Property, Plant and Equipment, Net

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment, Net

NOTE 7—PROPERTY, PLANT AND EQUIPMENT, NET

Property, plant and equipment consists of the following as of December 31, 2021 and 2020:

	Year Ended December 31,
	2021		2020
Land	$	595	$	—
Buildings and improvements		28,693		28,065
Machinery and equipment		246,670		246,874
Gas mineral rights		34,551		34,551
Construction work in progress		12,725		3,840
Total		323,234		313,330
Less: Accumulated depreciation and amortization		(142,341)		(126,929	)
Property, Plant & Equipment, Net	$	180,893	$	186,401

Depreciation expense for property plant and equipment was $19,617, $18,679 and $15,878 and amortization expense for gas mineral rights was $1,828, $1,965 and $2,355 for the years ended December 31, 2021, 2020 and 2019, respectively.

In May 2021, the Company completed a series of transactions (the “Asset Acquisition”) with a privately-held entity. The Company paid $4,142, including $341 in acquisition costs, for land, building, mobile equipment and other property, plant and equipment for the Montauk Ag Renewables Acquisition. In October 2021, the Company completed a separate purchase with an unrelated privately-held entity. The Company paid $5,531, including $31 in acquisition costs, for land, land improvements and a building. The asset acquisitions were accounted for as an asset purchase in accordance with ASC 805, Business Combinations, and the purchase price and direct transaction costs have been allocated to the individual assets obtained.