yes / In all industrial petrochemical plants and refineries, the furnace is the source of heat resulting from fuel combustion with air. The model-based furnace simulation is considered one of the efficient methods help to reduce the energy loss and maintain fixed refinery revenues, conserving energy, and finally reducing external fuel consumption and total fuel cost. In this paper, a model-based simulation is carried out for a natural air draught industrial scale furnace related to Liquified Petroleum Gas (LPG) production plant in Libya to thoroughly investigate the most responsible factors in lowering the furnace butane exit temperature, which is supposed to be two degrees Fahrenheit higher than inlet temperature. Therefore, to resolve this industrial problem, Aspen Hysys V10, coupling with EDR (exchanger design and rating) is used to carry out rigorous model-based simulation. This is specifically used to assess the impact of heat loss from inside the firebox to the surrounding medium and heat loss from the furnace stack and walls, besides the effect of excess air on the furnace efficiency. Furthermore, this research intends to verify whether the operating conditions, such as furnace tubes inlet flow rate, temperature and pumping pressure, are conforming to the upstream process design specifications or need to be adjusted. The results confirm that increasing furnace outlet temperature two degrees Fahrenheit from off specification 190 °F instead of 184 °F is successfully achieved by decreasing upstream stream flowrate 25% below the operating value and cutback excess air gradually until 20%. Also, the results clarify the necessity of increasing the flue gas temperature by 7% over design condition, to gain a significant reduction of heat loss of 31.6% and reach as low as 35.5 MBtu/hr. This improvement is achieved using optimum operating conditions of an excess air of 20%, and flue gas oxygen content of 3.3% delivered to stack. Accordingly, the furnace efficiency has been increased by 18% to hit 58.9%. Furthermore, the heat loss from the furnace walls can be also reduced by 68% from 5.41 MBtu/hr to 1.7 MBtu/hr by increasing the refractory wall thickness to 6 in., which entails an increase in the furnace efficiency by 3.66% to reach 58.96%. Decreasing the heat loss fraction through the refractory wall, pip doors, expansion windows and refractory hair cracks would also increase the efficiency by 21% to reach a high of 59.7%. Accordingly, a significant reduction in daily fuel consumption is observed, which costs 1.7 M$ per year. The outcomes of this research clearly show the potential of reducing the operation and maintenance costs significantly.

Planning, scheduling and real time optimization (RTO) are currently implemented by using different types of models, which causes discrepancies between their results. This work presents a single model of a crude distillation unit (preflash, atmospheric, and vacuum towers) suitable for all of these applications, thereby eliminating discrepancies between models used in these decision processes. Hybrid model consists of volumetric and energy balances and partial least squares model for predicting product properties. Product TBP curves are predicted from feed TBP curve, operating conditions (flows, pumparound heat duties, furnace coil outlet temperatures). Simulated plant data and model testing have been based on a rigorous distillation model, with 0.5% RMSE over a wide range of conditions. Unlike previous works, we do not assume that (i) midpoint of a product TBP curve lies on the crude distillation curve, and (ii) midpoint between the back-end and front-end of the adjacent products lies on the crude distillation curves, since these assumptions do not hold in practice. Associated properties (e.g. gravity, sulfur) are computed for each product based on its distillation curve. Model structure makes it particularly amenable for development from plant data. High model accuracy and its linearity make it suitable for optimization of production plans or schedules. / Thesis / Master of Applied Science (MASc)

Ph. D. Thesis / In order to compute more realistic production plans and schedules, techniques using nonlinear programming (NLP) and mixed-integer nonlinear programming (MINLP) have gathered a lot of attention from the industry and academy. Efficient solution of these problems to a proven ε-global optimality remains a challenge due to their combinatorial, nonconvex, and large dimensionality attributes. The key contributions of this work are: 1) the generalization of the inventory pinch decomposition method to scheduling problems, and 2) the development of a deterministic global optimization method. An inventory pinch is a point at which the cumulative total demand touches its corresponding concave envelope. The inventory pinch points delineate time intervals where a single fixed set of operating conditions is most likely to be feasible and close to the optimum. The inventory pinch method decomposes the original problem in three different levels. The first one deals with the nonlinearities, while subsequent levels involve only linear terms by fixing part of the solution from previous levels. In this heuristic method, infeasibilities (detected via positive value of slack variables) are eliminated by adding at the first level new period boundaries at the point in time where infeasibilities are detected. The global optimization algorithm presented in this work utilizes both piecewise McCormick (PMCR) and Normalized Multiparametric Disaggregation (NMDT), and employs a dynamic partitioning strategy to refine the estimates of the global optimum. Another key element is the parallelized bound tightening procedure. Case studies include gasoline blend planning and scheduling, and refinery planning. Both inventory pinch method and the global optimization algorithm show promising results and their performance is either better or on par with other published techniques and commercial solvers, as exhibited in a number of test cases solved during the course of this work. / Thesis / Doctor of Philosophy (PhD) / Optimal planning and scheduling of production systems are