Stay time/Holding time is analogous to residence time. Typically, based on DTG curves, peak decomposition temperature is identified, and a holding/stay time is provided at this temperature to ensure complete reaction/pyrolysis.

Muhammad Umair staged pyrolysis is very weel optimized process of slow pyrolysis the low temperature but need lonfg yime in days for wood , the fast pyrolysis the high temperatures at lower time , but the combination this too first the voltaile hemicellulose as well the cabohydrate linked to lignin can me made to be seperated very fast even at low temperatures as very good products mostly hydrocarbonates leaving celulose and lignin de cabonations with hydrogen rich solow pyrolysis gas , the cjharcoal left is again decabonazied via fast pyrolysis to char m tar nancarbons , Thus the complete convversion is achieved in shortest time as well as better better products analysis made possible , other wise just one may get c02 ,co , h20 prolonged fast pyrolysis , incomplete partcial oxidations too

Hemicellulose present in the material is decomposed in the range of 300-350 C and it is major part of volatile matter. Hence, holding at 350 is favorable. second holding time at final temperature provides high time for secondary pyrolysis reaction, which provides batter pyro-yields.