Patent Publication Number: US-2011070135-A1

Title: Processes and Apparatuses for Purifying Greenhouse Gases

Description:
BACKGROUND 
     1. Technical Field 
     This invention relates to processes and apparatuses for purifying greenhouse gases. This invention relates to processes and apparatuses for drying carbon dioxide and/or producing syngas. 
     2. Discussion of Related Art 
     Issues of greenhouse gas levels and climate change have led to development of technologies seeking to reduce and/or eliminate carbon emissions to the atmosphere. Electrical power plants that emit greenhouse gases have large capital expenditures, large maintenance expenses, high operating costs, complex operations, and generate waste streams. As technologies advance to reduce greenhouse gas emissions, various techniques to remove one or more impurities from gas streams have been developed, such as using membranes, or molecular sieves. 
     However, even with the above advances in purification techniques, there still remains a need and a desire for additional processes and apparatuses to purify and dry greenhouse gases, such as carbon dioxide. There also remains a need and a desire for energy production and industrial product manufacturing with reduced emissions of the greenhouse gases. 
     SUMMARY 
     This invention relates to processes and apparatuses for purifying greenhouse gases. This invention relates to processes and apparatuses for drying carbon dioxide and/or producing syngas. Methods and uses for greenhouse gas mitigation may employ streams with reduced impurities. The plants with this invention can have reduced capital expenditures (avoiding a separate dehydration unit, for example), lower maintenance expenses (less equipment, for example), lower operating costs (same solvent as used in an acid gas recovery unit, for example), less complex operations, and/or reduced waste streams than conventional plants. Additional benefits of the processes and apparatuses of this invention may include purification and/or drying of greenhouse gases, such as carbon dioxide, along with energy production and/or industrial product manufacturing having reduced emissions of the greenhouse gases. 
     According to a first embodiment, this invention includes a process for purifying greenhouse gases. The process includes the step of contacting a greenhouse gas stream having a contaminant with a solvent stream to at least partially reduce an amount of the contaminant and form a used solvent stream. The process includes the step of using the greenhouse gas stream for carbon sequestration, enhanced oil recovery, industrial gas supply, chemical synthesis and production, and/or the like. 
     According to a second embodiment, this invention includes an apparatus for purifying greenhouse gases. The apparatus includes a greenhouse gas stream having a contaminant and a solvent stream. The apparatus includes a contacting unit connected to the greenhouse gas stream and the solvent stream, and a contacting unit effluent stream connected to the contacting unit with a reduced amount of the contaminant. The apparatus includes a used solvent stream connected to the contacting unit. 
     According to a third embodiment, this invention includes a process of drying carbon dioxide. The process includes the step of reacting a feedstock stream in a reactor unit to form a reactor unit effluent stream, and the step of converting the reactor unit effluent stream in a shift conversion unit to form a shift conversion unit effluent stream. The process includes the step of separating the shift conversion unit effluent stream in an acid gas removal unit to form a hydrogen stream, a hydrogen sulfide rich stream, and a carbon dioxide stream, and the step of recovering sulfur from the hydrogen sulfide rich stream in a sulfur recovery unit to form a sulfur stream and a sulfur recovery unit effluent stream. The process includes the step of contacting the sulfur recovery unit effluent stream in a tail gas treatment unit to form a tail gas treatment unit effluent stream having a reduced amount of hydrogen sulfide and a contaminant, and the step of contacting the tail gas treatment unit effluent stream in a contacting unit with a solvent stream to form a used solvent stream and a purified tail gas treatment unit effluent stream having carbon dioxide and a reduced amount of the contaminant. The process includes the step of combining the carbon dioxide stream and the purified tail gas treatment unit effluent stream to form a combined carbon dioxide stream, and the step of using the combined carbon dioxide stream for carbon sequestration, enhanced oil recovery, industrial gas supply, chemical synthesis and production, and/or the like. 
     According to a fourth embodiment, this invention includes an apparatus for producing syngas. The apparatus includes a feedstock stream, and a reactor unit connected to the feedstock stream. The apparatus includes a reactor unit effluent stream connected to the reactor unit, and a shift conversion unit connected to the reactor unit effluent stream. The apparatus includes a shift conversion unit effluent stream connected to the shift conversion unit, and an acid gas removal unit connected to the shift conversion unit effluent stream. The apparatus includes a hydrogen stream connected to the acid gas removal unit, and a hydrogen sulfide rich stream connected to the acid gas removal unit. The apparatus includes a carbon dioxide stream connected to the acid gas removal unit, and a sulfur recovery unit connected to the hydrogen sulfide rich stream. The apparatus includes a sulfur stream connected to the sulfur recovery unit, and a sulfur recovery unit effluent stream connected to the sulfur recovery unit. The apparatus includes a tail gas treatment unit connected to the sulfur recovery unit effluent stream, and a tail gas treatment effluent stream having a contaminant connected to the tail gas treatment unit. The apparatus includes a solvent stream connected to the acid gas removal unit, and a contacting unit connected to the tail gas treatment unit effluent stream and the solvent stream to reduce an amount of the contaminant. The apparatus includes a contacting unit effluent stream connected to the contacting unit, and a used solvent stream connected to the contacting unit and the acid gas removal unit. The apparatus includes a greenhouse gas unit connected to the contacting unit effluent stream for carbon sequestration, enhanced oil recovery, industrial gas supply, chemical synthesis and production, and/or the like. The greenhouse gas unit may include of one or more compressors and/or a combination of compressors and pumps. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the features, advantages, and principles of the invention. In the drawings: 
         FIG. 1  schematically shows an apparatus for purifying greenhouse gases, according to one embodiment; 
         FIG. 2  schematically shows an apparatus for purifying greenhouse gases, according to one embodiment; 
         FIG. 3  schematically shows an apparatus for purifying greenhouse gases, according to one embodiment; 
         FIG. 4  schematically shows an apparatus for purifying greenhouse gases, according to one embodiment; 
         FIG. 5  schematically shows an apparatus for purifying greenhouse gases, according to one embodiment; 
         FIG. 6  schematically shows an apparatus for purifying greenhouse gases, according to one embodiment; 
         FIG. 7  schematically shows an apparatus for producing syngas, according to one embodiment; 
         FIG. 8  schematically shows an apparatus for producing syngas, according to one embodiment; 
         FIG. 9  schematically shows a reactor unit, according to one embodiment; and 
         FIG. 10  schematically shows an apparatus for producing syngas, according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     This invention relates to processes and apparatuses for purifying greenhouse gases. This invention relates to processes and apparatuses for drying carbon dioxide and/or producing syngas. 
