Process intensification by applying chemical looping in natural gas to dimethyl ether conversion process-Implications for process design education

摘要

Process intensification (PI) is an important concept in the profession of chemical engineering. In this article, we use the chemical looping reforming for dimethylether synthesis (CLR-DME) as an example to explain five aspects of PI and how they can be achieved by utilizing chemical looping to replace the conventional autothermal reforming (ATR-DME) process. Two CLR-DME process configurations, one with single reducer and the other with modular reducers, are modeled in ASPEN plus v10.0 and compared to the conventional ATR-DME process. The originality of this work is the construction of the overall process model encompassing both the chemical looping section and the downstream methanol and DME syntheses, and a heat exchanger network built over the whole process to enhance energy efficiency. The chemical looping approach significantly intensifies the process by eliminating the air separation unit (ASU) in both two configurations, and fuel gas combustion turbine and amine scrubber in modular design. A more intensified process has less process losses thus can significantly improve the thermal efficiency and reduce the CO2 emissions. In the end of the article, the applicability of this process for teaching undergraduate process design and meeting ABET learning outcomes is discussed.