Athanasios Dimitriadis

Hydrotreating of waste cooking oil for biodiesel production. Part I: Effect of temperature on product yields and heteroatom removal.

Hydrotreating of waste cooking oil (WCO) was studied as a process for biofuels production. The hydrotreatment temperature is the most dominant operating parameter which defines catalyst performance as well as catalyst life. In this analysis, a hydrotreating temperature range of 330-398 degrees C was explored via a series of five experiments (330, 350, 370, 385 and 398 degrees C). Several parameters were considered for evaluating the effect of temperature including product yields, conversion, selectivity (diesel and gasoline), heteroatom removal (sulfur, nitrogen and oxygen) and saturation of double bonds. For all experiments the same commercial hydrotreating catalyst was utilized, while the remaining operating parameters were constant (pressure=1200 psig, LHSV=1.0 h(-1), H(2)/oil ratio=4000 scfb, liquid feed=0.33 ml/min and gas feed=0.4 scfh). It was observed that higher reactor temperatures are more attractive when gasoline production is of interest, while lower reaction temperatures are more suitable when diesel production is more important.

Hydrotreating of waste cooking oil for biodiesel production. Part II: Effect of temperature on hydrocarbon composition.

This study focuses on the use of waste cooking oil (WCO) as the main feedstock for hydrotreatment to evaluate the effect of temperature on the product hydrocarbon composition. A qualitative analysis was initially performed using a GC x GC-TOFMS indicating the presence of mainly paraffins of the C15-C18 range. A quantitative analysis was also performed via a GC-FID, which gave both n-paraffins and iso-paraffins in the range of C8-C29. The results indicate that hydrotreating temperature favors isomerization reactions as the amount of n-paraffins decreases while the amount of iso-paraffins increases. For all experiments the same commercial hydrotreating catalyst was utilized, while the remaining operating parameters were constant (pressure=1200 psig, LHSV=1.0 h(-1), H(2)/oil ratio=4000 scfb, liquid feed=0.33 ml/min, and gas feed=0.4 scfh).

Evaluation of a Hydrotreated Vegetable Oil (HVO) and Effects on Emissions of a Passenger Car Diesel Engine

In the coming years, the application of paraffinic biofuels, such as Hydrotreated Vegetable Oils (HVO), in the transportation sector is expected to increase. However, as the composition of HVO is different compared to conventional diesel, the engine optimized for conventional fuel cannot take full advantage of the HVO beneficial properties. Suitable adjustment of a number of engine parameters, if not complete engine re-calibration, will enable the full exploitation of such fuels’ potential for lower exhaust emissions and reduced fuel consumption. In the present work, the emission characteristics of HVO fuel in a light-duty Euro 5 diesel engine have been studied, under steady-state operation, as well as during the New European Driving Cycle (NEDC). The study was expanded to the investigation of exhaust emissions under modified Main Injection Timing (MIT) and EGR rate. The NEXBTL fuel, produced by Neste, was considered in the study and was compared with conventional market diesel. Emissions of nitric oxides (NOx), soot, carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbons (HC) were studied. At default MIT and EGR settings the use of HVO resulted in a significant reduction of all regulated emissions. In addition, it was observed that the adjustment of MIT and EGR can enhance the exploitation of HVO potential for emissions reduction, highlighting the differences with the conventional diesel fuel.

Residual lipids incorporation in a petroleum refinery

The aim of this study was to evaluate the technical feasibility and environmental benefits from integrating waste cooking oil (WCO) in a refinery, towards producing a new hybrid diesel. This new hybrid diesel, partially of fossil- and partially of bio-based origin, was evaluated as an alternative to market diesel according EN 590 specifications, showing comparable if not superior quality in the case of the former. Another scope was to compare the environmental impacts of the new hybrid diesel and the market diesel, in order to identify the most environmentally friendly fuel with the higher sustainability potential. The comparison was based on a well-to-tank (WTT) analysis including only the production processes of both fuels considered. Based on this study, the new hybrid diesel produced via co-hydroprocessing petroleum fractions with WCO presented the lower carbon foot-print, validating its sustainability superiority. It is evident that integrating residual biomass in a refinery is the most sustainable approach for incorporating biomass in the transportation sector.