     According to one embodiment, this invention may include recycling methanol from an acid gas removal unit into a tail gas treating unit to dry carbon dioxide without a separate dehydration unit. Benefits of this configuration can include reduced capital expenditures for the separate dehydration unit, reduced maintenance and/or operating expense of an overall integrated gasification combined cycle plant, simplified operations, and/or reduced waste handling. The invention can include recycling methanol from the acid gas removal system (Rectisol unit) into the tail gas treating unit to dry the tail gas from the tail gas treatment unit absorber, such as to permit dried tail gas to be combined with carbon dioxide product for export. 
       FIG. 1  schematically illustrates an apparatus  110  for purifying greenhouse gases, according to one embodiment. The apparatus  110  includes a greenhouse gas stream  112  connected to a contacting unit  116 . The apparatus  110  includes a solvent stream  114  connected to the contacting unit  116 . The apparatus  110  includes a used solvent stream  118  connected to the greenhouse gas stream with a reduced amount of contaminant or a contacting unit effluent stream  120 . The contacting unit effluent stream  120  can be used for at least one of carbon sequestration  122 , enhanced oil recovery  124 , industrial gas supply  126 , chemical synthesis and/or production,  127 , and/or the like. 
       FIG. 2  schematically illustrates an apparatus  210  for purifying greenhouse gasses, according to one embodiment. The description of the apparatus  210  proceeds in accordance with the description of the apparatus  110  in  FIG. 1  with changes made to the leading digit of the corresponding reference numerals. The apparatus  210  in  FIG. 2  also differs from the apparatus  110  in  FIG. 1  in that the apparatus  210  includes an acid gas removal unit  228  to supply the solvent stream  214  and receive the spent or used solvent stream  218 . 
       FIG. 3  schematically illustrates an apparatus  310  for purifying greenhouse gasses, according to one embodiment. The description of the apparatus,  310  proceeds in accordance with the description of the apparatus  110  in  FIG. 1  with changes made to the leading digit of the corresponding reference numerals. The apparatus  310  in  FIG. 3  also differs from the apparatus  110  in  FIG. 1  in that the apparatus  310  includes a sulfur recovery unit  330  and a sulfur recovery unit tail gas stream  332 , which forms at least a portion of the greenhouse gas stream  312 . 
       FIG. 4  schematically illustrates an apparatus  410  for purifying greenhouse gasses, according to one embodiment. The description of the apparatus  410  proceeds in accordance with the description of the apparatus  110  in  FIG. 1  with changes made to the leading digit of the corresponding reference numerals. The apparatus  410  in  FIG. 4  also differs from the apparatus  110  in  FIG. 1  in that a tail gas treatment unit  434  processes at least a portion of the green house gas steam  412  before the contacting unit  416 . 
       FIG. 5  schematically illustrates an apparatus  510  for purifying greenhouse gasses, according to one embodiment. The description of the apparatus  510  proceeds in accordance with the description of the apparatus  110  in  FIG. 1  with changes made to the leading digit of the corresponding reference numerals. The apparatus  510  in  FIG. 5  also differs from the apparatus  110  in  FIG. 1  in that a tail gas treatment unit  534  processes at least a portion of the green house gas steam  512  before the contacting unit  516 . The apparatus  510  also includes a recycle compression unit  536  on the contacting unit effluent stream  520  before the carbon sequestration  522 , enhanced oil recovery  524 , industrial gas supply  526 , chemical synthesis and/or production  527 , and/or the like. The apparatus  510  also includes an acid gas removal unit  528  to supply the solvent stream  514  and receive the spent or used solvent stream  518 . 
       FIG. 6  schematically illustrates an apparatus  610  for purifying greenhouse gasses, according to one embodiment. The description of the apparatus  610  proceeds in accordance with the description of the apparatus  110  in  FIG. 1  with changes made to the leading digit of the corresponding reference numerals. The apparatus  610  in  FIG. 6  also differs from the apparatus  110  in  FIG. 1  in that the apparatus  610  also includes a compression unit  638  on the contacting unit effluent stream  620  before the carbon sequestration  622 , enhanced oil recovery  624 , industrial gas supply  626 , chemical synthesis and/or production  627 , and/or the like. The apparatus also optionally includes a booster compressor or pump  640  on the green house gas stream  612 . 
