Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue and cost of goods sold
Revenue from contract with Customer	$ 3,825	$ 6,403
Total revenues	3,825	6,403
Cost of goods sold	8,139	8,961
Gross loss	(4,314)	(2,558)
Operating expenses
Research and development expense	580	978
Selling, general and administrative expense	2,783	2,092
Restructuring expenses	299
Total operating expenses	3,662	3,070
Loss from operations	(7,976)	(5,628)
Other income (expense)
Interest expense	(545)	(755)
(Loss) on modification of 2020 Notes	(669)
Gain from change in fair value of derivative warrant liability	7	1
(Loss) gain from change in fair value of 2020/21 Notes and 2020 Notes embedded derivative liability	(100)	246
Other income	30
Total other income (expense), net	(1,277)	(508)
Net loss	$ (9,253)	$ (6,136)
Net loss per share - basic and diluted (in dollars per share)	$ (0.64)	$ (0.60)
Weighted-average number of common shares outstanding - basic and diluted (in shares)	14,472,798	10,153,873
Ethanol Sales and Related Products [Member]
Revenue and cost of goods sold
Revenue from contract with Customer	$ 3,700	$ 5,664
Total revenues	3,700	5,664
Hydrocarbon [Member]
Revenue and cost of goods sold
Revenue from contract with Customer	125	739
Total revenues	$ 125	$ 739