Contenido, distribución y origen de hidrocarburos en sedimentos de tres lagunas urbanas de Concepción - Chile

Aliphatic hydrocarbon content, distribution and origin in superficial and deep sediments of three interconnected urban lagoons located in Concepción-Chile were studied. In all lagoons, the analysis showed that aliphatic hydrocarbons present were of biogenic and anthropogenic origin, and n-alkanes were predominantly from odd carbon, confirmed by a relatively high Pristane/Phytane ratio. The most abundant Polycyclic Aromatic Hydrocarbons (PAHs) were two high-molecular weight species (Fluoranthene and Pyrene) whose presence may be related with the regular activities of the area as well as with combustion processes.

Imobilização e caracterização de lacase e seu uso na biodegradação de efluentes de indústrias papeleiras

Laccase from Aspergillus sp was immobilized on glutaraldehyde-activated chitosan beads. A comparative study between free and immobilized laccase was conducted and the potential of the resulting immobilized derivative in the biodegradation of pulp and paper mill effluent was evaluated. The immobilized laccase is more resistant to various denaturing conditions, which allows for the reduction of 65% of the phenols (total and low molecular weight) and loss of 60% of total color in the effluent. These results show the potential of the immobilized laccase in the biodegradation of phenols, the chemical agents responsible for the high toxicity of the effluent generated in cellulose pulp industries.

Terpanos pentacíclicos como indicadores de heterogeneidades composicionais em reservatório de petróleo biodegradado

Reservoir geochemistry has been effectively used to evaluate compositional heterogeneity in petroleum reservoirs by employing oil fingerprinting technique to assess reservoir continuity, primarily in paraffin oil accumulations. In-reservoir biodegradation has resulted in vast deposits of heavy oils globally; therefore, the application of reservoir geochemistry to such accumulations becomes necessary. We recommend the use of pentacyclic terpanes instead of lower molecular compounds, which are less resistant to biodegradation. Using oil fingerprinting technique in this novel way enabled the differentiation of oil composition among sedimentary facies of tar sands (Pirambóia Formation, Paraná Basin).

Avaliação da eficiência de degradação de hidrocarbonetos aromáticos por bactérias provinientes de estação de tratamento de efluente de refinaria de petróleo

Three bacterial strains were isolated from the activated sludge system of petroleum refinery wastewater, identified by partial sequencing of 16S rDNA, and classified as Acinetobacter genomospecies 3, Bacillus pumilus, and Bacillus flexus. The degradation efficiency of aromatic hydrocarbons was evaluated by gas chromatography with a flame ionization detector. In a mineral medium containing anthracene and phenanthrene and the consortium of microorganisms, the removal efficiency was 96% and 99%, respectively, after 30 days. The good rate of hydrocarbon degradation proves the operational efficiency of the microbial consortium in treating effluents containing these compounds.

Biodegradação bacteriana de compostos organoclorados

Due to their recalcitrant nature, organochlorides are already found in environment and the search for alternatives to eliminate these compounds such as biodegradation using native microorganisms is of great interest. A screening trial to select environmental bacteria able to degrade DDD, PCP and dieldrin was conducted. Among 14 isolates, the soil bacteria Pseudomonas aeruginosa L2-1 showed the highest tolerance to increasing concentrations of the organochlorides and was selected for further studies. Biodegradation was assessed in liquid medium, varying the concentrations of glucose and the presence of rhamnolipids (RL). The best medium for the occurrence of biodegradation of the compounds contained 0.5% glucose, giving approximately 50% yield after three days of incubation. Results showed that the biodegradation rates of the organochlorides by P. aeruginosa L2-1 were greater at low concentrations of glucose and in the presence of rhamnolipids.

