BIODIESEL DIDACTIC PLANT AND INDUSTRIAL SIMULATION

Transcription

1 BIODIESEL DIDACTIC PLANT AND INDUSTRIAL SIMULATION Alex N. Brasil 1, Leandro S. Oliveira 2, Karla T. Kucek 3 Abstract Planning, designing and building teaching equipment in universities, by research groups, reflects a Brazilian need on the development of technologies in various sectors, enabling the development and improvement of products, reduction of costs, and aggregation of financial and intellectual values to the "Made in Brazil manufacturing. This paper presents the study, design, procedure for construction and operation of a model plant of industrial-scale biodiesel, consisting of a collaboration solution for procurement of equipment related to training and studies for biofuel production. The Project refers to a system and process for production of biodiesel in a didactic and small-volume, providing a reaction system and process which simulates the conditions and characteristics existing in industrial production of biodiesel, making it possible to study knowledge and control of important process variables. By having transparent borosilicate glass, high strength tanks, it makes it possible to monitor, from an educational perspective, all stages of the process and, and considering the small volume processed, it provides a savings in the use and consumption of reagents and supplies, besides being easily transported and allocated in confined spaces. Index Terms Biodiesel, biofuel production, biodiesel unit, didactic biodiesel plant. 1 Alex N. Brasil, Programa de Pós-Graduação em Engenharia Mecânica-UFMG / FAEN-Universidade de Itaúna, brasil@uit.br 2 Leandro S. Oliveira, Departamento de Engenharia Mecânica-UFMG, leandro@demec.ufmg.br 3 Karla T. Kucek, Biominas Engenharia de Energias, karla@biominas.ind.br 1

2 INTRODUCTION Brazil has great potential for generating energy from biomass resources due to favorable soil and climatic development of various crops [1]. The search for new bioenergy sources and further escalation is necessary to transmute the research labs to companies, performing the cycle of R&D technology. Biodiesel is a biofuel derived from renewable biomass for use in internal combustion engines with compression ignition or as rules for generating other types of energy, which can partially or totally substitute fossil fuels. It is a clean burning alternative fuel produced from domestic resources, and it is renewable. Biodiesel contains no petroleum, is biodegradable, nontoxic and essentially free of sulfur and aromatic compounds [3]. Biodiesel is chemically defined as the alkyl monoesters of long chain fatty acids derived from renewable feedstocks such as vegetable oils, animal fats and recycled cooking oil. The most widely known process consists of a chemical reaction in which the triacylglycerides (TAGs) found in these fatty materials (e.g., soybean oil) combine with an alcohol (methanol or ethanol) in the presence of an alkaline catalyst (usually NaOH, KOH and their alkoxides) to produce alkyl monoesters (biodiesel) and glycerin. As a co-product, glycerin has little or no fuel value but its several industrial applications are critical to support the economics of the process. Nowadays in Brazil, there are some companies that have technology to build biodiesel plants with high aggregate technology, selling plants with high production capacity, from 1000 liters/day; the final prices that exceed of $300, (three hundred thousand dollars), which makes impossible the acquisition of such equipment by small farmers, settlers and academic research groups [4]. The development and use of a teaching module for biodiesel production, are inserted in an effort directed towards improving the teaching disciplines of renewable energies given in undergraduate courses in engineering from the University of Itaúna. The perceived importance of the experimental study, particularly for biofuels, in undergraduate courses is reinforced face the current context in terms of generation and utilization of energy [2]. 2

3 Making use of the module teaching of biofuels, it becomes possible to perform scheduling of experimental studies of biodiesel production and it can easily vary the types of oils, alcohols and catalysts used in the process. Both the laboratory and the teaching plant were built in the same spirit of using equipment that has ease of operation, transportation, installation and maintenance. Therefore, this paper aims to disseminate information about the design, construction and assembly of a didactic model for biodiesel plant at low cost and easy operation, capable of producing six (6) liters of biodiesel per batch. The process of transesterification may use any vegetable oil or animal fats through the routes methyl or ethyl. The proposal of designing and building a plant to produce biodiesel on a small scale follows the philosophy of having to use a low equipment cost, relative to those industrial domestic or imported, easy to use and easy to be transported. Mobility and ease of use were primary factors for the development of the project. MATERIALS AND METHODS The plant producing biodiesel on a small scale followed the philosophy of having to use a low equipment cost, relative to those industrial national or imported, equipments, which are easy to use and easy to be transported. The reactor is capable of producing up to six (6) liters of biodiesel per batch, which allows its use in structures that can be assembled in biofuel analysis and production laboratories. The didactic plant, showed on Figure 1, was designed to work with any type of oilseed including oils from food frying processes. In the specific case we have the initial proposal to work with the following oils: soybean, sunflower, jatropha, palm, rapeseed, crambe and their mixtures [1]. The ethyl and methyl alcohols are used as reagents in the process, giving priority to ethanol because it comes from renewable sources and because Brazil has a large availability of this input. As catalysts, there has been the proposal to work with NaOH and sodium methoxide (30%) as it is already being used in the synthesis bench, not preventing that other catalysts may be used. 3

