This report portrays the design of a devulcanization process for natural rubber-based tire material in a twin screw extruder. This process is tailored in the first instance in an internal mixer on small scale in the UT/ETE/SES labs, and industrial upscaling is done in an extruder at RubberGreen Industries, the industrial partner in this project. In the current section, the project background, motivation, introduction of the company and outline of the thesis are described.