CN1262808C - 改进的闭合回路单混合制冷剂工艺 - Google Patents

改进的闭合回路单混合制冷剂工艺 Download PDF

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CN1262808C
CN1262808C CN01810895.4A CN01810895A CN1262808C CN 1262808 C CN1262808 C CN 1262808C CN 01810895 A CN01810895 A CN 01810895A CN 1262808 C CN1262808 C CN 1262808C
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S·D·霍夫阿特
B·C·布莱斯
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Black and Veatch Pritchard Inc
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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Abstract

一种闭合回路单混合制冷剂工艺和系统,其中,通过提高热交换制冷区中所制备的液化材料温度,然后通过闪蒸部分液化材料来冷却上述液化材料,以制备进一步冷却的液化材料和一部分被循环至热交换制冷器的闪蒸气体,从而提高了工艺效率。该工艺和系统提高了工艺的效率和灵活性。

Description

改进的闭合回路单混合制冷剂工艺
                      发明背景
发明领域
本发明涉及一种闭合回路单混合制冷剂工艺,其中,通过调节此工艺所产生的液化流体材料的温度,可增大该工艺的制冷量。
现有技术简述
由于其洁净燃烧性和便利性,天然气近年来已经被广泛应用。若干天然气资源位于偏远地区,这不便于任何商业市场获得这种气体。如果不能用管道将天然气输送到商业市场,则通常将制备的天然气加工成液化天然气(LNG)而输送到市场。LNG设备的一个显著特点是需要大量的设备资金投入。液化设备由若干基本系统组成,包括气体处理以除去杂质、液化、制冷、动力设施、储存和船运设施。这些设备的成本可以有很大变化,但是设备制冷部分的成本一般最高可占总成本的30%。LNG制冷系统十分昂贵的原因在于需要大量制冷来液化天然气。在温度为40~约120°F的条件下,典型的天然气流压力约为250psig(每平方英寸量器的磅数)~约1500psig。主要为甲烷的天然气不能象用作能源的重质烃类那样,只通过简单增加天然气压力来进行液化。甲烷的临界温度为-82.5℃(-116.5°F),这表明无论附加压力有多大,甲烷也只能在这个温度以下才能液化。因为天然气通常是一种气体混合物,因此它是在一定温度范围内液化。天然气的临界温度一般为约-121°F~约-80°F。通常,在大气压下,天然气组合物的液化温度范围为约-265°F~约-247°F。由于制冷装置占LNG设备成本的显著部分,因此,人们为了降低制冷成本已经付出了相当多的努力。
各种制冷循环已经被用于液化天然气,其中最常见的三种循环是:阶式循环,它利用多种渐进式排列的单组分制冷剂和热交换器来将气体温度降低至液化温度;膨胀器循环,它使气体从高压膨胀至低压来相应地降低温度;和多组分制冷循环,它利用多组分制冷剂和专业设计的热交换器来液化天然气。
在很多情况下,也可使天然气液化,以将其储存在需要天然气的地区附近,例如在居住人口密集地区,这些地区在冬季对天然气的需求量超过了通过管道系统可提供的量。在这种情况下,可将液化天然气储存于储罐、地下储洞等中,这样,在天然气高峰负荷月份就可以使用这些液化天然气。为了储存而液化这种气体的设备可稍微小于那些为了船运到市场而在偏远地区液化天然气的设备等。
其它气体也被液化,但是频率稍微低一些。这些气体可通过上述工艺来进行液化。
以前,象天然气这样的物质已经通过下列工艺来进行液化,例如于1977年7月5日授予Leonard K.Swenson的美国专利4,033,735,和于1997年8月19日授予Brian C.Price的美国专利5,657,643,在这里整体引入这两个专利作为参考。在这些工艺中使用了一种单混合制冷剂。与其它工艺例如阶式系统相比,这些工艺具有许多优点,它们所需设备比阶式工艺设备价格更便宜,操作更简单。令人遗憾的是,单混合制冷剂工艺所需动力稍微大于阶式系统。
