Centro Azúcar Journal

ALUMINOTHERMIC OBTAINING OF IRON ALLOY AND CERAMIC USING MILL SCALE AS THE MAIN RAW MATERIAL

Lorenzo Perdomo González — 2026-05-11

Introduction:
Mill scale is an industrial waste generated during the hot rolling of steel, representing approximately 2 % of the produced steel. In Cuba, it is generated by companies like Antillana de Acero and Acinox Las Tunas and is currently underutilized.
Objective:
To obtain iron alloys and refractory ceramics through aluminothermic processing using lamination scale as the fundamental raw material.
Materials and Methods:
A McLean Anderson experimental design was used, varying the proportions of mill scale, aluminum chips, and limestone. Seven charges were prepared and processed in a graphite reactor to obtain the corresponding alloys and ceramics.
Results and Discussion:
The resulting alloys contained carbon (0.3 – 0.67 %), silicon (0.3 – 1.61 %), manganese (0.1 – 0.96 %), and aluminum (0.25 – 1.88 %), with a metal recovery rate of 73 – 91 %. The ceramics, composed mainly of aluminum and iron oxides, showed a recovery rate of 93 – 110 %.
Conclusions:
The results demonstrate the technical feasibility of the process. This method allows for obtaining iron alloys for industrial use and ceramics suitable for developing abrasive and refractory materials. The proposal represents a viable solution for valorizing this waste, contributing to environmental preservation.

EFFECT OF STEP-BY-STEP MASHING TO IMPROVE THE SENSORY PROFILE OF CRAFT BEER

Ulbio Eduardo Alcívar Cedeño — 2026-05-11

Introduction:
The research analyzes stepped maceration applied at different successive temperatures as a strategy to optimize the extraction of compounds that influence the physicochemical and sensory quality of craft beer. This method allows for modulation of enzymatic activity during the brewing process, which could impact the composition of the wort and the final characteristics of the product.
Objective:
To evaluate the effect of stepped maceration on the physicochemical and sensory properties of craft beer by applying three mashing temperatures (65 °C, 70 °C, and 75 °C) with variations in exposure times, analyzing their influence on the final density and sensory attributes.
Materials and Methods:
Wort was produced under three thermal regimes (65 °C, 70 °C, and 75 °C) with variable residence times. Physicochemical analyses included pH, density, titratable acidity, °Brix, and turbidity, along with microbiological controls to ensure product safety. Sensory evaluation was conducted through comparative tests using a trained panel. The data were analyzed using ANOVA and Turkey's test.
Results and Discussion:
The commercial beer achieved a higher overall score (2.55) than the experimental sample (2.18). This discrepancy was attributed to the presence of astringent notes and pronounced acidity in the stepped sample, suggesting that extraction efficiency alone does not necessarily ensure sensory quality.
Conclusions:
Stepped maceration improves physicochemical parameters; however, further adjustments are necessary to achieve an appropriate sensory balance.

IN VITRO INTERACTION BETWEEN TRICHODERMA HARZIANUM RIFAI LBMA 34 AND METARHIZIUM ANISOPLIAE LBMA 11

Claudia Arias Rodríguez — 2026-05-11

Introduction:
Agriculture faces challenges such as excessive pesticide use and pest resistance, making it necessary to employ innovative alternatives such as biological control agents to ensure its sustainability and productivity.
Objective:
To evaluate the in vitro behavior of the growth of the fungus Trichoderma harzianum LBMa 34 against Metarhizium anisopliae LBMa 11.
Materials and Methods:
The distance at which the fungi faced each other was measured, using distances of 2, 4, and 6 cm on an 8.5 cm plate. Radial growth between them and separately was measured, and the quality parameters corresponding to concentration, viability, and purity were determined.
Results and Discussion:
Trichoderma harzianum LBMa 34 grows faster than Metarhizium anisopliae LBMa 11 by 1.8 mm/day. Both maintain similar quality parameters, and the greater distance between them (6 cm) favors the development and expansion of M. anisopliae by reducing competition.
Conclusions:
Trichoderma harzianum LBMa 34 exhibits faster growth than Metarhizium anisopliae LBMa 11, although the latter is significantly favored by greater spatial separation (6 cm vs 2 cm), which reduces competition and allows for rapid establishment.

