate the future capacity of the hydrogen-based steelmaking process in Sweden by 2050 while also examining the pathway for transitioning to hydrogen-based steelmaking in other European countries in comparison to the Swedish case. To achieve this goal, a systematic literature search was conducted using Scopus and Web of Science databases to identify relevant case studies and reviews that focused on green steel solutions and that discussed associated challenges and barriers. A aconsupteal model was designed by simplifying the process into three production steps, hydrogen storage, and hot briquette iron storage to calculate the energy consumption and material requirements for the hydrogen direct process in Sweden. Additionally, a survey providing insights regarding current practices and perspectives was administered to seven companies in Sweden and two in other European countries, namely the Netherlands and Germany. Furthermore, a comparative analysis of the literature review on life cycle assessment was conducted to compare the carbon emissions associated with two different steel production processes: the conventional process using the basic oxygen furnace and the emerging hydrogen-based steel production process.  An analysis of the energy consumption within the hydrogen-based steelmaking process reveals several components, including the electrolyze, direct reduction shaft furnace, electric arc furnace, and briquetted iron and hydrogen storage. The model results showed that electrolyzing alone accounts for 60% of the energy needed in the process. The model showed that hydrogen direct reduction steelmaking needs 3.66 MWH of electricity per ton of liquid steel produced in Sweden.  Only a few of the Swedish companies have adopted innovative approaches while the remaining steel mills primarily rely on scrap-based methods. While they may obtain hydrogen-reduced iron as a raw material in the future, emissions reduction is not their primary focus. These mills contribute to emissions through fuel usage, and efforts are underway to transition from fossil fuels to electricity, bio -based gas, or hydrogen. Hydrogen-based steel production produces significantly lower greenhouse gas emissions than conventional steel productio, by up to 90 percent, depending on the specific process and energy used, as stated in the life cycle analysis reviews.  This thesis shows key factors for the success of hydrogen-based steel production methods; low -emission electricity and flexibility to store hydrogen. All three countries have expressed interest in and invested in hydrogen-based steelmaking. the share of renewable energy produced and consumed in hydrogen-based steel production in Sweden is expected to make up a share of 2.3% of the total renewable energy production in the country, while Germany and the Netherlands are projected to contribute a modest 1.5% and 1.3% respectively. However, the search for ways to lower carbon dioxide emissions is costly in terms of the amount of electricity required. There are practical reasons for the restricted usage of this steelmaking process in Europe, including the availability of steel scrap, electricity demand, and the low likelihood of scrap generation and recycling scrap availability on the EU  market. Because of this, it is challenging to predict capacity and carbon dioxide reduction by 2050.

The Well-To-Wheels (WTW) methodology is widely used for policy making in the transportation sector. In this paper updated WTW calculations are provided, relying on 2013 statistic data, for the carbon intensity (CI) of the European electricity mix; detail is provided for electricity consumed in each EU Member State (MS). An interesting aspect presented is the calculation of the GHG content of electricity traded between Countries, affecting the carbon intensity of the electricity consumed at national level. The amount and CI of imported electricity is a key aspect: a Country importing electricity from another Country with a lower CI of electricity will lower, after the trade, its electricity CI, while importing electricity from a Country with a higher CI will raise the CI of the importing Country. In average, the CI of electricity used in EU at low voltage in 2013 was 447 gCO2eq/kWh, which is the 17% less compared to 2009. Then, some examples of calculation of GHG emissions from the use of electric vehicles (EVs) compared to internal combustion engine vehicles are provided. The use of EVs instead of gasoline vehicles can save (about 60% of) GHG in all or in most of the EU MSs, depending on the estimated consumption of EVs. Compared with diesel, EVs show average GHG savings of around 50% and not savings at all in some EU MS.

Access to modern energy services derived from renewable sources is a prerequisite, not only for economic growth, rural development and sustainable development, but also for energy security and climate change mitigation. The least developed countries (LDCs) primarily use traditional biomass and have little access to commercial energy sources. They are more vulnerable to problems relating to energy security, air pollution, and the need for hard-cash currency to import fossil fuels. This thesis evaluates sugarcane-molasses bioethanol, a renewable energy source with the potential to be used as a transport fuel in Nepal. Sustainability aspects of molasses-based ethanol have been analyzed. Two important indicators for sustainability, viz. net energy and greenhouse gas (GHG) balances have been used to assess the appropriateness of bioethanol in the life cycle assessment (LCA) framework. This thesis has found that the production of bioethanol is energy-efficient in terms of the fossil fuel inputs required to produce it. Life cycle greenhouse gas (GHG) emissions from production and combustion are also lower than those of gasoline. The impacts of important physical and market parameters, such as sugar cane productivity, the use of fertilizers, energy consumption in different processes, and price have been observed in evaluating the sustainability aspects of bioethanol production. The production potential of bioethanol has been assessed. Concerns relating to the fuel vs. food debate, energy security, and air pollution have also been discussed. The thesis concludes that the major sustainability indicators for molasses ethanol in Nepal are in line with the goals of sustainable development. Thus, Nepal could be a good example for other LDCs when favorable governmental policy, institutional set-ups, and developmental cooperation from donor partners are in place to strengthen the development of renewable energy technologies. / QC 20101029

In this paper, biochemicals with the potential to substitute fossil reference chemicals in Germany were identified using technological readiness and substitution potential criteria. Their greenhouse gas (GHG) emissions were quantified by using life cycle assessments (LCA) and their economic viabilities were determined by comparing their minimum selling prices with fossil references’ market prices. A bottom up mathematical optimization model, BioENergy OPTimization (BENOPT) was used to investigate the GHG abatement potential and the corresponding abatement costs for the biochemicals up to 2050. BENOPT determines the optimal biomass allocation pathways based on maximizing GHG abatement under resource, capacity, and demand constraints. The identified biochemicals were bioethylene, succinic acid, polylactic acid (PLA), and polyhydroxyalkanoates (PHA). Results show that only succinic acid is economically competitive. Bioethylene which is the least performing in terms of economics breaks even at a carbon price of 420 euros per ton carbon dioxide equivalent (€/tCO2eq). With full tax waivers, a carbon price of 134 €/tCO2eq is necessary. This would result in positive margins for PHA and PLA of 12% and 16%, respectively. From the available agricultural land, modeling results show high sensitivity to assumptions of carbon dioxide (CO2) sequestration in biochemicals and integrated biochemicals production. GHG abatement for scenarios where these assumptions were disregarded and where they were collectively taken into account increased by 370% resulting in a 75% reduction in the corresponding GHG abatement costs.