Science, Tech, Math › Science Liquefaction Definition in Science What Is Liquefaction? Share Flipboard Email Print Studio 504/Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated January 13, 2020 Liquefaction is the process of converting a substance from its solid or gas phase into its liquid phase. Liquefaction occurs naturally and artificially. Sometimes liquification is considered to be the same as liquefaction. However, some authors consider liquification to be a mis-spelling of liquefaction. Examples Gases are liquefied by condensation or cooling. Solids are liquefied by heating. Coal liquefaction yields liquid fuels. In the kitchen, a blender may be used to liquefy solids, such as fruits and vegetables. Source Speight, James G. (2012). The Chemistry and Technology of Coal (3rd ed.).