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Introduction: In this work, based on the necessary technological linkage that exists in a raw sugar factory with a nearby sugar refinery, a strategy is proposed to strengthen its material and energy linkage in its development, extracting the juice from the filters. Objective: To evaluate the impact of extracting the juice from the filters on the influence on the quality of raw sugar, determining the optimal percentage of extraction to achieve the energy linkage of the combined raw sugar factory, refinery and torula cream. Materials and methods: The effect of the extraction of the juice from the filters on the quality of this type of sugar, and with it on that of refined sugar, is evaluated through the statistical modeling of the process through the aggregation of the models of the component elements, considering variations of the models in the purification stage for different per hundreds of extraction. Results and discussion: The global models of the process obtained through the aggregation of models of the partial stages are effective for predicting the sugar quality parameters. The extraction of the juice from the filters significantly increases the amount of leftover bagasse in the production of raw sugar. Conclusions: The extraction of the juice from the filters benefits the quality parameters of the produced sugar and significantly increases the amount of excess bagasse in the production of raw sugar, being an alternative to contribute to other productive demands. [ABSTRACT FROM AUTHOR]

The biorefineries concept from renewable sources has gained much attention in recent years because they improve sustainability with regard tofossil fuel refineries that are limited by the depletion of petroleum reserves. In this perspective, the production of ethanol from sugar cane bagasse is highly attractive because it reduces the fossil fuels consumption, the energy costs and the greenhouse gases emission. In this context, this paper aims to develop an optimal model design of an ethanol plant, considering bagasse pretreatment stages for subsequent simultaneous saccharification and fermentation (SSF). SSF variant, as its name suggests, has the advantage that enzymatic hydrolysis and fermentation stages are simultaneously carried out on the same equipment, obtaining directly the ethanol as a main product. The proposed approach is based on a mixed integer linear programming model which is optimized by GAMS-CPLEX package. [ABSTRACT FROM AUTHOR]

Introduction: Most of the ethyl alcohol produced is from sugar sources, molasses, but this is becoming more and more sought after due to the increase in biotechnological productions, so it is necessary to study other sources of sugar substrates and/or their mixtures. Objective: To carry out a preliminary study in the alcoholic fermentation stage of the use of filter juice mixture, molasses and syrup. Materials and Methods: A simple trellis-type design of experiments was carried out, performing the preparation of culture media, some as a base and the rest are combinations of them. Up to 100% of sugars in total reducing agents (ART) of the substrates are taken into account. The response variable is alcoholic percentage. Results and Discussion: The fermented musts had percentages between 5.22 and 5.50. The highest was reached in experiments four and five, where the substrates molasses and syrup were used, 5.48 and 5.50 % respectively. On the other hand, when using the juice from the filters (experiments one, two and three), the lowest levels of alcoholic concentration in the medium were obtained, values that differ from those reached in other fermentation studies. Conclusions: The use of syrup in fermentation allows a better utilization of cane that should not be destined for sugar production, given its low quality. In the study, the highest alcoholic percentage is reached when this stream is used as substrate. [ABSTRACT FROM AUTHOR]

The present work is the second and last part of the wide theoretical study that it allows to continue with the development of the procedure to the synthesis and optimal design of batch systems. Starting from the theoretical study the heuristic scheme is obtained it is a continuation of the scheme developed in the first part of the work. In this scheme are kept in consideration the equipments and the involved materials problems, and also rather aspects related with the uncertainty are also involved the time as in the input variables. The synthesis and optimal design is achieved by means of the application of optimization rules to superstructures that are previously proposed by the process researcher, for that which rigorous computational tools are employed. The material and energetic integration of the process tt is also analyzed. [ABSTRACT FROM AUTHOR]

