Property, Plant and Equipment (Tables)

3 Months Ended

Mar. 31, 2017

Property Plant And Equipment [Abstract]

Property, Plant and Equipment by Classification

The following table sets forth the Company’s property, plant and equipment by classification (in thousands).

	Useful	March 31,			December 31,
	Life	2017			2016
Construction in progress		$	574		$	293
Plant machinery and equipment (1)	10 years		15,574			15,397
Site improvements	10 years		7,050			7,050
Luverne retrofit asset (1)	20 years		70,842			70,791
Lab equipment, furniture and fixtures and vehicles	5 years		6,508			6,431
Demonstration plant	2 years		3,597			3,597
Buildings	10 years		2,543			2,543
Computer, office equipment and software	3 years		1,621			1,594
Leasehold improvements, pilot plant, land and support equipment	2 - 5 years		2,535			2,526
Total property, plant and equipment			110,844			110,222
Less accumulated depreciation and amortization			(36,306	)		(34,630	)
Property, plant and equipment, net		$	74,538		$	75,592

(1) In May 2016, certain assets of the Luverne retrofit asset were reclassified from plant, machinery and equipment to the Luverne  retrofit asset.