Importance of heat maintenance in sulphur recovery units. Scribd is the worlds largest social reading and publishing site. Zeeco offers a complete line of vapor and liquid incinerators also known as thermal oxidizers to dispose of waste streams. The basic process used in sulphur recovery unit sru is claus process which involves combustion of a part of h 2 s gas to form so 2. Environmental legislations in most countries require a recovery efficiency in the range of 98. Claus sulfur recovery unit the claus sulfur recovery unit sru converts hydrogen sulfide into elemental sulfur. Sulsim technology, the leading sulfur recovery process simulator developed by sulphur. Guidelines for corrosion control through construction and. Sulfur recovery process tail gas incinerators the tail gas resulting from the upstream claus unit contains sulfur bearing compounds that must be incinerated in order to oxidize the various compounds to sulfur dioxide and sulfur trioxide. In continuous operations, h2s is generated in high quantity during. Improve your gas plants performance in the middle east. They process concentrated hydrogen sulfide h 2 s fractions, converting them into sulfur dioxide so 2 and ultimately elemental sulfur they can also remove pollutants, particularly those caused by decomposing ammonia today, many refinery operators are challenged to manage rising h 2 s levels.
Accumulation of the liquid sulphur can impede the flow of process gas in the unit. The main burner and the reaction furnace are extremely important pieces of equipment and therefore must be protected from potential damaging circumstances emanating from. Sre offers onsite sulfur recovery unit sru, amine unit, and simulation training for operators, engineers, and management teams. The various reheat methods can be used with any so 2 production method, whereas the technique used for the production of so 2 is determined by the h 2 s content of the acid gas feedstock. In a typical unit, h 2 sbearing gas enters at about 8 psig. The sulphur recovery course covers all aspects of the modifiedclaus process and is recognized globally as the premier training course on this subject. The sulfur recovery unit sru is based on the modified claus process, which is a twostep reaction scheme overall. Basf has a full portfolio of products to supply the complete sru package. The incineration process typically occurs between 12001600of 650.
By recycling the hydrogen sulfide rich stream to the unit, this method can raise sulfur recovery to 99. For lean acid gas streams, the recovery typically ranges from 93% for two2 s and so 2. Klm technology group sulfur recovery units performance test. Environmental legislation imposes limits on the total quantity of sulphur compounds, such as hydrogen sulphide h2s and sulphur.
The feedstock is sent into a proprietary burner system, where it is burnt substoichiometrically with air. Of particular importance is control of the furnace process temperatures to prevent damage to the furnace refractory and assurance that reaction or destruction. The catalytic recovery of sulfur consists of three substeps. Lastly, it will be shown that modifications to sulphur condensers throughout the plant may allow simultaneous degassing and, possibly, an increase in overall sulphur recovery. To achieve an efficiency this high, it is necessary to. Methane emissions from a typical petroleum refinery arise from process equipment leaks, crude oil storage tanks, asphalt blowing, delayed coking units, and blow down systems. Later this so 2 is reacted conversion with h 2 s in presence of catalyst cobalt molybdenum aluminum oxide to form elemental sulphur and steam. Feed gas for a claus sulfur recovery unit usually originates in an acid gas. The most commonly used process in sulfur recovery practice is claus process, which is to burn the incoming gas with oxygen, refrigerate the burnt gas and recover sulfur from the burnt gas. Although many operators are always in arush to shutdown and restart a sulphur recovery unit. Removing sulfur, which is one of the products of reaction, from the process flow allows additional reaction to proceed in the next conversion stage. Optimal operation of sulphur recovery unit sru furnaces require accurate process gas flame measurement and refractory measurement for operational safety high temperature alarms. Spe188706ms corrosion control in sulphur recovery units.
