To this end, a case study was performed for a commercial gas sweetening unit to analyze the effect of various operating conditions on the plant efficiency. The sweetened gas flows through the sweet gas cooler where it is cooled before going to the overhead scrubber. Several unit operations are employed to simulate a typical gas sweetening process. The absorber overhead gas enters ko drum, where any entrained solution is separated out. The different gas sweetening processes to be applied depend on the quality and quantity of acid. The most common methods for acid gas removal are via amines, physical solvents, or membranes, the choice of which depends on the levels of. Paris sandieoo san francisco s1noapore sydney tokyo oulfproteulowl publuhinii mimprintofbikvict. If not removed from the gas they are a cause of corrosion in equipment. This rich amine is then routed into the regenerator to produce a lean amine that can. Amines as gas sweetening agents amines as gas sweetening agents. Designed for engineers, technologists, and operations personnel involved in the design and operation of gas processing facilities, the book starts with an explanation.
Gas sweetening package amine gas sweetening process. Gas sweetening units, also known as amine treating units, are a processing unit that removes contaminants from gas, making it environmentally suitable for transportation and commercial use. The removal of h 2 s from sour gas is called sweetening. The mea solution is used for deep removal of co2 when the feed gas is free from h2s, h2s. Video sample from amine sweetening, overview and explanation of principles, supported with onsite viewing and clear graphics. The entire process is very energy intensive and results in high operating costs. Next, the hydrocarbonfree dea solution is fed to a regeneration column. The inlet stream to the gas treatment unit gtu typically arrives at a temperature of 30 to 45 degrees c. Influence of ammonia on gas sweetening units using amine soluti. Natural gas processing encyclopedia of life support systems. Amine gas treating, also known as amine scrubbing, gas sweetening and acid gas removal, refers to a group of processes that use aqueous solutions of various alkylamines commonly referred to simply as amines to remove hydrogen sulfide h 2 s and carbon dioxide co 2 from gases. Contents part 1 gassweetening 1 processingnaturalgas 1 introduction 1 natural gas processing 2 oil andcondensate removal 4.
Thus, sour gas or acid gas must be treated to remove these toxic components. Modelling of natural gas sweetening and dehydration prior. Co from natural gas sweetening to kick start eor in the. H2s is poisonous and if leakage occurs, people in the surroundings can be.
The regenerator gas is then routed back to the inlet gas ltercoalescer. Optimization of new and existing amine gas sweetening plants. The processes used for removal of acid gas are referred to as sour gas sweetening, amine gas sweetening. The acidic components removed are termed acid gas streams containing h2s, and may be flared, incinerated, or converted to elemental sulphur in a sulphur recovery unit. Power engineering 4th class ch 144 flashcards quizlet. The sweet gas is removed overhead and the rich amine is drained and. Detailed description of typical amine unit process. In the transmission of natural gas further condensation of water is problematic. Typical process flow sheet for amine absorption unit prepared in 58. Gas sweetening units risk assessment using hazop procedure. Each case must be considered on an individual basis due to a wide range of conditions and requirements for gas processing units.
Ifp energies nouvelles effect of the tower type on the gas sweetening process abdolkarim sharifi 0 elham omidbakhsh amiri 0 0 department of chemical engineering, university of mazandaran, babolsar iran the removal of acid gases, co2 and h2s from natural gas streams is essential for environmental and health reasons. To illustrate the impact of stabilization and crude oil sweetening on the quality of crude oil, the properties of oil before and after treatment are compared as follows. The conventional merox process for the removal of mercaptans i. Gas absorption is one of the very first mass transfer unit operations studied. Scribd is the worlds largest social reading and publishing site.
The basic principles for process design of main equipment, piping, and instrumentation together with guidelines on present developments and process selection in the gas sweetening process are the main. Gas sweetening processes the different gas sweetening processes to be applied depend on the quality and quantity of acid gas contaminants to be removed. Uops merox tm process is a leading technology for lpg extraction, gasoline sweetening, and jetkerosene sweetening. H2s form acidic gas ability to selectively no no yes b. The eti hte heater introduces cool ambient air or recirculated flue gas into the combustion chamber in order to reduce the combustion gas temperature to the desired level. For the ammonia free base case, the unit requires 920 gpm of 15 weight.
Different types of organic and inorganic species were found as. Prior to joining saudi aramco, since 1979 and for 7 years, he had been. Two key passages are the sweetening removal of h 2s and co 2 and the dehydration processes. Commercial gas plants often turn to amine sweetening units, systems with compliant stainless and carbon steel that can resist the corrosive forces of solvents like amines, which chemically bond with acidic gases to form unstable salts that eventually break down. Moreover, the objective of each sweetening unit may. Pdf gas sweetening process subhasish mitra academia. The gas proceeds through the contactor column where the acid gasses co2 and h2s are removed from the gas stream. An overview natural gas processing and the removal of various components from it tend to involve the most complex and expensive processes. Amine gas sweetening is a proven technology that removes h. Web to pdf convert any web pages to highquality pdf. These amine chemicals are regenerated, and not consumed, as with scavenger type systems. Doctor test is qualitative test for detecting hydrogen sulfide and mercaptan sulfur in hydrocarbon liquids. The principle process stream is the removal of the acid gases by counter flowing contact with an amine solution, commonly known as amine gas sweetening.