       FIG. 7  schematically shows an apparatus  710  for producing syngas and/or drying carbon dioxide, according to one embodiment. The apparatus  710  includes a feedstock stream  712  connected to a reactor unit  714  with a reactor unit effluent stream  716 . The reactor unit effluent stream  716  connects to a shift conversion unit  718  with a shift conversion unit effluent stream  720 . Optionally, the reactor unit  714  can have one or more unshifted and/or unconverted streams, such as for use in methanol, synthetic natural gas, Fischer Trophsch liquids, and/or the like. Unshifted steams may include a suitable amount of carbon monoxide. The shift conversion unit effluent stream  720  connects to an acid gas removal unit  722  with a hydrogen stream  724 , a hydrogen sulfide rich stream  726 , a carbon dioxide stream  728 , and optionally a chemical stream (not shown). The chemical stream may be used with an unshifted stream. The carbon dioxide stream  728  connects to a greenhouse gas unit  748 . The hydrogen sulfide rich stream  726  connects to a sulfur recovery unit  730  with a sulfur stream  732  and a sulfur recovery unit effluent stream  734 . The sulfur recovery unit effluent stream  734  connects to a tail gas treatment unit  736  with a tail gas treatment effluent stream  738 . The acid gas removal unit  722  supplies a solvent stream  740  to a contacting unit  742  with a contacting unit effluent stream  744  and a used solvent stream  746 . The tail gas treatment effluent stream  738  also connects to the contacting unit  742 . The contacting unit effluent stream  744  connects to a greenhouse gas unit  748  for at least one of carbon sequestration  750 , enhanced oil recovery  752 , industrial gas supply  754 , chemical synthesis and/or production  755 , and/or the like. 
       FIG. 8  schematically illustrates an apparatus  810  for producing syngas and/or drying carbon dioxide, according to one embodiment. The description of the apparatus  810  proceeds in accordance with the description of the apparatus  710  in  FIG. 7  with changes made to the leading digits of the corresponding reference numerals. The apparatus  810  in  FIG. 8  also differs from the apparatus  710  in  FIG. 7  in that the apparatus  810  also includes a compression unit  856  on the tail gas treatment unit effluent stream  838  or the contacting unit effluent stream  844 . 
       FIG. 9  schematically shows a reactor unit  914 , according to one embodiment. The reactor unit  914  receives a feedstock stream  912  and produces a reactor unit effluent stream  916 . The reactor unit  914  may include at least one of a gasification unit  958 , a reforming unit  960 , a partial oxidation unit  962 , a pyrolysis unit  964 , and/or the like. 
       FIG. 10  schematically shows an apparatus  1010  for producing syngas and/or drying carbon dioxide, according to one embodiment. The description of the apparatus  1010  proceeds in accordance with the description of the apparatus  710  in  FIG. 7  with changes made to the leading digits of the corresponding reference numerals. The apparatus  1010  in  FIG. 10  also differs from the apparatus  710  in  FIG. 7  in that the apparatus  1010  also includes on the hydrogen stream  1024  at least one of an electricity generation unit  1066  with an electricity stream  1068 , an ammonia generation unit  1070  with an ammonia stream  1072 , a methanol generation unit  1074  with a methanol stream  1076 , a hydrocarbon product generation unit  1078  with a hydrocarbon product stream  1080 , and/or the like. 
     According to one embodiment, the invention may include a process for purifying greenhouse gases. The process may include the step of contacting a greenhouse gas stream having a contaminant with a solvent stream to at least partially reduce an amount of the contaminant and form a used solvent stream. The process may include the step of using the greenhouse gas stream for at least one of carbon sequestration, enhanced oil recovery, industrial gas supply, chemical synthesis and production, and/or the like. 
     Process broadly refers to a proceeding, a series of events and/or steps, progress and/or the like, such as to accomplish a task, a goal, and/or an outcome. Processes may be batch, semi-batch, discrete, continuous, semi-continuous, and/or the like. 
     Purify broadly refers to removing, reducing, and/or eliminating a defilement, a contaminant, an imperfection, an undesirable element, and/or the like. Purifying can remove any suitable amount of a contaminant, such as by at least about 10 percent, at least about 25 percent, at least about 50 percent, at least about 75 percent, at least about 90 percent, at least about 95 percent, at least about 99 percent, and/or the like of the contaminant from an incoming stream on a mass basis, a volume basis, a mole basis, and/or the like. 
     Gas broadly refers to not being primarily in a solid state and/or a liquid state, such as having a generally indefinite volume (compressible) and/or a generally indefinite shape (fills its container). Gases may be primarily vapors but also may include solid or particulate matter and/or fine liquid droplets, such as to form a suspension and/or an aerosol. 
     Greenhouse gases broadly refer to gases and/or vapors in an atmosphere that can absorb and/or emit radiation within the thermal infrared range, such as carbon monoxide, carbon dioxide, water vapor, methane, ethane, propane, ozone, hydrogen sulfide, sulfur oxides, nitrogen oxides, halocarbons, chlorofluorocarbons (CFCs), and/or the like. 
