PetrÃleo Brasileiro S/A / O objetivo principal à determinar a atividade catalÃtica residual e as causas da desativaÃÃo de amostras de catalisadores de uma unidade de HDT de lubrificantes. Foram realizadas corridas em unidade piloto, caracterizaÃÃo dos catalisadores e coletados dados do histÃrico operacional da unidade industrial. A atividade catalÃtica foi determinada atravÃs das conversÃes das reaÃÃes de HDA, HDS e HDN bem como pelos parÃmetros cinÃticos aparentes de um modelo de lei das potÃncias e lei de Arrhenius. Os catalisadores dos leitos principais de entrada e saÃda dos reatores industrial foram os mais desativados e o menos desativado o do leito intermediÃrio sendo estabelecida a seguinte ordem de atividade catalÃtica residual: R1L3 (meio) > R1L2 (topo)  R2L2 (fundo). Os resultados de teor e caracterÃsticas do coque, contaminantes e propriedades texturais sugerem que mecanismos distintos tenham causado a desativaÃÃo desses catalisadores: deposiÃÃo de metais e deposiÃÃo de coque. Os mecanismos de desativaÃÃo foram fortemente influenciados pelo posicionamento das amostras no interior do leito catalÃtico. No inÃcio do leito, a contaminaÃÃo por metais (notadamente Si e As) revelou-se o principal mecanismo de desativaÃÃo. Jà no final do leito, a deposiÃÃo de coque foi o mecanismo preponderante e a temperatura de reaÃÃo identificada como a principal causa para o maior envelhecimento do coque. / The main objective of this work is to study the residual catalyst activity and the mechanisms of deactivation of catalyst from a lube-oil hydroprocessing industrial unit. In order to accomplish this, pilot plant tests were carried out followed by spent catalysts characterization. The residual catalytic activity was determined by HDA, HDS and HDN conversions and adjusted by a power law apparent kinetic model. Pilot plant tests revealed different levels of residual activity for spent catalyst samples. Catalyst samples taken from the first and last of the five catalytic beds showed higher deactivation than others. Catalyst characterization results pointed out two mechanisms as the main reason for the catalytic deactivation through the industrial reactor: poisoning by metal deposition (mainly Si and As) and coke deposition. Poisoning was the main deactivation mechanism for the first bed spent catalyst sample, while coke deposition was predominant at the last catalytic bed sample. Reactor temperature was identified as the most important operational parameter considering coke aging.

The global oil refining industry with its present product distribution essentially shifted towards fuels such as gasoline and diesel will most likely hold the fort for considerable time. However, conditions are changing and refinery survival will very much depend on long-term planning, process and product flexibility and being at the frontiers of refining technology, a technology where catalysts play leading roles. Today oil refiners are faced with the challenge of producing fuels that meet increasingly tight environmental specifications, in particular with respect to maximum sulphur content. At the same time, the average quality of crude oil is becoming poorer with higher amounts of aromatics, heteroatoms (sulphur and nitrogen) and heavy metals. In order to stay competitive, it is of decisive importance for refiners to upgrade dense petroleum fractions of low quality to highly value-added products. A practicable route, for example, is upgrading the catalytic cracking by-product Light Cycle Oil (LCO) into a high-quality diesel-blending component in a two-step catalytic process. In the first step the LCO is hydrotreated over a Pt Pd based acidic catalyst bringing about heteroatom and aromatic reduction and isomerization of C6 to C5 naphthenic structures. In the second step these naphthenic structures are selectively opened over an Ir-based catalyst to improve the cetane value. The present thesis is mainly devoted to the second catalytic step of LCO upgrading and was partly conducted within the framework of the European Union project RESCATS. From the patent literature it is evident that iridium-based catalysts could be good candidates for ring-opening purposes. A literature survey covering ring opening of naphthenic structures made in the beginning of the project (in 2001), showed the need for extending investigations to heavier hydrocarbons, more representative of the diesel fraction than model compounds such as alkylated mono C5 and C6 naphthenic rings frequently employed in previous academic studies. Ring-opening catalysts, mainly Pt-Ir based, were synthesised at KTH by two different techniques: the microemulsion and the incipient wetness techniques. Paper I is a review of the microemulsion technique and its applications in heterogeneous catalysis. Characterization of catalysts was performed employing a multitude of techniques including quantitative TPR, TEM-EDX, XPS, CO FT-IR, NH3-DRIFTS and XRF etc. Catalytic screening at 325 oC and atmospheric pressure with hydrogen and pure indan as model substance was conducted to investigate ring-opening activity in terms of conversion and selectivity to desired cetane-boosting products. This development process is the topic of Papers II-IV. The possible industrial implementation of the best catalyst candidate is demonstrated in Paper V. When designing a catalytic system aimed at refining petroleum, it is crucial to monitor the evolution of the sulphur distribution throughout the different stages of the process so that catalyst properties and reaction parameters may be optimised. The final section of this thesis and Paper VI are devoted to high-resolution sulphur-distribution analysis by means of a sulphur chemiluminescence detector (SCD) following gas chromatographic separation. / QC 20101014

No description available.