DEGRADAÇÃO MICROBIOLÓGICA E ENZIMÁTICA DE POLÍMEROS: UMA REVISÃO

Polymer recycling has been one of the most important trend in the petrochemical area. Among different technologies, biotechnological (enzymatic and/or microbial) degradation of polymers for the recovery of monomers and oligomers is environmentally-friendly and meet some green chemistry principles. In this work, conditions for the biotechnological degradation of some industrially-relevant polymers (e.g. poly(ethylene terephthalate) and polyethylene) were revised, and the main biocatalysts were identified. In most cases, biodegradation mechanisms are still unclear, thus being necessary more studies to unravel these promising bioprocesses. Polymer biodegradation studies also present considerable importance for other fields, including biomedical and agricultural.

PRODUÇÃO DE BIODIESEL A PARTIR DE ÁCIDOS GRAXOS PROVENIENTES DO REFINO DE ÓLEOS VEGETAIS VIA CATÁLISE ÁCIDA HETEROGENEA E MICRO-ONDAS

This work presents the biofuel production results of the esterification of fatty acids (C12-C18) and high-acid-content waste vegetable oils from different soap stocks (soybean, palm, and coconut) with methanol, ethanol, and butanol by acid catalysis. We used Amberlyst-35 (A35) sulfonic resin as a heterogeneous acid catalyst and p-toluenesulfonic acid as a homogeneous catalyst for comparison. Both the heterogeneous (A35) and homogeneous (p-toluenesulfonic acid) reactions were performed with 5% w/w of catalyst. The final products were analyzed by proton nuclear magnetic resonance (1H NMR). The homogeneous catalyzed esterification of fatty acids with methanol, ethanol, and butanol produced esters with yields higher than 90%. In the reaction with fatty acids and methanol catalyzed by A35, the best results were achieved with lauric acid and methanol, with a yield of 97%. An increase in the hydrocarbon chain decreased the rate of conversion and yield for stearic acid with methanol, which was 90%. Maximum biodiesel production was achieved from coconut and soybean soap stocks and methanol (96%-98%), which showed conversions very close to those obtained from their respective fatty acids. Microwave irradiation reduced the reaction time from 6 to 1 h in the esterification reaction of fatty acids with butanol.

USE OF A LOW-COST TEMPLATE-FREE ZSM-5 FOR ATMOSPHERIC PETROLEUM RESIDUE PYROLYSIS

To understand the physicochemical properties and catalytic activity during the pyrolysis of atmospheric petroleum residue, a template-free ZSM-5 zeolite was synthesized using a direct method without additional seeds or an organic structure director and compared with conventionally synthesized ZSM-5. The crystallinities of the two zeolites were evaluated by XRD and FTIR and were quite similar; however, structural analyses using SEM and argon physisorption revealed that the zeolites diverged in particle diameter and in the external surface area of the micropores. The synthesis procedure without a template incorporated additional aluminum into the crystalline network, according to ICP-AES and TPD NH3 experiments. The catalytic pyrolysis performed over the template-free ZSM-5 generated results comparable to those for pyrolysis performed over the conventional ZSM-5 according to its hydrocarbon distribution. The selectivity to aromatics compounds was exactly the same for both ZSM-5 zeolites, and these values stand out compared to thermal pyrolysis. The template-free ZSM-5 produced 20% of light hydrocarbons (C4-C6), where such compounds are olefins and paraffins of great interest to the petrochemical industry. Therefore, template-free ZSM-5 is promising for industrial use due to its lowered synthesis time, low-cost and significant distribution to light hydrocarbons.

Suojavaatemateriaalien kemikaaliläpäisevyyden testaaminen metyylisalisylaatilla -mittaus- ja analyysimenetelmien kehittäminen ja validointi