At some of these locations separators are referred to as knockouts, free liquid knockouts, and traps. An amine solution to absorb the hydrogen sulphide from the sour gas c. Ngl2 adip unit for utility gas sweetening of umm said. The quality of aqueous mdea used as solvent in this natural gas sweetening unit, deteriorates while absorbing h 2 sco 2 causing corrosion and foaming in the process. A typical amine sweetening process includes an absorber unit and a regenerator unit. Arnold, gas sweetening and processing field manual, usa. Hazard evaluation of gas sweetening units natural gas is supplied to this plant. A process for treating a gas stream comprising hydrogen sulphide, the process comprising the steps of. The facilities consist of inlet gas dehydration, cryogenic ngl recovery and heat medium unit. Amine solution to absorb the hydrogen sulphide from the gasoline e. Since the gas leaving the sweetening unit is usually water saturated, almost all plants. Amine sweetening is a reliable and proven technology for removing h 2 s andor co 2 from sour gas and in situations in which low outlet concentrations are required.
Gas sweetening is the process for the removal of mainly acid gases h 2 s and co 2 and, in addition, the simultaneous removal of sulphur organic species rsh, cos, cs 2 from process gas. In the absorber, the amine solution absorbs h2s and co2 from the sour gas to produce a sweetened gas stream as a product and a rich amine solution with the absorbed acid gases. Amine gas treating sweetening of sour gas lec048 chemical engineering guy. Uop benfield process a thermallyregenerated, cyclical solvent process using low cost solvent, tailored for bulk or trace acid gas removal. The purpose of this study was to perform a detailed analysis of the natural gas sweetening case shown in fig.
This process continuously injects just a few ppm of caustic into the feed naphtha. S removal acid gas treatment and removal technologies separate sour gaseshighly corrosive co 2 and often deadly h 2 s acid gasesfrom saleable natural gas streams in a process known as gas sweetening. Effect of the tower type on the gas sweetening process. Features of transtex treating amine unit 100% nace compliant. Product definition frames amine systems efficiently sweeten gas by removing hydrogen sulfide, andor carbon dioxide. All of the h2s and most of the water vapor, co2, and n2 must be removed first. Optimization of new and existing amine gas sweetening. For the absorber block, the user must specify the amine type mea, dea, or dga, the weight percent amine, and either the desired acid gas loading or the percent of equilibrium acid gas loading. This process injects small amounts of ammonia and water rather than caustic into the.
Amine contractor untreated natural gas containing carbon dioxide c0 2 and hydrogen sulfide h 2 s flows into the bottom of the amine contactor where it contacts countercurrent flowing amine. Heat to drive off the hydrogen sulphide from the sour gas b. The process is referred to as sweetening and it processes gases so they no longer have the sour, foul odors of mercaptans and hydrogen sulphide. The mercaptan oxidation reaction takes place in an alkaline environment as the feedstock jet fuel or kerosene, mixed with compressed air, flows through a fixed bed of catalyst in a reactor vessel. Modelling of natural gas sweetening and dehydration processes. The co2 is removed from the process gas stream in twostage co2 absorber. Improve amine unit efficiency by optimizing operating. It is an essential step of sour gas processing for natural gas treatment, ngl recovery. Main menu p rocess categories gas processes 2004 index contributor index gas processes articles process categories gas processes handbook 2004 dehydrogenation drying effluent cleanup flue gas treatment hydrogen liquid treating ngl and lng prereforming sulfur sulfur recovery synthesis gas treating premier sponsor. The design of the plant has been optimized to recover the maximum amount of ethane to produce a ygrade product that meets commercial specifications while minimizing utilities usage and ensuring trouble free, low maintenance operations. If the h 2 s content exceeds the sales gas specification limit, the excess h 2 s must be separated from the sour gas. If h2s and co2 volumes are appreciable, this lowers the heating value of the sales gas.
Operating data for this unit was used to quantify the impact of tuning various process conditions and to provide guidelines to achieve optimum operation of the amine sweetening unit. Conventional linear control schemes based on rigorous mathematical models, implemented in sweetening units, show poor performance and lead to offspecification products. Final selection is ultimately base d on process economics. The amine solution sweetens the natural gas by absorbing the c0 2 and h 2 s upon contact. Unless the gas is completely free of any liquids, the ng must go into an inlet. Acid gas loading in amine solutions for natural gas. Role of aqueous methyldiethanolamine mdea as solvent in. If foaming does occur it can result in high amine losses, offspec gas. The dry stream is compressed and heated to regenerate the mol sieve bed. Sour natural gas compositions can vary over a wide concentration of h 2 s and co 2 and a wide concentration of hydrocarbon components. The treated gas exits the unit at a higher temperature than the feed gas. The inlet filter is used to remove unwanted solid particles and liquid hydrocarbons from the sour gas stream before it goes through the sweetening loop.
