Procel is the duke named in entry 49 of the Goetia.
The angel-shaped duke
Joseph H. Peterson’s transcription describes an angelic appearance, geometry and liberal sciences, waterlike noises where no water is present, and effects on warm water and baths. It assigns Procel forty-eight legions and reports his claim to have belonged to the order of Potestates before his fall.
Peterson’s editorial note compares the entry with Weyer’s number 38, Pucel, and Scot’s spelling Procell.
Sources
Goetia, entry 49 and editorial note 56; Pseudomonarchia Daemonum, entry 38, Peterson’s digital editions.