Long-term prepayments

12 Months Ended

Dec. 31, 2018

Long Term Prepayments [Abstract]

Long Term Prepayments [Text Block]

9. Long-term prepayments

Balances of long-term prepayments were $2,617,419 and $3,715,445 as of December 31, 2018 and 2017, respectively, which represented prepayments for equipment purchases.