REVENUES (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue
Total revenues	$ 37,383,632	$ 37,799,259	$ 94,961,188	$ 120,777,263
Base oil
Disaggregation of Revenue
Total revenues	6,365,772	9,776,292	20,006,371	26,357,561
Pygas
Disaggregation of Revenue
Total revenues	1,184,433	2,741,557	4,815,040	7,656,125
Industrial fuel
Disaggregation of Revenue
Total revenues	103,834	1,226,573	1,397,662	7,216,133
Distillates
Disaggregation of Revenue
Total revenues	12,234,672	0	17,359,234	54,697
Oil collection services
Disaggregation of Revenue
Total revenues	2,449,454	1,953,924	5,707,017	4,261,391
Metals
Disaggregation of Revenue
Total revenues	3,160,581	1,724,025	9,549,144	5,988,895
Other Re-refinery Products
Disaggregation of Revenue
Total revenues	834,438	3,084,778	4,289,343	10,482,298
VGO/Marine fuel sales
Disaggregation of Revenue
Total revenues	11,050,448	17,292,110	31,837,377	58,760,163
Northern United States
Disaggregation of Revenue
Total revenues	7,484,798	12,325,941	23,210,428	31,530,289
Southern United States
Disaggregation of Revenue
Total revenues	29,898,834	25,473,318	71,750,760	89,246,974
Black Oil
Disaggregation of Revenue
Total revenues	19,988,122	32,330,531	61,062,628	103,053,529
Black Oil | Base oil
Disaggregation of Revenue
Total revenues	5,632,592	9,135,650	17,914,941	23,918,490
Black Oil | Pygas
Disaggregation of Revenue
Total revenues	0	0	0	0
Black Oil | Industrial fuel
Disaggregation of Revenue
Total revenues	21,190	891,676	1,262,266	5,714,478
Black Oil | Distillates
Disaggregation of Revenue
Total revenues	0	0	0	0
Black Oil | Oil collection services
Disaggregation of Revenue
Total revenues	2,449,454	1,953,924	5,707,017	4,261,391
Black Oil | Metals
Disaggregation of Revenue
Total revenues	0	0	0	0
Black Oil | Other Re-refinery Products
Disaggregation of Revenue
Total revenues	834,438	3,057,171	4,341,027	10,399,007
Black Oil | VGO/Marine fuel sales
Disaggregation of Revenue
Total revenues	11,050,448	17,292,110	31,837,377	58,760,163
Black Oil | Northern United States
Disaggregation of Revenue
Total revenues	7,484,798	12,325,941	23,210,428	31,530,289
Black Oil | Southern United States
Disaggregation of Revenue
Total revenues	12,503,324	20,004,590	37,852,200	71,523,240
Refining & Marketing
Disaggregation of Revenue
Total revenues	13,501,749	3,076,454	22,309,670	9,212,477
Refining & Marketing | Base oil
Disaggregation of Revenue
Total revenues	0	0	0	0
Refining & Marketing | Pygas
Disaggregation of Revenue
Total revenues	1,184,433	2,741,557	4,815,040	7,656,125
Refining & Marketing | Industrial fuel
Disaggregation of Revenue
Total revenues	82,644	334,897	135,396	1,501,655
Refining & Marketing | Distillates
Disaggregation of Revenue
Total revenues	12,234,672	0	17,359,234	54,697
Refining & Marketing | Oil collection services
Disaggregation of Revenue
Total revenues	0	0	0	0
Refining & Marketing | Metals
Disaggregation of Revenue
Total revenues	0	0	0	0
Refining & Marketing | Other Re-refinery Products
Disaggregation of Revenue
Total revenues	0	0	0	0
Refining & Marketing | VGO/Marine fuel sales
Disaggregation of Revenue
Total revenues	0	0	0	0
Refining & Marketing | Northern United States
Disaggregation of Revenue
Total revenues	0	0	0	0
Refining & Marketing | Southern United States
Disaggregation of Revenue
Total revenues	13,501,749	3,076,454	22,309,670	9,212,477
Recovery
Disaggregation of Revenue
Total revenues	3,893,761	2,392,274	11,588,890	8,511,257
Recovery | Base oil
Disaggregation of Revenue
Total revenues	733,180	640,642	2,091,430	2,439,071
Recovery | Pygas
Disaggregation of Revenue
Total revenues	0	0	0	0
Recovery | Industrial fuel
Disaggregation of Revenue
Total revenues	0	0	0	0
Recovery | Distillates
Disaggregation of Revenue
Total revenues	0	0	0	0
Recovery | Oil collection services
Disaggregation of Revenue
Total revenues	0	0	0	0
Recovery | Metals
Disaggregation of Revenue
Total revenues	3,160,581	1,724,025	9,549,144	5,988,895
Recovery | Other Re-refinery Products
Disaggregation of Revenue
Total revenues	0	27,607	(51,684)	83,291
Recovery | VGO/Marine fuel sales
Disaggregation of Revenue
Total revenues	0	0	0	0
Recovery | Northern United States
Disaggregation of Revenue
Total revenues	0	0	0	0
Recovery | Southern United States
Disaggregation of Revenue
Total revenues	$ 3,893,761	$ 2,392,274	$ 11,588,890	$ 8,511,257