WO2014168855A1

WO2014168855A1 - System and method for compressing carbon dioxide

Info

Publication number: WO2014168855A1
Application number: PCT/US2014/033130
Authority: WO
Inventors: James Sorokes
Original assignee: Dresser-Rand Company
Priority date: 2013-04-08
Filing date: 2014-04-07
Publication date: 2014-10-16
Also published as: EP2984344A4; EP2984344A1; EP2984344B1

Abstract

A system and method are provided for a compression system. The system and method may include a driver having a drive shaft extending therethrough. The driver may be configured to provide the drive shaft with rotational energy. The system and method may also include a first single-stage compressor and a second single-stage compressor, each having a rotary shaft coupled with or integral with the drive shaft. The first and second single-stage compressors may be configured to compress a high molecular weight process fluid to provide a compressed process fluid having a pressure ratio of about 10:1 or greater. The compressed process fluid may contain heat from the compression thereof. A heat recovery system may be fluidly coupled with the first and second single-stage compressors and may be configured to receive the compressed process fluid and absorb at least a portion of the heat contained in the compressed process fluid.

Description

System and Method for Compressing Carbon Dioxide Cross -Reference to Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application having Serial No. 61 /809,503, which was filed April 8, 2013. This priority application is hereby incorporated by reference in its entirety into the present application to the extent consistent with the present application.

Background

[0002] Reliable and efficient compression systems have been developed and are utilized in a myriad of industrial processes (e.g., petroleum refineries, offshore oil production platforms, and subsea process control systems). There is, however, an ever-increasing demand for smaller, lighter, and more compact compression systems. Accordingly, compact motor-compressors that incorporate compressors directly coupled to high-speed electric motors have been developed. Conventional compact motor-compressors may combine a high-speed electric motor with one or more compressors, such as a centrifugal compressor, in a single, hermetically sealed housing. Recently, for conventional compact motor-compressors to be considered economically and commercially viable for various industrial processes, it is desired that the compact motor-compressors achieve higher compression ratios (e.g., 10:1 or greater) while maintaining a compact arrangement.

[0003] In view of the foregoing, compact motor-compressors may often attempt to achieve the higher compression ratios by increasing the number of compression stages within the single, hermetically sealed housing. Increasing the number of compression stages, however, increases the overall number of components (e.g., impellers and/or other intricate parts) required to achieve the desired compressor throughput (e.g., mass flow) and pressure rise to achieve the higher compression ratios. Increasing the number of components required in these compact motor-compressors may often increase length requirements for the rotary shaft and/or increase distance requirements between rotary shaft bearings. The imposition of these requirements often results in larger, less compact motor-compressor arrangements as compared to previous compact motor-compressors utilizing fewer compression stages. Further, in many cases, increasing the number of compression stages in the compact motor-compressors may still not provide the desired higher compression ratios or, if the desired compression ratios are achieved, the compact motor-compressors may exhibit decreased efficiencies that make the compact motor- compressors commercially undesirable.

[0004] What is needed, then, is an efficient system and method of compression that provides increased compression ratios in a compact arrangement that is economically and commercially viable.

Summary

[0005] Embodiments of the disclosure may provide a compression system. The compression system may include a driver having a drive shaft extending therethrough and configured to provide the drive shaft with rotational energy. The compression system may also include a first single-stage compressor and a second single-stage compressor. The first single-stage compressor and the second single-stage compressor may each include a rotary shaft coupled with or integral with the drive shaft of the driver. The first single- stage compressor and the second single-stage compressor may be configured to compress a high molecular weight process fluid to provide a compressed process fluid having a pressure ratio of about 10:1 or greater. The compressed process fluid may contain heat from the compression thereof. A heat recovery system may be fluidly coupled with the first single-stage compressor and the second single-stage compressor. The heat recovery system may be configured to receive the compressed process fluid and absorb at least a portion of the heat contained in the compressed process fluid.

