Centro Azúcar Journal

CHARCOAL OBTAINED BY PHYSICAL ACTIVATION OF MAMEY (MAMEY) SEED AND ITS USE AS AN ADSORBENT OF COPPER (II) IONS

Julio Omar Prieto García — 2025-03-12

Introduction:
Charcoals obtained by chemical and physical activation are good adsorbents of gases, molecules and ions in aqueous solution.
Objective:
To obtain the mathematical parameters of the kinetic, thermodynamic and diffusive processes of the heterogeneous system in equilibrium aqueous solution of copper (II)- charcoal.
Materials and Methods:
Copper (II) solutions are used. Charcoal is synthesized by physical activation of mamey seeds and its chemical and physical parameters are determined. The kinetic and diffusive equations at 298 and 338 K are used. The adsorption isotherm is determined at 298 K.
Results and Discussion:
With a 47.6% yield, a coal with a high tortuosity and C/N ratio is obtained. The activation energy of 8.18 kJ/mol. The Temkin isotherm fits the thermodynamic data.
Conclusions:
1. Charcoal is a good adsorbent of Cu(II) ions.
2. The kinetic equations respond to a pseudo-first order.
3. Diffusion coefficients of the order of 10-10 m2/s are obtained.

AGRICULTURAL BIOPRODUCTS: FUNDAMENTALS FOR THEIR PRODUCTION

Gabriel Alejandro Iglesias Barreto — 2025-02-18

Introduction:
The beneficial action of microorganisms and their metabolic derivatives on plants and soils is well documented, representing a highly effective alternative to the use of chemical fertilizers and pesticides.
Objective:
To examine the foundations for the agricultural bioproducts industrial production.
Materials and Methods:
Classical and updated research aimed at fermentative productions of agricultural supplies and their applications in crop fields were addressed.
Results and Discussion:
Products obtained from microorganisms and metabolites prove to be a highly reliable option for the management of sustainable agriculture and soils recovery. Research is mainly focused on the selection of new microorganisms with a broad action on crops and soils, more stable formulations with multipurpose functions (microbial consortia with fertilizing, pesticide and/or stimulant action in a single presentation), design of new more specific technological schemes and optimization of culture media for cell growth at higher scales.
Conclusions:
Although the benefits of bioproducts in agriculture have been demonstrated, market projections dictate that they have not yet displaced conventional agrochemicals, mainly due to their manufacturing cost and complexity in terms of their use. Instead, research into immobilized cell systems and fed-batch systems is essential as highly productive alternatives to traditional techniques such as submerged batch and solid-state fermentation.

CURING KINETICS IN ELASTOMERS. A LITERATURE REVIEW

Blanca Rosa Cruz Cal — 2025-03-05

Introduction:
The development of elastomers from rubber has allowed to expand their applications. Therefore, it is necessary to study the curing kinetics through different techniques that allow the study. The selection of the technique depends on the available equipment, the nature of the data, which may be isothermal or not. The common objective is to obtain the activation energy (Ea), the reaction rate (n) and the rate constant (k) through mathematical models.
Objective:
To summarize the main aspects on the subject published to date.
Materials and Methods:
Several bibliographical queries of different scientific references were made without language hierarchy, nor date limit referring to the contents chosen through keywords.
Results and Discussion:
Elastomers are vulcanized to improve their properties. This is a very complex process from a chemical point of view, which occurs in three phases: induction, curing and over-curing. The techniques applied are based on the measurement of a property that varies with the progress of cross-linking. The most studied models are those based on a phenomenological approach.
Conclusions:
To describe curing kinetics, several models have been developed, grouped into two categories: mechanical kinetics and empirical or phenomenological models. The empirical model is considered the most practical, due to the complexity of the mechanical one. The model proposed by Kamal-Sourour is one of the most applied to describe the evolution of the curing process.

