The increase of energy efficiency is an option to reduce greenhouse gas emissions (GHG). This benefits the industrial sector by reducing the energy consumption required to manufacture products, increasing production levels, and improving the competitiveness of the industry at a national and international level.
Surface-stabilized combustion (SSC) is a fuel-flexible technology that extends the stability limits of lean premixed systems, while achieving ultra-low emissions of NOx, CO and UHC (unburned hydrocarbons). To evaluate these attributes, the present study quantifies (1) operability characteristics i.e., lean blowoff limit and flashback behavior and (2) pollutant emissions (CO, N2O, NH3, NO and NO2) of a commercial SSC burner when operating at a fixed fire rate on a wide range of fuel compositions.
The polytropic coefficient is an important variable for determining errors in pressure and volume measurements and for apparent heat release calculation in engine combustion analysis. For commercial gasoline-fueled spark-ignition engines and diesel-fueled compression-ignition engines, a wide understanding about the thermodynamic models and values of the polytropic coefficient exists; however, in other technologies, in which gaseous fuels are used, the pressure treatment strategies and heat transfer models should be adjusted to allow for a better calculation of the polytropic coefficient.
The use of high compression ratios on spark ignition engines enables the increase of thermal efficiency, but also contributes to the reduction of high load limit because of the higher auto-ignition tendency in the end-gas. Gaseous fuels provide a good option to expand the high load limits because of their high octane ratings, mostly in small engines. Biogas is a renewable fuel, mainly composed by CH4 and CO2 that exhibits high auto-ignition temperature and slow laminar flame speed.
This paper addresses the experimental and numerical modeling of NOx emissions and lean blow off (LBO) stability limits of natural gas and biogas fuels reactions stabilized with a low swirl burner (LSB). The paper presents the methodology to set up a chemical reactor network (CRN) based on experimental results and computational fluid dynamics (CFD) simulations. The CRN is a simplified representation of the fluid dynamics and energy balance of the reactive gases in the boiler environment.
The wet compressor (WC) has become a reliable way to reduce gas emissions and increase gas turbine efficiency. However, fuel source diversification in the short and medium terms presents a challenge for gas turbine operators to know how the wet compressor will respond to changes in fuel composition. For this study, we assessed the operational data of two thermal power generators, with outputs of 610 MW and 300 MW, in Colombia.
In this work, the energy audits and evaluation of the kilns used in the calcination stage of the calcium oxide production process of two Colombian factories are shown. The energy intensity and usage distribution were evaluated, as well as the technological state of the presently used heating equipment as compared with the most advanced technology available for the calcination process.
The cement industry is one of the world’s largest energy consumers. In this work, a walk-through study of representative cement companies was carried out to characterize the energy profile of the cement industry in Colombia, with emphasis on evaluating the degree of obsolescence of the technology used in the processes, as well as identifying the main barriers that prevent the adaptation of more efficient technologies. Perception-surveys were performed among the energy managers to determine the barriers that hinder the implementation of energy efficiency measures.
This article addresses the numerical modeling of NOx emissions and lean blowoff (LBO) limits of confined and pressurized turbulent premixed flames stabilized with a low swirl burner. The study also evaluates existing numerical methods that can be used to predict exhaust pollutant emissions and reaction instability close to the LBO limit. One of the strategies presented in the article consists of establishing a chemical reactor network (CRN), which is a simplified model of the fluid dynamics and energy balance of the system coupled with a detailed reaction mechanism.
This paper presents the experimental results of the addition (increasing thermal power) and substitution (constant thermal power) of a sub-bituminous pulverized coal in a natural gas flame in a laboratory-scale premixed burner. The analyzed variables include radiation intensity, temperature profile, and flame shape. It was found that with the addition of 15% and 30% coal (energy based) into the natural gas flame, the radiation intensity was increased by 37% and 65%, respectively.