[0006] Embodiments of the disclosure may further provide another compression system. The compression system may include a driver having a drive shaft extending therethrough and configured to provide the drive shaft with rotation energy. The compression system may also include a first single-stage compressor having a first rotary shaft operatively coupled with a first end of the drive shaft. The first single-stage compressor may have a compression ratio of at least about 3.8:1 and may be configured to compress a process fluid containing carbon dioxide to provide a first compressed process fluid. The compression system may further include a second single-stage compressor having a second rotary shaft operatively coupled with a second end of the drive shaft. The second single-stage compressor may have a compression ratio of at least about 2.7:1 and may be configured to compress the first compressed process fluid to provide a second compressed process fluid. The second compressed process fluid may contain heat from the compression thereof and may have a pressure ratio of at least about 1 0:1 .

[0007] Embodiments of the disclosure may further provide a method for compressing a process fluid. The method may include driving a first single-stage compressor and a second single-stage compressor via a drive shaft. The drive shaft may be operatively coupled with the first single-stage compressor and the second single-stage compressor and may be driven by a driver. The method may also include compressing the process fluid via the first single-stage compressor and the second single-stage compressor to provide a compressed process fluid. The compressed process fluid may contain heat from the compression thereof and may have a pressure ratio of about 10:1 or greater. The method may further include directing the compressed process fluid to a heat recovery system and absorbing at least a portion of the heat contained in the compressed process fluid in the heat recovery system.

Brief Description of the Drawings

[0008] The present disclosure is best understood from the following detailed description when read with the accompanying Figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0009] Figure 1 illustrates a schematic of an exemplary compression system for pressurizing a process fluid, the compression system including a plurality of compressors coupled with a driver, according to one or more embodiments disclosed.

[0010] Figure 2 illustrates a flowchart of a method for compressing a process fluid, accordingly to one or more embodiments disclosed.

Detailed Description

[0011] It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the exemplary embodiments presented below may be combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.

[0012] Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Additionally, in the following discussion and in the claims, the terms "including" and "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to." All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. Furthermore, as it is used in the claims or specification, the term "or" is intended to encompass both exclusive and inclusive cases, i.e., "A or B" is intended to be synonymous with "at least one of A and B," unless otherwise expressly specified herein.

[0013] Figure 1 illustrates a schematic of an exemplary compression system 100 for pressurizing a process fluid, the compression system 1 00 including a plurality of compressors 140, 1 50 coupled with a driver 102, according to one or more embodiments. The compressors 1 40, 150 may be direct-inlet or axial-inlet, centrifugal compressors. In at least one embodiment, each of the compressors 1 40, 150 may be a single-stage compressor having compression ratios of at least about 2.5:1 or greater.

[0014] As illustrated in Figure 1 , each of the compressors 1 40, 150 may include a rotary shaft 1 1 4, 1 16 coupled with a drive shaft 1 08 of the driver 1 02. Each of the compressors 1 40, 1 50 may be coupled with the driver 1 02 at opposing ends of the drive shaft 1 08 in a "double-ended" configuration or arrangement. For example, a rotary shaft 1 1 4 of a first compressor 1 40 may extend therefrom and may be coupled with a first end 104 of the drive shaft 1 08, and a rotary shaft 1 16 of a second compressor 1 50 may extend therefrom and may be coupled with a second end 106 the drive shaft 1 08. In at least one embodiment, the rotary shafts 1 1 4, 1 16 of the first compressor 1 40 and/or the second compressor 150 may be coupled with the drive shaft 1 08 via one or more gears (not shown). The one or more gears coupling the rotary shafts 1 14, 1 16 of the first compressor 1 40 and/or the second compressor 150 with the drive shaft 1 08 may allow the rotary shafts 1 14, 1 16 to spin at a faster or slower rate than the drive shaft 1 08. In another embodiment, the rotary shafts 1 14, 1 1 6 of the first compressor 140 and/or the second compressor 1 50 may be integral with the drive shaft 1 08 of the driver 102. The driver 102 may drive the first and second compressors 1 40, 1 50 by providing rotation energy to the drive shaft 1 08, thereby rotating the rotary shafts 1 14, 1 16 coupled therewith . The drive shaft 1 08 may include a single segment or multiple segments (not shown) coupled with one another via one or more gears (not shown). The one or more gears coupling the multiple segments of the drive shaft 1 08 may allow a first segment of the drive shaft 108 to spin at a faster or slower rate than a second segment of the drive shaft 1 08.

