https://concentrica.cua.uam.mx/handle/123456789/2 Sat, 19 Sep 2026 03:09:50 GMT 2026-09-19T03:09:50Z https://concentrica.cua.uam.mx/handle/123456789/1311 Título : Comparative thermodynamic analysis of the performance of an organic Rankine cycle using different working fluids Autor : MENDEZ CRUZ, LADISLAO EDUARDO; GUTIERREZ LIMON, MIGUEL ANGEL; LUGO MENDEZ, HELEN DENISE; LUGO LEYTE, RAUL; LOPEZ ARENAS, MARIA TERESA; SALES CRUZ, ALFONSO MAURICIO Resumen : Today, the study of thermal systems that take advantage of residual thermal sources in the power generation sector is of great importance to mitigate environmental impact and promote sustainable alternatives in this sector. Among these alternatives, the organic Rankine cycle (ORC) is of great relevance since it allows taking advantage of residual energy sources at low temperatures. This work presents a methodology to evaluate the feasibility of using a refrigerant as a working fluid in an organic Rankine cycle based on an exergetic viability index. As a case study, R134a, R600a, R245fa, and R123 refrigerants were considered. A residual thermal source was used that came from the Hybrid Cycle Plant of the Valley of Mexico. Thermodynamic analysis was performed to determine generated power, thermal efficiency, refrigerant mass flow, pinch point temperature difference, specific steam consumption, unused thermal exergy flow, exergy efficiency, and total heat transfer requirement. The weighted average of the differences between these indicators, the global warming index, and the ozone depletion potential relative to the most favorable indicator corresponded to the definition of the exergetic viability index of the refrigerant. The results indicate that the ORC operating at condensing temperatures of 25, 35, and 45 C with R245fa shows the highest rate of exergetic viability despite not generating the greatest amount of power and being one of the refrigerants with the highest total heat transfer requirement. Finally, at condensing temperatures above 45 C, it is observed that R600a is exergetically the most viable refrigerant used in the ORC. Sat, 01 Jan 2022 00:00:00 GMT https://concentrica.cua.uam.mx/handle/123456789/1311 2022-01-01T00:00:00Z https://concentrica.cua.uam.mx/handle/123456789/1310 Título : Analysis of the propionate metabolism in bacillus subtilis during 3-Indolacetic production Autor : CASTILLO ALFONSO, FREDDY; QUINTANA MENENDEZ, ALEJANDRO; VIGUERAS RAMIREZ, JUAN GABRIEL; SALES CRUZ, ALFONSO MAURICIO; ROSALES COLUNGA, LUIS MANUEL; OLIVARES HERNANDEZ, ROBERTO Resumen : The genera Bacillus belongs to the group of microorganisms that are known as plant growthpromoting bacteria, their metabolism has evolved to produce molecules that benefit the growth of the plant, and the production of 3-indole acetic acid (IAA) is part of its secondary metabolism. In this work, Bacillus subtilis was cultivated in a bioreactor to produce IAA using propionate and glucose as carbon sources in an M9-modified media; in both cases, tryptophan was added as a co-substrate. The yield of IAA using propionate is 17% higher compared to glucose. After 48 h of cultivation, the final concentration was 310 mg IAA/L using propionate and 230 mg IAA/L using glucose, with a concentration of 500 mg Trp/L. To gain more insight into propionate metabolism and its advantages, the genome-scale metabolic model of B. subtilis (iBSU 1147) and computational analysis were used to calculate flux distribution and evaluate the metabolic capabilities to produce IAA using propionate. The metabolic fluxes demonstrate that propionate uptake favors the production of precursors needed for the synthesis of the hormone, and the sensitivity analysis shows that the control of a specific growth rate has a positive impact on the production of IAA. Sat, 01 Jan 2022 00:00:00 GMT https://concentrica.cua.uam.mx/handle/123456789/1310 2022-01-01T00:00:00Z https://concentrica.cua.uam.mx/handle/123456789/1309 Título : Thermodynamic optimization of trigeneration power system Autor : MENDEZ CRUZ, LADISLAO EDUARDO; GUTIERREZ LIMON, MIGUEL ANGEL; LUGO LEYTE, RAUL; SALES CRUZ, ALFONSO MAURICIO Resumen : Worldwide, the growing demand for energy has been largely met through power cycles utilizing fossil fuels. Combined cycles, which integrate a gas turbine with a steam cycle, prove to be the best alternative due to their power generation capacity and high efficiencies. This efficiency is primarily attributed to the ability to harness exhaust gases to generate steam in the heat recovery boiler, allowing additional power generation through the steam turbine. Currently, there is a quest for the integration of low-temperature power cycles to maximize the utilization of residual thermal energy flows for power generation. Therefore, this work conducts an exergetic optimization of a power trigeneration system aimed at maximizing exergetic efficiency. This system includes a gas turbine and a steam cycle coupled with three different configurations of the Organic Rankine Cycle (ORC): a simple ORC, a supercritical ORC, and an ultracritical ORC. The ORC configurations are analyzed using eight organic working fluids, namely R1234yf, R290, R134a, R1234ze, R152a, R600a, R245fa, and R123. The results show that the maximum exergetic efficiency is achieved by using R152a in the ultracritical ORC configuration coupled with the combined cycle, achieving an exergetic efficiency of 55.79%. Furthermore, the maximum power generated is attained by the steam cycle with 85,600.63 kW and 3101.21 kW for the ultracritical ORC. Mon, 01 Jan 2024 00:00:00 GMT https://concentrica.cua.uam.mx/handle/123456789/1309 2024-01-01T00:00:00Z https://concentrica.cua.uam.mx/handle/123456789/1308 Título : Thermodynamic evaluation of the hybrid combined cycle power plant in the Valley of Mexico Autor : MENDEZ CRUZ, LADISLAO EDUARDO; SALAZAR PEREYRA, MARTIN; LUGO LEYTE, RAUL; SALES CRUZ, MAURICIO; TORRES ALDACO, ALEJANDRO; LUGO MENDEZ, HELEN DENISE Resumen : Modern power generation aims to maximize the extraction of thermal energy from fossil fuels to produce electricity. Combined cycle power plants, leaders in efficiency, sometimes require an additional steam generator to compensate for insufficient exhaust gas energy in the heat recovery steam generator (HRSG), leading to hybrid combined cycles. This study presents a comprehensive thermodynamic analysis of the hybrid combined cycle power plant located in the Valley of Mexico, operating under both full-load and partial-load conditions. The investigation begins with an energy analysis evaluating key performance parameters under real operating conditions, including the power generation, heat flow supply, thermal efficiency, fuel consumption rates, steam flow, and specific fuel consumption. Subsequently, the analysis examines the performance of the steam cycle using the β factor, which quantifies the relationship between heat flows in the steam generator and the HRSG, to maintain a constant steam flow. This evaluation aims to determine the potential utilization of exhaust gas residual energy for partial steam flow generation in the steam turbine. The study concludes with an exergy analysis to quantify the internal irreversibility flows within the system components and determine the overall exergy efficiency of the power plant. The results demonstrate that, under 100% load conditions, the enhanced utilization of exhaust gases from the HRSG leads to fuel savings of 33,903.36 tons annually and increases the exergy efficiency of the hybrid combined cycle power plant to 54.08%. Wed, 01 Jan 2025 00:00:00 GMT https://concentrica.cua.uam.mx/handle/123456789/1308 2025-01-01T00:00:00Z