VANADIUM RECOVERY FROM SPENT CATALYSTS: A TECHNICAL, ENVIRONMENTAL, AND ECONOMIC SOLUTION FOR CUBA

Laura Ailin Perdomo Gómez — 2026-05-11

Introduction:
Catalytic residues generated in the production of sulfuric acid in Cuba contain vanadium, a metal classified as critical and without natural deposits in the country, which represents an environmental and economic problem. These polluting residues are stored in unsafe conditions or confined in facilities with limited capacity, which makes it necessary to seek sustainable solutions.
Objective:
To present the technical, economic, and environmental considerations regarding the recovery of vanadium contained in catalytic waste from sulfuric acid production.
Materials and Methods:
At Universidad Central “Marta Abreu” de Las Villas, a technological process has been developed based on crushing, acid leaching, filtration, precipitation, and calcination, using domestic reagents.
Results and Discussion:
The result is a concentrate with 37.8% V₂O₅, which can be marketed or transformed into ferrovanadium for the manufacture of recharge electrodes, an industrial input that Cuba currently imports at high cost. The research shows that processing these catalysts makes it possible to convert hazardous waste into a strategic raw material, reducing dependence on the international market and applying principles of circular economy and cleaner production. Alternatives are proposed for utilizing the solid and liquid by-products obtained, minimizing the generation of new waste.
Conclusions:
From a social and economic point of view, the proposal would contribute to import substitution, the strengthening of national industry, and environmental sustainability, while also generating a positive impact on strategic sectors, integrating science, innovation, and sustainable development in Cuba.

EVALUATION OF SUGAR CANE BAGASSE ASH AS A DEVELOPING POWDER FOR FINGERPRINT DETECTION

Jesús Rolando González Morrell — 2026-05-11

Introduction:
The recovery of latent fingerprints is fundamental in criminal investigations. The search for effective, safe, and low-cost developing is a priority.
Objective:
To evaluate the quality of sugarcane bagasse ash (SBA) as a latent fingerprint developing powder using a comprehensive methodology that considers physicochemical, practical, and efficacy parameters.
Materials and Methods:
SBA was characterized through physical (density, porosity) and chemical (XRF) analysis. Its performance as a developer was evaluated using an adapted methodology that included technical verification, performance characterization under controlled conditions, and pseudo-operational validation, comparing it to a reference standard.
Results and Discussion:
SBA presented an apparent density of 0.341 g/cm³, a porosity of 66.95 %, and a specific surface area of 11.79 m²/g. Its predominant chemical composition, expressed as oxides, was SiO₂ (43.55 %), K₂O (18.49 %), P₂O₅ (12.85 %), SO₃ (10.05 %), CaO (6.67 %), and MgO (6.12 %). In development tests, it showed high adhesion and contrast, with an Effective Development Rate (EDR) exceeding 80 % on glass and stainless steel, without generating false positives. Its performance was statistically equivalent to the standard in pseudo-operational tests.
Conclusions:
Sugarcane bagasse ash is a viable, effective, and sustainable fingerprint developing powder. Its quality is demonstrated through a comprehensive scientific evaluation, and its incorporation into Cuban criminalistics protocols is recommended.

EXPERIMENTAL MIXTURE DESIGN FOR MOLDING CASTING IN A FERROUS FOUNDRY

Jany Granado Ojito — 2026-06-04

Introduction:
Ferrous foundries are significant pollution sites due to manual molding and shakeout processes that generate large volumes of waste sand, justifying the need to reinforce sustainable development policies through reuse alternatives.
Objective:
To evaluate an experimental mixture design for molding iron castings at the "9 de Abril" Factory in Sagua la Grande.
Materials and Methods:
A designed experiment based on the simplex lattice method was applied, incorporating waste sand into new mixtures. The software STATGRAPHIC Centurion 16.1.8 was used to analyze the influence of each component on mold properties, obtain mathematical models, and perform multivariable optimization.
Results and Discussion:
Statistical analysis showed that the special cubic model provides the best fit for permeability and strength, while the quadratic model was most suitable for moisture. Technical optimization determined a mixture with 38% return sand, 34% arimao sand, and 28% bentonite. However, economic optimization reduced costs by 35.4% by increasing return sand (49.1%) and decreasing bentonite (14.1%), while keeping properties within established quality parameters.
Conclusions:
Incorporating waste sand into molding mixtures proved technically feasible, meeting the required quality parameters, achieving a 49.1% reuse of return sand, a 35.4% cost reduction, and consolidating this alternative as a circular economy practice.