阶式系统例如1974年12月24日授予Simon等人的美国专利3,855,810中所列系统,主要是利用多制冷区,在多制冷区中蒸发沸点降低的制冷剂来制备冷却剂。在这些系统中,一般是将沸点最高的制冷剂单独地或与其它制冷剂一起压缩、冷凝和分离,以在第一制冷区中进行冷却。然后,将经过压缩和冷却的沸点最高的制冷剂进行闪蒸,以提供冷制冷流,用于冷却第一制冷区中被压缩的沸点最高的制冷剂。在第一制冷区中,某些沸点较低的制冷剂也可被冷却,然后经冷凝和蒸发后,用作第二或后续制冷区等中的冷却剂。因此,该工艺主要是压缩沸点最高的制冷剂,这比压缩全部单混合制冷流更有效。但是应注明的是,这些工艺所需设备更加昂贵。
为了降低单混合制冷剂工艺的设备成本和操作难度,人们已经进行了不懈地努力来改善这种工艺,其中,动力需求已经降低,并且工艺灵活性已经增大。
                       发明概述
本发明提供了一种改善闭合回路混合制冷剂工艺效率的方法,用于使流体材料由超过200°F的温度冷却到低于约-200°F的温度。
该方法包括:将从闭合回路混合制冷剂工艺的制冷区排出的液体流体材料的温度调节至为约-200~约-245°F,降低该液体流体材料压力以使其温度降低至小于约-245°F并制备一种闪蒸气体,从上述液体流体材料中至少分离大部分闪蒸气体,将至少部分闪蒸气体加热至温度高于约40°F,将至少部分加热闪蒸气体压缩至压力至少等于加入制冷区的流体材料压力,和合并至少部分压缩加热闪蒸气体与加入制冷区的流体材料。
该方法还包括一种通过在闭合回路制冷循环中与单混合制冷剂的热交换来提高闭合回路混合制冷剂工艺效率和灵活性的方法,用于使流体材料由超过200°F的温度冷却至低于约-200°F的温度,该工艺包括:压缩一种气态混合制冷剂以制备压缩混合制冷剂,冷却该压缩混合制冷剂,将冷却压缩混合制冷剂加入制冷区并在该制冷区中冷却该压缩混合制冷剂,以制备基本为液态的混合制冷剂;使该液态混合制冷剂通过膨胀阀以制备一种低温制冷剂,将该低温制冷剂与冷却压缩混合制冷剂和流体材料进行逆流热交换,以制备基本为液态的混合制冷剂、基本为液态的流体材料和气态混合制冷剂,该方法包括:将液体流体材料的温度调节至为约-200~约-245°F,降低该液体流体材料压力以使其温度降低至小于约-245°F并制备一种闪蒸气体,从上述液体流体材料中至少分离大部分闪蒸气体,将至少部分闪蒸气体加热至温度高于约40°F,将至少部分加热闪蒸气体压缩至高于流体材料进入制冷区的入口压力;和合并至少部分压缩加热闪蒸气体与加入制冷区的流体材料。
本发明还包括一种闭合回路单混合制冷剂工艺,用于通过在闭合回路制冷循环中与单混合制冷剂的热交换来使流体材料由超出200°F的温度冷却至低于约-200°F的温度,该工艺包括:压缩一种气态混合制冷剂以制备压缩混合制冷剂,冷却该压缩混合制冷剂以制备冷却压缩制冷剂,将冷却压缩制冷剂加入制冷区并在制冷区中进一步冷却该冷却压缩制冷剂,以制备基本上为液体的混合制冷剂,使该液体混合制冷剂通过膨胀阀以制备一种低温制冷剂,将该低温制冷剂与冷却压缩制冷剂和流体材料进行逆流热交换,以制备基本液体的混合制冷剂、温度为约-200~约-245°F的冷却的基本液体流体材料和气态混合制冷剂,将该气态混合制冷剂再循环至压缩步骤,降低上述基本液体流体材料压力以使其温度进一步降低至小于约-245°F并制备一种闪蒸气体,从上述液体流体材料中至少分离大部分闪蒸气体以制备分离闪蒸气体,将至少部分分离闪蒸气体加热至温度高于约40°F以制备加热分离闪蒸气体,将至少部分上述加热分离闪蒸气体压缩至高于加入制冷区的流体材料压力以制备压缩部分,和合并至少部分加热分离闪蒸气体的压缩部分和流体材料。