     Without being bound by theory, greenhouse gases are believed to receive and/or retain solar radiation and/or energy that becomes trapped in the atmosphere and causes an increase in average global atmospheric temperatures and/or climate change. According to one embodiment, the greenhouse gas includes primarily, mostly, and/or substantially carbon dioxide, such as at least about 50 percent, at least about 80 percent, at least about 90 percent, at least about 95 percent, and/or the like on a mass basis, a volume basis, a mole basis, and/or the like. The greenhouse gas can be at any suitable temperature, pressure, and/or have any suitable phase and/or state, such as a solid phase, a liquid phase, a gas phase, a supercritical fluid phase, and/or the like. 
     Contact broadly refers to bring into communication (fluid), join, mix, combine, and/or the like. According to one embodiment, contact includes intimate mixing of streams and/or substances. Contact may result in reaching at least a portion of thermodynamic equilibrium (flash). Contact may include a use of shear, velocities, gradients, diffusion, kinetics, other physical principles, other chemical principles, and/or the like. 
     Stream broadly refers to a flow, a succession, a supply, and/or the like of a material, a substance, and/or the like. 
     Contaminant broadly refers to unwholesome and/or undesirable elements, materials, compounds, and/or the like, such as to corrupt, soil, infect, pollute, defile, make impure, make inferior, make tainted, and/or the like. The contaminant may be in any suitable amount, such as between about zero percent and about 50 percent, between about 0.001 percent and about 20 percent, between about 0.01 percent and about 5 percent, and/or the like on a mass basis, a volume basis, a mole basis, and/or the like. 
     Solvent broadly refers to a substance and/or material capable at least in part of dissolving and/or dispersing one or more other materials and/or substances, such as to provide and/or form a solution. The solvent may be polar, nonpolar, neutral, protic, aprotic, and/or the like. The solvent may include any suitable element, molecule, and/or compound, such as methanol, ethanol, propanol, glycols, ethers, ketones, other alcohols, amines, salt solutions, and/or the like. The solvent may include physical solvents, chemical solvents, and/or the like. The solvent may operate by any suitable mechanism, such as physical absorption, chemical absorption, chemisorption, physisorption, adsorption, pressure swing adsorption, temperature swing adsorption, and/or the like. 
     At least partially reduce includes any suitable amount lowered and/or removed, such as by at least about 10 percent, at least about 25 percent, at least about 50 percent, at least about 75 percent, at least about 90 percent, at least about 95 percent, at least about 99 percent, and/or the like of the contaminant from an incoming stream on a mass basis, a volume basis, a mole basis, and/or the like. 
     Form broadly refers to make up, constitute, develop, give shape, and/or the like. 
     Used solvent stream broadly refers to at least a portion of the solvent stream having at least some amount of the contaminant. The used solvent stream may include any suitable amount of the contaminant such as between about 0.001 percent and about 50 percent, between about 0.01 percent and about 25 percent, between about 0.1 percent and about 10 percent, and/or the like on a mass basis, a volume basis, a mole basis, and/or the like. 
     Use broadly refers to put into action or service, to carry out a purpose, and/or the like. 
     Carbon sequestration broadly refers to long-term storage of carbon dioxide and/or other forms of carbon, such as by use of geoengineering techniques to deposit carbon into the ocean, land surface, and/or the like. Carbon sequestration may also include aspects of carbon capture and storage, such as injection into geologic formations. The carbon sequestration may use any suitable device and/or equipment, such as a carbon sequestration unit with compressors, pumps, and/or the like. 
     Enhanced oil recovery broadly refers to techniques and/or strategies to increase an amount of hydrocarbon recovered and/or removed from a geological structure. Enhanced oil recovery may include gas injection, chemical injection, ultrasonic stimulation, microbial injection, thermal recovery, and/or the like. Enhanced oil recovery may increase an amount of crude oil, natural gas, bitumen, coal, and/or the like. The enhanced oil recovery may use any suitable device and/or equipment, such as an enhanced oil recovery unit with compressors, pumps, and/or the like. 
     Industrial gas supply broadly includes uses and gases for commercial purposes and/or applications, such as refrigeration, food preservation, food preparation, beverage preparation, medical usage, chemical processes, biological processes, metallurgical processes, and/or the like. The industrial gas supply may use any suitable device and/or equipment, such as an industrial gas supply unit with compressors, pumps, and/or the like. 
     Chemical synthesis and production broadly includes materials and/or compounds derived at least in part from the streams of the processes and/or, apparatuses, such as the greenhouse gas stream and/or carbon dioxide stream. The chemical synthesis and production may use any suitable device and/or equipment, such as a chemical synthesis and production unit compressors, reactors, pumps, and/or the like. According to one embodiment, the chemicals may include urea, carbonic acid, other fertilizers, and/or the like. The chemical synthesis and production unit may include a urea unit, a carbonic acid generation unit, and/or the like. 
     According to one embodiment, the process further may include the step of supplying the solvent stream for contacting the greenhouse gas stream from an acid gas removal unit, and the step of returning the solvent stream after contacting with the greenhouse gas stream to the acid gas removal unit. The acid gas removal unit may be the supply and/or source of the solvent stream and the return and/or disposal of the used solvent stream. Desirably, but not necessarily, the acid gas removal unit removes at least a portion of the contaminant, such as to regenerate and/or recycle the solvent. 
