There are mainly three sources of hydrogen for refineries: By-product hydrogen from crude oil processing, including by-products from reforming units, recovery of hydrogen-rich gases, and by-products from ethylene, electrolysis and dehydrogenation units in the chemical systems supporting integrated refining and chemical complexes. Hydrogen produced by independent hydrogen production units built in refineries. Purchased external hydrogen supply.
Reforming by-product hydrogen accounts for about 0.5% to 1.0% of the total crude oil volume.
Hydrogen by-products from reforming and other units can hardly meet the increasing demand for processing sour crude oil and inferior crude oil.
Meanwhile, large-scale hydrogenation refineries are being rapidly constructed in China, leading to a sharp rise in hydrogen consumption.
The supporting hydrogenation capacity now accounts for more than 70% of the crude oil processing capacity.
It has become difficult to balance and meet the plant-wide hydrogen demand through conventional in-plant processing routes alone, making it necessary to build independent hydrogen production units.
Selection of Hydrogen Production Feedstock Routes
Refineries have high requirements for the stability of hydrogen demand.
For supporting independent hydrogen production facilities, priority must be given to stable unit operation, consistent feedstock quality and supply volume, as well as mature and reliable process technologies.
The selection of a hydrogen production feedstock route depends on feedstock availability, technological maturity, and economic rationality.
Main feedstocks for hydrogen production include refinery dry gas, natural gas, coal, light naphtha, and heavy oil.
However, with the growing demand for chemical products in China and the increasing trend of valuing heavy oil and naphtha as chemical raw materials,
traditional heavy oil-based hydrogen production units have become increasingly uneconomical in terms of cost-effectiveness due to underutilization of feedstock value,
thus undermining the overall economic benefits of refineries and leading to their successive shutdown.
In actual production, hydrogen production units using dry gas as feedstock must comprehensively resolve conflicts in the plant-wide fuel balance.
As independent feedstock options, natural gas-based hydrogen production and coal-based hydrogen production are emerging as the two most important development directions for hydrogen generation.