[0015] The driver 102 may be an electric motor, such as a permanent magnet motor, and may include a stator (not shown) and a rotor (not shown). It may be appreciated, however, that other embodiments may employ other types of electric motors including, but not limited to, synchronous motors, induction motors, brushed DC motors, or the like. The driver 102 may also be a hydraulic motor, an internal combustion engine, a gas turbine , or any other device capable of driving the rotary shafts 1 1 4, 1 1 6 of the first and second compressors 1 40, 1 50, either directly or through a power train.

[0016] As illustrated in Figure 1 , the compressors 140, 150 may be overhung at opposing ends of the driver 102. For example, the first compressor 1 40 may be positioned or located along the rotary shaft 1 14 such that the first compressor 1 40 may not include additional bearings on the upstream (e.g., left, as illustrated in Figure 1 ) side of the rotary shaft 1 1 4. Similarly, the second compressor 150 may be positioned or located along the rotary shaft 1 1 6 such that the second compressor 150 may not include additional bearings on the downstream (e.g., right, as illustrated in Figure 1 ) side of the rotary shaft 1 16. In another embodiment, however, at least one of the compressors 1 40, 150 may be positioned about its respective rotary shaft 1 1 4, 1 16 between two or more bearings (not shown).

[0017] The compressors 1 40, 150 may be fluidly coupled with one another via a network of piping 1 30. The piping 1 30 may be formed from a plurality of pipes, commonly referred to as lines or conduits, configured to fluidly couple the compressors 1 40, 1 50 with one another. One or more process fluids may flow through the compressors 1 40, 150 and the piping 1 30 fluidly coupling the compressors 140, 1 50. The compressors 140, 150 and the piping 130 may form, at least in part, a process fluid passageway through which the process fluids may be flowed, as further described herein. The process fluid flowing through the process fluid passageway may have a measurable pressure, temperature, and/or mass flow rate. The piping 130, including the lines or conduits thereof, may be configured to accommodate the process fluids and/or one or more properties (e.g., pressure, temperature, and/or mass flow rate) of the process fluids flowing therethrough. For example, a construction and/or sizing (e.g., diameter, thickness, composition, etc.) of the conduits may vary and may be determined, at least in part, by the process fluids and or properties thereof flowing therethrough.

[0018] In at least one embodiment, the process fluids pressurized, circulated, contained, or otherwise utilized in the compression system 100 may be in a fluid phase, a gas phase, a supercritical state, a subcritical state, or any combination thereof. In at least one embodiment, the compression system 1 00 may be utilized to compress various process fluids including high molecular weight process fluids, low molecular weight process fluids, or any mixtures or combinations thereof. High molecular weight process fluids may include those process fluids having a molecular weight of nitrogen or greater. Illustrative high molecular weight process fluids may include, but are not limited to, hydrocarbons, such as ethane, propane, butane, pentane, and hexane. Other high molecular weight process fluids may include, but are not limited to, carbon dioxide (CO2) or mixtures containing carbon dioxide. Low molecular weight process fluids may include those process fluids having a molecular weight greater than or equal to hydrogen and less than or equal to nitrogen. Illustrative low molecular weight process fluids may include, but are not limited to hydrogen or mixtures containing hydrogen.

[0019] Utilizing carbon dioxide as the process fluid or as part of a mixture of the process fluid in the compression system 100 may provide one or more advantages over other compounds that may be utilized as the process fluid. For example, carbon dioxide may provide a readily available, inexpensive, non-toxic, and non-flammable process fluid. Due in part to a relatively high working pressure of carbon dioxide, the compression system 1 00 incorporating carbon dioxide, or mixtures containing carbon dioxide, may be more compact than other compression systems incorporating other process fluids. The high density and high heat capacity or volumetric heat capacity of carbon dioxide with respect to other process fluids may make carbon dioxide more "energy dense," meaning that a size of the compression system 1 00, and/or components thereof, may be reduced without reducing performance of the compression system 100. The carbon dioxide may be of any particular type, source, purity, or grade. For example, industrial grade carbon dioxide may be utilized as the process fluid without departing from the scope of the disclosure.

