Estudo da influência da umidade da lenha e temperatura da água de alimentação na geração de vapor e consumo de lenha para a produção de papel reciclado

Abstract

Brazil is a large producer of paper, both virgin fiber and recycled fiber paper. For paper manufacturing, one of the most important steps is drying the sheet, which is also the most energy-consuming activity. Therefore, present study aimed to analyze the interference of firewood humidity and boiler feedwater temperature on steam generation for the paper production machine. To this end, during the year 2022, data on the humidity of received firewood and feedwater temperature were collected through sensors. It was evaluated and observed that, even with an increase in the price of firewood when the humidity is lower, it is still worthwhile to use less moist firewood. Additionally, it was noticed that feedwater temperature is of paramount importance, as there is a 0.86% increase in firewood consumption for every 5°C decrease in temperature. Thus, it was concluded that the two studied factors, firewood humidity and feedwater temperature, are highly relevant to steam production, but there are alternatives to improve parameters such as purchasing higher-value firewood with lower humidity and increasing condensate return, originating from the paper drying cylinders, by redirecting excess condensate that was originally destined for the paper machine to the boiler.