I’m not familiar with this expression, and I would expect that it is used within some charismatic circles. In the strictest sense, I would not consider ‘praise intercession’ biblical in the same way I would consider other things to be “biblical.” When I think of something as ‘biblical’ I think of something that I see commanded by our Lord and His apostles, and which I find practiced by the early church. (Thus, practices like infant baptism, for example, I look at with great suspicion, and especially if infant baptism replaces or overshadows believers’ baptism – which we see practiced throughout the New Testament.) Prayer, confession of sin, helping those in need, proclaiming the good news of the gospel are biblical because the Bible commands us to do so. The term ‘praise intercession’ is not found in the Bible (at least not as I search for it). The most important question may then be, “Is ‘praise intercession’ unbiblical?” Praising God is certainly not unbiblical, for we are often commanded to do so. Intercession is not unbiblical, either. I would mainly be concerned that whatever is done as ‘praise intercession’ is rooted deeply in the Word of God, in principle, if not by the actual words ‘praise intercession.’ I would also like to see it practiced by the New Testament church. I think that one danger would be that something like this might be given more emphasis and priority than things that are clearly commanded. I would beware of placing too much emphasis on this, even though it may have some profit.