     Unit broadly refers to a collection, a group, and/or an assembly of devices and/or equipment, such as to accomplish and/or perform a task and/or an outcome. Units may include any suitable process equipment and/or devices, such as vessels, columns, pumps, valves, compressors, control systems, and/or the like. 
     Acid gas removal unit broadly refers to any suitable device and/or equipment to separate at least a portion of acid gas from another process stream, such as a hydrogen stream and/or syngas stream. Acid gas broadly refers to a gas and/or vapor that contains hydrogen sulfide, carbon dioxide, other similar contaminants, and/or the like. Desirably, the acid gas removal unit can separate and/or form a hydrogen stream or a purified syngas stream, and an acid gas stream. The acid gas removal unit may also separate the acid gas stream into one or more components and/or constituents, such as into a carbon dioxide stream and a hydrogen sulfide stream. 
     The acid gas removal unit may include any suitable device and/or equipment, such as pumps, valves, pipes, compressors, heat exchangers, pressure vessels, distillation columns, control systems, and/or the like. According to one embodiment, the acid gas removal unit includes one or more absorber towers and one or more stripper towers. The acid gas removal unit may recover and/or separate any suitable amount of acid gas from a process stream, such as at least about 50 percent, at least about 75 percent, at least about 85 percent, at feast about 90 percent, at least about 95 percent, at least about 99 percent, and/or the like on a mass basis, a volume basis, a mole basis, and/or the like. 
     The acid gas removal unit may include Rectisol systems from Linde AG, Munich, Germany, and/or Lurgi GmbH, Frankfurt, Germany, Selexol systems from UOP, Des Plaines, Illinois, U.S.A., methanol systems, alcohol systems, amine systems, promoted amine systems, hindered amine systems, glycol systems, ether systems, potassium carbonate systems, water scrubbing systems, other suitable solvents, and/or the like. 
     According to one embodiment, the solvent stream includes primarily methanol. The solvent stream may be at any suitable pressure and/or temperature, such as a temperature of between about 40 degrees Celsius and about −100 degrees Celsius, between about 20 degrees Celsius and about −80 degrees Celsius, between about 0 degrees Celsius and about −60 degrees Celsius, and/or the like prior to contacting the greenhouse gas stream. 
     According to one embodiment, a sulfur recovery unit tail gas steam supplies at least a portion of the greenhouse gas stream. Sulfur recovery unit broadly refers to any suitable device and/or equipment to convert at least a portion of sulfur containing compounds into elemental sulfur and/or other suitable materials, such as converting hydrogen sulfide into molten elemental sulfur. Recovering elemental sulfur may include any suitable process and/or chemical reaction, such as such as converting hydrogen sulfide into molten elemental sulfur. Elemental broadly refers to relating to being primarily an element. Elemental states may include any suitable form, such as amorphous forms, crystalline forms, solid forms, liquid forms, and/or the like. Recovering sulfur in other forms and/or compounds is within the scope of this invention. 
     The sulfur recovery process may any suitable include reactions, such as those used in a Claus unit like oxidation, decomposition, forming pollutants, and/or the like. The sulfur recovery process may include any suitable device and/or equipment, such as with one or more burners, one or more condensers, one or more catalyst beds, and/or the like. The sulfur recovery unit may convert any suitable portion of hydrogen sulfide in a feed stream to elemental sulfur, such as at least about 50 percent, at least about 75 percent, at least about 85 percent, at least about 90 percent, at least about 95 percent, at least about 99 percent, and/or the like on a mass basis, a volume basis, a mole basis, and/or the like. 
     Tail gas broadly refers to an exit stream and/or an exhaust from a unit and/or device. The tail gas may be at any suitable temperature and/or pressure. The tail gas may be vented to atmosphere, used in subsequent processing, used in subsequent pollution control devices, used in subsequent heat recovery, used in subsequent power recovery, and/or the like. 
     The sulfur recovery unit effluent tail gas stream may supply any suitable amount of the greenhouse gas stream, such as about 100 percent, between about 10 percent and about 95 percent, and/or the like on a mass basis, a volume basis, a mole basis, and/or the like. 
     Effluent broadly refers to flowing out of, leaving and/or exiting. 
     According to one embodiment, the process may include the step of treating and/or processing the greenhouse gas stream in a tail gas treatment unit before contacting with the solvent. 
     The contaminant may include any suitable material and/or substance, such as primarily water. 
     The greenhouse gas stream with a reduced amount of the contaminant may include any suitable moisture content, such as a dew point of between about 20 degrees Celsius and about −80 degrees Celsius, between about 0 degrees Celsius and about −60 degrees Celsius, between about −20 degrees Celsius and about −40 degrees Celsius, and/or the like. 
     The invention has been generally described with integrated use of acid gas removal solvent for drying carbon dioxide, but embodiments with separate (independent) and/or different solvent streams and/or dehydration systems are within the scope of this invention. 
     According to one embodiment, the invention may include an apparatus for purifying greenhouse gases. The apparatus may include a greenhouse gas stream having a contaminant, and a solvent stream. The apparatus may include a contacting unit connected to the greenhouse gas stream and the solvent stream, and a contacting unit effluent stream connected to the contacting unit with a reduced amount of the contaminant. The apparatus may include a used solvent stream connected to the contacting unit. 
