Property, plant and equipment, net (Schedule of Plant and Equipment, Net) (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Cost
Construction in progress	$ 23,105,557	$ 20,769,452
Furniture, fixtures and office equipment	3,132,082	3,066,411
Leasehold improvement	812,550	99,477
Machinery and equipment	17,061,481	15,807,695
Motor vehicles	1,370,476	1,316,717
Building	819,346	271,921
Property, plant and equipment, cost	46,301,492	41,331,673
Less: accumulated depreciation	8,835,234	7,869,304
Property, plant and equipment, net	$ 37,466,258	$ 33,462,369