two very important tasks in industrial practice. Their objective is to ensure optimal utilization of raw materials and equipment to reduce production costs. In order to compute realistic production plans and schedules, it is often necessary to replace simplified linear models with nonlinear ones including discrete decisions (e.g., “yes/no”, “on/off”). To compute a global optimal solution for this type of problems in reasonable time is a challenge due to their intrinsic nonlinear and combinatorial nature. The main goal of this thesis is the development of efficient algorithms to solve large-scale planning and scheduling problems. The key contributions of this work are the development of: i) a heuristic technique to compute near-optimal solutions rapidly, and ii) a deterministic global optimization algorithm. Both approaches showed results and performances better or equal to those obtained by commercial software and previously published methods.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-06-30T19:19:44Z No. of bitstreams: 1 Sergio Satt Junior.pdf: 2776264 bytes, checksum: de08438865c711b12dacc3721b268331 (MD5) / Made available in DSpace on 2015-06-30T19:19:44Z (GMT). No. of bitstreams: 1 Sergio Satt Junior.pdf: 2776264 bytes, checksum: de08438865c711b12dacc3721b268331 (MD5) Previous issue date: 2012-07-06 / Nenhuma / O ambiente empresarial atual apresenta determinados eventos de alta incerteza e de difícil previsibilidade, é necessário que as empresas e seus gestores estejam preparados para atuar em novos e diferentes ambientes de negócios. A mudança no ambiente do refino de petróleo no Brasil iniciou com a abertura do mercado de combustíveis em 1997, Lei 9.478/97. Essa lei propiciou a participação de outros agentes, além da Petrobras, no exercício das atividades de importação e exportação de derivados de petróleo. O segmento de refino no Brasil tem apresentado ciclos de baixa e alta, pois os preços dos derivados nas refinarias não têm sido reajustados na mesma velocidade dos movimentos de preços dos derivados no mercado internacional. Com isso, as refinarias não integradas, é o caso estudado neste trabalho - a Refinaria de Petróleo Riograndense, têm apresentado menor rentabilidade se comparadas com refinarias integradas. Portanto, é necessário identificar eventuais vantagens competitivas que permitam sustentar o negócio deste tipo de refinaria a partir de uma perspectiva de longo prazo. Para tal, foi aplicado o método de construção de cenário Global Business Network (GBN), a fim de criar cenários futuros que apontem alternativas de atuação para uma refinaria de petróleo de baixa escala e não integrada. Além disso, verificar quais as contribuições que o método de construção de cenários GBN trouxe para a empresa e seus gestores. A pesquisa foi caracterizada como qualitativa, exploratória, utilizando o método pesquisa-ação para descrever melhor a construção dos cenários na empresa pesquisada. O resultado da pesquisa foi a geração de dois cenários futuros para a Refinaria Riograndense, onde se apresentam caminhos distintos de atuação no segmento de refino, considerando o ambiente futuro dos negócios e as características da empresa, ou seja, refinaria de petróleo de baixa escala e não integrada. As conclusões do trabalho indicam que o método de construção de cenário GBN contribui para melhorar a percepção da empresa e dos seus gestores sobre o ambiente do futuro do negócio, reduzindo erros no processo de tomada de decisão. Com isso, foi possível apontar caminhos futuros de sobrevivência para a empresa em um ambiente de forte competitividade e restrições ambientais. Também, o método GBN mostrou-se ser flexível às características da empresa, permitindo valorizar os conhecimentos e experiências dos gestores, bem como incentivar o envolvimento dos gestores no processo de construção de cenários. / In the current business environment, there are certain events with high uncertainty that make predictability difficult; thus, companies and their managers must be prepared to act in new and different business environments. Changes in the environment of oil refining in Brazil began with the opening of the fuel market in 1997, since Law 9,478/97 enabled other agents, in addition to Petrobras, to participate in activities related to the import and export of oil products. The refining segment in Brazil has experienced cycles with low and high prices because they have not been adjusted at the same speed as the ones of oil products in the international market. From this perspective, non-integrated refineries were analyzed in this study, mainly the Riograndense Oil Refinery, which has shown lower profitability than integrated ones. Therefore, potential competitive advantages that enable the business to support this type of refinery in the long term were identified. The method of building Global Business Network (GBN) scenarios was applied in order to create future scenarios which can suggest alternatives to a small-scale and non-integrated oil refinery. Besides, the contributions that the method of building GBN scenarios brought to the company and its managers were verified. This qualitative and exploratory research used action research to better describe scenario building in the company. Results generated two scenarios (Maverick and Revolution) for the future of the Riograndense Refinery; they showed distinct paths to be followed in the refining segment, taking into consideration the future of the business environment and the characteristics of the company, i. e., a small-scale and non-integrated oil refinery. The study concludes that the method of constructing GBN scenario helps to improve the perception of the company and its managers about the future of the business environment, reducing errors in the process of decision making. In addition, future directions for the company to survive in an environment with strong competition and environmental constraints could be identified. Furthermore, the GBN method proved to be flexible concerning the characteristics of the company since it valued managers’ knowledge and experience and encouraged them to get involved in the process of scenario building.