Introduction: In the Cuban sugar industry it is strategic to study the possible development as a biorefinery, obtaining alcohol, torula yeast and xylitol. Objective: To determine the optimal proportions of juice extraction from filters to obtain torula yeast and the use of leftover bagasse in the production of xylitol in the biorefinery concept. Materials and Methods: Statistical analysis is used to obtain the models of each stage of the process of obtaining raw sugar, using data in harvest period. The models that represent intermediate streams, such as the juice from the filters, are studied in depth, analyzing different extraction percentages of this stream, its benefits in the purification stage and in the amount of bagasse left over. Economic indicators are determined for the alternatives studied. Results and Discussion: The optimum percentage of juice extraction from the filters, in the purification stage, is 21.9%. This value allows a reduction in steam consumption in the sugar process. Sugar and molasses losses are in the order of 545322.43 USD per year and are exceeded by gains in xylitol and torula yeast production. Conclusions: The amount of filter juice extracted in the sugar process, guarantees the production of molasses to obtain torula yeast, throughout the year. The economic losses, caused by the decrease in the production of sugar and molasses, when extracting juice from the filters, are surpassed by the profit from the xylitol and torula yeast production. [ABSTRACT FROM AUTHOR]

Presently, energy is limited by the way it is produced and the wide range of possibilities applied to get it is not varied and the use of active and/ or passive sun techniques, by the mass market demand is too cautious. The residential area is one of the sectors in which a larger quantity of household waste is produced as well as a larger wastefulness of electricity, heating and refrigeration, this matter becomes worst owed to architectural fashions that give priority to design instead of giving it to a greater autonomy of the building to get the necessary comfort established in parameters of 16 °C to 18 °C and 60% to 80% of humidity. The biogas production from residential area as well as the application of passive and active sun techniques in construction, will not only make a wider range of energetic matrix for every country, but it will also make citizens more conscious and autonomous, and so a substantial change in social conscience will be achieved. [ABSTRACT FROM AUTHOR]

Due to the great quantity of aspects that are necessary in analyzing the development of a discontinuous process; in this work a methodology for the analysis of these systems is presented. For they are analyzed it the fundamental characteristics of the discontinuous systems, giving a continuity to the different steps and achieving a systematic characterization, with that which a heuristic diagram is obtained that will be the one that directs future works. In this diagram the equipment and the involved materials was related, as well as aspects related with the time uncertainty and the requirements. [ABSTRACT FROM AUTHOR]

Introduction: It has been decided to evaluate the possibilities of obtaining products derived from sugar cane in industrial facilities in the territory of Villa Clara also obtaining a benefit in the energy balance of the sugar factory. Objective: To evaluate the percent of filter juice that can be optimally extracted to improve the energy balance of a Villa Clara sugar factory, having as destination a Torula yeast production plant annexed to it. Materials and Methods: The effect of the extraction of a fraction of juice from the filters on the energy balance of the plant was studied using mass and energy balances. The design methods of chemical industry facilities were used. Results and Discussion: It was obtained that the optimal percent of juice extraction from the filters is 20 %, achieving a profit of 1824435.40 $/year needing to buy 9427 t/year of missing molasses. The investment cost for 20 % extraction is $7797596.34 is profitable the investment having a total production cost of 4371490.21 $/year with profit of 2636509.79 $/year, NPV is $12900494.64, IRR 40 % and 3.1 years of payback period. Conclusions: The extraction of the juice from the filters of the sugar production process allows an energetic benefit to the technological process that can be used in new productions, which increases as the extraction percent increases. [ABSTRACT FROM AUTHOR]

Introduction: Sugarcane is an alternative source of energy with great potential for the production of derivatives, so it is necessary to accelerate the diversified development of this industry. Objective: To optimally design the capacities of a xylitol plant, produced by fermentative way with sugarcane bagasse, taking as main raw material the leftover bagasse coming from a sugar plant of Villa Clara province, Cuba. Materials and Methods: The statistical software Statgraphics Centurion was used to obtain models of the raw sugar production process stages, using data plant during the harvest period. Material balances were applied to these data to obtain models representing the quality of intermediate products and final sugar, with juice extraction from the filters. The models are aggregated to obtain the global models of the process knowing with these the benefits of the extraction of filter's juice in purification stage and the leftover bagasse for each extraction percentage. Results and Discussion: 625 tons/year of xylitol will be produced, requiring 6250 tons/year of bagasse. The optimum extraction rate of juice from the filters is 80%, reducing steam consumption by 5.16%. Sugar and molasses losses are outweighed by gains from xylitol sales. Conclusions: The extraction of juice from the filters in a sugar plant is satisfactory for sugar quality and energy balances, providing surplus bagasse for obtaining xylitol. [ABSTRACT FROM AUTHOR]

