SEGMENT REPORTING (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information
Total revenues	$ 58,083,993	$ 36,203,429
Cost of revenues (exclusive of depreciation and amortization shown separately below)	43,346,274	26,836,854
Depreciation and amortization attributable to costs of revenues	1,347,820	1,178,594
Gross profit	13,389,899	8,187,981
Selling, general and administrative expenses	7,926,580	6,700,518
Depreciation and amortization attributable to operating expenses	482,869	455,953
Income from operations	4,980,450	1,031,510
Base oil
Segment Reporting Information
Total revenues	9,409,208	8,165,626
Pygas
Segment Reporting Information
Total revenues	2,972,431	2,457,841
Industrial fuel
Segment Reporting Information
Total revenues	311,693	1,209,888
Distillates
Segment Reporting Information
Total revenues	15,989,828	0
Oil collection services
Segment Reporting Information
Total revenues	1,638,358	1,198,828
Metals
Segment Reporting Information
Total revenues	6,280,047	3,358,567
Other re-refinery products
Segment Reporting Information
Total revenues	1,468,229	2,656,704
VGO/Marine fuel sales
Segment Reporting Information
Total revenues	20,014,199	17,155,975
Black Oil
Segment Reporting Information
Total revenues	32,158,248	29,531,370
Cost of revenues (exclusive of depreciation and amortization shown separately below)	19,836,446	20,066,240
Depreciation and amortization attributable to costs of revenues	1,074,260	936,895
Gross profit	11,247,542	8,528,235
Selling, general and administrative expenses	6,421,696	5,411,222
Depreciation and amortization attributable to operating expenses	353,948	335,105
Income from operations	4,471,898	2,781,908
Black Oil | Base oil
Segment Reporting Information
Total revenues	9,113,893	7,362,727
Black Oil | Pygas
Segment Reporting Information
Total revenues	0	0
Black Oil | Industrial fuel
Segment Reporting Information
Total revenues	0	1,157,136
Black Oil | Distillates
Segment Reporting Information
Total revenues	0	0
Black Oil | Oil collection services
Segment Reporting Information
Total revenues	1,561,927	1,198,828
Black Oil | Metals
Segment Reporting Information
Total revenues	0	0
Black Oil | Other re-refinery products
Segment Reporting Information
Total revenues	1,468,229	2,656,704
Black Oil | VGO/Marine fuel sales
Segment Reporting Information
Total revenues	20,014,199	17,155,975
Refining & Marketing
Segment Reporting Information
Total revenues	19,273,952	2,510,593
Cost of revenues (exclusive of depreciation and amortization shown separately below)	18,150,770	2,596,052
Depreciation and amortization attributable to costs of revenues	125,634	105,768
Gross profit	997,548	(191,227)
Selling, general and administrative expenses	759,410	592,389
Depreciation and amortization attributable to operating expenses	108,471	100,398
Income from operations	129,667	(884,014)
Refining & Marketing | Base oil
Segment Reporting Information
Total revenues	0	0
Refining & Marketing | Pygas
Segment Reporting Information
Total revenues	2,972,431	2,457,841
Refining & Marketing | Industrial fuel
Segment Reporting Information
Total revenues	311,693	52,752
Refining & Marketing | Distillates
Segment Reporting Information
Total revenues	15,989,828	0
Refining & Marketing | Oil collection services
Segment Reporting Information
Total revenues	0	0
Refining & Marketing | Metals
Segment Reporting Information
Total revenues	0	0
Refining & Marketing | Other re-refinery products
Segment Reporting Information
Total revenues	0	0
Refining & Marketing | VGO/Marine fuel sales
Segment Reporting Information
Total revenues	0	0
Recovery
Segment Reporting Information
Total revenues	6,651,793	4,161,466
Cost of revenues (exclusive of depreciation and amortization shown separately below)	5,359,058	4,174,562
Depreciation and amortization attributable to costs of revenues	147,926	135,931
Gross profit	1,144,809	(149,027)
Selling, general and administrative expenses	745,474	696,907
Depreciation and amortization attributable to operating expenses	20,450	20,450
Income from operations	378,885	(866,384)
Recovery | Base oil
Segment Reporting Information
Total revenues	295,315	802,899
Recovery | Pygas
Segment Reporting Information
Total revenues	0	0
Recovery | Industrial fuel
Segment Reporting Information
Total revenues	0	0
Recovery | Distillates
Segment Reporting Information
Total revenues	0	0
Recovery | Oil collection services
Segment Reporting Information
Total revenues	76,431	0
Recovery | Metals
Segment Reporting Information
Total revenues	6,280,047	3,358,567
Recovery | Other re-refinery products
Segment Reporting Information
Total revenues	0
Recovery | VGO/Marine fuel sales
Segment Reporting Information
Total revenues	$ 0	$ 0