Thesis (MBA)--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The Chevron Cape Town refinery was constructed in 1996 with a crude capacity of 100,000 barrels per day (bpd). The focus of the unit is production and meeting the nameplate market demand. The project environment for the refinery is that of maintenance and gradual upgrade. The majority of projects handled are small capital projects. The aim of this research is to identify what the success criteria for project management should be for projects carried out within the small capital projects department of Chevron's Cape Town refinery. An important distinction to make is that this study looks at project management success and not project success, although the aspects of project success will be discussed to highlight how closely related the two concepts are. Project success is not directly proportional to project management success and neither is project management success directly proportional to project success. In the past decades, project management success was usually indicated by the project completion within the time, cost and performance constraints (Kerzner, 2004:29). This has now evolved to understanding all the objectives of the project. Project management can still be deemed successful even if it did not meet all the objectives of the project and vice versa, as long as there are mutual trade-offs agreed to by the developer (project manager) and the client. White and Fortune (2002:1-11) conducted a survey to identify common criterion used for defining project management success. The three criteria identified for judging project success are completion on time, within the budget and to performance (specification). Project management success has been found to be a very difficult topic to define. This research report shown that project management success needs to be moved beyond the iron-triangle to other criteria like safety and meeting the objectives of the client. What was evident was that criteria, factors, dimensions and measures are concepts widely used by researchers and it is hoped that these topics. A very interesting discovery during my first interview was that project management success comes in three phases or parts, which are pre-delivery, delivery and post-delivery. What was evident from this research was that the criteria for project management success need to be established up front before the project gets to the delivery phase. There is no way that one can measure project management success when the success criteria one is looking for at the end of the project have not been established up front. The case study is summarised using the diagram in chapter five showing the new project management success criteria that needs to be adopted by the refinery. Future research into project management success criteria could include a survey which could go out the whole refinery and not just the representative sample who were interviewed for this report which could confirm the project management criteria found in this report. / AFRIKAANSE OPSOMMING: Die Chevron Kaapstad raffinadery is in 1996 gestig met 'n ruolie kapasiteit van 100,000 vate per dag. Die fokus van die eenheid is produksie en om aan die marknavraag te voldoen. Die projekomgewing van die raffinadery is instandhouding en mettertydse opgradering van die raffinadery. Die meerderheid van projekte wat hanteer word is klein-kapitaalprojekte. Die doel van hierdie navorsing is om te identifiseer wat die sukseskriteria vir projekbestuur behoort te wees vir projekte wat binne die klein-kapitaaldepartement van Chevron se Kaapstad raffinadery behartig word. 'n Belangrike onderskeid om te maak is dat hierdie studie na projekbestuursukses kyk en die projeksukses nie, alhoewel die aspekte van projeksukses ook bespreek sal word om uit te lig hoe naby verwant die twee konsepte aan mekaar is. Projeksukses is nie direk proporsioneel tot projekbestuursukses nie en omgekeerd. In die afgelope dekades was projekbestuursukses gewoonlik aangedui deur die afhandeling van die projek binne die tydsraamwerk, koste en prestasiebeperkinge (Kerzner, 2004:29). Hierdie konsep het intussen uitgebrei na 'n verstaan van al die doelwitte van die projek. Projekbestuur kan steeds as suksesvol beskou word al het dit nie aan al die doelwitte van die projek voldoen nie, en omgekeerd, solank as wat daar wedersydse toegewings deur beide die ontwikkelaar (projekbestuurder) en die kliënt gemaak word. White en Fortune (2002:1-11) het 'n opname gemaak om die algemene kriteria te identifiseer wat gebruik word om projekbestuursukses te definieer. Die drie kriteria wat uitgewys is om 'n projek te evalueer, is afhandeling van die projek binne die tydsraamwerk, koste en prestasiebeperkinge. Projekbestuursukes is 'n baie moeilike onderwerp om te definieer. Hierdie navorsingsverslag wys dat projekbestuursukses verby die “yster-driehoek” moet beweeg om ander kriteria soos veiligheid en die voldoening aan die kliënt se doelwitte, in te sluit. Wat duidelik na vore gekom het is dat kriteria, dimensies en metings konsepte is wat wyd deur navorsers gebruik word. 