[0020] As previously discussed, the process fluids may be a mixture or process fluid mixture. The process fluid mixture may be selected for the unique attributes possessed by the mixture within the compression system 100. For example, the process fluid mixture may include a liquid absorbent and carbon dioxide, or a mixture containing carbon dioxide, enabling the mixture to be compressed to a higher pressure with less energy input than required to compress carbon dioxide, or a mixture containing carbon dioxide, alone.

[0021] As shown in Figure 1 , the piping 130 may include a system inlet 132 configured to provide the process fluids to the compression system 1 00. The process fluids provided to the system inlet 1 32 may be from one or more external sources (not shown). The external sources may include, but are not limited to, a process fluid storage tank, a fluid fill system, a separate system, such as a heat engine system, or any combination thereof. The system inlet 1 32 may be fluidly coupled with an axial inlet 1 42 of the first compressor 1 40 and may be configured to provide the process fluids thereto. The process fluids may be compressed by the first compressor 140 and discharged via an outlet 144 of the first compressor 140. In at least one embodiment, the first compressor 1 40 may have a compression ratio of about 2.5:1 or greater. For example, the compression ratio of the first compressor 1 40 may be from a low of about 2.5:1 , about 2.6:1 , about 2.7: 1 , about 2.8:1 , about 2.9:1 , about 3.0:1 , about 3.1 :1 , about 3.2:1 , about 3.3: 1 , about 3.4:1 , about 3.5:1 , about 3.6:1 , about 3.7:1 , about 3.8:1 , about 3.9:1 , or about 4:1 to a high of about 4.1 :1 , about 4.2:1 , about 4.3:1 , about 4.4:1 , about 4.5:1 , about 5:1 , or greater.

[0022] To achieve the compression ratio, the first compressor 140 may include one or more inlet vanes (e.g., guide vanes), impellers, diffusers (e.g., vaned or vaneless), discharge volutes, or any combination thereof. For example, in at least one embodiment, one or more inlet vanes (not shown) may be movably coupled with the first compressor 1 40 and disposed in or about the axial inlet 142 and/or inlet passageway (not shown) of the first compressor 1 40. The axial inlet 1 42 and/or the inlet passageway may be defined by a compressor chassis or body (not shown) of the first compressor 1 40. In at least one embodiment, the axial inlet 142 and/or the inlet passageway may be circular or substantially circular and the inlet vanes may be arranged about the circular cross-section of the axial inlet 1 42 in a spaced apart orientation. The impeller may be coupled with or mounted to the rotary shaft 1 14 extending through the first compressor 1 40. The impeller may be positioned or located downstream of the axial inlet 1 42 and/or the inlet passageway of the first compressor 140. The axial inlet 1 42 and/or the inlet passageway may be configured to provide a straight or substantially straight flowpath to the impeller. The inlet vanes may guide or direct the process fluids flowing through the axial inlet 1 42 and/or the inlet passageway directly to an inlet of the impeller.

[0023] In at least one embodiment, the diffuser may be defined by the compressor chassis of the first compressor 1 40 and may include a diffuser passageway extending from a location downstream of the impeller. The diffuser may be receive the process fluids from the impeller and may convert kinetic energy of the process fluids from the impeller into increased static pressure. In at least one embodiment, the diffuser may include one or more moveable vanes. Alternatively, the diffuser may not include any moveable vanes (e.g. vaneless). The discharge volute may be positioned downstream of the diffuser and configured to collect the process fluids from the diffuser and discharge the process fluids to the outlet 1 44 of the first compressor 1 40.

