TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: Refrigerant blend comprises Refrigerant-218 (0-0.2). Refrigerant blend comprises Refrigerant-123 (0.09-0.14), Refrigerant-23 (0.09-0.14), Refrigerant-170 (0.11-0.14), Refrigerant-14 (0.25-0.29), Argon (0.09-0.15), Refrigerant-124 (0.06-0.13) and Refrigerant-125 or Refrigerant-218 (0.10-0.16). Refrigerant blend comprises Refrigerant-123 (0.29-0.35), Refrigerant-23 (0.11), Refrigerant-170 (0.11), Refrigerant-14 (0.17), Argon (0.16) and Refrigerant-125 or Refrigerant-218 (0.10). Refrigerant blend comprises Refrigerant-123 (0.12), Refrigerant-170 (0.20), Refrigerant-14 (0.25), Argon (0.26), Refrigerant-124 (0.08) and Refrigerant-125 or Refrigerant-218 (0.09). Refrigerant blend comprises Refrigerant-123 (0.29), Refrigerant-23 (0.31), Refrigerant-14 (0.22), Argon (0.08) and Refrigerant-125 or Refrigerant-218 (0.10). The refrigerant blends are used in autorefrigerating cascade, single expansion device refrigeration device or klimenko type system in a single compressor cycle. Refrigerant blends comprising refrigerant-218 are used to achieve refrigerating temperature of -60 to -183degreesC preferably -60 to -163degreesC. The refrigerating system alternatively permits flow of cold or hot refrigerant to evaporator. The refrigerant blends in the refrigeration system provides same thermodynamic performance compared to conventional blends comprising (mol fraction) Refrigerant-123, Refrigerant-23, Refrigerant-170, Refrigerant-14 and Argon (at least0) and Refrigerant-22 (greater than 0). The refrigeration system has an object cooled by refrigerant. The object is either a metal tube in vacuum chamber for freezing and trapping undesirable gases such as water vapor or a heat exchanger which removes heat from a secondary fluid stream containing liquid, gas, condensing gas or condensing gas mixture or a metal element having internal flow passages and cooling silicon wafer, piece of glass or plastic or aluminum disc with or without magnetic coating or a biological freezer which freezes and stores biological tissues.