PRODUCTION AND INDUSTRIAL APPLICATIONS OF PHYCOCYANIN AS A BIOACTIVE PIGMENT

Estela Guardado Yordi — 2025-03-19

Introduction:
Phycocyanin (PC) is a biopigment obtained mainly from Arthrospira platensis (spirulina), with wide applications in food, cosmetics, and pharmaceutical industries. Its growing demand is due to its safety, chemical stability, and bioactive properties, such as antioxidant and anti-inflammatory activity. However, its extraction and purification face technological and economic challenges that limit its commercial expansion.
Objective:
To evaluate the potential of PC as a natural biopigment, its industrial applications, extraction and purification methods, and the main challenges and opportunities for its production and commercialization.
Materials and Methods:
A bibliographic review was carried out in scientific databases such as ScienceDirect, Springer-Nature, SciELO, Taylor & Francis, PubMed, and Google Scholar, considering studies published between 2015 and 2025 on the production, extraction, and applications of PC.
Results and Discussion:
PC is a viable alternative to synthetic dyes, with applications in various industries. Advanced extraction methods, such as ultrasound, pulsed electric fields, and supercritical fluids, have improved its purity and yield. However, its high cost and lower stability remain limitations.
Conclusions:
PC is a promising biopigment. Its large-scale implementation will depend on innovations in production, stabilization strategies, and regulations that favor its competitiveness in the global market.

ACCELERATED TEST TO DETERMINE THE CORROSION BEHAVIOR OF STEELS IN BOILERS BURNING SUGARCANE BIOMASS

Abel Rivas Gutierrez — 2025-02-16

Introduction:
In order to increase the percentage of sugarcane agricultural residues used in a mixture with bagasse to generate electricity in biomass boilers, it is necessary to study the corrosion behavior caused in superheater tubes due to its high content of alkalis and chlorides compared to bagasse.
Objective:
To develop a tentative accelerated test, at laboratory scale, to predict the corrosion behavior, in high temperature zones, of type steels used in the superheater of high parameter steam generators.
Materials and Methods:
Metallography of steels, determination of composition and creation of synthetic ash to be used, corrosion rate calculation and analysis at the steel/oxides/deposits interface.
Results and Discussion:
In both steels studied, an increase in the corrosion rate was observed for the synthetic ash composition of the similar composition to that of higher concentration of sugarcane agriculture residues. Similarly, a greater thickness of oxide layers was observed when the steels were treated with synthetic ashes of composition similar to that of higher percentage of residues mixed with bagasse.
Conclusions:
This study carried out allowed to determine, comparatively, the behavior in the first stages of corrosion at 540 °C of two steels used in the construction of high-parameter superheaters boilers attacked by ashes simulating those formed in the combustion of different concentrations of sugarcane agricultural residues mixed with bagasse.

PRODUCTION OF SPIRITS FROM SYRUP AT "HÉCTOR MOLINA RIAÑO" DISTILLERY

Grettel Castillo Cabrera — 2025-02-16

Introduction:
Given the low availability of molasses, the use of sugarcane juice and syrup as alternative raw materials to molasses is being considered. At the agroindustrial sugar company "Héctor Molina Riaño", a column has been installed to produce spirits from syrup from sugarcane that is not suitable for obtaining sugar.
Objective:
To evaluate the feasibility of using syrup as an alternative raw material in the production of spirit.
Materials and methods:
Mass and energy balances were carried out in the sugar and spirit production processes using two substrates: syrup and molasses. Costs associated with the production of spirit from both materials and the negative environmental impacts were determined.
Results and discussion:
It was established that for a production capacity of 100 hL/d, 368.05 kg/h of spirit was obtained and a steam consumption saving of 76 475 031 t/year in obtaining molasses of 76 475 031 t/year in the sugar production process. It was obtained that, using molasses, the process was feasible with a profit of 502 549 438 CUP/year. A saving in dilution water and fuel consumption of 20 160 m3/year and 143 385 t/year respectively, and a reduction in CO2 production of more than 6% was reported.
Conclusions:
It is feasible to use syrup instead of molasses to produce spirit, making use of the backward cane, consuming less fuel, and reducing gas emissions to the atmosphere.