'n Baie interessante ontdekking gedurende die eerste onderhoud was dat projekbestuursukses in drie fases of dele voorkom, naamlik voor-lewering, lewering en na-lewering. Wat duidelik uit die navorsing is, is dat die kriteria vir projekbestuursukses voor die aanvang van 'n projek vasgestel moet word, voordat die projek die afleweringsfase bereik. Daar is geen manier wat projekbestuursukes gemeet kan word wanneer die sukseskriteria wat aan die einde van 'n projek gesoek word, nie aan die begin vasgestel is nie. Die gevallestudie word opgesom deur die diagram in hoofstuk vyf te gebruik wat die nuwe projekbestuursukseskriteria aandui wat deur die raffinadery aanvaar moet word. Toekomstige navorsing in projekbestuursukseskriteria kan 'n opname insluit wat aan die hele raffinadery gestuur kan word en nie net die verteenwoordigende steekproef met wie daar vir hierdie verslag se doeleindes onderhoud gevoer is om die projekbestuurkriteria van hierdie verslag te bevestig nie.

The State of Kuwait has three large refineries, namely, Mina Al Ahmadi Refinery, Mina Abdullah Refinery and Shuaiba Refinery. These refineries process and refine Kuwait Crude Oil through different process units. There are many heaters, boilers and flares that form a part of the complicated equipment which enhance the different petroleum processes. Fuel gas is used as a firing fuel for those heaters and boilers. As a result, stack emissions like SO2, NOx, CO are predominantly present in the flue gases and this study focuses on those emissions and their impact on the surrounding residential area. The area of interest will be Umm Al-Hyman residential area. This study accumulates emission inventories from the three refineries and the respective ground level concentration of the pollutants in the neighboring residential area. It also focuses on the impact of emissions from the refinery operations on the ground level concentrations in the surrounding areas by using the inventory model and latest emission factors to provide accurate emission estimates. The models were developed and the results were verified with the actual data from the area of impact. As a result of the findings of the major pollutants, namely SO2, NOx & CO, it is found that SO2 and CO are not exceeding Kuwait EPA Ambient Air Quality Standards for Residential Areas normally. However, NOx is observed to exceed occasionally. Even though, NOx emissions from refineries sources represented by plume models were much less, there is a consistent increase in the measured NOx. Furthermore, in 2007, the measured hourly, daily and annual NOx concentration exceeded the international standard many times. The increasing trend in NOx is attributed to continuous increase in population and the number of motor vehicles. The study will go further step in recommending engineering solutions and best practices to reduce the pollutants concentrations which will help in the reduction of human health risks and protect the environment.

Petroleum refineries emit a variety of airborne substances which may be harmful to human health. HEIDI II (Health Effects Indicators Decision Index II) is a computer-based decision analysis tool which assesses airborne emissions from Canada's oil refineries for reduction, based on ordinal ranking of estimated health impacts. The model was designed by a project team within NERAM (Network for Environmental Risk Assessment and Management) and assembled with significant stakeholder consultation. HEIDI II is publicly available as a deterministic Excel-based tool which ranks 31 air pollutants based on predicted disease incidence or estimated DALYS (disability adjusted life years). The model includes calculations to account for average annual emissions, ambient concentrations, stack height, meteorology/dispersion, photodegradation, and the population distribution around each refinery. Different formulations of continuous dose-response functions were applied to nonthreshold-acting air toxics, threshold-acting air toxics, and nonthreshold-acting CACs (criteria air contaminants). An updated probabilistic version of HEIDI II was developed using Matlab code to account for parameter uncertainty and identify key leverage variables. Sensitivity analyses indicate that parameter uncertainty in the model variables for annual emissions and for concentration-response/toxicological slopes have the greatest leverage on predicted health impacts. Scenario analyses suggest that the geographic distribution of population density around a refinery site is an important predictor of total health impact. Several ranking metrics (predicted case incidence, simple DALY, and complex DALY) and ordinal ranking approaches (deterministic model, average from Monte Carlo simulation, test of stochastic dominance) were used to identify priority substances for reduction; the results were similar in each case. The predicted impacts of primary and secondary particulate matter (PM) consistently outweighed those of the air toxics. Nickel, PAH (polycyclic aromatic hydrocarbons), BTEX (benzene, toluene, ethylbenzene and xylene), sulphuric acid, and vanadium were consistently identified as priority air toxics at refineries where they were reported emissions. For many substances, the difference in rank order is indeterminate when parametric uncertainty and variability are considered.

