In this section we discuss the process simulation results of CNC production for two different materials (CNC61 and CNC64). Since sulfuric acid is the largest material input in the CNC production process, we investigate how recycling design affects the environmental performance of the whole system. First, we run our process model calculations for CNC production without sulfuric acid recycling. This is done to set up a benchmark value for materials and energy flows for the process and to estimate the environmental impacts (LCA)