Cracked gas compressor train

A torquemonitoring system was recently installed on a cracked gas compressor train at qenos olefins in australia to determine the causes of a power limitation. Compressor strings can include two to four compressor bodies in addition to the specified driver. Singh, consultant, kuala lumpur, malaysia produced gas pressure at the wellhead normally is not sufficient to allow export for sales and further treatment. Elliott to supply compressor trains for indias largest. Prediction of cracking gas compressor performance and its. Turbomachinery trains typically consist of a cracked gas compressor, an ethylene refrigerant compressor and a propylene refrigerant compressor. Distillation column automation control and optimization.

Major shutdown in dow terneuzen, elliott cracked gas compressor train 15 mw with ge steam turbine. The lowpressure compressor is a double flow type, while the intermediate and high. Quality monitoring existent gums quantity monitoring dp. Our experience in crack gas applications allows flexibility in engineering compressor and driver configurations.

Aug 20, 2010 in addition to the cracked gas compressor train, the contract includes an ethylene compressor train consisting of a 70m86 compressor driven by an snv8 steam turbine, and a propylene compressor train consisting of a 46m98 compressor and a 56m6i compressor driven by an snv6 steam turbine. If the compressor or turbine trips, whether due to excess vibration, malfunctioning instruments or surge, it can bring the entire operation to a halt for up to five working days. We have delivered gas compressor packages for power plants up to 200 mw based on 2 up to 4 gas turbines. Ejector systems, liquid ring pump systems, steam surface. As gases are compressible, the compressor also reduces the volume of a gas. Feed study front end engineering design for replacement of control and protection systems for one steam turbine cracked gas compressor train, one motor driven ethylene compressor, one motor driven propylene compressor and one expander of different brands, and for 7 reciprocating compressors. Problem in crack gas compressor start up chemical plant.

From that point, the cracked gas went through a caustic scrubber to remove traces of co2 before it was dried we used mol sieves and started down the cold train and then the. This key equipment performance susceptibility to fouling has been studied in this paper. This article describes the basic design and operation of these compressors. Compressors are the heart of these plants and as such exert a significant influence on plant profitability. The two machines are similar and this paper concentrates on the turbine driving the cracked gas compressors. An air compressor uses a crankshaft to transfer rotation from a motor to a piston.

Optimize compressor parameters for reduced inlet pressure. Feed points available at the suction piping injection spray atomizers enhance distribution increased wash oil injection rate to 34% vol. Petrochemical and natural gas adsorbents petrochemical applications. Whether naphtha or natural gas feedstock, graham has proven experience with cracked gas compressor, ethylene refrigeration compressor, propane refrigeration compressor installations supporting the largest producing plants. At the olefins plant, the operating cycle of the steamdriven, crackedgas compressor train is 7 to 8 years. A separator filters out liquids, solids, and other particulate matter that may be in the gas stream. The effluent cracked gas is then cooled in a quench tower where the overheads are sent to a cracked gas compressor train to raise the pressure of the process stream. Usually, a cracked gas compressor train in an ethylene plant consists of two, three, or four compressor bodies driven by a steam turbine. Overview of cracked gas compressor fouling theories and. Sep 01, 2015 ethylene plant yield is a function of pyrolysis furnace backpressure, among other factors. Maximizing steam turbinecompressor performance with precise. Moreover the compressor faced with insufficient flow. Cracked gas from the furnaces is compressed by the charge gas compressor. An air compressor is a specific type of gas compressor.

Detailed modelling and optimisation of an ethylene plant. Modeling and computation of fouling of a 36mw multistage. Adequate wash oil selection and antifoulant injection enables cracker extension of cracked gas compressor run lengths by reducing the amount of polymer fouling. This compact system includes equipment which supplies lubrication oil to the bearing that supports the rotor in the compressor train. Crack gas, propylene and ethylene compressor trains from elliott are custom engineered to meet the high volume, high efficiency requirements of todays mega ethylene plants. Dec 05, 2007 compression is used on natural gas to extract moisture, but ive never heard it referred to as a compression train.

However, during this cycle the plant reached its production limitations because the compressor train encountered a power limit. Lube and seal oil systems, and steam and process gas piping require a thorough cleaning before a new machinery train can be commissioned. Redesign of large steam turbines for increased reliability. Emerson process management has the technology and expertise to make it happen. In practice, however, cleaning these systems rarely gets the attention deserved. Gas is further cooled with water in the quench column, scrubbed and dried before being compressed in the cracked gas compressor and fed to the cold box. Gas toflare valves are installed at numerous locations throughout the gas treatment and recovery section. Cleaning seal and lube oil systems is also often required during a machinery turnaround. During start up of an ethylene plant, discharge temperature of the crack gas compressor fifth stage was drastically increased, meanwhile very high amount noises like fast opening and closing of a valve was observed. Cracker plants convert naphtha or gas to ethylene and propylene and subsequently to the relevant polymers. Thermoplastic labyrinth seals in centrifugal compressors 15. In many cases a combination of these are used to keep the compressor free.