PROPORSAL FOR A BIODIESEL AND HIGH MOLECULAR WEIGHT ALCOHOLS PLANT FOR A SUGAR INDUSTRY

Fernando Ramos Miranda — 2026-08-26

Introduction:
The sugar industry in Cuba is undergoing a process of restructuring and resizing to achieve greater technological, economic, and ecological benefits, imposed by the current economic and environmental conditions. Proposals for biorefineries have been developed within the sugar industry, serving as a tool to reduce energy consumption and the discharge of polluting residues into the environment in industrial processes.
Objective:
To evaluate the technical and economic feasibility of producing biodiesel and high molecular weight alcohols from filter cake generated in sugar factory.
Materials and Methods:
An evaluation of different technologies was carried out, taking into account existing quality control standards for these products to be implemented in the factory. The feasibility was analyzed from an economic, environmental, and social perspective. The project was conducted by applying the methodology proposed by (Ramos, 2014). The technology outlined by (Albernas, 2007), which enables the production and/or development of biodiesel from filter cake, was suggested.
Results and Discussion:
It was determined that the best alternative evaluated is VI, which proposes the production of biodiesel, in batches with NaOH catalyst, on an industrial scale, with HMWA (High Molecular Weight Alcohols). Values of an IRR of 56%, with a payback period of 3.4 years and a ROR (Return on Investment Index) of $ 2 279 512.35 were reported.
Conclusions:
The proposed investment is economically feasible for the company, as it provides economic benefits.

ACUTE TOXICITY OF REFINED JATROPHA CURCAS L. OIL ON LACTUCA SATIVA L. SEEDS

Sara Duany Timosthe — 2026-08-26

Introduction:
The use of Jatropha curcas L. oil as a biofuel for agricultural machinery represents a sustainable and promising alternative to reduce dependence on fossil fuels. However, its safe and successful implementation requires a rigorous toxicity study, as it could contaminate soils, water bodies, and agricultural ecosystems, ensuring that its management does not pose an environmental risk.
Objective:
To evaluate the acute toxicity of refined Jatropha curcas L. oil on Lactuca sativa L. seeds.
Materials and Methods:
A sensitivity bioassay was conducted using lettuce seeds (Lactuca sativa L.) in petri dishes, for different treatments and one sample as a negative control.
Results and Discussion:
It was determined that the refined oil of Jatropha curcas L. showed signs of toxicity for the 1 % and 3 % treatments, while for 10 % and 100 % it was considered toxic. This compound exhibited phytotoxic effects on the root and apical systems.
Conclusions:
In the acute toxicity test of refined Jatropha curcas L. oil, an increase in germination inhibition, radicle elongation, and hypocotyl growth was observed in Lactuca sativa L. seeds used as biomodels, as concentrations increased.

EXPERIENCES ON KAOLINITIC CLAYS ACTIVATION AT PILOT SCALE: ISLA, MOA, YAGUAJAY AND REMEDIOS AS CASE STUDIES

Guillermo Esperanza Pérez — 2026-08-26

Introduction:
The industrial processes of thermal activation of kaolinitic clays represent an alternative approach in the implementation-expansion phase to reduce global CO2 emissions.
Objective:
To present experiences, and some of the most relevant results obtained during calcination tests of kaolinitic clays from different deposits in Cuba, in the existing experimental pilot plant at Universidad Central “Marta Abreu” de Las Villas.
Materials and Methods:
The main physical and chemical characteristics of the clays under study, determined using XRF and XRD techniques, are described, and the stages of the technological process for activating these materials in the experimental facility are analyzed. The changes that occur in the particle size distribution are compared by sieving.
Results and Discussion:
The degree of dehydroxylation, and the pozzolanic reactivity of the material subjected to thermal modification are correlated with its chemical and mineralogical composition; and the results of the compressive strength achieved in standardized mortars for different formulations of activated kaolinitic clays are evaluated, both in the laboratory and at pilot scale.
Conclusions:
It is demonstrated that the initial preparation of raw materials through fine grinding, and the strict control of oven temperature and rotation, are essential parameters for achieving satisfactory dehydroxylation indicators. All national kaolinitic clays activated at pilot scale meet the necessary quality parameters and requirements for their use as supplementary cementitious materials.

