*1.1. The Essence of Circular Economy*

It seems that "circular economy" has recently become the most important and discussed topic, especially within the European Union member states. The circular economy appeared in the literature through three main activities-the so-called 3R principles, namely: reduction, reuse, and recycle [10–13]. In addition, the basic principles of the circular economy include the following: rational environmental management through stock optimization, counteracting negative environmental externalities; circulation of natural resources along ecological and technical material flows; non-waste organic production; adaptability to external conditions by using the optimal business model; circular design when creating new products at the development stage with the improvement of the composition and technology of the product.

Ensuring a sustainable production cycle, considering existing resources, is directly related to economic development, which in the circular economy model increasingly depends on the consumption of these resources [14].

When analyzing existing research on the circular economy, the leader is obviously China with over 40 case studies. This is logically explained by the fact that the country continuously faces huge environmental, human health, and social problems. This is the first country so far, having in force a circular economy law. In contrast, the European Union is paying significant attention to this issue but so far, the circular economy has been seen as a recommendation and not mandatory.

As explained by Heck (2006) [15] circular economy (CE) means reducing resource use and reducing the load on natural sinks. The CE concept is a central part of the environmental economy and industrial ecology (IE) which is expected to lead to more sustainable development [16–19].

Sustainable development is made possible by adhering to its principles of recycling and reuse (circular economy), the use of renewable materials or their joint consumption (sharing economy), the reduction of carbon dioxide emissions, and the use of renewable raw materials of plant origin (low carbon economy) [20–22].

As emphasized by George et.al. (2015), recycling is considered to be a significant aspect of most developed economies. It is also an important objective of policy, so the concept of the circular economy has to be incorporated into theoretical considerations [23].

The circular economy is a concept for changing and adopting new habits and completely new systems for the use of primary resources and raw materials [24–26].

The circular economy model is mainly associated with waste disposal, which has the following relationships: production of products from waste; recycling; regeneration; and recovery. Moreover, the key advantages of CE are namely: the transition to the cyclical nature of value chains capable of continuous reproduction; increasing the eco-efficiency of production and more environmentally friendly products through the technological process; and service products through sharing models [27].
