In terms of raw materials, what are the methods for making ammonia?

Preparation of feedstock Gas: 

Feedstock like coal and natural gas are processed into crude raw gas containing hydrogen and nitrogen. Solid materials like coal and coke are typically gasified to produce synthesis gas. Residue oil can be obtained through non-catalytic partial oxidation to obtain synthesis gas. For gaseous hydrocarbons and naphtha, an industrial method involving two-stage steam conversion is used to produce synthesis gas.　　 

Purification Process: The crude raw gas, derived from materials like coal and natural gas, undergoes purification to remove impurities, excluding hydrogen and nitrogen. This involves transformation processes, desulfurization, decarbonization, and gas refining. 

Ammonia Synthesis: In the ammonia synthesis process, pure hydrogen-nitrogen mixture is compressed to high pressure and, under the influence of a catalyst, synthesized into ammonia.