Exergy Analysis Applied to a Mexican Flavor Industry that Uses Liquefied Petroleum Gas as a Primary Energy Source

Abstract

An exergy analysis to a Mexican flavor industry, which uses liquefied petroleum gas as a primary energy fuel in their process equipment was carried out.. The analysis used a proposed method that quantifies efficiency by means of exergetic indicators. To apply it to this case study equipment, the system or process was assumed to be a block that interacts with the surroundings in three ways: heat, work and mass transfer. The analyzed blocks were boilers, a thermal oxidizer, dryers, a distillation tower and extractors. Work and heat needs were covered by liquefied petroleum gas. The exergy indicators quantify the degradation of energy by determinining the difference between the actual operation efficiency of the block and the maximum operation, both of them obtained from second law point of view. These indicators were exergy loss, efficiency, effectiveness, performance and potential of improvement. Following the exergetic method application, it was found that the indicators of the effectiveness and performance in all blocks analyzed are near zero. This means that the process equipments are using a high exergy source to perform their function and also in large quantity. The results show that the oxidizer presented the major irreversibilities, and it is the equipment with the greatest potential for improvement and the key to reducing fuel consumption.