Hydrocarbon plants

GRASYS hydrocarbon separation plants are produced with the use of the company brand-new proprietary membrane capable of delivering substantial benefits in comparison with other gas separation technologies.

Due to their cost-effectiveness combined with required longevity GRASYS membranes may be efficiently used in industrial applications where operating conditions excludes the adoption of other polymer membrane types. Besides, this membrane gas separation technology has a modular structure allowing expansion or modification of operated systems and prompt response to any changes in feed composition during the entire life cycle of a given source (e.g. increasing CO₂ concentration or changing hydrocarbon flow composition in a natural gas field) — and all this without unnecessary additional costs. The description below features some of the primary applications of GRASYS gas separation systems.

Natural gas treatment

These membrane separators are characterized by enhanced chemical stability and efficiency in separating natural gas flows: the membrane gas separation process is virtually streamlined along with the increase in heavy hydrocarbons concentration without any damage caused by liquid condensation. Among the membrane applications are natural gas sweetening and drying, nitrogen recovery from natural gas and hydrocarbon adjustment of natural gas dew point.

Hydrocarbon adjustment of natural gas dew point

This focus area includes methane recovery from high molecular weight hydrocarbon compounds. Separation of hydrocarbon compounds with high and low molecular weights forms the basic process which may be further divided into the following segments:

Adjustment of natural gas dew point during oil and gas resources development.

Associated gas recovery by oil production — processing of off-gas generated in the process of oil production. Currently, due to high cost of such treatment bulk of the gas is flared.
Natural gas production — processing of saturated natural gas containing a considerable amount of heavy hydrocarbons for pipeline requirements assurance. Currently, a variety of small, medium and large fields remain undeveloped or underdeveloped due to high capital or operating costs associated with gas processing.

Hydrocarbons recovery from process streams at petrochemical and refinery plants, e.g. recovery of propylene from off-gas at propylene and polypropylene production facilities, recovery and return of ethylene from waste streams of ethylene and polyethylene productions, recovery of С3+ fractions or hydrocarbon gases resulting from such processes as polymerization, reforming, cracking, hydrotreating, etc. These streams are either got lost, or require significant processing-related capital investments.

Hydrocarbon adjustment of natural gas dew point as a preliminary treatment for other processes, such as amine based absorption, or membrane gas separation, for instance by natural gas sweetening.

GRASYS has developed membranes using special materials for removal of high molecular weight (C3, C4, C5, and higher) components from natural gas. The primary application area for the hydrocarbon technology of dew point adjustment is the recovery and processing of off-gas at remote and small oil fields. Associated gas which so far, is normally flared may be processed without the need for application of cost-intensive technologies with the generation of two new grade streams: natural gas complying with the pipeline requirements due to heavy hydrocarbon removal which may be sold or used for heat generators and diesel engines, and heavy hydrocarbons recovered from off-gas and representing valuable feedstock for petrochemical industry.

Natural gas sweetening

Today, membranes are used for natural gas sweetening by means of acid gases, CO₂ and H₂S removal and ensuring its compliance with pipeline requirements as well as for carbon dioxide removal from methane and its subsequent injection in formation in the process of tertiary oil recovery. Frequently, natural gas streams contain aggressive or highly condensable components decreasing membrane capacity. For removal of these components or maintenance/control of their concentration within the membrane capacity critical limits expensive preliminary treatment is required. This restricts the conventional membranes area of application by natural gas processing and increases their functional complexity and operating costs. The new technology makes it possible to develop contamination-resistant and cost-effective membrane systems, highly efficient by gas separation.