<p>Циљ савременог гајења јабуке је да се у засаду велике густине садње, заснованом са садницама високог квалитета које рађају већ у години садње, и савременим сортиментом који укључује и сорте склоне алтернативној родности, успоставе редовни и високи приноси који ће се кретати од 50-70 t/ha и добар квалитет плодова. Мера која је од највећег значаја за регулисање родности јесте хемијско проређивање цветова и плодова јабуке.<br />Циљ обављених истраживања је да се испита утицај хемијског проређивања цветова и плодова на заметање, квалитет плодова и родност пупољака сорти јабуке као и да се испита интеракција између минералне исхране азотом и хемијског проређивања. Резултати истраживања били би смернице за хемијско проређивање плодова у агроеколошким условима Србије, са тежњом да у скорој будућности постану део законске регулативе и припадајућих правилника за интегралну производњу, као и развој побољшаних формулација препарата за проређивање.<br />На основу испитивања проређивања цветова може се закључити да сорте јабуке бребурн и златни делишес различито реагују на примену ATS и KTS. Примена 3% ATS и 1,5% KTS код сорте бребурн изазива јаке ожеготине на листовима које могу бити узрок смањеној маси плода и слабијем образовању родних пупољака. Код сорте златни делишес ATS концентрације 3% не испољава негативно дејство на крупноћу плодова и родност пупољака, али са друге стране није ефикаснији од ATS нижих концентрација, док KTS има знатно слабије дејство.<br />Ефикасност препарата на бази NAA у смањењу заметања и приноса сорте јабуке бребурн није зависила од примењене концентрације, док је маса плода у свим варијантама била веома велика, те се за практичну примену могу препоручити ниже концентрације, до 10 &mu;l/l NAA. Сви третмани са NAA у распону концентрација од 8 до 12 &mu;l/l били су једнако ефикасни у редуковању заметања и приноса плодова, док је BA испољио слабију ефикасност у проређивању сорте јабуке камспур. Родност пупољака у третманима проређивања плодова сорти бребурн и камспур није сразмерна повећању концентрације препарата, већ у великој мери зависи од године испитивања.<br />Значајна интеракција је утврђена између фактора ђубрење и проређивање за параметре заметања плодова. Интеракција ова два фактора огледа се у томе да се у режиму интензивног ђубрења азотним ђубривима концентрација препарата на бази NAA и BA треба повећати како би се постигао задовољавајући ниво проређивања.<br />Додавање нафтенских киселина нафтилсирћетној киселини и бензиладенину значајно доприноси повећању просечне масе плода сорте јабуке златни делишес у односу на формулације без нафтенских киселина, као последица биолошке активности нафтенских киселина у смеши. Запажено је повећање чврстине плода у варијантама где је примењена формулација BA са нафтенским киселинама у односу на формулације без<br />нафтенских киселина.<br />Датум прихватања теме од стране Сената:<br />ДП<br />30.5.2013.<br />Чланови комисије:</p> / <p>Cilj savremenog gajenja jabuke je da se u zasadu velike gustine sadnje, zasnovanom sa sadnicama visokog kvaliteta koje rađaju već u godini sadnje, i savremenim sortimentom koji uključuje i sorte sklone alternativnoj rodnosti, uspostave redovni i visoki prinosi koji će se kretati od 50-70 t/ha i dobar kvalitet plodova. Mera koja je od najvećeg značaja za regulisanje rodnosti jeste hemijsko proređivanje cvetova i plodova jabuke.<br />Cilj obavljenih istraživanja je da se ispita uticaj hemijskog proređivanja cvetova i plodova na zametanje, kvalitet plodova i rodnost pupoljaka sorti jabuke kao i da se ispita interakcija između mineralne ishrane azotom i hemijskog proređivanja. Rezultati istraživanja bili bi smernice za hemijsko proređivanje plodova u agroekološkim uslovima Srbije, sa težnjom da u skoroj budućnosti postanu deo zakonske regulative i pripadajućih pravilnika za integralnu proizvodnju, kao i razvoj poboljšanih formulacija preparata za proređivanje.<br />Na osnovu ispitivanja proređivanja cvetova može se zaključiti da sorte jabuke breburn i zlatni delišes različito reaguju na primenu ATS i KTS. Primena 3% ATS i 1,5% KTS kod sorte breburn izaziva jake ožegotine na listovima koje mogu biti uzrok smanjenoj masi ploda i slabijem obrazovanju rodnih pupoljaka. Kod sorte zlatni delišes ATS koncentracije 3% ne ispoljava negativno dejstvo na krupnoću plodova i rodnost pupoljaka, ali sa druge strane nije efikasniji od ATS nižih koncentracija, dok KTS ima znatno slabije dejstvo.