How does a high-pressure lubricating oil hydrogenation unit control the viscosity of various products?

Firstly, the reaction system is used to control the pour point of various lubricant products, not their viscosity. The catalytic cracking reaction is not excluded. Second: The viscosity of each product is primarily influenced by the viscosity of the crude oil and the extraction amount (temperature) of each product, that is, the degree of extraction. When the extraction volume of a certain side-product increases, it means that this side-product becomes heavier; the viscosity of the next side-product also rises. The heavier components in the distillation column move upward, the extraction temperature increases, the extraction rate of the oil product improves, and the dry point rises, resulting in higher viscosity. During operation, close attention should be paid to changes in the crude oil; in distillation, it is necessary to control the amount taken from each side stream and to regulate the temperature at the outlet of the heating furnace.