CHARACTERIZATION OF PETROLEUM USED IN THERMOELECTRIC PLANTS

Yosvany González Díaz — 2026-08-26

Introduction:
Cuban crude oil, as well as the various blends used in the power generation process at thermoelectric plants, is a crucial factor when evaluating its effects on steam generator efficiency. Therefore, its use requires a rigorous physicochemical characterization.
Objective:
To characterize the fuels employed in Cuban thermoelectric power plants by determining their physicochemical properties based on a historical series.
Materials and Methods:
For the characterization of the fuels used, the historical results of their physicochemical properties, available at the central laboratory of the thermoelectric power plant, are taken into account. These properties are determined according to ASTM-D standards for petroleum products. The collection of historical data is carried out from the fuel records in the central laboratory. Based on these data, descriptive statistics and the coefficient of variation are performed to determine which properties exceed 10%.
Results and Discussion:
For all fuels used, there is a great variability in almost all properties, many of which are above 10%, particularly for the composition in metals such as aluminum, silicon, sodium, and vanadium.
Conclusions:
The physicochemical properties of the fuels used exhibit considerable variability, affecting their quality. These characteristics lead to numerous operational challenges, including handling, transportation, and combustion, which must be considered in the operation of power generation units.

ENERGY PERFORMANCE ASSESSMENT OF HOTEL BUILDINGS IN VARADERO, CUBA

Osvaldo Fidel García Morales — 2026-08-26

Introduction:
Hotels are among the most energy-intensive building types; improving their efficiency offers both economic and environmental benefits. Reliable assessment of energy performance requires statistically validated baselines and performance indicators.
Objective:
To evaluate the energy performance of hotel buildings in Varadero, Cuba, using statistically derived baselines and performance metrics.
Materials and Methods:
Baseline energy consumption (EnB) was established for 15 hotels using the IDELIN_Hotel software tool, which integrates occupancy and cooling degree days (CDD) into a combined variable (Room Degree Days, RDD). Statistical validity was verified using the correlation coefficient (R2), the mean squared error coefficient of variation (CV-RMSE), and the normalized mean error coefficient (NMBE). Performance in the subsequent year was evaluated using specific energy consumption (Cee), non-service energy (Eo), energy variance (Ev), and cumulative sum of deviations (CUSUM).
Results and Discussion:
Twelve hotels achieved energy savings relative to their baselines, while three operated inefficiently. The best performance was observed in Hotel K, which saved 1300 MWh/year. Indicators highlighted the influence of occupancy and outdoor temperature on consumption patterns.
Conclusions:
The study confirms the statistical robustness of the baselines and demonstrates the utility of IDELIN_Hotel software tool for energy performance assessment. Comparative analysis of indicators provides actionable insights for energy management systems in the hotel sector.

APPLICATION OF EXPERIMENTAL PLANS FOR THE DETERMINATION OF OPTIMAL INVESTMENT CAPACITIES IN THE DAIRY INDUSTRY

Maura Serrano Rodríguez — 2026-05-10

Introduction:
There are no technologies in Villa Clara for utilizing the cream from fresh milk; there is only one facility in the province equipped with such technology.
Objective:
To determine the optimal investment capacities for skimming and processing fresh milk in Villa Clara.
Materials and Methods:
Evaluate, using saturated factorial designs, the possibilities of utilizing the cream contained in fresh milk at the pasteurization plants of Santa Clara and Sagua, employing cost per unit of weight produced as the optimization parameter.
Results and Discussion:
The inclusion of investments in fresh milk skimming lines and butter production in Sagua and Santa Clara showed a decrease in cost per unit weight, through previously non-existent capacities that are recovered in one year.
Conclusions:
The combination of economic analysis and experimental designs offers a robust framework for evaluating technological and economic alternatives.

