Bentonite/polymer compound development to application in drilling fluids: Part 2

The most important bentonite clays sources are placed at Paraíba state, Brazil. These clays are largely used as viscosity agent in drilling fluids. Unfortunately for some kinds of available clay their parameters are far from PETROBRAS standard. Treatments based on polymeric addition consist on method to improve such parameters. In order to improve these parameters, this work proposes a methodology to develop bentonite/polymers compound for use in water based drilling fluids. Besides the raw clay others samples have been evaluated: i) one sample of a commercial bentonite; ii) two samples of carboximethyl cellullose (CMC) and iii) one sample of partially-hydrolyzed polyacrylamide (PAM). Based on experimental planning, ten compositions of polymeric compound (mix of two and three polymers) have been evaluated. For each composition of polymeric compound three different concentrations was added to clay. All experimental fluids have been evaluated accordingly with PETROBRAS standard to determine apparent and plastic viscosity, yield stress, and water loss. The results of the analysis show that by polymeric treatment of bentonite clay with compound polymeric allow to obtain a mixture with improved rheologic properties. Finally, this procedure allows to use low quality bentonite clays for drilling fluids application.Os depósitos de bentonita da Paraíba constituem um dos mais importantes do país. Essas argilas são empregadas, dentre outras aplicações, como viscosificante em fluidos de perfuração. Contudo, atualmente, alguns tipos de argila encontradas nesses depósitos não apresentam os parâmetros exigidos pela PETROBRAS e a aditivação polimérica surge como alternativa para adequar essas propriedades. Sendo assim, este trabalho objetiva o desenvolvimento de compostos bentonita/polímeros para uso em fluidos de perfuração à base de água. Para tanto, foram estudadas uma amostra de argila bentonítica sódica industrializada da Paraíba, Brasil, duas amostras de carboximetilcelulose (CMC) e uma amostra de poliacrilamida (PAM). O dimensionamento do composto polimérico (misturas de dois e três polímeros) foi elaborado por meio do planejamento experimental, sendo estudadas dez diferentes composições. Os compostos poliméricos, em três diferentes concentrações, foram misturados à argila seca. Em seguida, foram preparados os fluidos de perfuração e determinadas as viscosidades aparente e plástica, o limite de escoamento e o volume de filtrado de acordo com as normas da PETROBRAS. Os resultados das análises mostraram que a aditivação da bentonita com o composto polimérico permite obter uma mistura com melhores propriedades reológicas e de filtração. Finalmente, esse procedimento permite o uso de argilas bentoníticas de qualidade inferior em fluidos de perfuração de poços de petróleo.20921

Surface Morphology Of A Catalytic Wall Microreactor Constructed By Direct Metal Laser Sintering Process

Micro-reactors technology have attracted considerable interest in chemical processing due to their potential advantages regarding improvements on mass and heat transfer, smaller size, energy and cost saving and safety. Various types of micro-structured reactors have been developed in the last decade. Among them, the most promising concept considers stacked systems of channelled metallic platelets, coated with active catalysts. This systems are fabricated using any traditional tooling, but in this work a relatively new technology enabling that three-dimensional parts can be easily fabricated was used. It is based on DMLS (Direct Metal Laser Sintering), a process that uses a metal powder and a laser beam to produce directly metal parts. This process is one of a few Rapid Prototyping (RP) technologies which possess the capability to produce metal parts and prototype tools directly from powders with a high precision. In this paper a micro-channels plate was fabricated using DMLS process and micro-channels surface for catalyst deposition was evaluated. The results of SEM study reveal that a porous surface on the walls was formed because powder was not wholly sintered. For microchannels plate applied for gas-phase reactions this porous surface is especially interesting because the surface area is increased and the mass of catalysts impregnated on the walls can also be increased, which consequently improves the conversion of products. Thus, the DMLS not only can facilitates the rapid development of catalytic wall microreactors, but also permit the control of the structures formed during sintering which are extremely relevant for some processes in micro-reactors for gas and liquid phase. © 2011, AIDIC Servizi S.r.l.24223228Cai, W., Wang, F., Van Veen, A., Descorme, C., Schuurman, Y., Shen, W., Mirodatos, C., Hydrogen production from ethanol steam reforming in a micro-channel reactor (2010) International Journal of Hydrogen Energy, 35, pp. 1152-1159(2009) EOSint M 270 User Manual, , EOSGu, D., Shen, Y., Processing conditions and microstructural features of porous 316L stainless steel components by DMLS (2008) Applied Surface Science, 255, pp. 1880-1887Hessel, V., Lowe, H., Müller, A., Kolb, G., (2005) Chemical Micro Process Engineering: Processing and Plants, , Wiley-VCH, WeinheimJardini, A.L., Costa, M.C.B., Bineli, A.R.R., Romao, A.F., Filho, R.M., Operability analysis and conception of microreactor by integration of reverse engineering and rapid manufacturing (2008) Computer Aided Chemical Engineering, pp. 853-858Khaing M.W, Fuh J.Y.H, Lu, L., Direct metal laser sintering for rapid tooling: Processing and characterisation of EOS parts (2001) Journal of Materials Processing Technology, 113 (1-3), pp. 269-272. , DOI 10.1016/S0924-0136(01)00584-2, PII S0924013601005842Kiwi-Minsker, L., Renken, A., Microstructured reactors for catalytic reactions (2005) Catalysis Today, 110, pp. 2-14Kolb, G., Schurer, J., Tiemann, D., Wichert, M., Zapf, R., Hessel, V., Lowe, H., Fuel processing in integrated micro-structured heat-exchanger reactors (2007) Journal of Power Sources, 171 (1), pp. 198-204. , DOI 10.1016/j.jpowsour.2007.01.006, PII S0378775307000997, Scientific Advances in Fuel Cell SystemsMen, Y., Kolb, G., Zapf, R., Hessel, V., Lowe, H., Ethanol steam reforming in a microchannel reactor (2007) Process Safety and Environmental Protection, 85 (5 B), pp. 413-418. , DOI 10.1205/psep07015Senthilkumaran, K., Pandey, P.M., Rao, P.V.M., Influence of building strategies on the accuracy of parts in selective laser sintering (2009) Materials & Design, 30, pp. 2946-295

