ASTM D4931

Gross Moisture in Green Petroleum Coke

Applicability: ASTM D4931 applies to green (uncalcined) petroleum coke in as-received condition from delayed or fluid coking units, including both shot and sponge coke morphologies with moisture contents typically in the range of 0.5% to 15% by mass. The method covers free surface moisture introduced during hydraulic decoking, water quenching, and open-air storage, and is designed for large bulk samples representative of commercial shipment lots. It is not applicable to calcined petroleum coke or to the small analysis samples used for volatile matter and ash determination.

Purpose: ASTM D4931 determines the gross moisture content of green petroleum coke by weighing a bulk sample before and after air-drying at ambient temperature or in a forced-air oven at 50°C until mass loss ceases, reporting the moisture as a percentage of the original wet mass. Gross moisture is a primary commercial quality parameter used for freight billing calculations, for converting analytical results to a moisture-free basis, and for controlling coke handling and blending operations; accurate measurement is essential for fair pricing in commercial transactions where petroleum coke is bought and sold on an air-dried or dry basis.