4 FIGURE. 1 Photo of biodiesel didactic and simulation plant. In the design of the plant there have been considered several factors directly linked with the technical and economical process of producing biodiesel. It was also taken into consideration the compatibility of materials used in pipes, fittings, registers, making the tanks. Figure 2 shows the schematic drawing of the scale model, identifying its various equipments and tanks. The didactic module in question was designed and built as a basic parameter and the need for a versatile equipment which could be used in conventional classrooms. Thus, we observed the following aspects to the equipment mechanical design: 4

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6 FIGURE. 2 Technical drawing of the didactic biodiesel plant. (1) Electric panel of central control: it allows the actuation of pumps, engines, equipment and flow system of compressed air and vacuum. It activates the distiller, mechanical stirrer and the reactor heating the reactor, it has digital temperature controller that allows the monitoring of the temperature process. For safety reasons, the electric panel has digital voltmeter that informs the voltage available to the plant and emergency button; (2) Alcohol and a catalyst tank: built in 304 stainless steel tube, receives the alcohol and catalyst which will be directed to the reactor by gravity; (3) Reactor: tank which holds the mixture of alcohol (ethanol or methanol), catalyst (NaOH, KOH or sodium methoxide 30%) and vegetable oil. The transesterification reaction is carried out with the aid of a mechanical shaker (4) naval propeller shaft with controlled temperature. The heating is accomplished by electrical resistance measurement and the dry and temperature control via thermocouple connected to digital temperature controller. The reactor is in cylindrical body type borosilicate glass of high resistance, with support flanges in 304 stainless steel and Viton seals; (4) Stirrer shaft with mechanic propeller naval and variable rotation: rpm; (5) First decanter: a cylindrical body type borosilicate glass of high resistance, with support flanges of 304 stainless steel and Viton seal. It has flow control valves to 6

7 adjust the injection of compressed air. Feeding of the mixture over the top and two outputs controlled by manual ball valve (304 stainless), a bottom for removal of heavy phase (glycerin) and the other side, for submission of biodiesel processing to the next stage of distillation; (6) Reflux condenser: it has the function to prevent loss of alcohol by evaporation during the reaction stage; (7) First centrifugal pump: with volute and rotor in stainless steel 304, transferring the reactor volume to the next step of decanting or distillation; (8) Glycerin tank:, built in stainless steel tube 304, which is intended to store and separate the glycerin produced in the process, which can be directed to the primary purification distiller, fueled by the top and exhausted from the bottom-controlled ball valve; (9) Distiller and heat exchanger: heating system with thermal oil, jacketed, with controlled temperature and time set by programmable logic controller (PLC). Feeding the mixture into the upper side and two outputs controlled by manual ball valve (304 stainless). Bottom outlet to the next destination of biodiesel purification step for removal and higher recovered alcohol. Coupled to this a vacuum pump to remove the alcohol vapor from the atmosphere of evaporation; (10) Alcohol vessel: "flask" type borosilicate glass with the superior side exit for coupling of the vacuum pump and top entry for targeting alcohol recovered in the distiller; (11) Vacuum and compressed air pump: it is intended to promote vacuum in the alcohol vessel in order to low the boiling temperature and thus favoring the distillation of alcohol. It also has the function to provide a positive pressure during the process of purifying biodiesel. (12) Second centrifugal pump: with volute and rotor in steel 304, it transfers biodiesel from distillers to the next stage of phase separation (decanting); (13) Second decanter: a cylindrical body type borosilicate glass of high resistance, with support flanges of 304 stainless steel and Viton seal. It has flow control valves to adjust the injection of compressed air. Feeding of the mixture over the top and two outputs controlled by manual ball valve (304 stainless), a bottom for removal of heavy phase (glycerin), and another top forward to the biodiesel processing to step purification; 7

