Property, plant and equipment - Schedule of property, plant and equipment (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 28,727,050	$ 28,627,477
Less accumulated depreciation and amortization	(4,164,641)	(3,561,641)
Property, plant and equipment, net	24,562,409	25,065,836
Land
Property, Plant and Equipment [Line Items]
Total property and equipment	705,363	718,586
Building and improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	13,567,702	13,297,489
Construction in process
Property, Plant and Equipment [Line Items]
Total property and equipment	2,542,044	2,105,873
Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	11,684,991	12,275,619
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	200,140	201,813
Vehicles
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 26,810	$ 28,097