1) increase steam consumption; ? 2) increase the system resistance and reduce the production capacity; 3) The temperature of the shift furnace cannot be maintained; 4) reduce reaction time and conversion rate.

As a basic chemical raw material and a new fuel, liquefied petroleum gas has attracted more and more attention. In chemical production, liquefied petroleum gas is a by-product of catalytic cracking and thermal cracking of crude oil in refineries.

Main components of FCC gas (%): hydrogen 5 ~ 6, methane 10, ethane 3 ~ 5, ethylene 3, propane 16 ~ 20, propylene 6 ~1,butane 42 ~ 46, butene 5 ~ 6. It is used to produce synthetic plastics, synthetic rubber, synthetic fibers, medicines, explosives and dyes.

Liquefied petroleum gas as fuel has been widely used in people's lives because of its high calorific value, smokeless, carbon residue-free and convenient operation and use. In addition, liquefied petroleum gas is also used for cutting metal, baking agricultural products and baking industrial furnaces.

Natural gas refers to the mixture of hydrocarbon and non-hydrocarbon gases naturally contained in the stratum. In petroleum geology, it usually refers to oilfield gas and gas field gas. Its composition is mainly hydrocarbons and contains non-hydrocarbon gases.