What is the typical weight percentage of liquefied gas components in catalytic cracking rich gas?

Liquefied petroleum gas is a by-product obtained from processes such as the extraction, cracking, and refining of oil. It is a mixture of hydrocarbons, with its main components including propane (C3H8), propylene (C3H6), butane (C4H10), butylene (C4H8), and butadiene (C4H6). It also contains small amounts of methane (CH4), ethane (C2H6), pentane (C5H12), and hydrogen sulfide (H2S). The composition of liquefied petroleum gas varies depending on the production process used. Under normal pressure, the boiling points of C3 and C4 compounds are below room temperature, allowing them to easily vaporize into gas. Since the boiling points of compounds with more than 5 carbon atoms are higher, they remain in liquid form in the container after the C3 and C4 compounds have vaporized; this liquid residue is what is referred to as residue. In China, the content of such residue in household-use liquefied petroleum gas is relatively high. Liquefied petroleum gas is also a by-product obtained in refineries during the catalytic cracking and thermal cracking of crude oil. The main components of catalytic cracking gas are as follows (%): hydrogen 5–6, methane 10, ethane 3–5, ethylene 3, propane 16–20, propylene 6–11, butane 42–46, butylene 5–6, with hydrocarbons having 5 or more carbon atoms accounting for 5–12%. The main components of thermal cracking gas are as follows (%): hydrogen 12, methane 5–7, ethane 5–7, ethylene 16–18, propane 0.5, propylene 7–8, butane 0.2, butylene 4–5, with hydrocarbons having 5 or more carbon atoms accounting for 2–3%.