Natural gas sweetening process simulation and optimization. Sebastine2 1school of chemical and petroleum engineering, koya university, kurdistan regioniraq 2school of science and engineering, teesside university, uk abstract natural gas is the most important and. A technical report on gas sweetening by amines subhasish mitra. To remove free water and liquid hydrocarbons, an inlet filter separator is used to reduce the likelihood of foaming. Caution should be used when referring to a vessel required for gasliquid separation as a scrubber. Amine sweetening units have been used in gas processing for nearly 80 years to remove h2s and co 2 from sour gas streams. Contaminants in amine gas treating by randy haws ccr technologies inc.
Caustic free merox for sweetening jet fuels and kerosenes. Once removed, the co 2 and h 2 s are usually vented in low concentrations, flared, and then reinjected or otherwise properly disposed of. During the last 20 years mdea has become a more popular solvent, especially when used for selective removal of h 2s over co. In order to achieve such speci cations, the raw gas must pass through a series of puri cation steps, which compose the socalled natural gas chain. Therefore, the need for advanced controls based on non. It is a common unit process used in refineries, and is also used in petrochemical plants, natural gas processing. The engineer may not have control over some variables such as inlet gas flow rate and composition. Gas sweetening and processing field manual 1st edition. Co2 h2s and co2 absorbed acid gas loading, molemole the amines 0. Pdf a technical report on gas sweetening system researchgate. Amine gas treating, also known as gas sweetening or acid gas removal, refers to a practice that uses various alkanolamines also known as amines to remove h 2 s and co 2 from natural gas streams.
Use pdf download to do whatever you like with pdf files on the web and regain control. Amine gas sweetening solutions amine gas sweetening is a proven technology that removes h2s and co2 from natural gas and liquid hydrocarbon streams through absorption and chemical reaction. Amines as gas sweetening agents henriette hansen, master thesis spring 2014 page 3 of 74 abstract co 2 and h 2s are acid components present in natural gas recovered from wells in the underground. Effect of the tower type on the gas sweetening process pdf. An amine solution to absorb the hydrogen sulphide from the crude oil d. Crude oil sweetening and stabilization aong website. Hydrogen sulfide h2s, carbon dioxide co2, mercaptans, and other contaminants are often found in natural gas streams.
Conventional merox for sweetening jet fuel or kerosene. Alfaddagh, engineering consultant instructor kefah alfaddagh joined saudi arabian oil company saudi aramco in 1986 and retired in 2012. In this work, the simulated gas sweetening unit with methyl. Primer and implications for gas processing white paper laurence reid conference, feb 2014 datasheet. The results showed that for the nordic region, natural gas sweetening i. The wet gas exiting the mol sieve bed passes through a regenerator gas cooler and regenerator gas separator to capture the steam and condense it back to water. In the present study, the composition of natural gas in natural gas sweetening unit was determined by gcms.
Energies free fulltext technoeconomic analysis of a novel. Pdf specification for glycoltype gas dehydration units. Each of the amines offers distinct advantages to specific treating problems. Gas sweetening using dea oli support center oli systems, inc. Using proven amine technology and fulfilling the requirements of our clients, frames gas sweetening is a reliable and costeffective solution that increases the value of gas resources. Emission data for sweetening processes other than amine types are very meager, but a. Khurmal sour gas is considered a highly loaded acid gas with more than 50,000 ppm of h2s and more than 4 % of co2 and successfully treated the problem by using latest version of aspen hysys v. Our expertise in sweetening processes includes multicomponent absorption of inorganic and organic sulphur species. It can increase pressure drop in the line and often leads to corrosion problems.
If you do not wish to use proprietary solvents then kasravand will optimize your gas sweetening plant for use with readily available, generic solvents the amine treating unit removes co2 and h2s from sour gas. The separation of the hydrocarbons, known as ngl c2 plus is carried out next. Co2 when this is the sole contaminant of the gas h2s when this is the sole contaminant of the gas co2 and h2s simultaneously. For over 50 years, uop has served the refining industry to meet increasingly difficult sulfur regulations and has more than 1800 process units. Caution should be used when referring to a vessel required for gas. Amines commonly used in the industry are monoethanolaminemea, diethanolamine dea and methyldietholamine mdea. Amine gas treating sweetening of sour gas lec048 youtube. This chapter covers the minimum process requirements, criteria, and features for accomplishment of process design of gas sweetening units. In the case of sweetening, the most common process technique. Semilean solution enters the top of the bulk section of the bulk of the co2 removal takes place. It is a proprietary catalytic chemical process developed by uop used in oil refineries and natural gas processing plants to remove mercaptans from lpg, propane, butanes, light naphthas, kerosene and jet fuel by converting them to liquid hydrocarbon disulfides. Tea type of amine primary secondary tertiary troublesome components in produced natural gas solution strengthin water, include. Natural gas containing high quantities of h2s and co2 is considered toxic. Gas sweetening and processing field manual provides engineers with the ability to understand and select the most efficient and cost effective method to fit their individual needs.
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