Pdf a simulation of claus process via aspen hysys for. These three steps are normally repeated a maximum of three times. Tail gas from the claus sulfur recovery unit sru is heated in an inline burner before entering the hydrogenation reactor, where all sulfur species are converted to hydrogen sulfide h2s. The stream, containing varying amounts of h 2 s and co 2, is saturated with water and frequently has small amounts of hydrocarbons and other impurities in addition to the principal components. The influence amine sweetening technologies have on sulfur recovery units is explored, along with competing sulfur recovery options. The scot unit uses a cobaltmolybdenum catalyst to convert so 2 to h 2 s, which is then removed in an absorber. Indirect reheaters steam are the preferred reheat method in the sru and must be protected from thermal shock to ensure the integrity of the tubes and tubesheet. The claus sulfur recovery unit sru may be considered in two general sections. This paper elaborates methods of soft sensor development for dynamic model identification and process control of sulphur recovery unit sru in refinery production. Pdf software sensor for sulphur recovery unit control.
Pdf sulfur recovery from acid gas using the claus process and. Hydrogen sulfide is a byproduct of processing natural gas and refining sulfur containing crude oils. The product stream is fed to the waste heat boiler. This may be preferred if the plant is located close to a sizeable market for sulfuric acid. Select the following link to download a copy of our 2019 sulphur recovery course brochure. Sulfur recovery units sru refractory services thorpe.
The sulfur recovery unit sru the sulfur recovery unit sru is based on the modified claus process, which is a twostep reaction scheme overall. Sulphur recovery is an integral part of the oil refining process. Guidelines for corrosion control through construction. The claus sulfur recovery unit is typically made up of a thermal reaction stage followed by 2 or 3 catalytic reactor stages the typical conversion of the hydrogen sulfide and its recovery as elemental in a claus sulfur recovery unit.
Todays refineries are processing crude slates with higher sulphur and nitrogen contents. Most plants are now built with 2 catalytic stages, although some air quality jurisdictions require 3. Finally, the degassing section decreases the hydrogen sulfide content in the liquid sulfur product to less than 10 parts per million by weight ppm wt. An alternative to treat sulfur of this size would be a liquid redox process such as locat. Top five fundamental integrity issues for sru waste heat. Sulfur recovery unit sru in refinery, claus process. Sulphur recovery and tail gas treatment process overview various processes such as hydrotreating, cracking and coking produce gases that contain hydrogen sulphide h 2 s and occasionally carbon dioxide co 2.
The demands on srus sulfur recovery units today are more severe than any time in the past. Hydrogen sulfide is a byproduct of processing natural gas and refining highsulfur crude oils. Spe188706ms corrosion control in sulphur recovery units claus process a. Some of these crude slates have such high nitrogen contents that the feed to the sulphur recovery unit sru contains a far higher sour water stripper sws acid gas to amine acid gas ratio than has been typical for existing ammonia nh3burning srus. Typical refinery fuel gas produces a similar stoichiometric flame temperature. High yields plus energy claus sulfur plants can normally achieve high sulfur recovery efficiencies. A true epc company, we provide complete designbuild services for claus plant projects on a lump sum, turnkey basis. It can also cause sulphur fires and equipment damage in the presence of oxygen 10 vol% and a source of ignition.
He has over 50 years experience in the design, startup, and troubleshooting of oil and gas facilities. Burn backflame impingement due to operation of the burner below the recommended. The claus process is an equilibrium process, and a modified. Sru is widely used to recover sulfurcontaining, poisonous acidic gas in oil refinery process. He has published extensively on sour gas treating, sulfur recovery, co2 treating, materials of construction, lng training, and cryogenic gas processing. Sulfur recovery process tail gas incinerators the tail gas resulting from the upstream claus unit contains sulfurbearing compounds that must be incinerated in order to oxidize the various compounds to sulfur dioxide and sulfur trioxide. This acid gas is then fed to a sulfur recovery unit sru, as shown in figure 2. The sulphur recovery course is a comprehensive fiveday course which focuses on nine key topics. These seminars are tailored to your specific plant, will address your operating concerns, and are designed to maximize value with respect to your time and budget constraints. A complete range of solutions for sulfur recovery vcmstudy.
