WIA Direct Air Capture Standard Guide

Direct air capture (DAC) is easy to describe and hard to account for. A machine pulls ambient air across a material that binds carbon dioxide, releases that CO2 as a concentrated stream, and hands it to a pipeline, an injection well or a mineralization site. What makes DAC difficult is not that description but what must be proven afterwards. How many tonnes left the atmosphere? How many of them came back as emissions from the energy that ran the plant? How many will stay stored, and for how long? Who has already claimed them? Every one of those questions is answered by data, and data from different operators, storage sites, verifiers and registries is useful only if it follows shared rules.

This chapter lays the groundwork for the rest of the book. It explains why capturing CO2 from air is physically harder than capturing it from a smokestack, how the three main technology families work, what happens to a molecule of CO2 from the contactor to the storage site, and why a credible removal claim has to be expressed as net removal rather than gross capture. It then introduces the WIA Direct Air Capture standard: its identifiers, its five-layer architecture, its seven-step data flow and the documents that make it up. The chapter closes with a map of the book and of the companion simulator.