Carbon Capture Utilization and Storage

Introduction

The share of the transportation sector in the emission of greenhouse gases in the world is 25%, of which 2.9% is the emission of pollution related to the marine industry. The change in global laws in order to reduce the environmental impact has forced the shareholders of the marine industry to implement measures in the direction of decarburization.

Alternative fuels such as ammonia, methanol, etc., have a long-term vision for universal and affordable use and are being developed. Also, there is no legislation on how to use them. Therefore, ship owners, shipyards and equipment manufacturers are looking for alternative solutions such as Carbon Capture Systems (CCS) or Carbon Capture Utilization and Storage (CCUS).

CCS and CCUS technologies have been available for decades but have recently become a hot topic in the marine industry. In 2021, the UN Climate Change Conference featured two CCUS-related focus events, and Nordic governments began providing significant funding for CCUS projects.

What is meant by the process of CCS & CCUS?

This technology is one of the ways to reduce carbon emissions, which is a great help in reducing global warming. The process of carbon capture and storage consists of three stages, firstly absorbing the carbon dioxide produced by burning fuel in power plants or industrial activities, then transferring it by ship, pipelines or other ways of transportation, and finally storing it in somewhere deep and underground.

What is CCUS? What is the difference between CCUS and CCS?

CCS is one of the aspects of CCUS, CCUS stands for Carbon Capture Utilization and Storage, where carbon can be reused in industries in addition to carbon storage. For example, stored carbons are converted into plastic, concrete or biofuel.

Does the CCS process work in the marine industry?

Ships equipped with carbon capture technology absorb the carbon produced by fuel combustion (diesel or LNG). This technology is able to absorb a significant part of the carbon dioxide released from the exhaust gases, i.e. more than 90% of it, but it still faces a challenge to achieve a higher percentage.

One of the methods of carbonization is the absorption of carbon dioxide in the solvent, which can be separated from the solvent using the wasted heat of the engine and turned into a gas phase. The carbon dioxide can then be compressed, liquefied and stored at a certain temperature, under normal atmospheric pressure.

In a second step, ships can transport the carbon absorbed by the carbonization process to the shore reception facilities or wherever it needs to be discharged. A part of it may be reused or stored in underground reservoirs. The companies implementing this technology use the same technology as ammonia and LPG for safe storage of carbon dioxide at a certain pressure and temperature during transportation.

Ship owners can use different methods to store carbon dioxide and also use a large tank or several small tanks due to the limited space of ships.

The transportation of carbon dioxide by ships brings certain safety challenges such as the possibility of suffocation, here we are faced with small differences compared to known gases such as LPG.

Liquid carbon dioxide is regularly used in several industries and its risk varies with the scale of application.

Another issue that needs to be overcome is the tanks and equipment for receiving carbon dioxide, so CCUS technology can only be used on routes and ports that are equipped with adequate infrastructure.

Where is the absorbed carbon in the CCS process stored?

Potential storage sites for carbon pollution include saline aquifers or drained oil wells and gas reservoirs that must be at least 0.62 miles (1 km) underground.

For example, the proposed storage site for the Zero Carbon Humber project in the UK is the Endurance aquifer, located in the southern North Sea, 90 km from the coast. Endurance has a depth of approximately 1.6 km from the seabed and has the ability to store a large amount of carbon dioxide.

How does CCS help prevent global warming?

The Intergovernmental Panel on Climate Change (IPCC) noted that if we are to meet the incentives of the Paris Agreement and limit future temperature increases to 1.5 degrees Celsius, we need to do more than try to reduce greenhouse gas emissions.

We need to develop technologies related to removing carbon from the atmosphere. CCS is one of these technologies and can play an important role in dealing with global warming.

Advantages of CCUS and CCS technology

Accessibility: unlike many alternative fuels and propulsion technologies, carbon capture and storage equipment for the offshore sector can be purchased from the market, the technology related to vessels is also in the experimental stage. Ship owners will soon be able to install this technology on their ships.

Sustainability: CCUS technology plays an important role in decarburization, both as a stand-alone solution and to create a green supply chain for other clean energies. For example, the process of generating energy from an offshore wind farm requires carbon-intensive building materials. By using CCUS technology, on the production line, manufacturers can minimize their environmental impact and increase the environmental credentials of their wind farm.

Efficiency: Compared to other carbon emission reduction methods, CCUS is superior. CCUS technology provides a long-term solution for capturing carbon dioxide and storing it in appropriate sites, ensuring that these harmful products are never released into the atmosphere.