本发明进一步包括一种闭合回路单混合制冷剂系统,用于通过在闭合回路制冷循环中与单混合制冷剂的热交换来使流体材料由超出200°F的温度冷却至低于约-200°F的温度,该系统包括:混合制冷剂吸入桶,入口与混合制冷剂吸入桶的气态混合制冷剂出口流体相连的压缩机,入口与压缩机出口流体相连的冷凝器,入口与第一冷凝器出口流体相连的制冷剂分离器,制冷容器,它包括与制冷剂分离器的气态制冷剂出口和液体制冷剂出口流体相连的第一热交换通路,与流体材料源流体相连的第二热交换通路,在制冷容器中与第一热交换通路和第二热交换通路逆流排列的第三热交换通路,和与第一热交换通路出口和第三热交换通路入口流体相连的膨胀阀,与第三热交换通路出口和混合制冷剂吸入桶入口流体相连的再循环制冷剂管线,与第二热交换通路出口相连的液化流体材料管线,与液化流体材料管线流体相连并具有液化流体材料出口的膨胀器,入口与减压液化流体材料出口流体相连并具有闪蒸气体出口和液化流体材料出口的闪蒸桶,入口与闪蒸气体出口流体相连并具有加热闪蒸气体出口的热交换器,和与加热闪蒸气体出口流体相连并具有与第二热交换通路流体相连的再循环闪蒸气体出口和第二闪蒸气体出口的闪蒸气体压缩机。
                      附图简述
图1公开了一种现有技术的闭合回路混合制冷剂工艺;
图2列出了本发明的闭合回路混合制冷剂工艺;
图3是一张图1所示现有技术工艺的产物回收部分的更加详细的草图;和
图4是一张图3所示工艺的产物回收部分的更加详细的草图。
                   优选实施方案描述
在各图的描述中,将采用相同序号来表示全部相应部件。图中并未列出获得所需流分所必需的所有阀和泵等,因为它们对本发明描述而言不是必需的。
图1中列出了现有技术的单混合制冷剂闭合回路系统。将混合制冷剂从制冷剂吸入桶10中吸出,通过管线12进入压缩机14。在压缩机14中压缩上述混合制冷剂,经管线16排出并进入充当制冷剂冷凝器的热交换器18,在这里通过与例如水或空气等制冷剂的热交换来冷却该混合制冷剂。然后,冷却的压缩混合制冷剂经管线22进入制冷剂分离器24,在这里制冷剂被分成液态制冷剂部分和气态制冷剂部分。气态制冷剂经管线26进入制冷剂和流体材料热交换器36。液态制冷剂从分离器24排出,经管线32进入泵30,在这里制冷剂经管线34被泵抽至与管线26的结合处,然后经管线28重新组成压缩混合制冷剂。然后,将该混合制冷剂通过热交换器36。压缩混合制冷剂经流路38通过热交换器36,进入卸出线40。在热交换器36中根据需要将混合制冷剂冷却至使其经热交换器进入管线40时完全为液体的温度。除去通过通路38和管线40时的管线损耗,管线40中制冷剂的压力基本上与管线28中的压力相同。使上述混合制冷剂通过膨胀阀42,在这里足量液态混合制冷剂被闪蒸,以使混合制冷剂温度降低至所需温度。天然气液化所需温度一般是热交换器出口温度为约-230°F~约-275°F。通常,温度约为-235°F。通过膨胀阀42使压力降低至为约50~约75psia。经流路46通过热交换器36时,低压混合制冷剂沸腾,因此当被排入管线50中时,混合制冷剂为气态。在排入管线50时,混合制冷剂基本上被蒸发。通过管线50的气态混合制冷剂经管线50进入制冷剂吸入桶10。如果任何痕量液态制冷剂经管线50被回收,可使其在制冷剂吸入桶10中积聚,在这里它们最终蒸发并剩余一部分混合制冷剂经管线12进入压缩机14。
尽管其它气体也可通过上述工艺来进行液化,但是天然气是最普通的液化气。天然气一般是干燥的并可经过处理,除去例如硫化合物和二氧化碳等物质。天然气经管线48加入热交换器36并且经热交换通路52通过热交换器36。可从热交换器36的中间点处抽出天然气流并输送至重质液体分离器部件(未列出),在这里含6个或更多碳原子的烃类被优先分离和回收,而天然气则由分离器返回到热交换器36的热交换通路52中。在某些情况下,为了用作产物或基于其它原因,可能需要在分离器中除去C2-C5+流。合适的重质液体分离器部件的用途和操作列于美国专利4,033,735中,前面已引入作为参考。本领域的技术人员应熟知这些重质材料的分离。在某些情况下,当天然气被冷却成液相时,天然气中的重质材料将在通路52中冻结,这就必须从天然气流中分离出这些重质材料。除去这些在通路52中会凝固的化合物,这样,这些重质材料将不存在或者其存在量足够小,因此在通路52中就不会产生固体材料沉淀。
在通常为约-230~约-275°F的温度下,经管线54从热交换器36中回收液化天然气。然后,上述液化天然气经管线54进入膨胀阀、水轮机或其它膨胀装置,或它们的组合装置,这里指的是膨胀器56,在该膨胀器中液化天然气闪蒸至较低压力,在压力约为1大气压的条件下可将液化天然气温度降低至约为-260°F。在该温度条件下,液化天然气可适当储存,可在大气压下为约-250~约~260°F保持为液态。如前面所注明的,这种方法描述于美国专利4,033,735中,前面已经引入作为参考。