<br />Efikasnost preparata na bazi NAA u smanjenju zametanja i prinosa sorte jabuke breburn nije zavisila od primenjene koncentracije, dok je masa ploda u svim varijantama bila veoma velika, te se za praktičnu primenu mogu preporučiti niže koncentracije, do 10 &mu;l/l NAA. Svi tretmani sa NAA u rasponu koncentracija od 8 do 12 &mu;l/l bili su jednako efikasni u redukovanju zametanja i prinosa plodova, dok je BA ispoljio slabiju efikasnost u proređivanju sorte jabuke kamspur. Rodnost pupoljaka u tretmanima proređivanja plodova sorti breburn i kamspur nije srazmerna povećanju koncentracije preparata, već u velikoj meri zavisi od godine ispitivanja.<br />Značajna interakcija je utvrđena između faktora đubrenje i proređivanje za parametre zametanja plodova. Interakcija ova dva faktora ogleda se u tome da se u režimu intenzivnog đubrenja azotnim đubrivima koncentracija preparata na bazi NAA i BA treba povećati kako bi se postigao zadovoljavajući nivo proređivanja.<br />Dodavanje naftenskih kiselina naftilsirćetnoj kiselini i benziladeninu značajno doprinosi povećanju prosečne mase ploda sorte jabuke zlatni delišes u odnosu na formulacije bez naftenskih kiselina, kao posledica biološke aktivnosti naftenskih kiselina u smeši. Zapaženo je povećanje čvrstine ploda u varijantama gde je primenjena formulacija BA sa naftenskim kiselinama u odnosu na formulacije bez<br />naftenskih kiselina.<br />Datum prihvatanja teme od strane Senata:<br />DP<br />30.5.2013.<br />Članovi komisije:</p> / <p>The goal of modern apple growing in high density orchards, established with high-quality nursery trees which bear fruits in the year of planting, often including varieties prone to biennial bearing is to achieve high and regular yields that range from 50 to 70 t/ha with good fruit quality. Chemical thinning of flowers and fruits is a technical practice which is of great importance for crop regulation.<br />The aim of the research was to investigate the effect of chemical thinning of apple flowers and fruits on fruit set, fruit quality and bearing potential of apple buds as well as to examine the interaction between the nitrogen supply and chemical thinning treatments. The research will result with guidelines for the chemical thinning in agroecological conditions of Serbia, aiming to become a part of the legislation and associated regulations for integrated production in the near future. Testing of improved formulations of thinning chemicals will be included into expe rimental plan.<br />Considering the results derived from flower thinning experiments, it could be concluded that cv. Braeburn and Golden Delicious react differently to the application of ATS and KTS. Application of 3% ATS and 1.5% of KTS in cv Braeburn causes severe leaf burns that may be causing reduced fruit weight and a decrease in bearing potential. In cv Golden Delicious ATS applied at the concentration of 3% does not exhibit a negative effect on fruit size and bearing potential, but at the other side is not more efficient than ATS at lower concentrations, whereas KTS has a much weaker thinning effect.<br />The efficacy of NAA in reducing fruit set and yield of apple variety Braeburn is not dependent on the concentration applied, while fruit size was very large within the range of NAA concentrations. Therefore, for the practical application, concentrations lower than 10 ml/l NAA would be recommended. All treatments with NAA at concentrations ranging from 8 to 12 ml/l were equally effective in reducing fruit set and yield, while the BA exhibited decreased efficiency in thinning apple variety Camspur. Fertility of buds in Braeburn and Camspur varieties was not proportional to the increase in concentration of chemical, but to a large extent depends on the conditions of the experimental year.<br />An interaction between nitrogen supply and chemical thinning significantly affected fruit set in a way that concentration of NAA and BA for fruit thinning should be increased in order to achieve a satisfactory level of thinning at a higher level of nitrogen supply.<br />Adding of naphthenic acids to NAA and BA significantly contributed to the increase of average fruit weight of apple variety Golden Delicious compared to same chemical formulation without naphthenic acids, as a result of the biological activity of naphthenic acids in the mixture. An increase of fruit firmness was detected in thinning treatments where naphthenic acids were added to BA compared BA applied alone.</p>

