Issue 13/2015 - Naphtha adsorption separation can "increase" ethylene production

The calibration report of the world's first naphtha adsorption and separation unit built by Yangtze Petrochemical was released last week, which tested the adsorption yield and the purity of the
extraction liquid under various loads.
The calibration results show that when the ethylene plant alone uses the n-paraffin separated by naphtha adsorption as ethylene raw material, the ethylene yield is as high as about 41%, which is about 12 percentage points
higher than that of ordinary naphtha raw material.
This study can greatly improve the comprehensive utilization value of naphtha, help increase ethylene yield, and improve the economic efficiency of
cracker operation.

The technology adopted by the naphtha adsorption and separation plant was jointly developed by Sinopec and UOP, and the world's first 1.
3 million tons pre-hydrogenation plant and 1.
2 million tons naphtha adsorption and separation industrial plant were built in Yangzi Petrochemical, and the plant is currently maintaining smooth operation
.

On March 23, the unit completed the operation calibration under various loads for 72 hours
.
The calibration results show that the purity of n-paraffins in the extraction solution is greater than 92%, and the yield is 84%~85%, which reaches the technical target value, and at the same time solves the operation bottleneck of the device, which creates conditions
for the stable and long-term operation of the device in the future.
In view of the problems exposed in the calibration, the research group will carry out further research and research
.

The continuous growth of global ethylene demand has driven the development of China's ethylene industry, and at the same time, it has also put forward higher requirements
for the supply and optimization of naphtha, the raw material for ethylene cracking.
According to technicians, naphtha is a chemical basic raw material, mainly used for cracking ethylene and producing aromatic hydrocarbons, of which n-alkane is a high-quality ethylene pyrolysis material, and isoalkane is a high-quality aromatic hydrocarbon raw material
.
When ethylene is produced with naphtha, the isoalkanes in it cannot be cracked into the target product components and become invalid loads of the device; When producing aromatic hydrocarbons with naphtha, the n-silane in naphtha becomes an ineffective load of the plant and wastes raw materials
.
The naphtha adsorption and separation device is to separate the n-iso-alkanes in naphtha through adsorbents and use them separately, so as to improve the purity of n-silane and ethylene yield in ethylene pyrolysis, and increase the payload of the device
.

In addition, due to the large number of heavy oils in China's crude oil, the yield of naphtha is low, and there have been problems of catalytic reforming and ethylene cracking as raw materials for a long time
.
Therefore, by separating the positive and isomeric hydrocarbons of naphtha, the desorption oil rich in normal paraffins as ethylene cracking raw material, and the absorbent oil rich in non-normal hydrocarbons as the catalytic reforming raw material or the blending component of high-octane clean gasoline, the comprehensive utilization value of naphtha can be greatly improved, and the different components can be fully utilized
.
(Su)