     Apparatus broadly refers to one or more devices and/or equipment to perform and/or accomplish a step, a task, and/or an outcome. Apparatuses may use mechanical principles, chemical principles, thermodynamic principles, and/or the Like. The apparatus and any parts and/or portions of the apparatus may have any of the features and/or characteristics with respect to processes and/or apparatuses described within this specification. 
     Device broadly refers to a piece of equipment and/or a mechanism, such as to perform and/or accomplish a step, a task, and/or an outcome. One or more devices may form a portion of a unit and/or an apparatus. 
     Connect broadly refers to join and/or establish communication, such as fluid communication. Fluid communication (flow) may be established by any suitable manner, such as pipes, tubing, conduits, channels, flow paths, placing in proximity, and/or the like. Connecting may include any suitable motive force devices, such as to move a substance and/or a material from one location to another. Motive force devices may include pumps, compressors, blowers, ejectors, eductors, conveyors, and/or the like. 
     The contacting unit may include any suitable equipment and/or structure, such as mixing valves, static mixers, trays, random packing, structured packing, demisters, and/or the like. The contacting unit may include one or more pressure vessels operating in series and/or parallel configurations. 
     According to one embodiment, the apparatus may further include a sulfur recovery unit tail gas treatment unit connected to the greenhouse gas stream to supply at least a portion of the greenhouse gas stream. The apparatus may further include an acid gas removal unit for supplying the solvent stream and receiving the used solvent stream. The apparatus may further include a recycle compression unit connected to the contacting unit effluent stream for at least one of carbon sequestration, enhanced oil recovery, industrial gas supply, chemical synthesis and production, and/or the like. 
     The sulfur recovery unit tail gas treatment unit may include any suitable devices and/or equipment, such as a burner, a catalyst bed, an ammonia scrubber, a brine treatment device, an amine contactor, a wash column, a regeneration column and/or the like. The tail gas treatment unit can reduce hydrogen sulfides, carbonyl sulfide, sulfur oxides and/or the like. 
     Recycle compression unit broadly refers to any suitable compression devices, such as centrifugal compressors, screw compressors, positive displacement compressors, reciprocating compressors, and/or the like. The compressors may include one or more stages operating in series and/or parallel configurations. The recycle compression unit can increase a pressure of the stream to any suitable value, such as below about vacuum, at least about 1 bar absolute, at least about 3 bar absolute, at least about 5 bar absolute, at least about 10 bar absolute, and/or the like. The recycle compression unit may liquefy at least a portion of a stream, such as to form liquid carbon dioxide. The recycle compression unit may form a supercritical fluid (above the critical point), such as to form supercritical carbon dioxide. 
     According to one embodiment, the apparatus further may include a compression unit on the greenhouse gas stream and/or the contacting unit effluent stream. The compression unit may include a single stage device, a multistage device, and/or the like. Optionally, a booster compression device and/or a pump may be on the green house gas stream. The compression unit may have any of the features and/or characteristics of the recycle compression unit described in this specification. 
     Optionally broadly refers to being not compulsory and/or needed, such as with an act of choosing. Optionally may include periodic and/or cyclic operations in addition to continuous operations. 
     According to one embodiment, the apparatus may include where the greenhouse gas stream may include primarily carbon dioxide, the solvent stream may include primarily methanol, and/or the contaminant may include primarily water. 
     According to one embodiment, the apparatus may include where the solvent stream has a temperature of between about 20 degrees Celsius and about −80 degrees Celsius, and the greenhouse gas effluent stream with a reduced amount of the contaminant after the contacting unit has a dew point of between about 0 degrees Celsius and about −60 degrees Celsius. 
     According to one embodiment, the invention may include a process of drying carbon dioxide. The process may include the step of reacting a feedstock stream in a reactor unit to form a reactor unit effluent stream, and the step of converting the reactor unit effluent stream in a shift conversion unit to form a shift conversion unit effluent stream. The process may include the step of separating the shift conversion unit effluent stream in an acid gas removal unit to form a hydrogen stream, a hydrogen sulfide stream, and a carbon dioxide stream, and the step of recovering sulfur from the hydrogen sulfide stream in a sulfur recovery unit to form a sulfur stream and a sulfur recovery unit effluent stream. The process may include the step of contacting the sulfur recovery unit effluent stream in a tail gas treatment unit to form a tail gas treatment unit effluent stream with a reduced amount of hydrogen sulfide and a contaminant, and the step of contacting the tail gas treatment unit effluent stream in a contacting unit with a solvent stream to form a used solvent stream and a purified tail gas treatment unit effluent stream with carbon dioxide and a reduced amount of the contaminant. The process may include the step of combining the carbon dioxide stream and the purified tail gas treatment unit effluent stream to form a combined carbon dioxide stream, and the step of using the combined carbon dioxide stream for at least one of carbon sequestration, enhanced oil recovery, industrial gas supply, chemical synthesis and production, and/or the like. 
     Drying broadly refers to reducing and/or removing at least a portion of moisture content from a material and/or a substance. Drying may include reducing a dew point by any suitable amount, such as. at least about 10 degrees Celsius, at least about 25 degrees Celsius, at least about 40 degrees Celsius, and/or the like. 
