**4. Conclusions**

New correlations are developed using the ultimate analyses of torrefied woody biomass comprising 152 data points and 15 different types of wood, for predicting the carbon content, hydrogen content, and heating value of a torrefied wood. The proposed relations given in Equations (18) through (22) allow estimation of the C and H contents and HHV of a torrefied wood as a function of solid mass yield, composition and heating value of untreated wood. The accuracy of the proposed correlations is examined using additional experimental data related to torrefaction of willow, miscanthus, and spruce. Overall, the agreemen<sup>t</sup> between the predicted and measured quantities of the carbon, hydrogen and HHV is satisfactory. The proposed correlations provide a useful tool that can be incorporated in process models of energy systems operating on torrefied wood.

**Author Contributions:** Conceptualization, Y.H.; Methodology, Y.H.; Validation, M.H.; Formal Analysis, M.H. and Y.H.; Investigation, M.H. and Y.H.; Data Curation, M.H.; Writing-Original Draft Preparation, M.H.; Writing-Review & Editing, Y.H. and E.K.; Supervision, Y.H. and E.K.

**Funding:** This research received no external funding.

**Acknowledgments:** The funding support of Central Michigan University is gratefully acknowledged.

**Conflicts of Interest:** The authors declare no conflict of interest.
