Carlos A. Díaz

Autonomous University of Bucaramanga | UNAB · Energy Engineering - Faculty of Engineering

The development and improvement of biomass gasification processes have been accelerated by the use of computational tools for process simulation, exploring their feasibility under different conditions and identifying key parameters that are validated through real experiments, contributing to maturing a gasification technology from laboratory to com...

A new way of classifying localities in off-grid areas of Colombia has been developed based on non-supervised machine learning techniques (Principal Component Analysis -PCA and clustering) to better understand the differences between these localities beyond the typical classification only by the number of users. Data from the variables available in...

Exergy analysis of substitution of low-grade coal by raw, pyrolysed, or torrefied oil palm kernel shell (PKS) was simulated. A comparison of coal combustion base cases with different co-firing cases was made. Exergy efficiencies of pyrolysis and torrefaction agree with reported data. PKS pyrolysis and torrefaction decrease the fuel consumption comp...

Exergy analysis of substitution of low-grade coal by raw, pyrolysed, or torrefied oil palm kernel shell (PKS) was simulated. A comparison of coal combustion base cases with different co-firing cases was made. Exergy efficiencies of pyrolysis and torrefaction agree with reported data. PKS pyrolysis and torrefaction decrease the fuel consumption comp...

An exergetic and exergoeconomic analyses of a power generation system based in biomass gasification in a downdraft gasifier and internal combustion engine, with surplus syngas accumulation in a storage tank in a non-interconnected zone (NIZ) in Colombia, has been made utilizing the Thermoflex software to obtain data of streams and properties and th...

A review of the aspects related to the sustainability of the biomass gasification and the use of syngas from biomass for small scale power generation is presented, taking as a frame of reference the sustainable development goals (SDG) of the UN. Initially, the most relevant aspects of the SDGs related to the energy transition and the energy trilemm...

A general review of biomass, modeling of biomass gasification process and gasifiers was made.

En este trabajo, se ha medido la velocidad de llama laminar de las mezclas de combustible biogás/H2, desde biogás puro hasta mezclas de este con una adición de 15% de H2 en volumen, utilizando el método del cono interno de la zona de combustión o método bunsen. La velocidad de la llama laminar se determina por medio de los parámetros geométricos de...

In this work, the laminar flame speed and flame structure of biogas/H2 fuel mixtures were studied numerically from pure biogas to biogas with an addition of 15% H2 in volume by using the CHEMKIN software with the GRIMECH 2.11 kinetic mechanism. The effect of hydrogen addition to biogas on laminar flame speed and flame structure has been studied as...

The use of biogas generated in landfills has gained importance in developing countries like Colombia. Taking into account that this biogas presents poor combustion properties that make interchangeability with other combustible gases difficult, the elimination of gases and vapors, such as CO2 and H2O, through a cleaning process, in which the biogas...

This work describes the unidimensional study of steam reforming of methanol at short pseudo-contact time. Steam reforming process (SRP) is important to hydrogen production as energetic vector. A compressible mathematical model 1-D is developed. Peppley kinetic mechanism (1999) is adopted. The numerical predictions show up the same trend as the expe...

The possibility of predicting the interchangeability of a fuel gas by another gas or a mixture of gases allows to estimate the variability of the behavior of the combustion in an equipment when the gas for which the equipment was originally set is replaced by another gas. The study of flame structure and flame extinction limits of premixed flames i...

Use of biogas generated in landfills is an issue that has gained importance in developing countries such as Colombia. Taking into account that this biogas presents poor combustion properties that difficult its interchangeability with other combustible gases, in this work a simulation was carried out using the Landfill gas emissions model from US EP...

The negative environmental impacts associated to the use of large hydropower plants have helped to focus the attention on small-scale plants, which reduce these impacts considerably. In Colombia, there is an important potential for the implementation of both, large and small-scale hydropower projects, which has been exploited mostly in large plants...

The utilization of new renewable energy sources has been of special interest during the past years, seeking to decrease our dependence on fossil fuels and the corresponding environmental impact derived from their use. The combustion properties of a simulated gas composed of 60% methane and 40% carbon dioxide in volume are determined in this paper b...

Utilization of new renewable energy sources have had a special interest in last years looking for decrease the dependence of fossil fuels and the environmental impact generated for them. This work studies experimentally the flame stability of a simulated biogas with a volumetric composition of 60% methane and 40% carbon dioxide. The objective of th...