Introduction: Because the need to explore for the best operational behavior in chemical and food processes, the present research proposes the use of Response Surface Methodology as an optimization tool. Objective: To identify the theoretical, methodological foundation, potentialities and results obtained in Response Surface Methodology application in chemical and food processes development. Materials and Methods: Method theoretical and practical definition was carried out. relationships between input factors for different models in the search phase and surface response adjustment were established. The most appropriate experimental designs and statistical packages were selected and a methodological proposal was made for conducting the optimization supported by its practical example's application. Results and Discussion: Response Surface Methodology theoretical foundation is shown taking into account its sequential character, approximation functions and experimental designs for both independent variables and mixing factors. In addition, optimization techniques according to the model and their application in chemical and food industry researches were considered. The achieved results show the method potentialities in the operational optimum search. Conclusions: The Response Surface Methodology is an extremely versatile technique that allows the use of different experimental designs and statistical tools to solve optimization problems in chemical and food industry processes. [ABSTRACT FROM AUTHOR]

Introduction: A number of alternatives arise daily on how to control transformative process in chemical process industry. To help in decision-making process, some calculations are carried out to estimate energy, technological or environmental indicators and then choose the best variant. Present investigation proposes mathematical methods use, mainly optimization, using linear programming as a tool in these decisions. Objective: To show linear programming applications in solving Chemical Processes industry problems. Materials and methods: Procedures used in Chemical Engineering doctorate defenses and articles derived from these investigations were used as this investigation basis. Results and Discussion: Results achieved by researchers using linear programming are detailed for each four directions in which uncertainty has been classified in Chemical Engineering according to Rudd and Watson. Investigations are grouped and offered for each classification: research problem, necessary requirements for its application, investigations carried out in each work direction and achieved results. Each applications group, according to uncertainty problems considered, has common features and restrictions. Conclusions: Linear programming is a versatile tool for solving uncertainty problems in chemical industry that is and will be present in traditional chemical industry facilities into more efficient facilities transformation procedures. [ABSTRACT FROM AUTHOR]

Introduction: The extraction of the juice from the filters makes possible a torula yeast cream production facility with the aim of promoting swine feeding, however, it is necessary to confirm the real possibilities and alternatives to execute investments in this direction in a factory, specifically, of sugar with its refinery. Objective: To substantiate the possibilities of torula yeast cream production technologies and the appropriate percentage of juice extraction from the filters to obtain said cream in a sugar factory with a refinery. Materials and Methods: For the study, there were considered the different possibilities of extraction of juice from the filters in the studied facility and, using the works reported by other authors, the different possible annual production capacities of torula yeast cream using juice from the filters in harvest time and final molasses in non-harvest time. Results and Discussion: There are technological and economic possibilities for the production of torula yeast cream in sugar factories with a sugar refinery since increases in the profit of the blend are achieved with different percentages of juice extraction from the filters. Conclusions: Under the current conditions of product price, cost of raw materials and investment estimates, the optimal extraction percentage of the juice from the filters is estimated at 20 percent. [ABSTRACT FROM AUTHOR]

