Renminbi demand and CNY rates
What the paragraph actually said is 


  "Fervent demand for renminbi from international investors has driven down rates in Hong Kong and thereby created incentives for companies considering using the renminbi for trade or financing," explains Financial Times correspondent Robert Cookson.


This means that international investors were buying offshore Renminbi (CNH) in Hong Kong and using that to buy offshore bonds denominated in Renminbi. That pushed the price of those bonds up, corresponding to reduction in their effective interest rates ("driving down rates").