Produção de energia elétrica a partir do GLP combinada com aproveitamento de calor em um spray dryer industrial

Abstract

The need to improve energy efficiency in industry plays an important role in minimizing climate change. Most thermoelectric plants are used to generate electricity due to their production flexibility, being used to balance energy supply and demand. The main problems with thermoelectric plants are low efficiency and high heat rejection. We worked with the proposal to generate electrical energy on-site using a thermal machine (gas turbine), and the rejected heat was used to heat the drying air of a Spray Dryer (SD). The performance of a conventional SD, which uses a burner with liquefied petroleum gas (LPG), was compared with an SD that uses a gas turbine to generate electricity and the rejected heat to heat the drying air, replacing the burner. The calculations were carried out using the iiSE Process Simulation process simulator, and the operational cost of the SD was calculated considering the prices of electrical energy and thermal energy (gas) for the ten largest economies in the world. The simulations observed that LPG consumption was 22.1% higher than the proposed alternative (SD with gas turbine). Conversely, 2.0 kW of electrical energy was produced per kg of LPG consumed, while a conventional SD does not produce electrical energy. Comparing the operational course, the system becomes viable in countries where the cost of electrical energy is higher than thermal energy, such as the United Kingdom, Italy, and Canada, and less viable in countries where electrical energy has similar costs to thermal energy, such as Brazil, China, and India.