PLANT, PIPELINE AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Schedule of Plant, Pipeline and Equipment

Plant, pipeline and equipment include the following at December 31:
	2021		2020
	(thousands of dollars)
Platinum catalyst	$	1,478	$	1,580
Catalyst	4,325		4,325
Land	5,428		5,428
Plant, pipeline and equipment	282,780		270,149
Construction in progress	7,213		6,422
Total plant, pipeline and equipment	301,224		287,904
Less accumulated depreciation	(115,703)		(100,800)
Net plant, pipeline and equipment	$	185,521	$	187,104