Mario A. Rosato is an electrical, electronic, and environmental engineer, as well as a scientific journalist. He built his first home-sized digester in Argentina when he was 16 years old. The son of a university professor and researcher, since his childhood, he learnt to employ sophisticated instruments in his favorite playground—his father’s lab. At the age of 25, he obtained a scholarship to specialize in renewable energies in Italy. At 28, he chose to leave the academic research world and devoted himself to developing industrial solutions. In 1990, he settled in Italy, and in 2000, he moved to Spain. In 2004, he became the scientific director of Bioenergía Aragonesa SL. In 2006, he patented the AFADS system, a multitrophic bioreactor for wastewater treatment. In 2009, he founded Sustainable Technologies SL in Barcelona (Spain) and moved its headquarters to Portogruaro (Italy) in 2019. Since 2010, he has provided technical training to biogas researchers and professionals in several private institutes in Italy and Spain, expanding this activity to the rest of the world in collaboration with the World Biogas Association since 2022. Mario A. Rosato has been running a laboratory for applied research and routine anaerobic digestion tests in Italy since 2011. Since 2014, he has been responsible for the column on bioenergy for Agro Notizie, a specialized e-zine catering to Italian agronomists and agricultural entrepreneurs. In 2015, he became a member of the technical commission responsible for drafting the Italian norm on the biochemical methane potential (BMP) test protocol, with his contributions focusing on error propagation analysis and improving both accuracy and precision. In 2022, the first edition of this volume was included in Book Authority's lists of the best 100 books and 20 e-books on chemical engineering.