A presente tese propõe-se a contribuir com os estudos sobre resistência e ação política das classes trabalhadoras no Brasil, a partir da análise de experiências de autoges­tão e recuperação de empresas por trabalhadores, fenômeno que surge no país no contexto de redemocratização e de forte crise econômica nas décadas de 1980 e 1990. Para isso, o trabalho investiga a história de luta dos trabalhadores daquela que foi considerada por estudiosos do tema a maior experiência de autogestão da América Latina, a Usina Catende, em Pernambuco. Situar os casos contemporâneos no rastro da história das experiências de autogestão dos trabalhadores, que ultrapassa as fronteiras nacionais e nos conduz às lutas associativistas do início da Revolução Industrial; apresentar um panorama atual das recuperações de empresas por trabalhadores no país, com a análise de dados coletados em estudo nacional realizado com pesquisadores de dez universidades brasileiras em 2012; e analisar a experiência dos trabalhadores de Catende no período em que lutaram para manter o seu trabalho, buscando criar novas relações sociais na produção do açúcar e em suas vidas são os objetivos dessa pesquisa, inspirada nos conceitos sobre história de Walter Benja min e em seu significado para os estudos sociológicos. / The purpose of this thesis is to contribute to the study of the working-class re­ sistance and political action in Brazil, through the analysis of experiences of work­ ers\' self-management and recovety of emerprises: a phenomenon which arises in the country in the context of re-democratization and a serious economic crisis in the 1980s and 1990s. To do this, the study investigates the history of a workers\' struggle considered by researchers to be the largest self-management experience in Latin America: the Catende sugar refinery in the Brazilian state of Pernambuco. The research was inspired by Walter Benjamin\'s concepts of history and its signif­ icance for sociological studies. Based on those, the objectives of this study are: to situate contemporary cases in the historical path of self-management experiences of workers, which transcends national borders and take us back to the associative struggles of the early Industrial Revolution; to present a current overview of the experiences of worker recovered enterprises in the country, with an analysis of the results of a national joint study conducted by researchers from ten Brazilian uni­ versities in 2012; and to analyze the experience of the Catende workers during the period in which they fought to keep their jobs, aiming to create new social rela­ tions in sugar production and in their lives.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2016-11-30T11:42:36Z No. of bitstreams: 1 Lucas Ricardo Alves Pessoa.pdf: 4038549 bytes, checksum: 5d94924c90bdd7954bdfd6dadbffc9b1 (MD5) / Made available in DSpace on 2016-11-30T11:42:36Z (GMT). No. of bitstreams: 1 Lucas Ricardo Alves Pessoa.pdf: 4038549 bytes, checksum: 5d94924c90bdd7954bdfd6dadbffc9b1 (MD5) Previous issue date: 2016-09-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In 1950 Cubatao presented "a population" under ten thousand people. Cubatao until then had its economy based on the cultivation of bananas and in just a few decades has been transformed into the largest petrochemical complex in Latin America. This industrialization, unprecedented in Brazilian history, began with the installation of President Arthur Bernardes Refinery in Cubatão (RPBC (RPBC). The concentration of this petrochemical complex and excessive introduction of air and water pollutants in Cubatao Valley provided a variety of illnesses to people's health and local ecosystems, leading the city to be regarded as "one of the most polluted in the world" in the late 1980. The points of this research are: Distinguish the motives for to the choice of Cubatao as the most appropriate location for the installation of RPBC; Analyze the possible manifestations of scientists about the choice of location and the losses of the process over the decades mentioned. Therefore, we used Digital Collection of documents from the National Archives, as well as other studies and research work of the period. The results indicate that several factors of military order, strategic, political and economic have been involved in the choice of location of the refinery installation, however the concern for the environment not has guided any discussion. The analyzed research suggests that the scientific community itself has supported the refinery installation in the region, or considered at first that the problems were natural and passenger character. When this community became aware of the irreversible ills, the military regime did not allow