Made available in DSpace on 2016-12-23T14:41:52Z (GMT). No. of bitstreams: 1 Thieres Magaive Costa Pereira.pdf: 7173330 bytes, checksum: 5a2aee56b5048351ab0fc838877f8030 (MD5) Previous issue date: 2013-08-23 / O petróleo é uma mistura complexa, sendo uma das misturas mais desafiadoras para as análises químicas. Muitas técnicas são empregadas para a caracterização dos constituintes do óleo. Entretanto, quando combinamos o altíssimo poder de resolução e exatidão da espectrometria de massas, em especial a Ressonância Ciclotrônica de Íons com Transformada de Fourier, (FT-ICR MS) com fontes de ionização a pressão atmosférica, uma atribuição precisa de mais de 20 000 compostos orgânicos do petróleo pode ser obtida. Na indústria do petróleo existe um grande interesse na análise de ácidos naftênicos e asfaltenos devido a problemas como corrosão e formação de depósitos, que aumentam os custos de produção. Portanto este trabalho tem como objetivo a avaliação da termodegradação de ácidos naftênicos, além do emprego das fontes de ESI, APCI, APPI, LDI e MALDI para aquisição de novos dados relativos a caracterização de asfaltenos. Dois petróleos foram utilizados nos ensaios de termodegradação, o petróleo A com acidez de 2,38 mg KOH g-1 e o petróleo B com 4,79 mg KOH g-1 os quais foram tratados a 280, 300 e 350 ºC pelo período de 2, 4 e 6 horas. De uma maneira geral, as principais classes identificadas para ambas às amostras foram O2, N e NO2, respectivamente. Uma leve redução do NAT e da abundância relativa referente à classe O2 foram observado em função da temperatura e do tempo de envelhecimento (T = 280 &#8594; 300 oC e t = 2 &#8594; 6 h), sendo que a temperatura de tratamento térmico a 350 ºC demonstrou-se determinante na remoção de compostos da classe O2. O perfil químico de amostras de asfaltenos brasileiros foi avaliado utilizando-se cinco diferentes métodos de ionização em ambos os modos de ionização: positivo e negativo, depois, a distribuição de peso molecular, distribuição de classe, parcelas típicas de número de carbono contra DBE e diagramas van Krevelen foram obtidos e discutidos. Um comportamento atípico foi observado para a fonte de LDI e MALDI (±) FT-ICR MS. Um amplo perfil, de m/z 500-3000, apresentando espaçamento de 24 Da foi observado, e este corresponde a formas alotrópicas de fulereno, C60. Em geral, os asfaltenos apresentaram um elevada proporção de espécies heteroatómicas como: HC, HC [H], N, N [H], N2O, N2O [H], N2, N2 [H], O, O[H] para o modo (+) e N, N [H], NO, NO [H], NO, NO2[H], N2O, N2O[H] para o modo negativo. Nos diagramas de DBE contra o número de carbono, os asfaltenos mostraram para cada valor de DBE uma pequena amplitude de compostos com respeito à NC, proporcionando assim, imagens que formam uma linha de 45 ° entre os eixos CN e DBE. Isto indica que estes compostos não exibem grandes cadeias de alquílicas, sendo composta principalmente por anéis aromáticos. Em geral os diagramas de van Krevelen mostraram alta proporção de compostos com razão H/C ~0,7, corroborando com a existência de espécies altamente aromáticas / Petroleum is a complex mixture, being one of the most challenging mixtures for chemical analyzes. Many techniques are employed to characterize constituents of the oil. However , when we combine the highest resolving power and accuracy of mass spectrometry , especially Ion Cyclotron Resonance Fourier Transform ( FT - ICR MS ) with sources of atmospheric pressure ionization , an assignment need more than 20 000 organic compounds in the oil can be obtained. In the oil industry there is a great interest in the analysis of asphaltenes and naphthenic acids due to problems such as corrosion and deposit formation, which increases production costs. Therefore this study aims to evaluate the thermodegradation of naphthenic acids, besides the use of sources of ESI, APCI, APPI, MALDI and LDI for the acquisition of new data on the characterization of asphaltenes . Two test oils were used in thermodegradation of the oil with an acidity of 2.38 mg KOH g -1 and Oil B with 4.79 mg KOH