Industrial symbiosis is a part of industrial ecology. It explains how groups of different organizations can work together to help create eco-friendly innovations, change long-term habits, share benefits that help all involved, and improve business and technical processes.

Even though industrial symbiosis often happens in areas where organizations are close together, being near each other is not required or enough. It also does not depend only on sharing physical resources like materials. Careful planning is needed to make the most of the benefits that come from being in the same area. In practice, using industrial symbiosis in business operations—such as using, recovering, and redirecting resources for reuse—keeps resources working in the economy longer. This helps create business chances, lowers the need for Earth’s resources, and helps move toward a circular economy, where resources are reused instead of wasted.

Industrial symbiosis is a part of industrial ecology, with a focus on sharing materials and energy. Industrial ecology is a newer field that uses ideas from nature, suggesting that industrial systems might work like natural ecosystems, where everything is reused. However, how simple and useful this idea is has been questioned by some.

Introduction

Eco-industrial development is a method that helps balance economic growth and environmental protection. Examples of eco-industrial development include:

• Circular economy (reusing materials and/or energy)
• Greenfield eco-industrial development (a specific area for new industries)
• Brownfield eco-industrial development (a specific area for industries that were previously used)
• Eco-industrial network (industries working together, even if they are not close)
• Virtual eco-industrial network (industries connected across large areas, such as a region)
• Networked Eco-industrial System (large-scale systems that connect industries across different regions)

Industrial symbiosis connects different industries to work together in a way that benefits all. This involves sharing materials, energy, water, and by-products. The most important factors for industrial symbiosis are teamwork and the advantages that come from industries being located near each other. These ideas have been studied and tested in the UK through the National Industrial Symbiosis Programme.

Industrial symbiosis systems help industries use materials and energy more efficiently than they could alone. For example, in Kalundborg, Denmark, companies have created a system where they share resources through many small improvements over time. However, designing such systems quickly from a larger planning perspective is difficult.

Access to information about by-products is often limited. These by-products are usually treated as waste and are not sold or listed on exchanges. Only a few specialized waste marketplaces handle this type of trading.

Example

Recent studies examine government policies needed to build a very large photovoltaic factory and other policies to support existing solar companies. These studies also explain the technical needs for an industrial system where different factories work together to improve manufacturing efficiency and reduce the environmental impact of solar cells. The analysis shows that creating a system with eight factories working together could be a good investment for governments over several years. This system would not only provide direct financial benefits but also help improve the global environment. This is because placing glass manufacturing and photovoltaic manufacturing in the same area creates benefits. For example, heat from glass manufacturing can be used in large greenhouses to grow food. Inside the photovoltaic plant itself, a secondary chemical recycling facility can reduce environmental harm while improving economic results for the group of factories.

At DCM Shriram Consolidated Limited (Kota unit), the company produces caustic soda, calcium carbide, cement, and PVC resins. Chlorine and hydrogen are created as by-products during caustic soda production. Calcium carbide is partly sold and partly treated with water to form a slurry (a water-based solution of calcium hydroxide) and ethylene. Chlorine and ethylene are then used to make PVC compounds. The slurry is used in cement production through a wet process. Hydrochloric acid is made by combining pure chlorine gas with hydrogen in the presence of UV light.