[0024] The outlet 144 of the first compressor 1 40 may be fluidly coupled with an axial inlet 1 52 of the second compressor 150 via a first conduit 134 of the piping 1 30. The discharged process fluid, or first compressed process fluid, from the first compressor 1 40 may be directed to the second compressor 150 via the first conduit 134. The first compressed process fluid may be further compressed by the second compressor 1 50 and discharged via an outlet 154 of the second compressor 150. The second compressor 1 50 may receive the first compressed process fluid from the first compressor 140 and may further compress the first compressed process fluid to provide a second compressed process fluid having to a pressure ratio of about 1 0: 1 or greater. In at least one embodiment, the second compressor 1 50 may have a compression ratio of about 2.5 or greater. For example, the compression ratio of the second compressor 1 50 may be from a low of about 2.5:1 , about 2.6: 1 , about 2.7:1 , about 2.8:1 , about 2.9:1 , about 3.0:1 , about 3.1 :1 , about 3.2:1 , about 3.3:1 , about 3.4:1 , about 3.5:1 , about 3.6:1 , about 3.7:1 , about 3.8:1 , about 3.9:1 , or about 4:1 to a high of about 4.1 :1 , about 4.2:1 , about 4.3:1 , about 4.4:1 , about 4.5:1 , about 5:1 , or greater.

[0025] To achieve the compression ratio, the second compressor 1 50, similar to the first compressor 140, may include one or more inlet vanes (e.g., guide vanes), impellers, diffusers (e.g., vaned or vaneless), discharge volutes, or any combination thereof. The arrangement or configuration of the second compressor 150 may be similar to that of the first compressor 1 40. For example, the second compressor 1 50 may include one or more inlet vanes (not shown) movably coupled with the second compressor 150 and disposed in or about the axial inlet 1 52 and/or inlet passageway (not shown) of the second compressor 1 50. The impeller (not shown) may be coupled with or mounted to the rotary shaft 1 16 extending through the second compressor 150 and may be positioned downstream of the axial inlet 152 and/or the inlet passageway of the second compressor 1 50. The diffuser (e.g., vaned or vaneless) may be defined by the compressor chassis of the second compressor 1 50 and may include a diffuser passageway extending from a location downstream of the impeller. The discharge volute may be positioned downstream of the diffuser and configured to collect the process fluids from the diffuse r and discharge the process fluids to the outlet 1 54 of the second compressor 150.

[0026] The compression system 100 including the compressors 140, 1 50 may have a compression ratio of at least about 1 0:1 or greater. For example, the compression system 1 00 may compress the process fluid to a pressure ratio from a low of about 10:1 , about 1 0.1 :1 , about 10.2:1 , about 10.3:1 , about 10.4: 1 , about 1 0.5:1 , about 1 0.6:1 , about 10.7:1 , about 10.8:1 , about 1 0.9: 1 , or about 1 1 :1 to a high of about 1 1 .2:1 , about 1 1 .3: 1 , about 1 1 .4:1 , about 1 1 .5:1 , about 1 2: 1 , about 12.5:1 , or greater. In at least one embodiment, the first compressor 140 may compress the process fluid to provide the first compressed process fluid at a desired pressure ratio, and the second compressor 1 50 may further compress the first compressed process fluid to provide a second compressed process fluid at a pressure ratio of at least about 1 0:1 or greater. The second compressor 150 may have a compression ratio sufficient to provide the second compressed process fluid at the pressure ratio of at least about 1 0:1 or greater. For example, the first compressor 1 40 may have a compression ratio of at least about 3.8:1 and may compress the process fluid to provide the first compressed process fluid at a pressure ratio of at least about 3.8:1 . The second compressor 1 50 may have a compression ratio of at least about 2.7:1 and may further compress the first compressed process fluid to provide the second compressed process fluid at a pressure ratio of at least about 10:1 or greater.