criticism. The many published works on the Cubatão´s environmental question after the democracy suggest that this phenomenon is related to the consolidation of some specific terms of the environmental science / Em 1950, Cubatão apresentava uma população inferior a dez mil pessoas, tinha sua economia baseada no cultivo de bananas e, em apenas algumas décadas, foi transformada no maior polo petroquímico da América Latina. Essa industrialização, sem precedentes na história brasileira, teve início com a instalação da Refinaria Presidente Arthur Bernardes de Cubatão (a RPBC). A concentração desse polo petroquímico e do lançamento excessivo de poluentes atmosféricos e hídricos no Vale de Cubatão proporcionou diversas mazelas para a saúde da população e para os ecossistemas locais, levando a cidade a ser considerada como “uma das mais poluídas do mundo”, na década de 1980. Os objetivos da presente pesquisa consistiram em: 1- identificar os motivos que levaram à escolha de Cubatão como o local mais apropriado para a instalação da RPBC; 2- analisar as eventuais manifestações de cientistas sobre a escolha do local e os prejuízos do processo ao longo das décadas mencionadas. Para tanto, foram utilizados documentos do Acervo Digital do Arquivo Nacional, além de outros estudos e trabalhos de pesquisadores do período. Os resultados apontam que diversos fatores de ordem militar, estratégica, política e econômica estiveram envolvidos na escolha do local de instalação da refinaria, entretanto, a preocupação ambiental não norteou qualquer discussão. As pesquisas avaliadas sugerem que a própria comunidade científica apoiava instalação da refinaria naquela região ou considerava, a princípio, que os problemas eram naturais e de caráter passageiro. Quando essa comunidade se deu conta das mazelas irreversíveis, o regime militar já não permitia críticas tão severas. Os inúmeros trabalhos publicados sobre a questão ambiental de Cubatão, pós reabertura democrática, sugerem que esse fenômeno está relacionado com a consolidação de alguns termos específicos das ciências ambientais

A presente tese propõe-se a contribuir com os estudos sobre resistência e ação política das classes trabalhadoras no Brasil, a partir da análise de experiências de autoges­tão e recuperação de empresas por trabalhadores, fenômeno que surge no país no contexto de redemocratização e de forte crise econômica nas décadas de 1980 e 1990. Para isso, o trabalho investiga a história de luta dos trabalhadores daquela que foi considerada por estudiosos do tema a maior experiência de autogestão da América Latina, a Usina Catende, em Pernambuco. Situar os casos contemporâneos no rastro da história das experiências de autogestão dos trabalhadores, que ultrapassa as fronteiras nacionais e nos conduz às lutas associativistas do início da Revolução Industrial; apresentar um panorama atual das recuperações de empresas por trabalhadores no país, com a análise de dados coletados em estudo nacional realizado com pesquisadores de dez universidades brasileiras em 2012; e analisar a experiência dos trabalhadores de Catende no período em que lutaram para manter o seu trabalho, buscando criar novas relações sociais na produção do açúcar e em suas vidas são os objetivos dessa pesquisa, inspirada nos conceitos sobre história de Walter Benja min e em seu significado para os estudos sociológicos. / The purpose of this thesis is to contribute to the study of the working-class re­ sistance and political action in Brazil, through the analysis of experiences of work­ ers\' self-management and recovety of emerprises: a phenomenon which arises in the country in the context of re-democratization and a serious economic crisis in the 1980s and 1990s. To do this, the study investigates the history of a workers\' struggle considered by researchers to be the largest self-management experience in Latin America: the Catende sugar refinery in the Brazilian state of Pernambuco. The research was inspired by Walter Benjamin\'s concepts of history and its signif­ icance for sociological studies. Based on those, the objectives of this study are: to situate contemporary cases in the historical path of self-management experiences of workers, which transcends national borders and take us back to the associative struggles of the early Industrial Revolution; to present a current overview of the experiences of worker recovered enterprises in the country, with an analysis of the results of a national joint study conducted by researchers from ten Brazilian uni­ versities in 2012; and to analyze the experience of the Catende workers during the period in which they fought to keep their jobs, aiming to create new social rela­ tions in sugar production and in their lives.