The online measurement of wood chip properties has been highly sought after for the pulp manufacturer. Wood chips varies in size, moisture content, species, density, lignin content, extractives, etc.. Furthermore, depending on the storage conditions and seasonality, chip quality can further change this biological raw material. Yet, it is one of the major inputs into the digester, along with white liquor, and could have a tremendous impact on the production rate and product quality. Furthermore, wood-chip cost is a major factor on pulp production costs.

This seminar will cover some of the previous and existing analyzers for chip properties measurements. We will discuss the use of a novel online NIR-based analyzer for measurements of woodchip moisture content and how it can be used to calculate the dry mass flow of wood chips entering the digester. This information has been used as feedforward data for production rate control with great gains. Measurements of liquor properties, including white liquor (WL) and Weak Black Liquor (WBL) for residual alkali can provide necessary information for feedback control.

Finally, we will show and discuss some of the latest results on the development of online measurements of woodchip properties, such as basic density, bulk density, soluble lignin, and total extractives.

As the industry moves forward and adopt new measurement technologies that provide fundamental properties of the raw materials and process chemistry, optimization and semi-autonomous operations could be possible.