8 (14) Air filter: it aims to remove the impurities in the air during the pressurization of the second decanter; (15) First dry wash column: in 304 stainless steel tube with displays properly positioned to monitor the process of purifying biodiesel and saturation of the resin contained therein. With access to the top and bottom feeding and removal of ion exchange resin. On the top tube of nylon attached by connector "quick release", exit at the bottom driven flow control valve. The flow of crude ester in the columns is continuous and the flow is provided by compressed air supplied by compressor blades; (16) Second dry wash column: as to the first column, working in series with the same; (17) Fuel filter: designed to retain any residual resin derived from the process of purifying biodiesel; (18) Tank of biodiesel: a cylindrical body type borosilicate glass of high resistance, with support flanges of 304 stainless steel and Viton seal. The feeding of the purified biodiesel is at the top and there is a bottom outlet controlled by manual ball valve (304 stainless) for biodiesel removal after the purification step; (19) Modular structure: made of carbon steel for attachment of tanks and equipment Biodiesel Plant Simulation Curriculum and Industrial; (20) Lugs used for the lifting of the plant during its transportation; (21) Mobile platform equipped with casters for easy movement within the plant laboratories; (22) Exhaust system: consisting of two axial exhaust fans; it has the function to prevent the entry of alcohol vapor in the box of bombs in the event of a leak; (23) Toolbox: store the tools necessary for proper operation and maintenance of the plant; (24) Box of bombs: an enclosed and equipped box with hoods to protect centrifugal pumps and vacuum. Mechanical Design Carbon steel was used to construct the modular structure. Due to the physicochemical properties of biodiesel, the entire line of hydraulic circuit was designed and developed in 304 stainless steel and nylon hose. Because the didactic plant operates in 8

9 batch, ball valves were designed to control the flow of fluids during the process. The transport of liquids in the plant is performed by centrifugal dimensional pumps for that purpose. Chemical project The reactor was designed for 6 liters of oil, having a volume of 8.5 liters and includes responses with molar ratios up to 6:1 (alcohol: oil). May be considered as reactive process: oil, alcohol and catalyst. To facilitate viewing and provide better monitoring of the process, the bodies of the reactor, and two decanters and a tank of biodiesel were designed and constructed in borosilicate glass Duran 90. The agitation of the solution is given by a mechanical shaker for semi-viscous fluids. The heating is accomplished through tubular resistance encapsulated and automatic temperature control. The system of separation and purification of biodiesel takes place initially by gravity through decanter tanks to separate the ester and glycerin. The withdrawal of the alcohol used in excess in the reactions can be made through distiller with a capacity of 9 liters per batch. Finally, the final purification of the ester (biodiesel) and alcohol (recovered) is given by column purification system that can be supplied with commercial adsorbents or developed in the laboratory. RESULTS AND DISCUSSION Through theoretical and practical knowledge, design and implementation was possible to develop the project of didactic plant, extending the range of options for research in laboratories at a cost affordable and providing results that allow the scheduling result bench for semi-industrial. Because of their mobility, convenience and versatility, the didactic plant enables the study variables such as molar ratios, types of oils, distillation, purification of type "Dry Wash", etc. kinetics of the reactions. 9

10 CONCLUSIONS The University of Itaúna Renewable Energy Group (ENERBIO), comes optimizing the processes of production of Biodiesel from various vegetable oils (soybean, sunflower, jatropha, crambe, etc.), and fresh and waste animal fats by both route methyl, ethyl as the collaboration of the laboratories of biofuels, UFMG, the research group G- Óleo/UFLA and the institution itself. The "Know-how acquired opens the way for new projects in the medium term and will form an interdisciplinary cooperative culture that can allow an effective increase in knowledge and development. In addition, the presentation of the methodology used to design the equipment as well as the steps to the physical construction of the model are several contributions that will enable schools to build a similar equipment, low cost and tailored to their needs and potential. REFERENCES [1] ANAIS DO 2º CONGRESSO DA REDE BRASILEIRA DE TECNOLOGIA DE BIODIESEL. Anais Vol. I e II. Brasília, MCT/ABIPTI, [2] BRASIL, A.B. et al. Projeto e Construção de um Modelo de Turbina Pelton em Escala Reduzida. II Congresso Nacional de Engenharia Mecânica, João Pessoa, Brasil, Ago. 2002, pp [3] MACEDO, I.C. ; NOGUEIRA, L.A.H. Biocombustíveis. Núcleo de Assuntos Estratégicos da Presidência da República, Cadernos NAE, Brasília, Brasil, Jan. 2005, 235p. [4] MACEDO, I.C. ; NOGUEIRA, L.A.H. Diretrizes de Política de Agroenergia Ministério da Ciência e Tecnologia, Ministério de Minas e Energia, Brasília, Brasil, 2006, 34p. [5] NASCIMENTO, U.M. et al. Montagem e Implantação de Usina Piloto de Baixo Custo para Produção de Biodiesel. 1º Congresso da Rede Brasileira de Tecnologia de Biodiesel, Brasília, Brasil, Ago. 2006, p [6] RESUMOS DO 5º CONGRESSO BRASILEIRO DE PLANTAS OLEAGINOSAS, ÓLEOS, GORDURAS E BIODIESEL. 5º Congresso Brasileiro de Plantas oleaginosas, Óleos, Gorduras e Biodiesel. Lavras: UFLA,