Natural Ocean Alkalinity for Carbon Storage — Natural Engineering Method Practice

Abstract

To achieve its latest requirements—the Paris climate goal (1.5°C), the UNFCCC needs to fulfill its basic commitments of promoting to make sustainable use of natural carbon sinks/reservoirs. In particular, it is imperative to make a breakthrough in the utilization of marine carbon sinks/reservoirs (accounting for more than 93% of the earth's natural carbon sinks/reservoirs) as soon as possible. Recent actual surveys and studies of several long-running large and medium-sized Eurasian power plants (a total of about 12 GW (Gigawatt), including a refinery and a marine tanker), have found that these commercial scale seawater scrubbing flue gas desulfurization (FGD) projects have captured substantially more CO2 than SO2 into the marine water column. These technical facts can explain that within the current national and international environmental regulations, there is a safe and marine eco-friendly use of natural ocean alkalinity for carbon storage to reduce the CO2 atmospheric emissions of fossil energy, which has been contributing to the atmosphere for well over 25 years. Based on the above technical facts and basic principles of marine chemistry, a natural engineering mitigation method is proposed. With this method, a portion of CO2 leaves the atmosphere and enters the ocean under controlled flux and rate to react with the natural alkalinity of the ocean (not artificial chemicals alkalinity) for ocean carbon storage. This method thus forms the technical foundation of a reversible, controllable (safe), and sustainable climate mitigation strategy, which can possibly mitigate climate change while avoiding ocean acidification (eliminating the root cause of ocean acidification: greenhouse chemical effects). Therefore, the natural seawater carbon capture and storage (NSW CCS) program was designed by using natural engineering mitigation methods, as the practical technology of using ocean natural alkalinity carbon sink/reservoir in a large scale, the main features of which are only using natural seawater with no additional artificial chemicals in the whole process. The entire cost of this CCS program is less than US$15/ton CO2; when the capture rate is 10%, the plant power consumption rate is about 1.4%; when the capture rate is 90%, plant power consumption rate is higher, about 10%, with a great potential for decline after the establishment of market structure. The funding threshold for pilot demonstration projects is low, and the program can be implemented step by step, which is conducive to the rapid deployment of commercial-scale projects, establishment of market structure and industrial chain, and development of new mitigation technologies and strategies. In view of the global mobility of oceans, it is recommended to carry out international cooperation under the management of UNFCCC Paris climate targets and initiate commercial demonstration research projects (including marine environmental monitoring and impact assessment system construction) with the progressive mode of capture rate, which use ocean natural alkalinity carbon storage. These projects can be prioritized to deploy in large point sources such as coastal power plants, refineries, and the international ocean shipping field.