     Feedstock broadly refers to any suitable material and/or substance for consumption, reaction, conversion, processing, and/or the like. According to one embodiment, the feedstock may include carbonaceous materials, such as coal, peat, coke, petroleum coke, bitumen, crude oil, tar sands, biomass, biomass char, and/or the like. Desirably, but not necessarily, at least a portion of the feedstock may originate and/or be supplied from renewable resources, such as non-fossil fuels. 
     Biomass broadly refers to plant and/or animal materials and/or substances derived at least in part from living substances, such as lignocellulosic sources. Lignocellulosic broadly refers to containing cellulose, hemicellulose, lignin, and/or the like, such as plant material. Lignocellulosic material may include any suitable material, such as sugar cane, sugar cane bagasse, energy cane, energy cane bagasse, rice, rice straw, corn, corn stover, wheat, wheat straw, maize, maize stover, sorghum, sorghum stover, sweet sorghum, sweet sorghum stover, cotton, cotton remnant, sugar beet, sugar beet pulp, soybean, rapeseed, jatropha, switchgrass, miscanthus, other grasses, algae, fungi, bacteria, timber, softwood, hardwood, wood bark, wood waste, sawdust, paper, paper waste, agricultural waste, manure, dung, sewage, municipal solid waste, any other suitable biomass material, and/or the like. 
     Reacting broadly refers to any suitable transformation with at least a portion of a chemical step, such as at least one of combustion, oxidation, partial oxidation, pyrolysis, cracking, thermal cracking, reforming, reduction, synthesis, decomposition, single replacement, double replacement, and/or the like. Reactions may be exothermic, endothermic, and/or the like. Reactions may or may not utilize a catalyst, such as to increase a reaction rate. Catalysts may be homogenous, heterogeneous, supported, unsupported, and/or the like. 
     According to one embodiment, the step of reacting produces at least some amount of hydrogen and/or syngas. Syngas broadly refers to a mixture of gases derived at least in part from synthetic steps and/or actions. The syngas may include any suitable composition, such as primarily hydrogen with some amount of carbon oxides (carbon monoxide and/or carbon dioxide) and/or other contaminants. The syngas may have any suitable energy content, such as high value syngas with an energy content greater than methane on a volumetric basis, syngas with an energy content about equal to methane on a volumetric basis, low value syngas with an energy content less than methane on a volumetric basis, and/or the like. The syngas may include any suitable ratio of hydrogen to carbon monoxide, such as may be useful for synthesis reactions and/or the like. Carbon monoxide content may be controlled by various manners, such as reactor unit operation, shift conversion . unit operation, shift conversion unit bypass (partial and/or complete), and/or the like. Embodiments without shift conversion units are within the scope of this invention. 
     The reactor unit may include any suitable equipment and/or devices, such as furnaces, reformers, combustors, gasifiers, fixed beds, fluidized beds, slurry beds, risers, downers, regenerators, heat exchangers, quenches, pressure vessels, pipes, valves, pumps, compressors, control systems, and/or the like. According to one embodiment, the reactor unit includes at least one of a gasification unit, a reforming unit, a steam methane reforming unit, an oxidation unit, a partial oxidation unit, a pyrolysis unit, a coking unit, a cracking unit, a catalytic cracking unit, a thermal cracking unit, and/or the like. The reactor unit may convert any suitable amount of the feedstock stream into hydrogen and/or syngas. 
     The reactor unit may form a portion of a larger plant, such as a power plant, a petroleum refinery, a chemical production complex, and/or the like. The plant may include simple cycle gas turbines, combined cycle gas turbines, heat recovery units, boilers, steam generators, and/or the like. The plant may include an integrated gasification combined cycle (IGCC) configuration optionally with carbon sequestration. Desirably, but not necessarily, the plant operates with reduced carbon emissions compared to plants of conventional configuration, such as a coal fired boiler exhausting directly to the atmosphere. 
     Converting broadly refers to changing from one thing and/or property into another, such as carbon monoxide into carbon dioxide. Reducing and/or lowing carbon monoxide content may include a water gas shift reaction that consumes water molecules and produces hydrogen molecules. The shift conversion unit may include one or more shift converters in series and/or parallel configurations optionally with cooling in between, such as one or more heat exchangers. The shift converters may operate in order of decreasing temperature, such as a high temperature shift converter and a low temperature shift converter. The shift converters may include any suitable catalysts, such as sweet shift catalyst, sour shift catalyst, and/or the like. 
     The hydrogen may be used for any suitable purpose, such as at least one of sold for industrial gas supply, sold for fuel, sold for transportation fuel, used to produce steam, used to produce electricity, used to produce ammonia, used to produce methanol, used to produce synthetic hydrocarbon products, and/or the like. Synthetic hydrocarbon products broadly refer to compounds made by gas to liquids techniques and/or the like, such as Fischer-Tropsch processes, methanol to olefins, and/or the like. Synthetic hydrocarbons may include straight chain molecules, branched molecules, saturated molecules, unsaturated molecules, cyclic molecules, aromatic molecules, and/or the like. The synthetic hydrocarbons may include any other suitable functionality, such as ethers, alcohols, ketones, and/or the like. The synthetic hydrocarbons may be suitable for fuel usage, such as gasoline, gasoline blending stock, diesel, diesel blending stock, aviation fuel, aviation fuel blending stock, heating oil, heating oil blending stock, other transportation fuels, and/or the like. In the alternative, the synthetic hydrocarbons may be suitable for other applications and/or uses, such as chemical feedstocks, chemical products, solvents, coatings, surfactants, adhesives, copolymers, fertilizers, pharmaceuticals, and/or the like. According to one embodiment, the methanol generation unit may supply at least of portion of the methanol used in the acid gas removal unit. 