[0027] The outlet 154 of the second compressor 1 50 may be fluidly coupled with an inlet 1 62 of a heat recovery system 1 60 via a second conduit 136 of the piping 130. The discharged process fluid, or second compressed process fluid, from the second compressor 1 50 may be directed to the heat recovery system 160 via the second conduit 1 36. The second compressed process fluid may contain thermal energy or heat generated from the compression of the process fluid in the first and second compressors 1 40, 150. The heat contained in the second compressed process fluid may be transferred to or captured by the heat recovery system 160, thereby cooling the second compressed process fluid and providing a cooled, compressed process fluid . The cooled process fluid from the heat recovery system 160 may be discharged via an outlet 164 of the heat recovery system 160. The outlet 164 of the heat recovery system 1 60 may be fluidly coupled with one or more downstream processing systems and/or components (not shown) via a third conduit 138 of the piping 1 30. The one or more downstream processing systems and/or components may be configured to further process the cooled process fluid.

[0028] The heat recovery system 1 60 may be any system known in the art capable of capturing and/or recycling heat (e.g. , heat of compression) generated from the compression system 1 00. For example, the heat recovery system 160 may include one or more components and/or heat recovery sections (not shown) capable of absorbing and/or transferring heat from the second compressed process fluid. Illustrative components and/or heat recovery sections of the heat recovery system 1 60 may include, but are not limited to, one or more recuperators, heat exchangers, heat recovery steam generators, or any combination thereof.

[0029] The captured or absorbed heat from the heat recovery system 160 may be directed to one or more downstream processes and/or components via conduit 166 of the piping 1 30. The captured heat may be utilized in various processes known in the art. For example, the captured heat may be provided as a waste heat stream in a heat engine system. The captured heat may be converted into useful energy by a variety of turbine generators or heat engine systems that may employ thermodynamic methods, such as Rankine cycles. Rankine cycles and similar thermodynamic methods may include steam- based processes that recover and utilize waste heat to generate steam to drive turbines, turbos, or other expanders coupled with electric generators, pumps, or other devices.

[0030] Figure 2 illustrates a flowchart of a method 200 for compressing a process fluid, accordingly to one or more embodiments. The method 200 may include driving a first single-stage compressor and a second single-stage compressor via a drive shaft operatively coupled with the first single-stage compressor and the second single-stage compressor, the drive shaft driven by a driver, as shown at 202. The method 200 may also include compressing the process fluid via the first single-stage compressor and second single-stage compressor to provide a compressed process fluid containing heat from the compression thereof and having a pressure ratio of about 10:1 or greater, as shown at 204. The method may further include directing the compressed process fluid to a heat recovery system, as shown at 206. The method may also include absorbing at least a portion of the heat contained in the compressed process fluid in the heat recovery system, as shown at 208.

[0031] The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

Claims I claim:

1 . A compression system, comprising:

a driver comprising a drive shaft extending therethrough, the driver configured to provide the drive shaft with rotational energy;

a first single-stage compressor and a second single-stage compressor, each comprising a rotary shaft coupled with or integral with the drive shaft, the first single-stage compressor and the second single-stage compressor configured to compress a high molecular weight process fluid and provide a compressed process fluid having a pressure ratio of about 1 0: 1 or greater, the compressed process fluid containing heat from the compression thereof; and

a heat recovery system fluidly coupled with the first single-stage compressor and the second single-stage compressor and configured to receive the compressed process fluid therefrom and absorb at least a portion of the heat contained in the compressed process fluid.

2. The compression system of claim 1 , wherein the first single-stage compressor has a compression ratio of at least about 3.8:1 and is operatively coupled with a first end of the drive shaft and configured to compress the high molecular weight process fluid to provide a first compressed process fluid.

3. The compression system of claim 2, wherein the second single-stage compressor has a compression ratio of at least about 2.7:1 and is operatively coupled with a second end of the drive shaft and configured to compress the first compressed process fluid from the first single-stage compressor to provide the compressed process fluid.

4. The compression system of claim 1 , wherein the first single-stage compressor and the second single-stage compressor are overhung at opposing ends of the drive shaft in a double-ended configuration.

5. The compression system of claim 1 , wherein an inlet of the first single-stage compressor is fluidly coupled with a system inlet, the system inlet configured to provide the high molecular weight process fluid to the first single-stage compressor from an external source.

