Disposal of business (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Plant and equipment	$ 8,948,349	$ 9,153,858
Total	$ 12,669,109	12,268,428
Disposal of Business
Proceeds on disposal		7,644,000
Accounts receivable		113,896
Plant and equipment		109,075
Total		222,971
Deferred revenue		(73,799)
Net assets and liabilities sold		149,172
Net profit realized on disposal		$ 7,494,828