DETERMINATION OF REDUCING SUGARS ON INVERTED SYRUPS OBTAINED BY ACID HYDROLYSIS OF SUCROSE AT A CUBAN FACTORY

Lázaro Andrés García Pérez — 2025-02-18

Introduction:
The inverted syrup that is obtained from acid hydrolysis of the sucrose contained in the refined sugar at the factory located at the Unidad Estatal de Base Derivados Chiquitico Fabregat, is a marketable product whose quality and, mainly, the content of reducing sugars needs to be certified through appropriate analytical methods.
Objective:
To quantify reducing sugars in the inverted syrups obtained by acid hydrolysis of the sucrose contained in the refined sugar applying the Miller or the 3,5-dinitrosalicylic acid Method.
Materials and Methods:
Reducing sugars were quantified by spectrophotometry using the Miller or the 3,5-dinitrosalicylic acid Method. The calibration curve was obtained, and determinations of reducing sugar content, conversion of soluble solids in reducers, pH and color were carried out on 30 samples of inverted syrups from the production process that were extracted between 2022 and 2023.
Results and Discussion:
The conversion of dissolved solids into reducers is between 86.58 and 99.84% with normal distribution of the values obtained for all variables in analysis. The efficiency of the acid process is slightly higher than that reported through enzymatic hydrolysis, although with a greater environmental and quality impact. The pH of the syrups and their color must be improved through the implementation of technological changes.
Conclusions:
The method used allowed obtaining representative data on reducing sugar values in inverted syrups that offers more information about this product for its possible commercialization and, allows, quantifying the effectiveness of the sucrose inversion stage.

ENERGY EFFICIENCY AND HEAT INTEGRATION IN THE SYRUP PRODUCTION PROCESS

Lisandra Guevara Orozco — 2025-03-05

Introduction:
The rational use of energy is of great importance in current times due to the scarcity of fossil fuels, their increase in cost and the negative impact they have on the environment. As a consequence of this, the terms of process integration are being handled, which allow reducing materials and energy consumption, as well as reducing gas emissions into the atmosphere.
Objective:
To evaluate the energy performance of syrup production and apply Process Integration (PI) to achieve potential savings in material and energy resources.
Materials and methods:
To determine and analyze the energy performance indicators (IDEns), the thermoenergy balance methodologies are applied, while the Pinch Analysis methodology is applied to the analysis and design of the heat exchanger network.
Results and discussion:
The results show the possibilities of energy savings being able to recover 95% of the maximum recoverable energy (MER).
Conclusions:
Syrup production presents several challenges in terms of its energy performance with inadequate management of heat recovery and steam generation. The results obtained through the construction of the problem table indicate that the process does not require cooling service. With the IP, annual savings of $526 525.79 can be obtained in fuel and cooling water.

TECHNICAL-ECONOMIC EVALUATION ASSOCIATED WITH THE TECHNOLOGICAL IMPROVEMENT OF THE PANELA PLANT AT THE UEB DERIVATIVES CHIQUITICO FABREGAT

Ernesto Suárez Bolaños — 2025-03-05

Introduction:
The production of panela, at the Chiquitico Fabregat company, is a potentially sustainable and feasible alternative if more favorable technological conditions than those currently existing can be implemented.
Objective:
To evaluate technically and economically the panela production of the Chiquitico Fabregat company considering the currently installed technology and an improved technological proposal.
Materials and Methods:
The technological and operational evaluation of the installed technology was carried out, determining its main weak points and proposing technological improvements that allow increasing efficiency, quality and reducing the energy impacts of the process. Technological schemes were prepared and the mass and energy balances were developed for both proposals, determining the material and energy demands. Based on the technological and operational evaluation and the information related to the acquisition of the equipment, a comparative analysis of the technical-economic behavior was carried out with dynamic indicators for both scenarios.
Results and Discussion:
The stages of reception, grinding, evaporation and manufacturing of panela were perfected. In evaporation, the kettles at atmospheric pressure were replaced by vacuum pans. The improved proposal increased energy efficiency and productivity, including granulated panela as a new product, and achieved more favorable dynamic economic indicators than current technology.
Conclusions:
The proposed technological modifications guarantee the sustainability of panela production, delivering a stable quality product, increasing added value and market acceptance and achieving more favorable economic-financial results.

