Petrochemical Filtration & Treatment
In the hydrotreating process, the gas-oil inlet stream, typically naphtha, kerosene, diesel or other gasoil from the crude oil distillation column, is mixed with hydrogen gas, heated and fed to the fixed bed catalyst hydrotreater or reactor.
The removal of sulphur is primarily a function of pressure, temperature, catalyst activity, hydrogen purity and the hydrogen/gas-oil ratio. The high temperature and pressure reaction generate hydrogen sulphide from sulphur compounds in the gas-oil feed and ammonia if nitrogen compounds are in the feedstock.
The hydrogen sulphide and ammonia gases are removed in a distillation column (fractionator) following the high/low pressure separator after the hydrotreater reactor.
Fluid and gas streams entering the hydrotreater contain solid and semi-solid contaminants that are produced by corrosion in upstream units, tankage and piping. These contaminants, if allowed to enter the hydrotreating system, will detrimentally impact the productivity and operating efficiencies of the refinery.
As the fouling progresses, however, differential pressure across the reactor will increase. Contaminants entering the hydrotreater will foul the hydrotreater catalyst bed resulting in:
- An increase in differential pressure across the reactor eventually causes the refiner to reduce gas-oil throughput.
- Catalyst deactivation
- An unplanned shutdown of the reactor to remove or skim the prematurely fouled bed and replace the fouled catalyst.
- Catalytic column and fixed bed reactor catalyst beds are protected from fouling, extending catalyst service life and enhancing conversion efficiency and process yield.
- Compressor efficiency is improved by protecting cylinders and nozzles to extend maintenance intervals while reducing system downtime.
Acid gas containing hydrogen sulphide is primarily generated during hydro-treating processes. Amine, such as MDEA or DEA, are used for the selective removal of the acid gas. Amine and water are pumped through an amine contactor. As the streams circulate, the amine selectively absorbs the acid gas. The rich amine is then fractionated to separate the hydrogen sulphide. The stripped or lean amine is recycled back to the contactor.
Solid and semi-solid contaminants in the amine system cause many problems:
- Foaming causes carry-over and reduced system throughput
- Contactor plugging results in amine carry-over, high differential pressure and reduced contactor capacity.
- Heat exchanger/reboiler fouling causes poor heat transfer and higher energy consumption.
- Carbon bed fouling causes a reduction of adsorptive capacity that ultimately requires frequent regeneration or bed replacement.
- Consistent protection of amine contactors, reducing or eliminating foaming and amine carry-over.
- Reduced fouling of heat transfer surfaces in heat exchangers/reboilers, extending the time between maintenance and shutdowns.
- Major reduction in filter cartridge use, labour and disposal costs.
Water and water vapor containing hydrogen sulphide along with other “sour” components are produced by many units in the refinery including crude distillation, hydrotreating, and catalytic cracking. The water is stored until treated to remove the sour components prior to further processing. Acid gas components are sent to an amine contactor for treatment. The stripped water is recycled for use in the refinery or sent to disposal.
Solids, such as iron sulphide and pipe scale in the sour water stream cause fouling of the stripper column, fouling or plugging of the reboiler and heat exchanger and contamination of downstream processes.
- Reduced fouling of the stripping column, heat exchanger and reboiler, extending service between maintenance and shutdowns.
- Elimination of carried over contaminant providing continuous long-term protection of the amine sweetening and sulphur plant processes.
Refineries require a process water filtration system to remove contaminants that cause refining system upsets. The system typically includes a complete reverse osmosis (RO) system, which supplies the refinery all the boiler feed water.
If not properly pre-filtered, source water will foul RO membranes necessitating frequent cleaning or back-washing and ultimately RO membrane replacement. The water treatment/RO filtration system must efficiently remove solid and semi-solid contaminant in order to prevent fouling of steam generators.
-RO membranes are protected from fouling, eliminating frequent cleaning whether in-place of off-line to provide a direct labour and material cost reduction.
Refineries and other facilities require cost-effective maintenance-free filtration of fuel oil delivered to boilers, furnaces and other fuel burning equipment to ensure that solid contaminants do not plug and erode burner nozzles.
Ideal for retrofitting inefficient and labour-intensive strainers and basket-type filters, our filter assemblies provide virtually maintenance-free filtration of fuel oil in refinery operations.
Blended gasoline, diesel fuel, kerosene/jet fuel oil are stored and filtered prior to delivery to customers. Each of these final products is a blend of several streams produced by various refinery processes.
Filtration of refinery final products ensures product quality by meeting or exceeding product specifications.
Final products containing solid contaminant including rust, pipe scale and other solid particles cause many problems including:
- Solid particulate in jet fuel/gasoline results in product rejections, reprocessing and potential loss of business.
- Fouling of distribution equipment including pumps, nozzles and meters results in unscheduled maintenance and costly repairs.
- Fouling of fuel gas streams causes control valve fouling and deposits of solids on burner tips and in transmission lines.
- Solid particulate in grease results in product rejection and frequent cleaning of baskets and strainers.
- Final products meet specification every time to eliminate loss of time and reprocessing costs.
- Eliminate fouling of distribution equipment to avoid costly repair and unscheduled maintenance.
- Reduced fouling of fuel gas systems to provide direct cost reduction by limiting burner system maintenance and repair.
