Work under Contract DE-AC21-80MC14399 comprised four tasks designed to advance development of the CNG acid gas removal process: Task 1 - development of a modified carbon dioxide triple-point crystallizer, Task 2 - acquisition of basic process data, Task 3 - extension of the process to low carbon dioxide content crude gases, and Task 4 - fate of trace contaminants in the CNG process. Task 2 covered crystallizer operation and data acquisition, other process data acquisition unrelated to the crystallizer, and process design studies. Task 2 is comprised of five subtasks. Rate and mechanical slurry handling data for the crystallizer were obtained under Subtask 2.1. For Subtask 2.2, apparatus was constructed and operated to obtain multi-component phase equilibrium data. For Subtask 2.3, crystallizer separation factors were determined for the binary systems carbon dioxide-hydrogen sulfide, carbon dioxide-carbonyl sulfide, carbon dioxide-ethane, carbon dioxide-ethylene, and carbon dioxide-methyl mercaptan. For Subtask 2.4, the minimum net positive suction head (NPSH) required to pump slurries of solid carbon dioxide in an organic liquid carrier solvent was determined for two gear pumps, a piston pump, and a centrifugal pump. For Subtask 2.5, alternative techniques for trace water removal from syngas mixtures were investigated, the likelihood of hydrate formation for methane, carbon dioxide, and hydrogen sulfide was assessed, and the solubility of water in liquid carbon dioxide was measured experimentally. 63 references, 64 figures, 50 tables.