Existing Building Renovation: A Review of Barriers to Economic and Environmental Benefits.

The renovation of old buildings provides an important approach to energy saving and emission reduction with low economic costs. The current important issue remains how to determine the optimal cost-effective technical path for a specific project, although there are a large number of retrofit technologies to choose from. Based on a systematic perspective, this paper conducts a quantitative analysis of the environmental and economic benefits of building renovation, and compares and studies the role and challenges of different countries in the process of recycling waste building materials and technological innovation to extend the life of buildings. Through the use of VOSviewer, 1402 papers from the Web of Science core collection database were visualized, analyzed, and deduced, and the research context and development trends of architectural renovation were sorted out and presented. Finally, this article discusses the status and application process of existing building renovation technologies, including the current obstacles that need to be resolved. It puts forward a vision for the future development of building renovation, emphasizing that top-down guidance is essential to future carbon neutral goals.

Literature Review on Power Battery Echelon Reuse and Recycling from a Circular Economy Perspective.

Developing new energy vehicles (NEVs) is necessary to grow the low-carbon vehicle industry. Many concentrated end-of-life (EoL) power batteries will cause large-scale environmental pollution and safety accidents when the time comes to replace the first generation of batteries if improper recycling and disposal methods are utilized. Significant negative externalities will result for the environment and other economic entities. When recycling EoL power batteries, some countries need to solve problems about lower recycling rates, unclear division of echelon utilization scenarios, and incomplete recycling systems. Therefore, this paper first analyzes representative countries' power battery recycling policies and finds out the reasons for the low recycling rate in some countries. It is also found that echelon utilization is the critical link to EoL power battery recycling. Secondly, this paper summarizes the existing recycling models and systems to form a complete closed-loop recycling process from the two stages of consumer recycling and corporate disposal of batteries. The policies and recycling technologies are highly concerned with echelon utilization, but few studies focus on analyzing application scenarios of echelon utilization. Therefore, this paper combines cases to delineate the echelon utilization scenarios clearly. Based on this, the 4R EoL power battery recycling system is proposed, which improves the existing recycling system and can recycle EoL power batteries efficiently. Finally, this paper analyzes the existing policy problems and existing technical challenges. Based on the actual situation and future development trends, we propose development suggestions from the government, enterprises, and consumers to achieve the maximum reused of EoL power batteries.