Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue	$ 9,420	$ 7,499	$ 17,663	$ 13,082
Grant and other revenue		43	25	75
Total revenues	9,420	7,542	17,663	13,157
Cost of goods sold	10,693	9,705	21,276	19,113
Gross loss	(1,273)	(2,163)	(3,613)	(5,956)
Operating expenses
Research and development expense	1,469	1,891	2,258	3,108
Selling, general and administrative expense	1,637	2,123	3,507	4,297
Total operating expenses	3,106	4,014	5,765	7,405
Loss from operations	(4,379)	(6,177)	(9,378)	(13,361)
Other (expense) income
Interest expense	(904)	(630)	(1,729)	(1,341)
(Loss) on exchange of debt	(2,181)	(3,969)	(2,202)	(4,933)
(Loss) from change in fair value of the 2017 Notes				(339)
(Loss)/Gain from change in fair value of derivative warrant liability	(3,517)	2,260	(3,040)	5,519
(Loss)/Gain from change in fair value of 2020 Notes embedded derivative	(511)	(1,662)	2,347	(1,662)
Other income		20	8	26
Total other expense, net	(7,113)	(3,981)	(4,616)	(2,730)
Net loss	$ (11,492)	$ (10,158)	$ (13,994)	$ (16,091)
Net loss per share - basic and diluted (in dollars per share)	$ (7.19)	$ (13.22)	$ (10.26)	$ (23.86)
Weighted-average number of common shares outstanding - basic and diluted (in shares)	1,597,242	768,625	1,363,394	674,451
Ethanol Sales and Related Products [Member]
Revenue	$ 8,813	$ 6,839	$ 17,031	$ 12,333
Total revenues	8,813	6,839	17,031	12,333
Hydrocarbon [Member]
Revenue	607	660	607	749
Total revenues	$ 607	$ 660	$ 607	$ 749