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Recebido em 22/10/10; aceito em 10/3/11; publicado na web em 5/5/11 CURRENT STAGE OF DEVELOPMENT OF GTL TECHNOLOGY AND PERSPECTIVES FOR BRAZIL. Although the production of liquid fuels from coal, natural gas (CTL and GTL processes) and other carbon sources has been discovered 90 years ago, the interest was renewed in the last years motivated by stranded gas reserves and by petroleum market instability. This review intends to show the scenario of these technologies nowadays, discussing the applied technologies, the steps in an industrial plant, the ways to produce syngas and liquid fuels, the catalysts used, the type of reactors and the operating plants with their respective capacities, besides the technical, economical and environmental viability, challenges and perspectives for Brazil.

A moving bed bioreactor containing cubes of polyether foam immersed in a synthetic wastewater (an aqueous mixture of meat extract, yeast extract, dextrose, meat peptone, ammonium chloride, potassium chloride, sodium chloride, sodium bicarbonate, potassium mono-hydrogen-phosphate and magnesium sulphate) was used to evaluate bacterial growth and biomass yield parameters based on Monod's equation. The wastewater was supplied in the bottom of the equipment flowing ascending in parallel with a diffused air current that provided the mixing of the reactor content. Suspended and attached biomass concentration was measured through gravimetric methods. Good agreement was found between experimental kinetic parameters values and those obtained by other researchers. The only significant difference was the high global biomass content about 2 times the values obtained in conventional processes, providing high performance with volumetric loading rates up to 5.5 kg COD/m³/d

-Filtration under an ultrasonic field is a technique that is gaining importance in the wastewater treatment research field, not only due to its ability as a cleaning mechanism, but also as a filtration intensifier. The main objective of this research was the study of the influence of ultrasonic waves on the filtration of the oilfield wastewater (known as produced water) in order to increase the operation performance and filter medium regenerative effectiveness. A 0.016 m 2 hollow cylindrical porous ceramic filter was submitted to the filtration of produced water by two mechanisms: conventional filtration under vacuum and filtration under the influence of ultrasonic waves. Experiments were carried out using synthetic produced water by analyzing the variables oil and grease content (O&G) and total suspended solids (TSS) for each filtration run. Backwashing of the filter medium with distilled water was also performed to evaluate the regeneration efficiency. During conventional filtration, permeate flux decreased gradually, becoming stable around 0.06 cm 3 .cm -2 .s -1 . Furthermore, in the filtration assisted by ultrasound, the permeate flux was around 0.15 cm 3 .cm -2 .s -1 . Therefore, ultrasonic waves provided an increase of about 150% in the permeate flux. Moreover, the sonication improved filter medium regeneration effectiveness, even under conditions of high TSS and O&G contents. Taking into consideration the very positive results associated with the application of ultrasonic waves, this filtration technique is likely to become an important industrial process.

No presente trabalho, foram estudadas as isotermas de adsorção do CO2 sobre carvão ativado produzido a partir de endocarpo de coco (Cocos nucifera L.) que constitui um resíduo gerado em diversos processos agroindustriais. O carvão sintetizado foi caracterizado por espectroscopia de infravermelho com transformada de Fourier (FTIR), fluorescência de raios X (FRX) e quantificação de grupos ácidos e básicos via método de Boehm. Na obtenção das isotermas de adsorção do CO2 foi utilizada a técnica volumétrica estática em uma coluna de leito fixo de 2 cm de diâmetro interno, 25 cm de altura e volume interno de 138,55 cm3, sob temperatura constante de 24 °C. Os resultados mostraram que a superfície do adsorvente apresentou grupos ácidos, fenólicos, lactonas e básicos. A isoterma de equilíbrio obtida seguiu o comportamento do tipo I da classificação da IUPAC. A capacidade máxima de adsorção de CO2 foi de 64,196 mg.g-1, sob pressão inicial de 3,4 bar e temperatura de 24°C.