A new prototype steam classification process apparatus has been designed, fabricated, and tested. The optimum operating conditions for the unit have been established, and additional process equipment has been added to facilitate the separation and recovery of a higher-quality cellulosic product that is more desirable for use both as a combustion fuel and as a feedstock for conversion into compost or fuels and chemicals. A comparison of certain mechanical features, operating procedures, and test results between the original and the new prototype process units shows that substantial improvements have been made in both the process apparatus and in the overall process that should enhance the commercial potential of steam classification.