This book introduces model-based optimization as an emerging practice in the industry. The topics like petroleum refining processes, refinery basic economics, basic concepts in mathematical programming, applications of mathematical programming for refinery optimization are covered. More importantly, case studies related to practical refinery configuration design, retrofit and issues with industrial size and significance are emcomprassed. It will benefit the technically-inclined reader as an accessible, easy-to-read introduction to the methods of mixed-integer optimization with practical applications.