The production of CO2 from waste and its potential industrial applications: transport, capture, and use for the creation of innovative materials, food, and sustainable fuels

by Marco Arezio

The issue of waste production and management presents a significant global challenge, not only for the visual and environmental impact it entails but also for its contribution to greenhouse gas emissions.

Among these gases, carbon dioxide (CO2) is one of the most significant, directly linked to the decomposition processes of organic waste in landfills and waste incineration plants.

CO2 produced from waste is often perceived as a byproduct to be managed, but recent technological and industrial innovations are transforming this emission into a usable resource.

In this article, we will explore what CO2 produced from waste means, the processes through which it is transported, and finally, how it is utilized industrially to generate value and contribute to the reduction of net greenhouse gas emissions.

CO2 produced from waste: origins and context

CO2 is a natural byproduct of organic matter decomposition. In municipal solid waste, the biodegradable fraction (composed of food, paper, wood, textiles, etc.) undergoes aerobic or anaerobic decomposition.

During aerobic decomposition (in the presence of oxygen), such as in composting facilities or mechanical-biological treatment plants, organic matter breaks down into carbon dioxide and water.

In anaerobic conditions (without oxygen), as occurs in landfills, decomposition instead generates a mixture of gases known as biogas, primarily composed of methane (CH4) and CO2.

Another significant source of CO2 production from waste comes from incineration plants. Incineration, a technology used to reduce the volume of municipal solid waste, involves the combustion of organic and inorganic materials at high temperatures.

During this process, organic materials release CO2 and other pollutants, which must be managed through filtration and smoke capture systems.

CO2 transport: challenges and solutions

Once produced, CO2 can be emitted directly into the atmosphere, contributing to the greenhouse effect, or captured and transported for its use or storage.

The transport of CO2, also known as CO2 transport, is a critical component of Carbon Capture, Utilization, and Storage (CCUS), a technology aimed at reducing net carbon dioxide emissions through gas capture and reuse.

CO2 can be transported in three main forms:

In gaseous form: under pressure through pipelines, often used for short distances. CO2 is compressed at moderate pressure (about 10-15 bar) to reduce volume and facilitate transport.

In liquid form: for long-distance transport, CO2 is liquefied through cooling and high-pressure compression (above 70 bar). Once liquid, it can be transported via tankers or ships similar to those used for liquefied natural gas (LNG) transport.

In solid form: as dry ice, CO2 can be transported in containers, although this method is less common due to the thermal management challenges of the solidification process.

In addition to the physical transport issue, the infrastructure network and associated costs must also be considered. CO2 pipelines require significant investments and precise management to avoid leaks and ensure safety, especially when transport occurs in densely populated areas.

However, pipeline technology is already widely used in the oil and natural gas sectors, making the conversion of some infrastructure for CO2 transport easier.

Industrial use of CO2: from emissions to the development of new products

CO2 captured from waste does not necessarily need to be treated as mere waste. In recent years, the industry has developed several innovative applications for CO2, transforming it into a valuable resource.

Below are some of the main ways in which CO2 is used industrially:

Production of synthetic fuels: CO2 can be used as a raw material for the production of synthetic fuels through chemical conversion processes. One of these is the reaction with hydrogen obtained from renewable sources (such as water electrolysis powered by wind or solar energy) to produce methanol or other synthetic hydrocarbons. These fuels can be used in transportation, contributing to the reduction of dependence on fossil fuels.

Production of construction materials: one of the most promising applications is the use of CO2 in the production of low-carbon cement and concrete. Through carbonation processes, CO2 can be trapped within building materials, reducing the overall amount of CO2 released into the atmosphere. Some start-ups are developing technologies to replace traditional cement with alternatives that absorb more CO2 than they emit during the production cycle.

Production of plastics and polymers: CO2 can be used as a raw material for the synthesis of polymers and plastics, reducing dependence on petrochemical products. For example, CO2 can be used to produce polyols, key components in the manufacture of polyurethane, a plastic widely used in various sectors, from automotive to construction.

Agriculture and greenhouse cultivation: CO2 can be used to increase agricultural productivity. In controlled environments such as greenhouses, increasing CO2 concentration promotes photosynthesis, accelerating plant growth and increasing crop yields.

Food and beverage industry: CO2 is widely used for the carbonation of beverages, such as the production of soft drinks and beer. Additionally, food-grade CO2 is used for refrigeration and modified atmosphere packaging, extending the shelf life of food products.

Conclusion

CO2 produced from waste, although one of the major challenges in terms of emissions, can be transformed into a valuable resource if properly managed.

CO2 transport, through pipelines or tankers, and its industrial use in numerous applications represent innovative solutions to help reduce global greenhouse gas emissions.

In the context of a circular economy, CO2 management should not only be seen as a problem but as a new business opportunity. Carbon capture, utilization, and storage technologies offer concrete solutions to harness the gas as a raw material, while simultaneously reducing environmental impact.

With investments in research and development and appropriate regulation, the industry could fully exploit the potential of CO2 to support the transition to a low-carbon economy.