The researchers studied how different types of plant waste, like fir wood and corn stalks, break down under high heat and pressure. They found that corn stalks have more hemicellulose but less cellulose and lignin than fir wood. Fir wood produces more solid products, while corn stalks produce more liquid products. Different parts of the plants break down at different temperatures, with cellulose turning into carbon microspheres and lignin into phenols. Overall, corn stalks are easier to convert into useful chemicals compared to fir wood.