Renewable diesel production by hydroconversion of waste cooking oil

This study produces an attempt to estimate the cost of future global energy supplies. The approach chosen to address this concern relies on a comparative static exercise of estimating the cost of three energy scenarios representing different energy futures. The first scenario, the business as usual scenario, predicts the future energy-mix based on the energy plans held by major countries. The second scenario is the renewable energy scenario, where as much of the primary energy supply as possible is replaced by renewable energy by 2050. The cost of the renewable energy generating technologies and their theoretical potential are taken into account in order to create a plausible scenario. The third scenario, the nuclear case, is based on the use of nuclear and renewable energy to replace fossil-fuels by 2050. Endogenous learning rates for each technology are modeled using an innovative approach where learning rates are diminishing overtime. It results from the analysis that going fully renewable would cost between -0.4 and 1.5% of the global cumulated GDP over the period 2009-2050 compared to a business as usual strategy. An extensive use of nuclear power can greatly reduce this gap in costs.The Miocene alkali basaltic rocks cover the northeastern part of Jordan, within Harrat Al-Shaam plateau. The volcanic concentrated along the Dead Sea boundary and spread around the north east of Jordan area, and was considered as interplat volcanic field in Jordan. The volcanic basalt is associated with xenoliths fragmental rocks or xenocryst minerals. Nine samples were collected from the study area and analyzed for XRD, XRF and SEM. These samples presented the xenoliths rocks and minerals existing in the study area. This study is focused on the garnet and pyroxene xenoliths minerals in Tulayl Al-Hasna area within Ufayhim Formation. Hand samples are characterized by coarse aggregates of garnets up to (2 cm in diameter) with dark brown to red color, and highly fresh fractures. Also, the pyroxene (<1.5 cm) with gray to dark green color, and the olivine (range 3 4 mm) are pale green to dark green and pale yellowish color. In thin sections, plagioclase phenocryst in the garnet presented corona texture. In addition, garnet surrounded by orthopyroxene refers to kelyphite texture. There are two types of kelyphite texture fibers and radial as shown in Scanning Electron Microscope photomicrograph. The mineralogical analyses of garnet for X-Ray Diffraction are composed of almandine, pyrope and majorite. The existence of minerals reflects the high pressure and temperature of the upper mantle origin. The chemical analysis showed the average composition of garnet as follow (Alm 42.78, Pyro 41.04, Gross 16.18), pyroxene (Wo 16.90, Fs 20.37, En 62.73). This referred to presentation of the following elements Mg, Fe and Ca in the garnet. As a result, the basaltic garnet xenoliths were from shallow lithosphere mantle origin.Context and objectives Fast Sodium Reactor (FSR) is one of the most promis ing nuclear reactor concept (“Generation IV systems”) to be issued in the next decades [1]. Thi s technology is intended to be much safer, to have a significantly better yield and to produce less wa stes with a lower nocivity. Liquid sodium is used as the thermal fluid in direct contact with the nuc lear core. Ideally, the heat extracted should be transferred between sodium and water in steam gener ators. BUT when sodium is brought in contact with liquid water, a highly exothermal chemical rea ction ensues which is believed to be explosive in certain situations [2]. Such a contact may happen i n a number of instances (repairs, decommissioning,..) and not only during major accid ents. This is thus a significant safety issue which may significantly handicap the development of this technology. Unfortunately the reasons for which the mixing of s dium with water may lead to an explosion, generating blast waves like an explosive material, do not seem to have been clarified so far not even deeply studied. The primary objective of this PhD w ork is thus to identify the details of the phenomenology, to isolate the leading mechanisms an d to propose a modelling approach.W examine the implications of increased unconventional crude oil production in North America. This production increase has been made possible by the existence of alternative oil-recovery technologies and persistently elevated oil prices that make these technologies commercially viable. We first discuss the factors that have enabled the United States to expand production so rapidly and the glut of oil inventory that has accumulated in the Midwest as a result of logistical challenges and export restrictions. Next, we assess the extent to which the increase in U.S. domestic production will affect global supply conditions and whether the U.S. experience can be repeated in other countries with unconventional oil sources. The evidence suggests that even in the bestcase scenario, the increase in U.S. oil production is unlikely to have a large effect on the global oil market’s demand–supply balance, so its effect on the price of oil is expected to be limited. Furthermore, the United States enjoys unique infrastructural and technological advantages that make it unlikely that rapid increases in unconventional production can be achieved elsewhere.T reactions of sunflower, rapeseed, corn and cameline oils in supercritical (sc) methanol were studied in a flow tubular reactor over a wide range of methanol (ether)/oil ratio, pressure, temperature, and residence time. Special attention was focused on the studies of the product distribution and how it varies upon variation of the above reaction parameters. Reaction conditions to enable high selectivity and conversion of vegetable oils transesterification were determined. Advantages of the reaction in supercritical alcohols and ethers over similar reaction in the presence homogeneous catalysts were demonstrated. It was found that the oil type produced insignificant effect on the product composition (fatty acid esters) and oil conversion value. The reaction conditions provided the selectivity and high conversion of the oils were selected.ID-215 INFLUENCE OF SILICA NANOPARTICLES ON THE TOUGHNESS OF FUSION BONDED EPOXY Patrícia Saliba, Herman Mansur UFMG, Brazil patalvessaliba@gmail.com, hmansur@demet.ufmg.brT Niger Delta is the hub of oil and gas production in Nigeria, and is one of the world’s most severely oil spill impacted areas. The exploration and exploitation of oil interfere with ecological and biodiversity integrity of ecosystems arising from flaring of associated gases, oil spills, use of drilling chemicals, etc. These processes can release heavy metals into coastal waters. Heavy metals are associated with crude oil in variable concentrations depending on the geologic background. Nigeria’s dominant and internationally preferred crude petroleum, Bonny Light, has associated with it metals, the main metals occurring in the order nickel>vanadium>cadmium>copper, lead. Recent pollution studies have revealed elevated levels of Zn, Cu, Pb, Cr, Ni, and V, in Niger Delta water, sediments and food species, thereby, compromising safety of the user population. Oil spills in the Niger Delta impact tremendously on the region’s flora and fauna which serve as the main livelihood support structures of the inhabitants. A recent UNEP study on a section of the Niger Delta revealed widespread oil contamination of land, groundwater and surface waters. Drinking water from wells in one community had benzene, a known carcinogen, 900 times above WHO permissible limit. The UNEP study concludes that restoration of the investigated area would take minimum of 30 years. This paper discusses the incidents of oil pollution, and prospect and challenges of ecosystem restoration of Niger Delta oil degraded environments.