"Chemical Reaction Engineering deals with that activities of engineering where something new is produced from old materials. Designing of a reactor and understanding fully in depth of reactions need more emphasis in reaction engineering. There are number of questions such as how to attach a particular problem dealing with chemical reactions, how best to get optimum products and how to optimize the variables for best required design. The book aims at giving clue to find out the solutions of the problems in fastest and easiest way. Any question can be answered if qualitative analysis, simplest design techniques, comparison between reactors on quantitative and qualitative basis are taken up. Attempts have been made to describe the theory in simple mathematical manner with the help of explanations wherever required. Most of the equations have been derived from the first principle and complicated part have been simplified. Many solved problems from industrial environmental have been added. Few challenging problems will serve as brainstorming sessions for students.