Overall, previous works neither deliver a convincing evaluation of an impact of a CCU system in energy transition, nor address the complexity of optimizing a CCU system composed of different carbon capture and utilization technologies. To address both challenges, this work focuses on an overseen scenario: CCU plants without renewable energy input considered in the initial design, and we develop a surrogate-based optimization methodology to assess its maximum potentials regarding emissions reduction and economic gain. Carbon pricing is included in the economic calculation to predict the future potential of this CCU system.