At this point, condensates from the chilling train are fed to a series of separation columns. And what do the ethylene and the propylene refrigerant compressors do. An ethylene plants most critical pieces of equipment are its cracked gas compressor and turbine. A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. Another possible scenario is that the current compressor on my 04 turbo may not even the correct one for that car. Charge gas compression and caustic wash ethylene introduction in ethylene production, the feedstock, usually naphtha or ethane, initially is cracked to produce the desired ethylene, and other useful by. Turbomachinery arrangement of latest main refrigerant compressor trains for 35 mtpa are recently built around aeroderivative gas turbines such as lm2500or lm600 0 while in the past frame 7 was most used. The compressed cracked gas is cooled and subsequently dried by molecular sieves that remove most of the water. The cracked gas is scrubbed with caustic soda to stop the sulfuring and remove the other acid gasses. This type of singleshaft, multistage compressors forms the heart of a petrochemical plant. The kopflex powerlign system utilizes phase displacement technology for longterm reliability, eliminating need for recalibration.

Fouling impacts are usually service specific for cracked gas compressors, steam turbines, and other services. Ethylene unit cracked gas compressor case studies on fouling. In typical crack gas applications, steam from the highest pressure header is used as the inlet for the steam. Mco receives order for compressors and steam turbines. It cracked the casting first time it was called to supply cold air and maybe it is clutched. During this cycle, the plant reaches production limitations because this compressor train encounters a power limit. Optimize compressor parameters for reduced inlet pressure and gas flow. Man energy solutions machinery trains comprise not only the process compressors. A system of this type was recently installed on a crackedgas compressor train at qenos olefins in australia to determine the causes of a power limitation. The largest single train methanol plants located in the middle east have our steam surface condensers. The dried cracked gas is fed to a cold box for the removal of hydrogen and light hydrocarbons, while minimizing ethylene losses.

Cracked gas is cooled in transferline exchangers which produce steam from the effluent gas energy. Ethylene sulfur may also promote stress corrosion on the cracked gas compressor rotor, the result being a derating. Elliott custom engineers cracked gas, propylene, and ethylene compressor trains to meet these highvolume, highefficiency requirements, and elliotts skills in. The cracked gas is rapid quenched to stop the degradation of the olefins and coke formation.

Elliotts field service crew also overhauled and rerated the steam turbine driver for the cracked gas train. Jul 09, 20 at the altona olefins plant, the operating cycle of the steamdriven, cracked gas compressor train is 7 to 8 years. Axial compressor centrifugal compressors centrifugal compressors accelerates the velocity of the gases increases kinetic energy which is then converted into pressure as the gas flow leaves the volute and enters the discharge pipe. Compressors for ethylene plants are ordinarily a compressor train of one of three types. Advanced turbomachinery controls improve ethylene plant yield.

The piston is connected to the crankshaft by a connecting rod yeah, go figure. The mechanical engineers who design the centrifugal compressors within ethylene plants are often disconnected from the process engineers who specify the pressure. A micronet tmr control system was installed on each of the following plant compressor trains. I need some advice on welding an air compressor tank. Mar, 20 a system of this type was recently installed on a cracked gas compressor train at qenos olefins in australia to determine the causes of a power limitation. Pdf ethylene unit cracked gas compressor case studies on. Photo courtesy of the national fuel gas midstream corporation. Maximizing steam turbinecompressor performance with. The cracked gas compressor is a multisection centrifugal compressor, with 4 or 5 stages of compression required to bring the cracked gas pressure up to the desired value of approx. Mitsubishi heavy industries compressor corporation mco shipped compressors and turbines for the worlds largest megaethylene plant in u. A torquemonitoring system was recently installed on a crackedgas compressor train at qenos olefins in australia to determine the causes of a power limitation. As demands for production capacity grows, processing equipment and drivers must increase in size, throughput and reliability. One drives the cracked gas compressor train and the other drives the propylene refrigeration compressor.

The equipment on order involves three compressor trains. Achieve optimal control and a more reliable cracked gas compressor train with emersons predictive and protective machinery health solutions. Maximize cracked gas compressor train performance if the compressor or turbine trips, whether due to excess vibration, malfunctioning instruments, or surge, it can bring your entire operation to an abrupt halt and force you to flare, creating environmental concerns. These multiple compressors are connected to a steam turbine which drives them. Maximizing steam turbine compressor performance with precise. Haqs 6 research works with 4 citations and 52 reads, including. Dont want a compressor seizure and then have to find and pay a flat bed tow to bring me the rest of the way. Deliver much higher flow rates than positive displacement compressors. Fluid machinery for the oil, gas and petrochemical industry. From the beginning of exploration for the gas to final delivery into homes and businesses the compressor stations are the only place that any type of compression takes place.

