En esta investigación se analiza la posición geoespacial del principal sector universitario de la ciudad de Manizales y su relación con las características operativas de la red de transporte y el estrato de sus principales usuarios (estudiantes y docentes). La metodología aplicada se basa en cuatro etapas teniendo como objetivo el análisis de accesibilidad media integral ofrecida por la red de transportes a la comunidad universitaria, a través de un modelo geoestadístico. Se encontró que los estudiantes que viven en barrios de estrato bajo son los que deben invertir más tiempo para desplazarse hacia la Universidad, situación contraria a la obtenida con los estudiantes y docentes que residen en barrios de estrato alto. Los resultados expresan la inequidad espacial que se refleja en altos tiempos de viaje, así como la ausencia de posibilidades reales de llegar al sector universitario, concluyendo que es necesario el ampliar la variedad de trasporte y mejorar la calidad de los modos de transporte que llegan a dicho sector desde la residencia de estudiantes y docentes.

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In this paper, fuel ethanol production from Chlorella vulgaris cake was evaluated by experimental and conceptual design techniques. Enzymatic hydrolysis and fermentation with Saccharomyces cerevisiae was performed to quantify the reducing sugars and ethanol from microalgae cake. Extractive distillation and molecular sieves were evaluated as alternative technologies for the dehydration of ethanol. The mass and energy balances were solved using the Aspen Plus software. The total ethanol production costs were evaluated using the Aspen Process Economic Analyzer software, and the Waste Reduction algorithm (WAR) was used to calculate the environmental impacts. Additionally, the effect of energy integration was included in the economic analysis and environmental assessment. The yields obtained for reducing sugars and ethanol were 0.55 and 0.17 g per g of cake, respectively. The global yield of ethanol was 211.9 L per tonne of cake, and the total production cost was 0.76 and 0.91 USD per liter using molecular sieves and extractive distillation, respectively. The most promising technology to produce ethanol from microalgae cake was dehydration by molecular sieves with full energy integration. For this technology, the production cost was 0.76 USD per liter, which resulted in an economic margin of 19.15%. From the environmental point of view, the potential environmental impact was 0.84 PEI/kg products. Additionally, bioethanol from microalgae was shown to be less harmful than bioethanol from corn and sugar cane.