What is the partial oxidation of residue to produce hydrogen?

Heavy oil feedstocks include atmospheric and vacuum residue, as well as fuel oils obtained through the deep processing of petroleum. Heavy oil reacts with water vapor and oxygen to produce hydrogen-containing gas products. The combustion of some heavy oil provides the heat required for the endothermic conversion reaction as well as a certain reaction temperature. Gas product composition: 46% (by volume) hydrogen, 46% carbon monoxide, 6% carbon dioxide. In the cost of hydrogen produced by this method, raw material costs account for about one-third; since the price of heavy oil is low, it attracts considerable attention. No catalyst is required. Naphtha hydrogen production: The feed hydrocarbons and water vapor are converted in a catalyst-equipped furnace tube into a mixture of hydrogen, carbon oxides, and residual methane. Conversion catalysts are prone to sulfur poisoning; therefore, proper desulfurization of the feedstock is a very critical step in hydrogen production plants.

"Does heavy oil react with water vapor and oxygen to produce hydrogen-containing gas products? I’m not quite sure; what is the reaction equation?

This post was last edited by myzfs on 2009-6-17 20:52. Let’s add more. The residue gasification process is the first step in the partial oxidation of residue to produce hydrogen, and it is also its most important component. Residue is mainly composed of alkanes, cycloalkanes, and aromatics with high carbon atoms; typically, its carbon content ranges from 85% to 86%, while the hydrogen content is between 9% and 11%. In addition, it contains a certain amount of sulfur as well as small amounts of ash and heavy metals. After the residue oil is thoroughly mixed with oxygen and water vapor in specially designed nozzles, it is fed into the gasification reactor (since the amount of oxygen is less than the theoretical amount, the hydrocarbons do not burn completely with oxygen), resulting in a partial oxidation reaction that produces gases primarily consisting of carbon monoxide and hydrogen. Due to the high temperature in the gasification reactor, no other hydrocarbons heavier than methane are present. Partial oxidation of residue is a highly complex reaction process. The residue droplets ejected from the nozzle evaporate and gasify due to the thermal radiation in the vaporization furnace; subsequently, the oil vapor undergoes complete combustion or partial oxidation with oxygen, while some of the oil droplets may also undergo thermal cracking at high temperatures ； The pyrolysis products are then subjected to hydrocarbon steam reforming, carbon gasification, and water-gas shift reactions with steam or carbon dioxide. Hydrocarbon combustion, partial oxidation, and shift reactions are exothermic reactions, whereas hydrocarbon cracking, steam reforming, and carbon gasification are endothermic reactions. These reactions occur almost simultaneously within a very short time, with the heat required for the endothermic reactions being provided by the exothermic reactions.

Thank you to the person above; the answer was very detailed!

Actually, my question is: why isn’t partial oxidation to produce CO used first in the production of hydrogen from dry gas and naphtha light hydrocarbons? Can it just react directly with water vapor? Is it because residue is heavier and tends to cause catalyst coking, that it needs to be oxidized to CO first?