Computer Simulation Of Hydrolytic Polymerization Of Sls Nylon 6 To Correlate Polymer Characteristics And Operational Parameters

In recent years, numerical simulation and optimization of chemical reactors in general, and polymerization reactors in particular, have become increasingly popular as a means of understanding the behavior of reactors and improving their performance. The commercial importance of Nylon 6 has stimulated a considerable amount of research directed towards the modeling and simulation of its polymerization through the hydrolytic route in various industrial reactors. Computer simulations based on the mathematical modeling of the polymerization process are of paramount importance for quality control and operational optimization of the existing plant, as well as in the design of similar new plants. The major objective in this work will be to apply modeling and simulation tools for development of new application for Nylon 6. The intention is to be able to correlate reaction parameters and operational parameters (as monomer concentration, water and additives, operational temperature), to final desired properties of the obtained polymer - especially to molecular weight (aiming the polymer production matching specifications to a desired application). In addition, that correlation analysis allows evaluating the variation on polymers production rate - (higher production that minimizes production costs). To make possible to meet such objectives its coupled experimental design procedure together with the nylon reactor mathematical modeling and literature information. The developed procedure showed to be an interesting and important tool to develop products with the required specification whereas keeping lower production costs. © 2009 Elsevier B.V. AU rights reserved.27C11071112Giori, C., Hayes, B.T., Hydrolytic polymerization of caprolactam. I. HydrolysisPolycondensation kinetics (1970) J. Polym. Sci, Polym. Chem. Ed., 8, pp. 335-349Agrawal, A.K., Devika, K., Manabe, T., Simulation of hydrolytic polymerization of nylon-6 in industrial reactors: Part I. Mono-acid-stabilized systems in VK tube reactors (2001) Industrial and Engineering Chemistry Research, 40 (12), pp. 2563-2572Gupta, S.K., Kunzru, D., Kumar, A., Simulation of nylon 6 polymerization in tubular reactors with recycle (1983) Journal of Applied Polymer Science, 28 (5), pp. 1625-1640. , DOI 10.1002/app.1983.070280507Gupta, A., Gupta, S.K., Ghandi, K.S., Mehta, M.H., Padh, M.R., Soni, A.V., Ankleswaria, B.V., Modeling of hydrolytic polymerization in a semi-batch nylon-6 reactor (1992) Chem.Eng. Commun., 113, pp. 63-89Seavey, K.C., Khare, N.P., Liu, Y.A., A. new phase-equilibrium, model for simulating industrial nylon-6 production trains (2003) Ind. Eng. Chem. Res., 42, pp. 3900-3913Tai, K., Teranishi, H., Tagawa, T., Kinetics of hydrolytic polymerization of ε- Caprolactam: 3. Formation of cyclic dimmer (1981) Polymer, 22, pp. 273-277Gupta, S.K., Kumar, A., (1987) Reaction Engineering of Step-growth Polymerization., p. 190. , Plenum Press: New Yor