Tässä diplomityössä kehitettiin mittaus- ja analyysimenetelmät suojavaatemateriaalien kemikaaliläpäisevyyden testaamiseksi sekä neste- että kaasumaisella metyylisalisylaatilla. Kehitystyö tehtiin standardin SFS-EN ISO 6529 pohjalta. Tämä standardi kuvaa kuitenkin varsin yleisellä tasolla suojavaatemateriaalien kemikaaliläpäisevyyden testimenetelmät, eikä se ole mikään tarkka työohje. Näytteenotto- ja analyysimenetelmät joudutaan siis valitsemaan sekä validoimaan jokaiselle kemikaalille erikseen, tässä tapauksessa metyylisalisylaatille. Työn tarkoituksena oli kehittää toimivat menetelmät ja laitteistot siten, että olisi mahdollista suorittaa metyylisalisylaatin määritys on-line mittauksena läpäisytestauksessa. Läpäisytestaustoiminnan nopeuttamiseksi työssä myös suunniteltiin ja rakennettiin laitteistot kolmen rinnakkaisen testikennon yhdenaikaista testausta varten sekä kaasumaisen että nestemäisen metyylisalisylaatin ollessa testikemikaalina. Havaittiin, että UV/VIS-spektrofotometri varustettuna läpivirtauskyvetillä ja näyteenottopumpulla on toimiva ja käyttökelpoinen analyysimenetelmä metyylisalisylaatin määrittämiseen nesteistä on-line mittauksena läpäisyn testauksessa. Kaasumaisen metyylisalisylaatin tapauksessa määritysmenetelmänä päädyttiin käyttämään kokonaishiilivetyanalysaattoria, joka on varustettu liekki-ionisaatiodetektorilla. Molemmissa tapauksissa saatiin aikaan toimivat ja on-line mittauksiin kykenevät näytteenotto- ja määritysmenetelmät, joilla loppukäyttäjä voi suorittaa laajempaa läpäisytestausta.

Insulation System in an Integrated Motor Compressor

A high-speed and high-voltage solid-rotor induction machine provides beneficial features for natural gas compressor technology. The mechanical robustness of the machine enables its use in an integrated motor-compressor. The technology uses a centrifugal compressor, which is mounted on the same shaft with the high-speed electrical machine driving it. No gearbox is needed as the speed is determined by the frequency converter. The cooling is provided by the process gas, which flows through the motor and is capable of transferring the heat away from the motor. The technology has been used in the compressors in the natural gas supply chain in the central Europe. New areas of application include natural gas compressors working at the wellheads of the subsea gas reservoir. A key challenge for the design of such a motor is the resistance of the stator insulation to the raw natural gas from the well. The gas contains water and heavy hydrocarbon compounds and it is far harsher than the sales gas in the natural gas supply network. The objective of this doctoral thesis is to discuss the resistance of the insulation to the raw natural gas and the phenomena degrading the insulation. The presence of partial discharges is analyzed in this doctoral dissertation. The breakdown voltage of the gas is measured as a function of pressure and gap distance. The partial discharge activity is measured on small samples representing the windings of the machine. The electrical field behavior is also modeled by finite element methods. Based on the measurements it has been concluded that the discharges are expected to disappear at gas pressures above 4 – 5 bar. The disappearance of discharges is caused by the breakdown strength of the gas, which increases as the pressure increases. Based on the finite element analysis, the physical length of a discharge seen in the PD measurements at atmospheric pressure was approximated to be 40 – 120 m. The chemical aging of the insulation when exposed to raw natural gas is discussed based on a vast set of experimental tests with the gas mixture representing the real gas mixture at the wellhead. The mixture was created by mixing dry hydrocarbon gas, heavy hydrocarbon compounds, monoethylene glycol, and water. The mixture was chosen to be more aggressive by increasing the amount of liquid substances. Furthermore, the temperature and pressure were increased, which resulted in accelerated test conditions. The time required to detect severe degradation was thus decreased. The test program included a comparison of materials, an analysis of the e ects of di erent compounds in the gas mixture, namely water and heavy hydrocarbons, on the aging, an analysis of the e ects of temperature and exposure duration, and also an analysis on the e ect of sudden pressure changes on the degradation of the insulating materials. It was found in the tests that an insulation consisting of mica, glass, and epoxy resin can tolerate the raw natural gas, but it experiences some degradation. The key material in the composite insulation is the resin, which largely defines the performance of the insulation system. The degradation of the insulation is mostly determined by the amount of gas mixture di used into it. The di usion was seen to follow Fick’s second law, but the coe cients were not accurately defined. The di usion was not sensitive to temperature, but it was dependent upon the thermodynamic state of the gas mixture, in other words, the amounts of liquid components in the gas. The weight increase observed was mostly related to heavy hydrocarbon compounds, which act as plasticizers in the epoxy resin. The di usion of these compounds is determined by the crosslink density of the resin. Water causes slight changes in the chemical structure, but these changes do not significantly contribute to the aging phenomena. Sudden changes in pressure can lead to severe damages in the insulation, because the motion of the di used gas is able to create internal cracks in the insulation. Therefore, the di usion only reduces the mechanical strength of the insulation, but the ultimate breakdown can potentially be caused by a sudden drop in the pressure of the process gas.

