Anthraquinone - A Review of the Rise and Fall of a Pulping Catalyst

摘要

The application of anthraquinone (AQ) as a pulping catalyst has been well documented in scientific studies and mill applications. AQ is known to increase the rate of delignification, enabling a reduction in pulping time, temperature, or chemical charge and an increase in pulp yield. Specific details of AQ use are not extensively reviewed in this work. The review focusses instead on the critical milestones in the AQ process life cycle including its initial introduction, investigation of the reaction mechanism and evaluation of best use by the pulping industry. The importance and difficulty of an economic justification for use of AQ is discussed. This is complicated by the modest improvement in yield obtained using AQ, and low cost of the displaced chemicals. In many mills, the ability to document increased net mill revenue due to the use of AQ has been impossible. Recent health and safety findings and regulatory decisions have put the continuing use of AQ by the industry in jeopardy. Given the unknown health risks, international regulatory environment, modest improvements available using AQ, and the difficulty in economically accounting for the benefits, this likely represents the final chapter in the AQ life cycle.