The remaining sections are structured as follows. Section 2 describes an industrial park where natural gas power plants are integrated with CCU. Section 3 illustrates the digitalization and optimization framework for the whole CCU system. Section 4 presents the single-objective optimization of maximizing the GHG reduction; this is set up to evaluate whether CCU can reduce CO2 effectively, as well as to validate the overall optimization framework. Following this, multi-objective optimization is applied to the whole system concerning GHG reduction and economic gain in Section 5. Section 6 introduces carbon pricing within the economic evaluation. The final section presents conclusions and outlooks.