Selection of microorganisms producer of lipase for fat removal from biodiesel purification water

The objective this study has been the selection of lipase productor microorganism, for removal of oils and grease, in the pre-treatment of biodiesel wastewater washing. For this, analyses of the physicist-chemistries characteristics had been made with the wastewater of the biodiesel washing, and then it had been isolated and chosen, by means of determinations of the lipase activity. Following, it was made a test of fat biodegradation, in the conditions: pH (5.95), temperature (35 ºC), rotation (180 rpm) and ammonium sulfate as nitrogen source (3 g L-1) and establishing as variable the two microorganism preselected and the time (24; 48; 72; 96 and 120 h). The biodiesel purification wastewater had presented high potential of environmental impact, presenting a concentration of O of 6.76 g L-1. From the six isolated microbiological cultures, two microorganisms (A and B) had been selected, with enzymatic index of 0.56 and 0.57, respectively. The treatment of the wastewater using the isolated microorganism (Klebsiella oxytoca) had 80% of the fatty removal in 48 h.

Ammonia nitrogen desorption from sanitary landfill leachate in filling towers

Sanitary landfill leachates present high concentrations of carbonaceous and nitrogenous materials. The crucial point is that carbonaceous materials are of difficult biodegradation, what compromises the performance of biological treatment processes, while nitrogenous materials, such as ammonia nitrogen, probably preclude the use of biological treatments. Therefore, the aim of this work was to study the desorption process of ammonia nitrogen from sanitary landfill leachate in filling towers. Desorption was carried out in filling towers of 35 L capacity. The leachate was collected from a sanitary landfill located in João Pessoa, Paraíba State, Brazil. Desorption efficiency for the pH values ​​adopted in four treatments was 93% minimum and 95.5% maximum, with aeration mean time ranging from 3 to 6 hours. The limiting factors of ammonia nitrogen desorption from sanitary landfill leachates in filling towers are associated with the use of alkalizer species for pH correction, and electricity costs for aeration.

Steroidien selektiivinen erottaminen sähköavusteisesti mikroemulsioita käyttäen

Mikroemulsiosähkökineettinen kromatografia on sähköavusteinen erotusmenetelmä. Yhdisteiden erottuminen tapahtuu mikroemulsiopisaroiden vaikutuksesta, kun nanometrien kokoiset öljypisarat ovat dispergoituneena veteen valmistettuun puskuriliuokseen. Yleensä mikroemulsiot valmistetaan raakaöljynkin sisältämistä hiilivedyistä, joita ovat esimerkiksi oktaani ja heptaani. Työn kokeellisessa osassa perehdyttiin seitsemän hydrofobisen ja varauksettoman steroidihormonin erottamiseen mikroemulsioliuoksessa kapillaarielektroforeesitekniikalla. Työssä valmistettiin öljyistä koostuvia mikroemulsioita, joista osan koostumus valittiin kirjallisuuden perusteella. Työssä kokeiltiin myös uusia mikroemulsiokoostumuksia, joissa käytettiin luonnosta peräisin olevia öljyjä: rypsi-, oliivi-, pellavansiemen- ja saksanpähkinäöljyä. Seitsemästä steroidihormonista viisi yhdistettä saatiin erottumaan optimoiduilla menetelmillä. Steroidien erotus perustuu niiden oktanoli-vesi jakautumiskertoimien avulla saatavaan migraatiojärjestykseen. Mikroemulsiossa, jossa käytettiin 1-oktanolia, steroidihormonit erottuivat nopeammin, kuin saksanpähkinäöljyä käytettäessä. Lyhyimmät migraatioajat saatiin mikroemulsiolla, jossa öljyfaasina käytettiin 1-heksanolia ja viidentenä yhdisteenä asetonitriiliä. Selektiivisimmillään menetelmä on, kun erotus tapahtuu liuoksessa, joka koostuu etyyliasetaatista, natriumdodekyylisulfaatista, butanolista, asetonitriilistä ja natriumtetraboraatista. Toteamisrajat tutkituille steroidihormoneille olivat 0,20–0,43 mg/L mikroemulsioissa.