Typically, two or threestage processes are used allowing a recovery of around 9098 %. The sulfur recovery rate of the claus process is about 95 to 97%. The claus process is the most significant elemental sulphur recovery process from gaseous hydrogen sulphide. If the sulfur recovery unit is located in a crude oil refinery, the typical reheat scheme uses 3536 to 4223 kpa. Altogether, this process series approach can achieve a typical overall sulfur recovery of 99. It is fed to a thermal stage combustion reactor of a claus process sulphur recovery unit sru at 40 c, 179 kpa and 5000 kmolh. Products or references stated may be trademars or reistered trademars of teir respective owners. Sulfur recovery refers to the conversion of hydrogen sulfide h 2 s to elemental sulfur. A portion of the total h2s is burned in the reaction furnace to form so2. Of particular importance is control of the furnace process temperatures to prevent damage to the furnace refractory and. The product stream is then separated into sulphur and other product streams. Numerous sulfur recovery units sru and or tail gas treating units tgtu employing fluor s proprietary technologies have been placed in operation over the last 15 years, including the worlds largest sulfur complex with a sulfur production capacity of 10,000 mtpd, consisting of 4 x 2,500 mtpd sru tgtu liquid sulfur degassing units. The advanced amine training and sulphur recovery course is specifically aimed at those who already have prior training andor experience i. This may be preferred if the plant is located close.
The resulting mixture of hydrogen sulfide and sulfur dioxide reacts to form elemental sulfur claus reaction. The objectives of the sulphur experts western research course are to. This is the second video in a mini series that provides an overview of the sulfur recovery process, covering. The sulfur recovery unit sru is often referred to as the claus process.
Several options are available for consideration when designing the primary sulphur recovery unit to process a rich acid gas feed. Liquid sulphur produced by the claus process contains residual h2s in both chemically combined and physically dissolved forms figure 1. The feed gas to a sulfur recovery unit sru is considered acid gas, as the. Overview of air permitting requirements and options for new sulfur recovery units. Thus, sulphur byproducts from flue gas desulphurization fgd processes would not typically be accounted for in acid gas sulphur recovery determinations. With growing air pollution concerns, sulfur recovery in claus type units is. Process scheme modified claus process for sulfur recovery. Experimental data are acquired from refinery unit and include available on line.
This process recovers elemental sulfur from petroleum and natural gas refining processes and reduces the hazardous sulfur emissions to limits permitted by national and local air quality requirements. Basf titania and alumina catalysts are installed in some of the largest claus units in the world. So2 is a toxic gas responsible for acid rain formation and equipment corrosion. Sulfur recovery units performance test arrangements operating manuals page 2 of 17 rev.
The most common conversion method used is the claus process. The sulfur recovery potential of your sru is a function of the specific reheat methods employed. We encourage applicants to use this information when preparing and submitting nsr. Sulfuric acid synthesis is an alternative to sulfur recovery via the claus process. The study details choices engineers must make when deciding the number of claus beds, adding a tail gas treatment unit, using a selective versus nonselective amine and other essential. Sulfur is used to model completely integrated claus, cba cold bed adsorption, and oxygenenriched sulfur recovery plants combined with tailgas cleanup units andor incineration systems. The conversion stages are a series of repetitive steps. Hydrogenation reactor effluent is then cooled by generating low pressure lp steam, followed by additional. Sulfur recovery units, also known as claus units, use a feedstock of acid gases from sweetening units and sourwater strippers. Sulfur recovery unit acid gas analysis is a reistered trademar of applied analytics, inc. Claus sulfur recovery units are generally classified according to the method used for the production of so 2 and the method used to reheat the catalyst bed feeds. Corrosionerosion in sulfur recovery reallife examples.
Figure 1 shows a simplified shell claus offgas treatment scot tail gas treating unit tgtu. Specific mechanical details of existing plants can be input to sulfur to accurately model realworld applications. This paper also discusses startup and shutdown considerations for aminebased tail gas treating units tgtu. Conditions in the middle east are often more sour and warmer than other. Fluor offers the most recent advancements in sulfur recovery processing to enhance the capacity of clients recovery processes at a reduced capital cost, provide an easy retrofit in a small footprint and increase the conversion, capacity and efficiency of existing sulfur recovery units. The new innovation is a process for recovering sulphur from the syngas streams from the power plants where the sulphur recovery is followed by the so2 recovery unit and the gas turbines or boilers in either sequence. The sulfur recovery process recovers elemental sulfur from the refining processes and the tail gas thermal oxidizer serves to thermally treat the residual hazardous sulfur emissions to limits permitted by national and local air quality requirements. The sulfur recovery unit abstract part one of this series of papers presented at gpa gcc 21st annual technical conference in 20 detailed various ways to optimize an amine sweetening unit, particularly sweetening units located in the middle east slagle, 20. Sulfur recovery unit thermal oxidizer caption economical and energy efficient thermally treating waste matter is a primary method for disposing hazardous and nonhazardous materials worldwideits safe and effective. Later this so 2 is reacted conversion with h 2 s in presence of catalyst cobalt molybdenum aluminum oxide to form elemental sulphur and steam the main chemical reactions involved are. Practically, claus units are limited to about 96% recovery. Materials and design approaches of yesteryear often result in unreliable performance and extended and expensive maintenance requirements. Recovery of elemental sulphur from acid gas was first performed via the claus process over 100 years ago.
