Coffee is a highly productive agricultural product in the department of Tolima. The wet fermentation process of coffee generates about 80% of the waste, which is highly contaminated with organic matter that pollutes water sources, so anaerobic co-digestion techniques are implemented in coffee wastewater using Taiwan type biodigesters. According to the study of three biodigesters fed with coffee waste and animal manure, the aim is to show their potential application in coffee farms. These biodigesters generated a biogas production with CH₄ concentrations between 49.1% ± 4.6 and 58.1% ± 2.4 in volume, in addition to the benefit of the biol used as fertilizer in the crops. The biogas produced can be used for cooking and can save around USD 40.17 in natural gas. Therefore, the biodigester is a potential tool to mitigate the harmful effects of coffee cultivation on the surrounding ecosystem and can project coffee production in a sustainable direction.

Coffee is one of the most representative agricultural products in Colombia; several factors related to how it is produced, processed and marketed make it particularly important in post-conflict situations. The cultivation of coffee has acquired a very important role in the post-conflict stage that Colombia is experiencing. The rural areas hit hardest by violence are now seeing how improving agricultural conditions can help promote sustainable development and build peace in their regions. In coffee processing, women play an important role, with between 20% and 30% of coffee farms around the world being female-operated and up to 70% of labor in coffee production being provided by women. Women not only contribute to coffee processing, but they are also responsible for family activities such as cooking, and those activities are often made in wood stoves, thereby increasing their health risk. Against this background, this study presents the design and implementation of a biodigester fed by waste produced at Coffee Production Units (CPUs) located in the rural area of Tolima department in Colombia (an important scene of the armed conflict) in order to produce biogas for domestic cooking activities. Results show that implemented biodigester can produce between 1362 and 1597 kg/day (1.1704 and 1.3604 Nm³/day), which is enough energy for domestic activities for a family of four. Furthermore, it demonstrates benefits in the economic, social and environmental context of CPUs. Additionally, due to the importance of women in coffee production, this paper also evaluates the impact of the implementation of biodigesters in farms, which has shown that biodigester implementation positively impacts the production activities and activities performed by women, thereby increasing their life quality.

This paper introduces the modelling, simulation of anaerobic digestion process for biogas production from organic waste. Insight on the relevant model parameters is obtained by performing a sensitivity analysis, followed by the estimation of the selected candidates using a sequential quadratic programming algorithm. Calibration and validation of the model are based on experimental data obtained from a pilot-scaled plant, showing that the proposed model is able to correctly predict the Methane production dynamics from few key measurements.

Introduction— Previous reactor models have been used to study the dynamic behavior of bioethanol production systems, however, few have elaborated a comparative study of control strategies that stabilize and control the variables of interest. Objective— The objective of this study is to analyze the stability of a fermentation system to obtain bioethanol, its dynamic behavior, the characterization of equilibrium points and bifurcation points of the mathematical model proposed by Jarzebski in 1992 for a continuous fermentation, taking into account the performance of the reaction in a bioreactor and the application of industrial control techniques for its optimization. Methodology— Review and design methods of quantitative and systematized type were used. Results— The comparison between two control strategies to control bioethanol production, PID control and Fuzzy. Conclusions— This work shows the importance of the stability analysis of a continuous system and how it can define the regions of operational interest, in this case for ethanol production, showing that productivity is inversely proportional to the dilution rate. Finally, it is concluded that a better dynamic behavior of the system is obtained when a Fuzzy controller is used. This work also shows the importance of the stability analysis of a continuous system and how it can define the regions of operational interest, in this case for the production of ethanol.

La bioeconomía es una misión de largo alcance que se consolida como una apuesta de país en la que el conocimiento y el capital natural convergen y se trasforman en una potente fuerza de crecimiento económico y desarrollo social y sostenible. En concordancia con lo anterior, la Universidad de Ibagué tiene como objetivo principal generar acciones académicas, de investigación y proyección social, de alto valor, que creen y potencien capacidades para la región. En este sentido, ha confiado en este modelo como motor de desarrollo económico para el departamento y el país, empleando procesos de investigación, desarrollo e innovación (I+D+i).