Carlos Ariel Cardona Alzate

Importance of stability study of continuous systems for ethanol production.

Fuel ethanol industry presents different problems during bioreactors operation. One of them is the unexpected variation in the output ethanol concentration from the bioreactor or a drastic fall in the productivity. In this paper, a compilation of concepts and relevant results of several experimental and theoretical studies about dynamic behavior of fermentation systems for bioethanol production with Saccharomyces cerevisiae and Zymomonas mobilis is done with the purpose of understanding the stability phenomena that could affect the productivity of industries producing fuel ethanol. It is shown that the design of high scale biochemical processes for fuel ethanol production must be done based on stability studies.

A comprehensive review on the implementation of the biorefinery concept in biodiesel production plants

Biodiesel is a promising alternative to petroleum diesel and its production from various generations of feedstocks by using different technologies has been constantly growing globally. However, in spite of such large scale of production, serious considerations should be taken into account to ensure the long-term sustainability of biodiesel production. This issue becomes more of concern given the fact that some generations of feedstocks used for biodiesel production are in clear conflict with food security. The concept of biorefinery has been at the center of attention with an aim to address these challenges by promoting an integral use of biomass to allow the production of multiple products along with biodiesel. Such implementation has been extensively studied over the last years and is expected to lead to economic, environmental, and social advantages over individual processes. The current review first presented an overview on biodiesel, its different feedstocks, and production technologies. Subsequently, the biorefinery concept and its correct implementation was technically discussed. Biodiesel production under the biorefinery scheme was also presented. Finally, techno-economic analysis of biodiesel production under the biorefinery concept by considering palm oil-based biorefinery as case study was investigated.

Environmental Assessment of Biorefineries

The development of the biorefinery concept is based on the techno-economic feasibility of the proposed process considering raw materials, process options, mass and energy integration, market constraints, etc. Nevertheless, along with all these considerations, the environmental assessment must be taken into account at the same time, and concepts like sustainability, land uses, environmental impacts, and other related issues must be included in the biorefinery design since the first moment. This work summarizes the main methodologies and aspects concerning the environmental assessment of biorefineries. Different case studies covering a wide range of raw materials and products are also presented.

Aproximación conceptual a la separación del dióxido de carbono en corrientes de combustión

El dioxido de carbono (CO2) es considerado uno de los principales gases causantes del efecto invernadero, responsable de los fenomenos de calentamiento global y cambio climatico; por ello se han propuesto distintas estrategias de captura y almacenamiento fisico o quimico de CO2, especialmente en las emisiones provenientes de corrientes de combustion. Este documento presenta, en primer lugar, una revision de los procesos de captura de CO2 en procesos de combustion, y, luego, dos escenarios de estudio para la captura de CO2 en un proceso de poscombustion usando metanol como combustible. En el primer escenario se separa el CO2 utilizando absorcion con monoetanolamina, y en el segundo se utiliza destilacion. Los resultados indican que ambas tecnologias son apropiadas, pero que el rendimiento es mayor con la destilacion.