The Cuban sugar industry opens possibilities for biorefinerydevelopment due the characteristics of its mass flow currents and its facilities for obtaining different products, co-products and energy. In present paper, biorefinery schemes were evaluated in a Cuban sugar factory with the integration of products and by-products. Two schemes were proposed for the development of a biorefinery in a Cuban sugar industry, considering the obtaining of second generation ethanol (2G) and third generation biodiesel (3G) (Alternative I), as well as obtaining ethanol from molasse -filters juices and bagasse hydrolyzed and biodiesel 3G (Alternative II). When analyzing these alternatives based on results of mass balances, the AlternativeI is not feasible from a technical point of view, since the amount of bagasse used for hydrolyzateproduction makes the plant not self-sufficient energetically, consuming 2 868 609 kW-h / year of the National Electric System (SEN). When carrying out the economic evaluation it was obtained that alternative IIis technically and economically feasible, since it has a NPV of $ 19 129 956, a TIR of 41.9% and a payback of 4.4 years, achieving in this way the integration of a sugar industry to a biorefinery that obtains second and third generation products. [ABSTRACT FROM AUTHOR]

El artículo presenta un editorial en que la autora comenta sobre los planes de la revista para el año 2014, incluyendo la participación en una conferencia sobre el azúcar, el acceso libre a la revista y los miembros del Comité Editorial de la revista.

In this research a study of the adsorption of acetic, benzoic, butanoic, fumaric, maleic and succinic acids on sugarcane baggase ash is made. The adsorber material is characterized through physical criteria such as apparent and pictometric density, compressibility, porosity, superficial area and tortuosity. The sample has been examined by X-rays Diffraction, thermal analysis, IR-quality analysis. The isotherm for the sorption process is determined, where it is shown that the Freundlich model is adjusted to benzoic acid, the Langmuir and Toth model to acetic acid, Bunauer-Emmett-Teller (BET) model to succinic acid and the butiric, maleic and fumaric acids are adjusted to Langmoir model. It is established that the first-order model is adjusted to the adsorption kinetics of the acetic and benzoic acids; while the rest of the acids are adjusted to a second-order model, in the case of the butanoic, succinic and maleic acids it is possible the occurrence of chemisorption processes. [ABSTRACT FROM AUTHOR]

The uncertainty has a great impact in the investment decisions, operability of the plants and in the feasibility of integration opportunitiesin the chemical processes. This paper, presents the steps to consider the optimization of process investment in the processes integration under conditions of uncertainty. It is shown the potentialities of the biomass cane of sugar for the integration with several plants in a biorefinery scheme for the obtaining chemical products, thermal and electric energy. Among the factories with potentialities for this integration are the pulp and paper and sugar factories and other derivative processes. Theses factorieshave common resources and also havea variety of products that can be exchange between them so certain products generated in a one of them can be raw matter in another plant. The methodology developed guide to obtaining of feasible investment projects under uncertainty. As objective function was considered the maximization of net profitablevalue in different scenariosthat are generated from the integration scheme. [ABSTRACT FROM AUTHOR]

In this work, the stages of losses and lower exergetic efficiency are determined when the sugar production process is integrated with others for the production of products such as biogas, torula yeast and electricity. The study is carried out in three scenarios of integrated processes for obtaining the indicated products. A sugar factory in which sugar and electricity are produced is considered as the base scenario and from this; a second scenario is inferred in which alcohol is produced from the molasses of the sugar process and biogas from the vinasse of the alcohol distillation process. Finally, a third scenario is exergetically evaluated in which sugar, electricity, biogas and alcohol are produced, but this last one from juices and molasses of the sugar process. For the exergetic analysis the integrated scheme was divided into 8 subsystems. From the analysis of results, the major subsystems that generate irreversibilities are: cogeneration (64.36-65.98%), juice extraction (8.85-9.85%), crystallization and cooking, (8.48 - 9.02%), fermentation (4.12-4.94%) and distillation (2.74-3.2%). Improvements are proposed to minimize irreversibilities, including the thermal integration of processes, technological modifications in the fermentation process and the introduction of more efficient equipment for the generation of electricity. The exergetic efficiency is between 78.95-81.10%, obtaining greater exergetic efficiency in the scheme of joint operation to produce sugar, alcohol and biogas. [ABSTRACT FROM AUTHOR]

