Correlations to Predict Elemental Compositions and Heating Value of Torrefied Biomass

Abstract

Measurements reported in the literature on ultimate analysis of various types of torrefied woody biomass, comprising 152 data points, have been compiled and empirical correlations are developed to predict the carbon content, hydrogen content, and heating value of a torrefied wood as a function of solid mass yield. The range of torrefaction temperature, residence time and solid yield of the collected data is 200–300 °C, 5–60 min and 58–97%, respectively. Two correlations are proposed for carbon content with a coefficient of determination ( R 2 ) of 81.52% and 89.86%, two for hydrogen content with R 2 of 79.01% and 88.45%, and one for higher heating value with R 2 of 92.80%. The root mean square error (RMSE) values of the proposed correlations are 0.037, 0.028, 0.059, 0.043 and 0.023, respectively. The predictability of the proposed relations is examined with an additional set of experimental data and compared with the existing correlations in the literature. The new correlations can be used as a useful tool when designing torrefaction plants, furnaces, or gasifiers operating on torrefied wood.

Fundamental Characteristics and Kinetic Analysis of Lignocellulosic Woody and Herbaceous Biomass Fuels

“…Through torrefaction, the surface of biomass with a pronounced distribution of hydrophilic functional groups turns hydrophobic, thus making it difficult for moisture adsorption to occur, which decreases the inherent moisture. The pretreatment process also assists with biomass pulverization via the destruction of its organic structure for higher effectiveness, and it mediates the devolatilization of a certain amount of volatile gases to increase the fixed carbon, thus resulting in increased calorific values [5][6][7]. Since torrefaction technology fundamentally depends on the pretreatment process under pyrolysis conditions for the production of carbon-rich fuels, it is essential that the basic pyrolysis characteristics of the biomass fuel are thoroughly understood through in-depth analyses of the biomass pyrolysis [8][9][10][11].…”

Achieving negative emissions through oceanic sequestration of vegetation carbon as Black Pellets

“…The CO 2e of pellet material on the sea floor is computed from measurements of the carbon contents of torrefied pellets taken from a literature review by Hasan et al (2018). This review provided a compilation of 152 measurements from many sources of the ultimate analysis of the carbon contents and heating values of pellets representing 15 different types of wood feedstocks under 43 different torrefaction conditions.…”

A GA-ANFIS Model for the Prediction of Biomass Elemental Properties

“…Therefore, the rapid and economical approach would be to develop a model which can be used to estimate the elemental constituent from the proximate value since it has been established that there is a relationship between these two experimental methods. Against all these odds, artificial intelligence, AI, has emerged with a potential to assist in fulfilling the objectives of biomass-to-energy exploration which centres around the estimation of the properties of biomass, such as the elemental composition and enthalpy of combustion [3,[5][6][7][8][9][10]. AI has the capability for modelling of complex systems with high degree of accuracy.…”

“…The GA has been extensively used in different fields [24][25][26] and most closely in the prediction of the heating value of biomass [13], but there is no any know GA application for the prediction of the elemental composition of biomass which covers different sources. There are quite a few published models which predict the elemental composition of solid biomass based on proximate analysis [3,5,[8][9][10][27][28][29][30]. Nhuchhen [30] developed a correlation which estimated the carbon, oxygen, and hydrogen constituent of untreated and torrefied biomass on the basis of proximate analysis.…”

“…Nhuchhen [30] developed a correlation which estimated the carbon, oxygen, and hydrogen constituent of untreated and torrefied biomass on the basis of proximate analysis. Similarly, Mahmudul et al [9] developed an empirical correlation towards the prediction of the elemental composition of torrefied woody biomass. Also, the correlation developed by Vakkilainen [29] is only limited to black liquor.…”