- Blended gasoline
- Kerosene/jet fuel
With the increase of environmental awareness, the disposal of any form of hazardous waste has become a great concern. Spent catalysts contribute to a significant amount of the solid waste generated by the petrochemical and petroleum refining industry. Hydro-cracking and hydrodesulfurization (HDS) catalysts are used in the petroleum refining and petrochemical industries. The catalysts used in the refining process lose their effectiveness over time. When the activity of catalysts below the acceptable level, they are usually regenerated and reused but regeneration is not possible every time. Recycling of some industrial waste containing base materials (such as V, Ni, Co, Mo) is estimated as an economical opportunity in the exploitation of these wastes. Several techniques are possible to separate the different metals, among those selective precipitation and solvent extraction are the most used.
Gas processing systems operate more efficiently and are protected from fouling with the properly selected filtration system. The installation of absolute-rated filters make it possible to improve to process efficiency and provide optimal process protection.
- Inlet Gas Separation
Natural gas gathering systems deliver large volumes of gas via pipeline to the central inlet of the gas processing facility. Removal of solid contaminants and free liquids in the inlet gas is an important first step in the protection of downstream processes. Effective removal of the contaminants can prevent fouling in gas sweetening and dehydration systems.
- Amine Sweetening
Gas processing facilities typically use amines as treatment solvents to remove acid gas components in the natural gas stream. Some amines absorb hydrogen sulphide and carbon dioxide to sweeten the gas stream. Efficient amine filtration is a critical part of a well-functioning system.
- Glycol Dehydration
Glycol is the treatment solvent used to remove water vapor from natural gas downstream of an amine sweetening system or as a stand-alone system. Filters installed at the absorber wet gas inlet will eliminate solids in the wet gas stream and prevent foaming.
Cartridges installed both upstream and downstream of the carbon bed in the water rich glycol stream will extend the life of the carbon bed, remove solids and carbon fines and protect all downstream equipment.
- Produced Water
Gas processing facilities employ a variety of “knock-out” devices and multi-stage separators to removes as much water vapor from the natural gas stream as possible. Rigid filter cartridges provide the required performance necessary in this critical application.
- Lube Oil System
Lubricating oil filtration is a key element in the efficient operation and protection of large engines used to power compressors and other equipment in refineries. Without efficient filtration, these systems have significantly shorter timer intervals between turnaround with increased occurrence of emergency maintenance and the resulting downtime. Our filter elements provide uniformly superior contaminant retention for lube oil filtration.
- Fuel Gas
Contaminated fuel gas can cause excessive valve wear, burner tip plugging and other equipment failures. Point-of-use filtration of fuel gas will reduce these problems and improve combustion while reducing overall maintenance.
- Instrument Gas
Contaminated natural gas can cause excessive valve wear, blockage of sensitive detection devices and metering equipment failures. The filtration of instrument gas will reduce these problems and overall maintenance.
- Point of use purification – potable water
- Potable water production
- Cooling/process water management
- Wastewater recovery
- Wastewater management
- Boiler feed water
- Water recovery
- Membrane process pre-treatment
The main goal for refiners is to increase production, maximise productivity and reduce operating costs. Our vast line of products can be used in the following refinery applications:
- Hydrotreating; catalyst recovery
- Amine plant and sour water stripping
- Lube oil systems; boiler feed water and fuel oil filtration
- Final product filtration
- Water treatment technologies
- Gas processing
- Reduces fouling of hardware components
- Minimizes corrosion due to abrasion
- Reduces incidents of particle-stabilized foaming
- Helps maintain a clean gas/liquid interface in the contactor for proper sour gas removal.
- Contributes to plant operational efficiency and helps optimize plant throughput.
The return condensate from stream production carries contamination that can originate from turbo generators, heat exchangers and waste heat boiler equipment. Contamination can be in the form of solids, iron sulphides (FES), as well as hydrocarbons and process fluid from tube side heat exchangers. Presence of this contamination may lead to deterioration of overall boiler feed water when the process condensate is recycled through Hotwells or used in downstream processes. Treatment and filtration of process condensate is important to allow for safe reuse downstream to maintain equipment reliability and process stability.
Controlling dissolved Oxygen (O₂) and Carbon dioxide (CO₂) levels is critical to boiler feed and steam applications. These gases are corrosive and can have a negative impact on boiler operation and ion exchange performance. It could also lead to early piping or component failure. If the carbon dioxide levels are high, it can increase the total ionic load in water, which will reduce the effectiveness of ion exchange purification technologies.
The presence of carbon dioxide in feed water to ion-exchange processes also known as demineralisation, may increase the exhaustion on strong base anion (SBA) resins leading to more frequent regeneration cycles of the anion column, often while the cation column still has capacity. The installation of degassers are usually an afterthought in such systems and comes with high capital costs and operational costs from auxiliary equipment such as compressor to create vacuum conditions. The installation of a membrane contactor may successfully reduce carbon dioxide levels to part per billion levels and have much lower operational costs. Sagisa has full capability to manufacture gas contactors using 3M Liqui-Cel™ technology.
- Boiler Feed Water
High pressure boilers require stringent boiler feed water quality to maintain operation, prevent destructive corrosion, reduce boiler block-down and maintain reliability. Traditionally oxygen in boiler feed water is controlled by chemicals known as oxygen scavengers as well as deaerators. Having a high cost on chemicals and high operational cost on chemicals and high operational costs, deaerators are self-sacrificial processes, requiring steam to produce quality BFW which goes into the production of steam. The installation of a membrane contactor may successfully reduce oxygen levels to part per billion levels and have much lower operational costs. Sagisa has full capability to manufacture gas contactors using 3M Liqui-Cel™ technology.