I acknowledged my dear mother Miten Ayenew Bitew and dear wife Woynshet Ayalew Desta for their personal support during my book preparation. I personally devoted in Chemical Engineering Department, Addis Ababa Institute of Technology, Addis Ababa University, Ethiopia laboratory for collecting all valuable data during completion of my work. I finally, admired Engineer Gizachew Shiferaw for his successful advising during the work.