CHEM 3103 Lecture 9 - Carbon Dioxide

A colorless, odorless gas that plays a vital role in the carbon cycle. It is produced by burning fossil fuels, a byproduct of respiration, and a greenhouse gas, absorbing infrared radiation and contributing to global warming.

Discovered by Joseph Black in the 18th century, CO2 was initially recognized for its ability to extinguish flames due to its inert nature.

CO2 molecules are linear and non-polar. Carbon has 4 valence electrons, which are equally shared with the two oxygen atoms, resulting in a stable octet.

A measure of a substance's change in temperature with a change in pressure. CO2 exhibits a large Joule-Thomson effect, meaning its temperature drops significantly as it expands.

A solid form of CO2 that sublimes (directly changes from solid to gas) at -78°C. It's widely used for refrigeration.

CO2 is essential for plants to produce food through photosynthesis. It also plays a crucial role in the Earth's natural balance.

CO2's inert nature makes it a useful shielding gas in welding processes, protecting the molten metal from atmospheric contamination.

CO2 can be used to preserve food like fruit, vegetables, cereals, coffee, acting as an inert atmosphere that prevents oxidation and microbial growth.

A chemical process that uses carbon dioxide (CO2) as a feedstock to manufacture urea (NH2)2CO.

A state of matter where a substance has properties of both a gas and a liquid. It exists at high pressure and temperature.

The infrared spectrum of CO2 shows two main absorption bands: one due to asymmetric stretching and the other due to bending.

The point where a substance can exist in all three states of matter: solid, liquid, and gas.

The point where a substance's liquid and gas phases are indistinguishable.

The process of converting a solid directly to a gas without going through the liquid phase.

Major sources of CO2 emissions include fossil fuel combustion, industrial processes like cement production, and the Haber-Bosch process.

The process of using CO2 as a raw material to produce other chemicals or materials.

A process that involves the conversion of urea into melamine, a key chemical ingredient in the manufacturing of melamine resins.

Polymers derived from formaldehyde and urea, commonly used in various applications like glues, laminates, and resins for wood products.

A chemical process involving the transformation of methanol into formaldehyde, a key starting material for manufacturing resins, polymers, and other chemicals.

A type of resin made from melamine and formaldehyde, known for its high thermal stability and resistance to chemicals, often used in laminates and kitchenware.

A linear polymer derived from formaldehyde, known for its high strength, rigidity, and excellent wear resistance, widely used in gears, bearings, and other engineering applications.

An organic compound used as a substitute for phosgene in the production of polycarbonates, offering a greener alternative.

A type of polymer formed from the reaction of bisphenol A and phosgene, known for its toughness and transparency, widely used in engineering and optical applications.

A class of polymers derived from the reaction of isocyanates and polyols, known for their elasticity and flexibility, commonly used in foams, coatings, and adhesives.

Ammonium carbamate (H2N-COONH4) is a compound that serves as an intermediate in the production of urea. It is formed through the reaction of ammonia and carbon dioxide in the first step of the Bosch-Meiser process.

The water gas shift reaction is a key process in the industrial production of hydrogen. It involves the reaction of steam with carbon monoxide to produce carbon dioxide and hydrogen. This reaction is important for removing carbon monoxide from feed gases as it can act as a poison for catalysts in other processes, such as the Haber-Bosch process.

Felice Fontana, an Italian scientist, played an important role in the development of the water gas shift reaction. He was the first to observe the reaction in 1780, even though its industrial importance was only realized later.

The Water Gas Shift reaction is exothermic, meaning that it releases heat. This implies that it favors lower temperatures for greater efficiency.

In the water gas shift reaction, a mixed metal oxide catalyst is typically used. These catalysts facilitate the conversion of carbon monoxide and steam to hydrogen and carbon dioxide.

The water gas shift reaction is often performed in two stages: a high-temperature stage and a low-temperature stage. The high-temperature stage uses Fe/Cr-based catalysts at temperatures between 310-450 °C, while the low-temperature stage utilizes Cu-based catalysts at temperatures between 200-250°C.

The largest proportion of recovered CO2 gas is used at the point of production as a feedstock. The primary applications are the production of urea and methanol.

CO2 can be converted to methanol, which in turn can be further converted to ethylene, propene, and other olefins. These olefins can then be polymerized into various plastics.