The scientists examined how lignite changes its structure when treated with ruthenium ions to break it down into simpler products. They found that lignite particles transformed from big chunks to tiny particles during this process, releasing smaller molecules. Nearly all of the lignite material changed into these simpler products. The molecules in the resulting mix varied in size, showing that the lignite particles broke down gradually, creating a series of different products. The breakdown of macromolecules into benzene polycarboxylic acids was the important slow step in this process. This study gives a detailed look at how lignite changes as it's broken down, helping us to understand and manage lignite depolymerization better.