Hi,

I will try to answer the 3rd question. For placing the side reboilers / different feed stages, one option will be to check any existing design of the column and place the stages / side reboilers. Then try plotting a Mccable Thiele diagram (I think option is there in Hysys with a added macro / file extension) and see if there is composition pinch. In case you encounter pinch, then try changing the locations and see if you can avoid the pinch. One suggestion is to read Distillation Design by Kister. He gives good methodologies and may help you.