Sequest has announced a new carbon dioxide removal methodology that leverages the hyper-arid environmental conditions of desert regions to store agricultural biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More residue. Agriculture generates more than 7 billion tonnes of organic residue globally every year, most of which decomposes or is incinerated, returning captured carbon dioxide to the atmosphere. Sequest’s approach focuses on arresting this decay process through long-term dry storage in custom-designed facilities, creating a durable carbon sink without relying on high-energy chemical transformation processes.

The primary operational challenge addressed by this methodology is preventing microbial decomposition in stored organic matter over extended timeframes. Decomposing microorganisms require ambient moisture to break down organic structures and release gas. In standard environments, high humidity and precipitation accelerate biomass decay, releasing methane and carbon dioxide. Mitigating this natural process historically required thermochemical transformation, such as pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More to create biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, or deep geological injection, both of which introduce high capital costs and logistical constraints.

Sequest’s solution involves transporting selected crop residues into hyper-arid desert locations and enclosing the material within patent-pending, above-ground engineered chambers. By combining ambient atmospheric dry conditions with engineered microclimate control, the system maintains the biomass moisture levels strictly below the threshold necessary for microbial activity. This operational framework uses established industrial practices—such as standard biomass transport, earthworks, and environmental monitoring—to scale capacity rapidly without waiting on technological development curves.

Initial operational deployment is underway through the “Horizon” project in Saudi Arabia, targeting an annual net removal of 1,000 tonnes of durable carbon dioxide. The project operates under local agreements covering land access and credit distribution, and the core methodology has completed a Preliminary Assessment by the Puro.earth durable CDR registry. While the broader durable removal market faces a structural gap between contracted volume and actual physical delivery, Sequest’s low-complexity dry storage framework offers a near-term path toward scalable delivery.