PROCEDURE FOR EQUIPMENT LAYOUT IN A CHEMICAL PLANT WITH INFRASTRUCTURE CONSTRAINTS

Néstor Ley Chong — 2026-05-11

Introduction:
The layout of equipment in existing chemical plants directly influences operating costs, as material transport has a direct impact on operating expenses. Optimizing these material flows in facilities with pre-existing infrastructure constraints requires specific methodological approaches.
Objective:
To propose a structured heuristic procedure for the reconfiguration and placement of equipment in existing chemical plants.
Materials and Methods:
A six-step procedure was designed based on analyses of technical documents and systematic site visits.
Results and Discussion:
The procedure allows for the identification of bottlenecks and redundant routes in operating plants, facilitates decision-making, and overcomes the limitations of ideal theoretical models that are not applicable to rigid infrastructures.
Conclusions:
The procedure provides a structured framework for equipment layout in existing plants, enabling improvements without large-scale investments in chemical industry facilities.

TECHNOLOGIES FOR OBTAINING MANGANESE SULFATE FROM MINERALS ADAPTED TO THE CUBAN CONTEXT

Lisandra Guevara Orozco — 2026-05-11

Introduction:
Manganese sulfate (MnSO₄) is a compound of high commercial value, essential for the production of agricultural fertilizers. In Cuba, there is availability of manganese-bearing minerals, as well as a growing need to develop domestic inputs for the agro-industrial sector.
Objective:
To analyze the main technological routes for producing MnSO₄ from minerals, and evaluate their possible adaptation to the Cuban context.
Materials and Methods:
A bibliographic review was conducted using databases such as ScienceDirect and google scholar. Analysis–synthesis and induction–deduction methods were applied to process information on minerals, metallurgical processes, and operational variables.
Results and Discussion:
Pyrolusite was identified as the most relevant oxidized mineral and is abundant in Cuban deposits. A comparative analysis of technological routes showed that hydrometallurgy, through acid leaching with reducing agents, is the most promising alternative due to its high efficiency, selectivity, lower energy requirements, and flexibility for small and medium scales. Critical process variables and various reducing agents were analyzed. The use of organic reductants, such as sawdust available locally as an agro-industrial by-product, emerges as an economically and environmentally attractive alternative.
Conclusions:
The hydrometallurgical route, using reducing agents of national origin, represents the most viable technological alternative for manganese sulfate production in Cuba, enabling the use of national mineral resources and promoting sustainable industrial development.

POLYOLS: PROPERTIES AND SYNTHESIS

Alejandro Rodríguez Borges — 2026-08-26

Introduction:
Polyols are a group of sweeteners that serve as precursors for many interesting products. They are produced by catalytic hydrogenation of monosaccharides or mixtures thereof in the presence of metallic catalysts, or by fermentation using microorganisms. Sorbitol, mannitol, and xylitol are three of the best-known polyols due to their widespread use in different industries.
Objective:
To review the literature regarding the industrial production and properties of three polyols of interest: sorbitol, mannitol, and xylitol.
Materials and Methods:
A bibliographic review was conducted using Google Scholar and ResearchGate, prioritizing recent publications. Synthesis routes were compared and the properties of the selected polyols were summarized.
Results and Discussion:
Sorbitol is considered a platform molecule. It is used in the production of food, pharmaceuticals, and polymers. Its production is based on the catalytic hydrogenation of glucose. Mannitol is less soluble and less sweet than sorbitol, with low hygroscopicity. It is produced by the hydrogenation of fructose or mannose, either enzymatically or by microbial fermentation. Xylitol has a sugar-like taste and anticariogenic properties. It is used in the production of chewing gum, dental products, and cosmetics. It is obtained by the hydrogenation of xylose, although the biotechnological route offers greater selectivity and sustainability.
Conclusions:
Polyols are healthy alternatives to sugar with applications in multiple industries. Sorbitol, mannitol, and xylitol stand out for their functional properties and health benefits. Biotechnological routes are emerging as more sustainable options compared to traditional chemical processes.