Cracked gas compressor challenges difficult to control steam during startup fouling of blades and related washing reduces throughput instrument drift creates potential. The critical compressor trains in an ethylene plant can result in millions in lost production as a result of. Because of the varying operating conditions found in an ethylene plant e. Mitsubishi heavy industries compressor corporation mco shipped compressors and.

Compressor train for megaethylene plant was shipped to u. The cracked gas compressor is usually driven by an extraction type steam turbine, using high pressure live steam and extracting steam to the plants medium. Nov 29, 2012 at the olefins plant, the operating cycle of the steamdriven, cracked gas compressor train is 7 to 8 years. American institute of chemical engineers new search for. Compression is used on natural gas to extract moisture, but ive never heard it referred to as a compression train. During this cycle the plant reaches production limitations because this compressor train encounters a power limit. I bought this compressor pretty cheap with a 60 gallon tank which has a one inch hairline crack on the top of it near the motor mount. To determine the cause of the power limit as turbine. Swing furnaces can crack any type of feed smk gas type furnaces, with some adaptations to crack liquid feeds spare furnace is a gas type furnace as liquid furnace design is not optimum to reach the 60 days run length when a gas furnace is being decoked normal operation gas feed cracked in 3 gas furnaces plus 2 swing furnaces. Centrifugal compressors gas compressor bearing mechanical. Smk gas type furnaces, with some adaptations to crack liquid feeds spare furnace is a gas type furnace as liquid furnace design is not optimum to reach the 60 days run length when a gas furnace is being decoked normal operation gas feed cracked in 3 gas furnaces plus 2 swing furnaces liquid feeds cracked in 4 liquid furnaces. Its energy demand and potential plant run length, linked to its volumetric flow, molecular weight, pressure ratio and associated contaminant removal, is a major design element within the entire ethylene unit.

The petrochemical industry uses molecular sieves to purify feedstocks and to dry and remove impurities from products such as ethylene and propylene. It could be delieverd moreover with the driver, generator as well as an expander. Wet gas compressor train the vapours or wet gases from the reactor are compressed by the wet gas compressor wgc before being transferred to the highpressure condenser. You can achieve an optimally controlled and more reliable cracked gas compressor train. They are primarily used during plant startup, shutdown, or shortduration upset conditions.

Modeling and computation of fouling of a 36mw multistage centrifugal compressor train operating in a cracked gas environment. Centrifugal compressors are used in ethylene plants for cracked gas compression and refrigeration services. Problem in crack gas compressor start up chemical plant design. Typically, the wet gas compressor is a twostage inter cooled centrifugal compressor driven by an industrial steam turbine. The schematic arrangement of the gas path from the furnaces to the compressor may be represented as. Mitsubishi centrifugal compressors and steam turbines for. Conventional cracking furnace and quench systems, conventional heavy oil removal and cracked gas compressor train, driers, and acetylene hydrogenation reactors.

Application note ethylene plant monitoring strategy the combined condition and performance monitoring strategy of a typical crack gas compressor train is shown in fig. We had a 5 stage centrifugal, 50 kpa suction to about 4000 kpa discharge with interstage cooling. Typical frame 7 train installed power is around 190mw just for main refrigerant compressor. There is really no visible gap but you can barely catch your fingernail on the crack and you can hear it leak. Andrey shvydkiy head of maintenance gazprom neft badra. Abstract cracking gas compressor is usually a centrifugal compressor.

Fifty per cent of all plastics are produced based on this process. Thermoplastic labyrinth seals in centrifugal compressors. The cracked gas compressor cgc is still the most critical unit in the entire ethylene production facility. The cracked gas is rapid quenched to stop the degradation of the olefins and. Grace petrochemical and natural gas adsorbents drying. Centrifugal compressors play an important role in ethylene production. A multistage centrifugal compressor may require many impellers and diffusers between the inlet and the discharge flange to meet the head requirement of the process designers stage. Cracked gas compressor fouling, which results from polymerization and saturated heavy hydrocarbons in olefins plant, remains one of the leading factors responsible for decreasing ethylene production revenues. I am now wondering how the three compressors cracked gas. The photo at right below shows a compressor model 4v9b and drive motor which are used for gas gathering at a gas processing plant in brazil. The path to improved cracked gas compressor performance. Multistage centrifugal compressor fouling evaluation at high. To determine the cause of the power limit as turbine fouling or compressor fouling or a combination of both was not con.