Idemitsu Invests in CREW Carbon to Advance CO2 Removal Using Wastewater Alkalinity Enhancement

Idemitsu Kosan Co., Ltd. has invested through Idemitsu CVC in CREW Carbon, a U.S.-based startup that became the first company in the world to generate carbon credits using WAE, or Wastewater Alkalinity Enhancement. CREW Carbon works on carbon dioxide removal (CDR) targeting wastewater treatment facilities. Through this investment, Idemitsu aims to gain business and technical expertise in CDR while jointly studying the feasibility and commercial potential of the business with CREW Carbon, including future deployment in Japan and expansion to other countries. To achieve carbon neutrality by 2050, it is essential not only to reduce CO2 emissions from business activities, but also to socially implement CDR technologies that reliably remove CO2 from the atmosphere. As demand grows for carbon credits generated through CDR, more advanced MRV systems, covering measurement, reporting, and verification, are needed to accurately measure CO2 removal volumes and ensure data transparency. CREW Carbon provides CDR solutions mainly for wastewater treatment facilities such as sewage treatment plants, and creates and sells high-quality carbon credits through its proprietary MRV system. Its technology reacts CO2 generated when organic matter in wastewater is decomposed by microorganisms with an alkaline substance, calcium carbonate (CaCO3), inside wastewater treatment facilities. The captured CO2 is discharged into rivers as bicarbonate ions (HCO3−), eventually transported to the ocean, and stably fixed for thousands of years or longer. The required additional equipment is limited to calcium carbonate storage and injection systems, plus monitoring equipment, so large-scale facility installation is unnecessary. The approach also replaces pH adjusters commonly used in wastewater treatment facilities with cost-competitive limestone, enabling low-cost CDR. CREW Carbon has also developed a proprietary MRV system that measures the amount of CO2 captured at wastewater treatment facilities and tracks HCO3− after discharge into rivers. The system enables accurate calculation of net CO2 reductions, including CO2 release from HCO3− after discharge, and supports the generation of carbon credits certified by an accreditation body. Japan is one of the world’s leading limestone-producing countries, making it relatively easy to secure a stable supply of calcium carbonate required for CREW Carbon’s CDR solution. As expectations grow for CDR deployment using domestic resources, Idemitsu and CREW Carbon will continue studying a business model for potential future introduction of the solution in Japan. Idemitsu said it will continue strengthening collaboration with startups, incorporating innovative technologies and ideas while working to create new value and solve social challenges.