g- 1 which were treated at 280 , 300 and 350 ° C for a period of 2 , 4 and 6 hours. Generally, the major classes identified for both samples O2, NO2, and C, respectively. A slight reduction of NAT and relative abundance refers to the class O2 were observed as a function of temperature and aging time (T = 280 &#8594; 300 ° C t = 2 &#8594; 6 h), and the heat treatment temperature at 350 ° C showed a determinant for the removal of class O2. The chemical asphaltenes Brazilian samples was evaluated using five different methods of ionization in both modes of ionization: positive and negative, then the molecular weight distribution, distribution class, typical plots versus carbon number and DBE van Krevelen diagrams were obtained and discussed. An unusual behavior was observed for the LDI and MALDI source ( ± ) FT - ICR MS . A comprehensive profile of m / z 500-3000, with spacing of 24 Da was observed, and this corresponds to allotropes of fullerene C60. In general, the asphaltenes had an heteroatómicas high proportion of species such as HC , HC [ H] , N, [ H] , N2O N2O [ H] N2, N2 [ M ] O O [ H] to mode (+) and N, [ H ] , NO [ H] , NO , NO2, [ H] , N2O N2O [ H ] for the negative mode . In the diagrams DBE against the carbon number , the asphaltenes shown for each value of DBE composed of a small amplitude with respect to NC, thus providing images that form a line of 45 ° between the axes CN and DBE. This indicates that these compounds do not exhibit large chain alkyl, composed mainly of aromatic rings. In general diagrams van Krevelen showed a high proportion of compounds ratio H / C ~ 0.7, confirming the existence of highly aromatic species

<p>Predviđena istraživanja u ovoj doktorskoj disertaciji su usmerena u<br />pravcu iznalaženja novih, efikasnijih i bržih mikrotalasno-stimulisanih<br />metoda hemijskih transformacija koje ne uključuju prisustvo<br />katalizatora i/ili organskih rastvarača. Primenom specijalnih silicijum-karbidnih reakcionih sudova, brzina i preciznost izvođenja<br />mikrotalasno-stimulisanih transformacija prikazana&nbsp; je kroz stresne<br />studije aktivnih farmaceutskih ingredijenata u SiC&nbsp; ploči, odnosno<br />HPLC/GC vialima kao reakcionim sudovima. Ispitano je postojanje<br />netermičkih mikrotalasnih efekata i njihov značaj za precizno tumačenje<br />rezultata mikrotalasne sinteze.<br />U drugom delu ove doktorske disertacije izvr&scaron;ena jemikrotalasno-stimulisana sinteza potencijalno biolo&scaron;ki aktivnih&nbsp; supstanci iz prirodnih<br />lako dostupnih materijala kao &scaron;to su naftenske kiseline. Sintetizovani su<br />amidi i estri individualnih i prirodnih naftenskih kiselina Velebit.<br />U radu je takođe ispitana biolo&scaron;ka aktivnost sintetizovanih derivata.<br />Proučavan je uticaj prirodnih naftnih kiselina Velebit injenih derivata<br />na rast pet sojeva&nbsp; Pseudomonassp., kao i uticaj odabranih sintetisanih<br />jedinjenja na proliferaciju pet&nbsp; ćelijskih linija humanih tumora pri&nbsp; čemu<br />je kao kontrola služila jedna zdrava humana ćelijska linija.</p> / <p>Scientific research predicted in this PhD thesis isdirected to ascertainment new, efficient and faster microwave-assisted methods of chemical transformations in the absence of catalysts and/or organic solvents. Applaying special silicon-carbide&nbsp; reaction vessels, speed and accuracy of microwave-assisted transformations are ilustrated within stress testing of active pharmaceutical ingredients in HPLC/GC vials placed in SiC plate. Existence of nonthermal microwave effects and their influence on &nbsp;accurate interpretation of microwave synthesis results are also investigated.&nbsp;<br />In the second part of this thesis microwave-assisted synthesis of potentionally biologically active compounds from readily available natural materials, such as &nbsp;naphthenic acid is accomplished. Amides and esters of individual and natural naphthenic acids Velebitare synthetised. The thesis also examined the biological activity ofthe synthesized products. The effect of natural petroleum acids&nbsp; Velebitand its derivatives are examined on the growth of five strains of Pseudomonas&nbsp;sp., and the impact of selected synthesized compounds on the proliferation of five human tumor cell lines in which a healthy human cell line is tused as the control.</p>