从膨胀器56中回收的流分经管线58进入分离器60,其中,闪蒸气流通过管线66进行回收,液化天然气通过管线62进行回收并进入储藏库64。管线66中的流分在热交换器68中一般被加热至温度为约40~约130°F,优选为约70~约120°F,并进入压缩机72,在这里它被压缩至用作燃料气体或类似物的合适压力。
在前面同样已经引入作为参考的美国专利5,657,643中列出了一种改进工艺,其中,采用了许多压缩机和中间冷却器。
根据本发明,如图2所示,进入压缩机72的闪蒸气流被压缩至足够大压力,以使部分闪蒸气体经管线78和阀80返回到管线48中,其中,入口流体材料或天然气流通过该管线进入热交换器36。通过管线74来回收一部分加热压缩气体并使其经过阀76用作燃料或其它用途。
在闭合回路混合制冷剂工艺的使用中,当工艺设备安装好时,可压缩量一般是固定的。因此,热交换器36的制冷量受已安装压缩设备的限制而固定。根据本发明,如果经管线54回收的液化流体材料或天然气温度增加约30~约75°F,则可在分离器60中回收额外的闪蒸气体。以前,必须限制管线54中的流分温度,以使制得的闪蒸气体量等同于LNG设备中燃料气的需要,或者等同于该地区天然气的其它消费需要。一般而言,这种液化厂修建在偏远地区,在这里除了驱动LNG设备自身之外,对天然气没有别的需求。因此,必须使管线54中的液化天然气保持较低温度(约-230~约-275°F),以使通过闪蒸制备的闪蒸气体量基本上等于设备操作所需的天然气量。必须分离闪蒸气体,将其加热至合适温度并压缩至适当压力,以供使用。
通常,视气体制备过程中的压力和输送至原料管道中的压力等而定,加入到这类设备中的天然气压力可以有很大变化。典型的压力为约250~约1500psig,更普通的压力为约400~约1300psig。如果在该压力下将液化天然气闪蒸至极低压力,例如为约0~约50psig,优选为约2~约15psig,则可蒸发显著量的闪蒸气体。因此,经闪蒸后液化天然气温度降低了约10~约70°F。闪蒸气体量由压力降低时液化天然气的温度所决定。合乎需求的是,选择管线54中的液化天然气温度,使其只闪蒸足量的用作设备燃料气的闪蒸气体,并提供管线62中的液化天然气,以在1大气压和温度低于约-250°F的条件下储存,优选温度为约-250~约-260°F。
这严格限制了设备的操作参数。除非在设备附近对闪蒸气体有显著需求,否则必须将管线54中的液化天然气冷却至较低温度。
根据本发明,管线54中的液化天然气流温度增加了大约30~75°F(即从约为-230~-275°F增加至约为-200~-245°F),因此在LNG膨胀器56中闪蒸了相当大量的天然气。优选管线54中的温度范围约为-215~-235°F。然后使该流分经管线58进入分离器60,在这里通过管线66来回收增量的天然气(闪蒸气体)并进入热交换器68。根据需要将温度升高至适当温度,即一般约为40~130°F,优选约为70~120°F,然后使上述气体进入压缩机72。在压缩机72中将闪蒸气体压缩至一定压力,使其足以用作燃料气并足以使部分闪蒸气体返回入口天然气流,经管线48进入热交换器36,其中,该压缩机是一种独立驱动的压缩机,它可以是电驱动的或是由气体涡轮机等所驱动的。
通过这种工艺,由于压缩再循环流分的压缩机72中的压缩量增加,就可获得额外制冷量。因此,管线54中的液化天然气可采用较高温度,这增加了热交换器36的效率,其原因在于热交换器36中的热交换动力是热交换器36中的天然气流至少在最低温度下获得的,并且热交换器36的热交换量受压缩机14可达到的压缩量所限制。因为热交换器36的热负荷随管线54中温度的增加而降低,所以通过相同设备可加工更大量的天然气。较高温度的结果是更多闪蒸气体被回收,但是通过如前面所讨论的再压缩和再循环,这种气体可以很容易地进行再循环。通过使用压缩机72,可以增加固定设备的容量,视燃料气等需要而定,可用该压缩机压缩不同量的闪蒸气体。此外,已经发现,通过使用本发明的方法,还可获得更大的工艺效率。
                     实施例
对比工艺列于图3和4。图3所示工艺是与图1所示工艺相同的现有技术工艺。图3稍微详细地列出了天然气回收部件的工艺。管线62中列出了泵82,并列出了燃料气处理部件84,制冷剂处理部件作为86列出。
图4是可对比的、更详细的本发明工艺描述。