     According to one embodiment, the process may include where the greenhouse gas stream includes primarily carbon dioxide, the solvent stream includes primarily methanol, and the contaminant includes primarily water. 
     According to one embodiment, the solvent stream includes a temperature of between about 20 degrees Celsius and about −80 degrees Celsius, and the purified tail gas treatment unit effluent stream includes a dew point of between about least 0 degrees Celsius and about −60 degrees Celsius. 
     According to one embodiment, the invention may include an apparatus for producing syngas. The apparatus may include a feedstock stream, and a reactor unit connected to the feedstock stream. The apparatus may include a reactor unit effluent stream connected to the reactor unit, and a shift conversion unit connected to the reactor unit effluent stream. The apparatus may include a shift conversion unit effluent stream connected to the shift conversion unit, and an acid gas removal unit connected to the shift conversion unit effluent stream. The apparatus may include a hydrogen stream connected to the acid gas removal unit, and a hydrogen sulfide stream connected to the acid gas removal unit. The apparatus may include a carbon dioxide stream connected to the acid gas removal unit, and a sulfur recovery unit connected to the hydrogen sulfide stream. The apparatus may include a sulfur stream connected to the sulfur recovery unit, and a sulfur recovery unit effluent stream connected to the sulfur recovery unit. The apparatus may include a tail gas treatment unit connected to the sulfur recovery unit effluent stream, and a tail gas treatment effluent stream with a contaminant connected to the tail gas treatment unit. The apparatus may include a solvent stream connected to the acid gas removal unit, and a contacting unit connected to the tail gas treatment unit effluent stream and the solvent stream to reduce an amount of the contaminant. The apparatus may include a contacting unit effluent stream connected to the contacting unit, and a used solvent stream connected to the contacting unit and the acid gas removal unit. The apparatus may include a greenhouse gas unit connected to the contacting unit effluent stream for at least one of carbon sequestration, enhanced oil recovery, industrial gas supply, chemical synthesis and production, and/or the like. 
     The contacting unit of the apparatus may include mixing valves, static mixers, trays, random packing, structured packing, demisters, and/or the like. The apparatus may include a compression unit on the tail gas treatment unit effluent stream and/or the contacting unit effluent stream. The apparatus may include where the tail gas treatment unit effluent stream includes primarily carbon dioxide, the solvent stream includes primarily methanol, and the contaminant includes primarily water. 
     The solvent may have a temperature of between about 20 degrees Celsius and about −80 degrees Celsius, and the contacting unit effluent stream may have a dew point of between about 0 degrees Celsius and about −60 degrees Celsius. The reactor unit may include at least one of a gasification unit, a reforming unit, a partial oxidation unit, a pyrolysis unit, and/or the like. 
     The apparatus may further include one or more of a steam generation unit, an electricity generation unit, an ammonia generation unit, a methanol generation unit, a synthetic hydrocarbon product generation unit, and/or the like. Generation broadly refers to producing, making, manufacturing, and/or the like. The generation units may use and/or consume at least a portion of the hydrogen stream. Optionally, a methantion unit may further remove carbon oxides and/or other contaminants from the hydrogen stream. 
     The steam generation unit may include any suitable device and/or equipment, such as heat exchangers, boilers, steam generators, turbines, condensers, and/or the like. The electricity generation unit may include any suitable device and/or equipment, such as electricity generators, transformers, and/or the like. The ammonia generation unit may include any suitable device and/or equipment, such as compressors, converters, refrigeration systems, and/or the like. The methanol generation unit may include any suitable device and/or equipment, such as compressors, converters, refrigeration systems, and/or the like. The synthetic hydrocarbon generation unit may include any suitable device and/or equipment, such as compressors, reactors, and/or the like. 
     As used herein the terms “has”, “having”, “comprising”, “with”, and “including” are open and inclusive expressions. Alternately, the term “consisting” is a closed and exclusive expression. Should any ambiguity exist in construing any term in the claims or the specification, the intent of the drafter is toward open and inclusive expressions. 
     As used herein the term “and/or the like” provides support for any and all individual and combinations of items and/or members in a list, as well as support for equivalents of individual and combinations of items and/or members. 
     Regarding an order, number, sequence, and/or limit of repetition for steps in a method or process, the drafter intends no implied order, number, sequence and/or limit of repetition for the steps to the scope of the invention, unless explicitly provided. 
     Regarding ranges, ranges are to be construed as including all points between upper values and lower values, such as to provide support for all possible ranges contained between the upper values and the lower values including ranges with no upper bound and/or lower bound. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed structures and methods without departing from the scope or spirit of the invention. Particularly, descriptions of any one embodiment can be freely combined with descriptions of other embodiments to result in combinations and/or variations of two or more elements and/or limitations. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered exemplary only, with a true scope and spirit of the invention being indicated by the following claims.