Are 2 vacuum towers required for the atmospheric and vacuum distillation unit with a capacity of 15 million tons per year?

It’s a good suggestion; should it be discussed based on the capacity of the device and the processing volume of the vacuum distillation tower?

Why are two pressure relief towers needed? The larger the unit, the more difficult it is to increase the light oil yield; using two atmospheric pressure columns and one vacuum column is a more suitable approach. Taking Middle Eastern crude oil as an example, the average yield of light oil in crude oil evaluation is 50%; if only 40% can be extracted during the production process, the remaining 10% of light oil will go into the vacuum distillation tower, which increases the load on that tower. After the vacuum distillation tower extracts the oils that cannot be obtained through atmospheric distillation, they still require further processing such as catalytic treatment, which increases the production costs of the entire refinery. Here, the annual increase in refining costs results in losses of over 1 billion yuan; recovering these losses would represent real profits. Currently, the bottleneck in oil refining is atmospheric and vacuum distillation, and the bottleneck in atmospheric and vacuum distillation is the atmospheric tower. If it’s possible to extract 10% of the light oil using a heat value of 10 kilograms per ton of fuel consumed, it would be better than allowing that heat value – which is already wasted in the first processing step – to be used again in a catalytic secondary processing process, where the light oil is extracted using a heat value of 60 kilograms per ton of fuel consumed. Moreover, after this secondary processing, most of this light oil breaks down into gas and liquid hydrocarbons; such refinery by-products no longer have the quality required for use as light oil, so where does the profit for the company come from? In the past, the atmospheric and vacuum distillation heaters used heavy oil as fuel; now they use gas. The large amount of gas comes from the cracking of light oil.