Our objective is to achieve the societal implementation of the Circular Economy Program for Automobile Carbon Fibers. This involves recycling carbon fibers sourced from carbon fiber reinforced plastics/carbon fiber reinforced thermoplastics (CFRP/CFRTP) discarded from automobiles and reintegrating them into the manufacturing processes of automobiles. Although, the existing carbon fiber recycling technology recycles the carbon fiber into a finely chopped state; it is not the original continuous carbon fiber product. A novel recycling technology is elucidated herein, referred to as the electrolytic sulfuric acid method (ESAM). The ESAM recycles carbon fibers by decomposing only the resin component of CFRP/CFRTP into CO2 and water using oxidative active species generated by electrolytic sulfuric acid. This method can (1) be applied to all resins, (2) maintains strength of the recycled carbon fibers, and (3) regenerates continuous carbon fibers. Moreover, it is the only technology applicable to CFRP pressure tanks. The successful recycling of continuous carbon fiber from pressure tanks has been achieved, enabling the production of new tanks and unidirectional CFRTP tape. This technology recycles the original continuous carbon fiber product, thus enabling a “close” resource circulation cycle. We have not yet confirmed the number of times recycling can be performed. However, according to the method described in this paper, the recycling process can yield continuous carbon fibers without a decrease in physical properties. Therefore, theoretically, it becomes possible to recycle indefinitely and revert the fibers to their original state, provided that the strength reduction during product use is not a significant consideration.

中文翻译：

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电解硫酸法连续碳纤维回收技术

我们的目标是实现汽车碳纤维循环经济计划的社会实施。这涉及回收来自汽车废弃的碳纤维增强塑料/碳纤维增强热塑性塑料（CFRP/CFRTP）的碳纤维，并将其重新整合到汽车的制造过程中。虽然，现有的碳纤维回收技术将碳纤维回收成细切状态；它不是原始的连续碳纤维产品。本文阐述了一种新颖的回收技术，称为电解硫酸法（ESAM）。ESAM 通过仅将 CFRP/CFRTP 的树脂成分分解为 CO 来回收碳纤维2以及使用电解硫酸产生的氧化活性物质的水。该方法可以（1）应用于所有树脂，（2）保持回收碳纤维的强度，以及（3）再生连续碳纤维。而且，它是唯一适用于CFRP压力罐的技术。已成功回收压力罐中的连续碳纤维，从而能够生产新罐和单向 CFRTP 胶带。该技术回收了原有的连续碳纤维产品，从而实现了“封闭”的资源循环循环。我们尚未确认可以进行回收的次数。然而，根据本文描述的方法，回收过程可以在不降低物理性能的情况下生产连续碳纤维。因此，理论上，只要产品使用过程中的强度下降不是一个重要的考虑因素，就可以无限期地回收并将纤维恢复到其原始状态。