Elena Sheina: Gas condensate must be used more widely to produce motor fuels

Ms. Elena V. Sheina, engineer of ONHP Process Engineering Department, explains to RCC reviewer the peculiarities of West Siberian gas condensate resources and steps of deep conversion focusing on higher yield of motor fuels.

- What could you say in regard to special aspects of GC processing?

- Gas condensate extraction and processing is relatively new for Russian oil and gas industry sector compared to oil or natural gas.

There are two principal directions of gas condensate processing:

-Chemical direction – monomers obtaining for organic synthesis industry (ethylene, propylene, ethyne, butadiene, benzene etc.);

-Fuel direction – gasoline, jet fuel, diesel and naphtha residue production.

Processing scheme for high aromatic gas condensate includes aromatics extraction and further processing of close cut fraction to produce extra aromatic hydrocarbons or blending fuels.

Urengoy condensates are high naphthenic consequently this gas condensate shall be considered as a rather valuable petrochemical feedstock to produce aromatic hydrocarbons.

It has been discovered that if Reforming Unit feedstock is substituted from oil to gas condensate, there is an increase of aromatic hydrocarbons yield. 

- What is special about West Siberian gas condensate resources?

- Gas condensate from West Siberian fields is distinguished by high content of light hydrocarbons broad fraction.

Low molecular alkanes are most important feedstock for petrochemical synthesis. Basic method to process them is pyrolysis. Gas fractionation units are applied to produce individual hydrocarbons suitable to be used for chemical purposes. The units are based on process of gas mix rectification and condensation methods. Depending on the composition the unit scheme can be performed with increasing or decreasing pressure mode. 

- In your opinion, what are the main advantages of this feedstock deep conversion, producing and using corresponding products?

The main part of Gas Condensate is currently processed as a blend with oil at the Refinery.

Consideration is given to expansion of feedstock base through stable gas condensate to be used for primary distillation at Gaspromneft-Omsk Refinery JSC to produce motor fuels of required quality, such as gasoline ­ IBP ­ 180 °C, a jet fuel, summer diesel fuel component. 

The advantages of stable gas condensate (SGC) as feedstock for primary distillation are the high content of fractions boiling up to 350 °C, lack of water and hydrocarbons C1-С3 and salt content of less than 3 mg/l. All these factors enable Refineries to process SGC without pre-desalting and dehydration and improve primary distillation depth and output of motor fuel fractions. 
For this reason, expansion of feedstock base by including stable gas condensate is currently central to produce motor fuels.

- What are the main characteristics of process “chains” within GC processing?

Stable gas condensate Fractionation Unit consists of heat exchanging, preflashing and atmospheric sections. Stable gas condensate processing scheme includes hydrocarbon feedstock preflashing in preflash column (K-1). After that stripped condensate is sent to main atmospheric column for jet fuel and summer diesel fuel component recovery. 

Computer model of stable gas condensate Fractionation Unit was developed in ONHP.

The model has two­column configuration. Unstable gasoline joins a single stream from two preflashing and atmospheric columns.

Atmospheric column is the main column of fractionation unit and it has two side cuts: jet fuel and diesel. Unstable gasoline is the top product.

Light component stripping is performed by using the heat of kerosene fraction vaporization in first stripping reboiler. Second pump around is used as heat-transfer medium.

Heat supply is provided by open steam for stripping light hydrocarbons in second stripper. 


Author: RCC
28 May 2015