Title: Exergetic assessment and exergoeconomic diagnosis of a sugarcane plant in northeastern Brazil

Authors: Edmilson José da Silva Júnior; Carlos Marlon Silva Santos; Markus Antonio de Oliveira Porangaba; Rafael Alves de Oliveira; Adriano da Silva Marques

Addresses: Graduate Program on Physical Engineering, Federal Rural University of Pernambuco, UACSA, Rua Cento e Sessenta e Três, 300, 54518-430, Cabo de Santo Agostinho/PE, Brazil ' Department of Mechanical Systems, Federal University of Reconcavo of Bahia, Rua Rui Barbosa, 710, 44380-000, Cruz das Almas/Ba, Brazil ' Graduate Program on Physical Engineering, Federal Rural University of Pernambuco, UACSA, Rua Cento e Sessenta e Três, 300, 54518-430, Cabo de Santo Agostinho/PE, Brazil ' Graduate Program on Physical Engineering, Federal Rural University of Pernambuco, UACSA, Rua Cento e Sessenta e Três, 300, 54518-430, Cabo de Santo Agostinho/PE, Brazil ' Department of Renewable Energy Engineering, Federal University of Paraiba, Cidade Universitaria, s/n, 58051-900, João Pessoa/PB, Brazil

Abstract: The increase in industrial needs increased the demand for fuels, electricity and the growth of climatic effects. This study performs an exergoeconomic evaluation in a sugar, ethanol and electricity production plant located in the Northeast of Brazil. The objective is to identify thermoeconomic inefficiencies, exergy destruction and efficiencies, determine the costs of exergy flows and a step by step of exergoeconomic diagnosis using the SPECO method. The results show the greatest inefficiencies presented in boiler 1 (48 MW, 28%), boiler 2 (43 MW, 25%) and boiler 3 (31 MW, 18%). The production of steam costs R$63.88 for each GJ of energy. The total cost of exergy destruction in the boilers is R$3,808 per hour of operation which means about 84% of all exergy destroyed in the plant. The exergoeconomic diagnosis concludes that the equipment that needs optimisation primarily is the deaerator (5,904% rk) and the condenser (1,674% rk).

Keywords: exergoeconomic; exergy destruction; specific exergy cost; SPECO; sugar cane; thermodynamic analysis.

DOI: 10.1504/IJEX.2023.128519

International Journal of Exergy, 2023 Vol.40 No.1, pp.15 - 33

Received: 05 Dec 2021
Received in revised form: 08 Apr 2022
Accepted: 30 Apr 2022
Published online: 25 Jan 2023 *