Biodegradable packaging materials in 2013 and their feasibility in chocolate industry

The development of biopolymers has been rapid in recent years and the range of available bioplastics is increasing continuously, driven by a growing demand for sustainable solutions. There are several key drivers behind this growth. The oil reservoirs are decreasing which is causing a price increase for the traditional plastic materials and therefore the gap to bioplastics’ price is getting smaller. In addition, other environmental topics, such as waste disposal and green production, have become more and more important factors for institutes, companies and consumers. Legislation and directives have to be taken into account as well in decision making concerning different packaging materials. The new environmental law with waste disposal responsibility will also have an effect on the packaging business. Therefore a need has risen to study closer the current offering closer of bio-based materials that could be used in chocolate packaging. In this Master’s Thesis the bioplastics’, and especially biodegradable materials’ technical properties and their development, availability, possible existing products in the markets, waste disposal possibilities and consumers attitude towards environmental friendly packaging is studied. This is a case study where the offering of biodegradable materials was investigated during March 2013 for Fazer Confectionary.

Aqueous-phase reforming of renewables for selective hydrogen production in the presence of supported platinum catalysts

The evolution of our society is impossible without a constant progress in life-important areas such as chemical engineering and technology. Innovation, creativity and technology are three main components driving the progress of chemistry further towards a sustainable society. Biomass, being an attractive renewable feedstock for production of fine chemicals, energy-rich materials and even transportation fuels, captures progressively new positions in the area of chemical technology. Knowledge of heterogeneous catalysis and chemical technology applied to transformation of biomass-derived substances will open doors for a sustainable economy and facilitates the discovery of novel environmentally-benign processes which probably will replace existing technologies in the era of biorefinary. Aqueous-phase reforming (APR) is regarded as a promising technology for production of hydrogen and liquids fuels from biomass-derived substances such as C3-C6 polyols. In the present work, aqueous-phase reforming of glycerol, xylitol and sorbitol was investigated in the presence of supported Pt catalysts. The catalysts were deposited on different support materials, including Al2O3, TiO2 and carbons. Catalytic measurements were performed in a laboratory-scale continuous fixedbed reactor. An advanced analytical approach was developed in order to identify reaction products and reaction intermediates in the APR of polyols. The influence of the substrate structure on the product formation and selectivity in the APR reaction was also investigated, showing that the yields of the desired products varied depending on the substrate chain length. Additionally, the influence of bioethanol additive in the APR of glycerol and sorbitol was studied. A reaction network was advanced explaining the formation of products and key intermediates. The structure sensitivity in the aqueous-phase reforming reaction was demonstrated using a series of platinum catalysts supported on carbon with different Pt cluster sizes in the continuous fixed-bed reactor. Furthermore, a correlation between texture physico-chemical properties of the catalysts and catalytic data was established. The effect of the second metal (Re, Cu) addition to Pt catalysts was investigated in the APR of xylitol showing a superior hydrocarbon formation on PtRe bimetallic catalysts compared to monometallic Pt. On the basis of the experimental data obtained, mathematical modeling of the reaction kinetics was performed. The developed model was proven to successfully describe experimental data on APR of sorbitol with good accuracy.