SOME PARAMETERS OF THE ADSORPTION OF URANYL IONS IN SUGAR CANE BAGASSE (SACCHARUM OFFICARUM)

Julio Omar Prieto García — 2025-03-12

Introduction:
Uranyl ions are radioactive. Sugar cane bagasse can serve as an adsorbent for these ions.
Objective:
To determine the adsorption parameters in the heterogeneous phase system of uranyl ions in aqueous solution and sugar cane bagasse.
Materials and Methods:
Solutions of uranyl ions whose concentration is determined by UV-VIS absorption. Sugar cane bagasse is used as an adsorbent for which a series of physical and chemical parameters have been determined. Pseudo-first-order, pseudo-second-order and Elovich kinetic models are used. The values of the variation functions of free energy, entropy and enthalpy are determined. The values of the pre-exponential diffusion coefficients are found.
Results and Discussion:
At 298 K and 333 K, the pseudo-first-order model with activation energy of 17.33 kJ/mol is determined. The process is spontaneous, exothermic and low randomness. The chemical potential is 0.83 kJ/mol. The diffusion coefficients are around 10-11m2/s. with a diffusion activation energy of 0.04 J/mol.
Conclusions:
Sugar cane bagasse is an adsorbent with low densities, specific surface area and form factor, but has high tortuosity and porosity. The adsorption at temperatures of 298 and 333 K correspond to a pseudo-first-order model with activation energy of 17.33 kJ/mol. Thermodynamic processes tend to be spontaneous, exothermic and have low randomness. The diffusion coefficients at working temperatures are of the order of 10-11 m2/s.

WORK SCENARIOS FOR THE DESIGN OF A DISTILLERY FOR ORGANIC SPIRITS PRODUCTION

Eliani Sosa Gómez — 2025-03-17

Introduction:
Currently, organic products have a great demand in the market and have a higher price, which makes them an excellent business opportunity.
Objective:
To compare two work scenarios for the design of a small distillery to obtain organic spirits.
Materials and Methods:
The fundamental raw material is organic molasses, obtained from sugar cane grown only with natural fertilizers, using juice from filters during the harvest period, and organic honey and water after the harvest, taking into account the availability of said raw materials by applying mass and energy balances.
Results and Discussion:
The use of filter juice provides 40% of the ART, which is needed for the beating in fermentation providing a saving in molasses that allows the extension of work outside the harvest period to 26 days in the first scenario and 45 days in the second scenario. This also translates into water savings when working during the harvest period. The project proved to be profitable for a sale price of organic spirit between 190 - 225 $/hL.
Conclusions:
The addition of juice from the filters significantly reduced the demand for molasses and water, extending the work days outside the harvest. The production of organic spirit in Cuba is presented as a viable and profitable alternative as long as the necessary raw material is available for the scheduled work days.

ENVIRONMENTAL TRAINING IN UNDERGRADUATE STUDENTS IN PHARMACEUTICAL SCIENCES. CASE STUDY

Daymí Isabel Carrazana García — 2025-03-19

Introduction:
The environmental training of pharmacists is a priority, given the growing environmental impact of medication waste and their professional work to identify, prevent and manage it.
Objectives:
To identify the degree of environmental knowledge of Bachelor of Pharmaceutical Sciences students at Universidad Central "Marta Abreu" de Las Villas in Cuba and analyze the internalization of basic knowledge or knowledge generated in the
professional environment and the impact of the study on their environmental training.
Materials and Methods:
An exploratory cross-sectional case study was carried out between september and december 2024. A questionnaire for each academic year was designed and applied on the Moodle interactive platform. Another on paper obtained the assessment on the first instrument.
Results and Discussion:
The environmental knowledge of the students is discordant with respect to the importance of environmental training. There is a slight predominance of the internalization of knowledge generated in the professional environment over the basic ones. The questionnaires encouraged the acquisition of new knowledge among the
participants. They point out the importance of the topic addressed, but consider the questionnaires to be long and difficult.
Conclusions:
The basic extracurricular environmental knowledge of Bachelor of Pharmaceutical Sciences students and the environmental focus of basic curricular aspects must be increased. It is necessary to take advantage of the potential of the pre-professional environment and the capabilities of students to increase their environmental training.
Although they can be improved, interactive questionnaires constitute a useful tool for
self-assessment and acquisition of environmental knowledge associated with the profession.