Carbon dioxide elongatus" has been genetically engineered to produce the fuels isobutyraldehyde and isobutanol from using photosynthesis. Liquid and solid carbon dioxide are important refrigerants, especially in the food industry, where they are employed during the transportation and storage of ice cream and other frozen foods. Solid carbon dioxide is called "dry ice" and is used for small shipments where refrigeration equipment is not practical. Solid carbon dioxide is always below −78.5 °C at regular atmospheric pressure, regardless of the air temperature. The global automobile industry is expected to decide on the next-generation refrigerant in car air conditioning. is one discussed option.(see
Carbon dioxide of hydrogen by steam reforming and the water gas shift reaction in ammonia production. These processes begin with the reaction of water and natural gas (mainly methane). This is a major source of food-grade carbon dioxide for use in carbonation of beer and soft drinks, and is also used for stunning animals such as poultry. In the summer of 2018 a shortage of carbon dioxide for these purposes arose in Europe due to the temporary shut-down of several ammonia plants for maintenance. Acids liberate from most metal carbonates. Consequently, it may be obtained directly from natural carbon dioxide springs, where