Method and apparatus for converting waste solid sustainable carbon material to chemical products is described herein. The methods add hydrocarbon derived from fossil sources to gas derived from gasifying waste solid sustainable carbon material to enhance hydrogen availability, and in some cases carbon availability, for production of the chemical products. Carbon dioxide made by the process is at least partially sequestered to yield a chemical manufacturing process with environmental burden substantially less than conventional processes. Use of the hydrocarbon boosts yield of final products.