The determination of the rate expressions of the acid hydrolysis of sugarcane bagasse using sulfuric acid, obtaining the approximate kinetic models is presented. For the experimental design to acid pretreatment a 2² factorial design was elaborated, varying the reaction temperature (175-185 °C) and the sulfuric acid concentration (0-1.25%). For acid pretreatment a 2³ factorial design was elaborated, varying the reaction temperature (175-195°C), ethanol concentration (10-30 %) and NaOH concentration (1.5-3.0%). For the determination of the rate expressions the differential method of data analysis is applied through of least squares technique. The values of activation energy in reactions of xylose liberation in the acid pretreatment and lignin liberation in basic are determined and compared with those reported in the literature. The influence of the acid concentration variation is studied, as well as the temperature variation through Arrhenius equation. [ABSTRACT FROM AUTHOR]

Introduction: As uncertainty affects the facilities economic indicators once the investment has been made, it is proposed to quantify it using experimental designs, in those, each technological variable was minimized. Objective: To anticipate quickly the uncertainty impacts in technological variables on an industrial facility design in order to define the research strategy to introduce a technology. Materials and Methods: By means of technology knowledge, theoretical tests were carried out to measure the process variables incidence in economic indicators of six technological variants. Due to the high number of independent variables, a combination of partial factorial designs was used to measure the indicators sensitivity to variables deviation. Results and Discussion: From the results of cost per liter of ethanol and production weight, the variables coefficients significance for the six variants was determined using the Plackett-Bürman design. Discarding the non-significant variables, and reducing the designs to partial factorials, the variables significance is identified as a measure of uncertainty and which ones should be investigated to solve the problems that limit the introduction of technologies. Conclusions: Applying partial factorial designs, the significance of incident variables in the economic indicators for technological variants was defined, with minimal experimental work, allowing the design of research policies in order to minimize expenses associated with technology. [ABSTRACT FROM AUTHOR]

Introduction: There are several types of lignin and, among them, which derives from processes that use organic solvents in the presence of catalyst, acid or basic has less environmental impact with respect to conventional ones since organic solvents are easily recovered by distillation, also this type of lignins, has specific uses because its structure. Hydrolysis of sugarcane bagasse produces lignin-rich currents that can be integrated into the biorefinery concept. Objective: Demonstrate the economic feasibility of integrating the lignin production process into the biorefinery concept based on its characteristics and the knowledge of its producers at the international level. Materials and methods: A search (briefing) that provides useful data for the development of the lignin obtaining process is carried out, based on this process is integrated into the concept of biorefinery and its economic indicators are determined. Results and Discussion: The applications of lignin as a result of bagasse hydrolysis can be: the elaboration of carbon fibers, vanillin, and in the production of phenol derivatives. By assessing the feasibility of investment in the biorefinery scheme with the integration of lignin, dynamic profitability indicators are obtained that demonstrate the feasibility of the proposal, maintaining the recovery of investment in 5.2 years as de Armas, (2019). Conclusions: The proposed process is justified with the applications of lignin and can be integrated into the biorefinery while maintaining its profitability. [ABSTRACT FROM AUTHOR]

Modeling and simulation of process integration in the production of sugar, ethanol and yeast is carried out. The possibilities of exchange mass and energy resources are identifying, achieving with it an integrated complex of technical, economic and environmental bigger efficiency. The impact of juice extraction from the filters and from last milling is simulated In order to use them in the ethanol production, obtaining improves in the quality of sugar and the molasses so that the alcoholic yields and fermentative efficiencies higher when comparing them with the traditional processes. Through the modeling a better redistribution of the water is predicted and an energy bigger efficiency is obtained in the integrated processes, that diminishes the steam consumption and bigger bagasse surpluses are obtained. A better distribution of water and energy resources is achieved in the integrated system. The economic efficiency of the process is favored with the integration alternatives simulated. [ABSTRACT FROM AUTHOR]