Instant Determination of Moisture and Bulk Density of Woodchips in Cellulose Industry

Abstract

Purpose: This research aims to achieve the instantaneous determination of moisture content and bulk density of wood chips for energy generation and pulp production in the pulp and paper industry. Theoretical framework: The moisture content and bulk density of woodchips influence the quality of biomass for energy generation and cellulose production in various ways. These variables affect the calorific value, mass and volume of logistical transport, the quantity of reagents in the reactor for wood delignification, among other factors. For this reason, a quick and accurate evaluation of these factors in the field is of fundamental importance to improve industrial quality and productivity. Method: To achieve this goal, a pilot test was conducted using a capacitive sensor and a portable scale to determine the moisture and bulk density of wood chips. Calibration equations were developed in the laboratory for the sensor, correlating the readings with the actual moisture content of seven types of wood chips, including Eucalyptus spp. and Pinus spp. The results of field measurements using these equations were compared with the gravimetric method, as well as bulk density measurements. Results and conclusion: The moisture calibration equations showed a high correlation between the capacitive sensor and the gravimetric method. The field density results were similar to those obtained in the laboratory. It was concluded that the investigated methods show promise for use in the pulp and paper industry. Research implications: The validation and accuracy of portable instruments for the instantaneous determination of moisture content and bulk density of wood chips are of utmost importance for manufacturers of portable meters and for industries that use this raw material. Originality/value: The instantaneous determination of moisture content and bulk density can contribute to improving the energy and production efficiency of boilers that generate heat for pulp digesters. Moreover, it optimizes logistical transportation and quality control against the attack of xylophagous organisms, preventing waste of raw materials, which is essential for sustainable development.