6. The compression system of claim 1 , wherein the first single-stage compressor and the second single-stage compressor are axial-inlet centrifugal compressors.

7. The compression system of claim 1 , wherein each of the first single-stage compressor and the second single-stage compressor further comprises:

an axial inlet configured to receive the process fluid;

an impeller operatively coupled with the drive shaft and positioned downstream the axial inlet;

an inlet vane movably coupled with the axial inlet and configured to guide the process fluid to the impeller;

a diffuser positioned downstream from the impeller and configured to receive the process fluid from the impeller; and

a discharge volute positioned downstream the diffuser and configured to collect the process fluid from the diffuser and discharge the process fluid via an outlet.

8. The compression system of claim 7, wherein the diffuser comprises a moveable vane.

9. A compression system, comprising:

a first single-stage compressor comprising a first rotary shaft operatively coupled with a first end of the drive shaft, the first single-stage compressor having a compression ratio of at least about 3.8:1 and configured to compress a process fluid comprising carbon dioxide to provide a first compressed process fluid; and

a second single-stage compressor comprising a second rotary shaft operatively coupled with a second end of the drive shaft, the second single-stage compressor having a compression ratio of at least about 2.7:1 and configured to compress the first compressed process fluid to provide a second compressed process fluid, the second compressed process fluid containing heat from the compression thereof and having a pressure ratio of at least about 10:1 .

1 0. The compression system of claim 9, wherein the first single-stage compressor comprises:

an axial inlet configured to receive the process fluid;

an impeller coupled with the first rotary shaft, the impeller positioned downstream the axial inlet;

a discharge volute positioned downstream the diffuser and configured to collect the compressed process fluid from the diffuser and discharge the process fluid via an outlet.

1 1 . The compression system of claim 10, wherein the axial inlet of the first single-stage compressor is fluidly coupled with a system inlet, the system inlet configured to provide the process fluid to the first single-stage compressor from an external source.

1 2. The compression system of claim 9, further comprising a heat recovery system fluidly coupled with the second single-stage compressor and configured to receive the second compressed process fluid and absorb at least a portion of the heat contained in the second compressed process fluid.

1 3. The compression system of claim 9, wherein the first single-stage compressor and the second single-stage compressor are axial-inlet centrifugal compressors.

1 4. A method for compressing a process fluid, comprising: driving a first single-stage compressor and a second single-stage compressor via a drive shaft operatively coupled with the first single-stage compressor and the second single-stage compressor, the drive shaft driven by a driver;

compressing the process fluid via the first single-stage compressor and the second single-stage compressor to provide a compressed process fluid containing heat from the compression thereof and having a pressure ratio of about 1 0:1 or greater;

directing the compressed process fluid to a heat recovery system; and

absorbing at least a portion of the heat contained in the compressed process fluid in the heat recovery system.

1 5. The method of claim 14, further comprising:

compressing the process fluid via the first single-stage compressor to provide a first compressed process fluid having a pressure ratio of at least about 3.8:1 .

1 6. The method of claim 15, further comprising feeding the process fluid to the first single-stage compressor from an external source.

1 7. The method of claim 15, further comprising:

directing the first compressed process fluid from the first single-stage compressor to the second single-stage compressor via piping; and

compressing the first compressed process fluid via the second single-stage compressor to provide the compressed process fluid having a pressure ratio of about 10:1 or greater.

1 8. The method of claim 14, wherein the first single-stage compressor and the second single-stage compressor are overhung at opposing ends of the drive shaft in a double- ended configuration.

1 9. The method of claim 14, wherein the first single-stage compressor and the second single-stage compressor are axial-inlet centrifugal compressors.

20. The method of claim 14, wherein each of the first single-stage compressor and the second single-stage compressor comprises:

an axial inlet configured to receive the process fluid;

a rotary shaft coupled with or integral with the drive shaft;

an impeller coupled with the rotary shaft and positioned downstream the axial inlet; an inlet vane movably coupled with the axial inlet and configured to guide the process fluid to the impeller;