From recycling to economy: opportunities for resource recycling technology in reducing carbon emissions

If the circular economy is to replace the scale and cost advantages of the existing linear economy, it must adopt a pricing mechanism for environmental and social costs. The pricing of carbon emissions and the ESG assessment mechanism of enterprises are slowly creating new incentives for enterprises to rethink the use of recycled materials to change the carbon footprint structure of products, and to use lower-carbon recycled materials to strengthen the company's ESG efforts and the international competitiveness of its products.

The cost difference between the linear economy and the circular economy mainly comes from the cost of collecting and converting materials. From the perspective of the circular economy system, the variability of material sources, the difficulty of collection or the difficulty of transportation are all reasons for the high initial cost. Therefore, the relevant issues discussed in this special topic are to make good use of the construction of existing environmental protection systems, or directly extract materials near the production source, design appropriate production volume and technology development, reduce collection costs, and find a lower-cost conversion and purification method. Only in this way can the supply of circular materials be driven by the economy and the circular economy system can be expanded.

The most effective strategy for material collection is effective classification and collection at the production source. There are many applicable opportunities for domestic manufacturers or regions with large enough industrial scale. By analyzing the distribution of important chemicals in China, we can find that there are enough chemicals in China that are worth considering for closed or cross-industry recycling through separation and purification. For example, hydrofluoric acid can be used to obtain pure calcium fluoride through the introduction of new technologies, or the recovery of sodium sulfate in fly ash from the glass industry mentioned in another topic.

In addition, the recycling collection pipeline has been established by making good use of the existing environmental protection system, and its collection cost has been internalized. At this time, innovative separation and purification technology or market demand is needed to create the value of material recycling. For example, the demand for high-quality plastic recycling materials has increased in recent years, and the international demand for recycled lithium battery materials has stimulated the increase in demand for recycled materials. How to effectively reduce the cost of separation and purification or conversion and recycling is an important issue.

Of course, in addition to the cost considerations of collection, technological innovation allows materials to be upgraded or closed-loop low-cost technologies, which are important foundations of decentralized recycling. The sharing of this topic focuses on the technical comparison of separation and purification of various materials, the explanation of different conversion technologies to reduce energy consumption and by-products. Among them, the aluminothermic method uses waste aluminum slag as a reaction heat source to transform other difficult-to-treat waste into useful pellets. It is hoped that through these analyses, readers can more easily grasp the development trends of these material recycling technologies, lead to more innovative investment, and strengthen the future carbon reduction competitiveness of the circular economy for Taiwan's industries.

This special topic would like to thank the Ministry of Environment's Resources and Environmental Protection Administration for its guidance and financial support for the development of related technologies in the past few years. Through dialogues between different technical fields and management perspectives, the development of related technologies has been oriented towards the integration of waste reduction, recycling and economic value, allowing research colleagues to give full play to their strengths and create a better living environment.