Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue	$ 5,058	$ 9,420	$ 11,461	$ 17,663
Grant and other revenue	28		28	25
Total revenues	5,086	9,420	11,489	17,663
Cost of goods sold	8,452	10,693	17,413	21,276
Gross loss	(3,366)	(1,273)	(5,924)	(3,613)
Operating expenses
Research and development expense	945	1,469	1,923	2,258
Selling, general and administrative expense	2,182	1,637	4,274	3,507
Total operating expenses	3,127	3,106	6,197	5,765
Loss from operations	(6,493)	(4,379)	(12,121)	(9,378)
Other (expense) income
Interest expense	(767)	(904)	(1,522)	(1,729)
Loss on exchange of debt		(2,181)		(2,202)
Gain (loss) from change in fair value of derivative warrant liability	2	(3,517)	3	(3,040)
Gain (loss) from change in fair value of 2020 Notes embedded derivative	148	(511)	394	2,347
Other income	20		20	8
Total other expense, net	(597)	(7,113)	(1,105)	(4,616)
Net loss	$ (7,090)	$ (11,492)	$ (13,226)	$ (13,994)
Net loss per share - basic and diluted (in dollars per share)	$ (0.60)	$ (7.19)	$ (1.20)	$ (10.26)
Weighted-average number of common shares outstanding - basic and diluted (in shares)	11,885,524	1,597,242	11,024,482	1,363,394
Ethanol Sales and Related Products [Member]
Revenue	$ 4,966	$ 8,813	$ 10,630	$ 17,031
Total revenues	4,966	8,813	10,630	17,031
Hydrocarbon [Member]
Revenue	92	607	831	607
Total revenues	$ 92	$ 607	$ 831	$ 607