Review the science behind the modified clause reaction. Claus plants play a key role in refinery productivity. A simplified flow diagram of a typical sru is shown in figure 1. Sru is widely used to recover sulfur containing, poisonous acidic gas in oil refinery process. The amine treating course is designed to complement the indepth training available at the sulphur recovery technical training course, and is offered annually in canada, asia, usa and europe.
Gases with an h 2 s content of over 25% are suitable for the recovery of sulphur in the claus process. The recovered sulfur is stored in the sulfur pit and shipped as product after undergoing a degassing process to remove h 2 s. Sulphur recovery units sru wonder engineering technologies. John morgan is based in denver, colorado, and is the chairman emeritus of petroskillsjohn m. The experimental design for this study was collected. Elemental sulphur is recovered from various waste gas streams, which are byproducts of plant operation using sulphur recovery units srus. Sulfur recovery refers to the conversion of hydrogen sulfide h2s to elemental sulfur. It is vital to keep the correct h 2 sso 2 ratio in the tail gas.
Corrosionerosion in sulfur recovery reallife examples by. Acid gas enrichment unit age sulfur recovery unit sru acid gas from gsu. Feed gas for a claus sulfur recovery unit usually originates in an acid gas sweetening plant. The multistep claus process recovers sulfur from the gaseous hydrogen sulfide found in raw natural gas and from the byproduct gases containing hydrogen sulfide derived from refining crude oil and other industrial processes.
The byproduct gases mainly originate from physical and chemical gas treatment units selexol, rectisol. The course will be an intensive five days as described in the program. For the sulfur recovery process most of the previous studies have concentrated on the claus catalytic conversion reactors and the tail gas. Lummus technology specializes in providing effective sulfur control and removal solutions to the global refining industry. If the sulfur recovery unit is located in a natural gas processing plant, the type of reheat employed is typically either auxiliary burners or heat exchangers, with steam reheat being used occasionally. Pdf sulfurbearing compounds are very detrimental to the environment and to industrial process equipment.
The aim of this study is to get a simulation that is suitable for the characterization of sulfur recovery units. This is controlled by manipulating the inlet air flow rate to the. Sulphur plant and tail gas treating unit startup and. Sulphur recovery from hydrogen sulphide gas youtube. Liquid carryover, which can cause plugging of the vanesjets andor refractory failure followed shortly by a carbon steel shell failure. Where an incineration or tailgas treatment unit tgtu is added downstream of the claus plant, only two catalytic stages are usually installed. The amount of sulphur in refinery and gas plant gases is legislated to meet hse and gas pipeline specifications.
Finally the elemental sulphur is condensed and run down into a sulphur pit. Capital cost for a 1 tday locat unit would be about can. Contact us now to create a what if model of your sru. Sulphur recovery unit free download as powerpoint presentation.
Hydrogen sulphide produced, for example, in the hydrodesulphurization of refinery products is converted to sulphur in claus plants yamaguchi, 2003. The amount of sulphur in refinery and gas plant gases is legislated to. In addition, the accumulated liquid sulphur can freeze if the plant is let to cool down, or can turn into sulphur concrete due to poor. Some units are forced to use high hydrogen content fuels which have even higher stoichiometric flame. Sulfur recovery unit sru in refinery, claus process plant. This article examines some claus modifications which can alleviate operational difficulties and improve overall sulphur recovery. The tail gas that contains unrecovered sulfur is fed to the tail gas treating unit tgt.