图3所示工艺对比实施方案和图4所示工艺被详细列于表1中。
                                       表1
                图3                      图4
  管线序号   温度(°F)   压力(psig)   管线序号   温度(°F)   压力(psig)
  48   100   755   48   100   755
  54   -239.2   745   54   -224.7   745
  58   -252.4   3   58   -252.4   3
  62   -252.4   3   62   -252.4   3
  66   -252.4   3   66   -252.4   3
  70   90   1   70   90   1
  74   105   785   74   105   785
  78   105   785
应注明的是,图4所示实施方案中管线54中的温度已经增加。仍然在相同温度和压力下于管线62中制备天然气。类似地,仍然在相同温度和压力下于管线74中制备燃料气。在所列实施方案中,虽然制备了等量的液化天然气,但是与图3相比,图4中操作总工艺所需的动力降低了大约2.4%。
如上所述,本发明方法可增加闭合回路混合制冷剂工艺操作的效率和灵活性。上述实施例清楚表明工艺效率得到了提高,其本质在于,如果需要,在增加管线54中的温度的情况下,可增加热交换器36中所制备的液化天然气量。
虽然参照优选实施方案描述了本发明,但是应当指出,上述实施方案的本质只是阐述性的,而非限制性的,并且在本发明范围内的若干变化和修改是可能的。在回顾上述优选实施方案描述的基础上,本领域的技术人员应理解这些变化和修改是显而易见的和合乎需要的。

Claims (8)

1.一种提高闭合回路混合制冷剂工艺效率和灵活性的方法,用于在具有三管束单制冷区的闭合回路制冷循环中,使气态材料温度由高于94℃冷却至低于-129℃,以制备基本液化的气态材料,该方法包括:压缩气态混合制冷剂以制备压缩气态混合制冷剂,冷却该压缩混合制冷剂,将上述经冷却的压缩混合制冷剂以气液混和状态加入制冷区并在制冷区中冷却该压缩混合制冷剂,以制备基本为液态的混合制冷剂;使该液态混合制冷剂通过膨胀阀以制备低温制冷剂,在制冷区中使该低温制冷剂与进一步冷却的压缩混合制冷剂和气态材料进行逆流热交换,以制备基本为液态的混合制冷剂、基本液化的气态材料和气态混合制冷剂,该方法包括:
a)通过使制冷区中所制备的基本液化的气态材料的温度增高16℃至42℃而达到-129℃至-154℃的温度,来增加闭合回路混合制冷剂工艺的制冷量;
b)降低制冷区中所制备的上述基本液化气态材料的压力,以使其温度降低至低于-154℃并制备闪蒸气体;
c)在分离器中从上述基本液化气态材料中至少分离大部分闪蒸气体;
d)将至少部分闪蒸气体加热至温度高于4℃;
e)将至少部分经加热的闪蒸气体压缩至压力大于气态材料进入制冷区的入口压力;和,
f)使至少部分经压缩加热的闪蒸气体与加入制冷区的气态材料合并。
2.权利要求1的方法,其中,所述气态材料是天然气。
3.权利要求2的方法,其中,所述基本液化的气态材料的压力被降低至低于345Kpa。
4.权利要求3的方法,其中,所述压力被降低至低于69Kpa。
5.权利要求1的方法,其中,所述基本液化的气态材料的温度被降低至至少为-156℃。
6.权利要求1的方法,其中,所述基本液化的气态材料温度被降低至至少为-162℃。
7.一种闭合回路单混合制冷剂系统,用于在闭合回路制冷循环中,使气态材料温度由高于94℃冷却至低于-129℃,以制备基本液化的气态材料,上述制冷循环具有含三条热交换通路的单制冷区,该系统包括:
a)混合制冷剂吸入桶;
b)入口与混合制冷剂吸入桶的气态混合制冷剂出口流体相连的压缩机;
c)入口与压缩机出口流体相连的热交换器;
d)入口与热交换器出口流体相连的制冷剂分离器;
e)制冷区,包括与制冷剂分离器的气态制冷剂出口和制冷剂分离器的液体制冷剂出口流体相连的第一制冷区通路,与气态材料源流体相连的第二制冷区通路,在制冷容器中与第一制冷区通路和第二制冷区通路逆流排列的第三制冷区通路,和与第一制冷区通路出口和第三制冷区通路入口流体相连的膨胀阀;
f)与第三制冷区通路出口和混合制冷剂吸入桶入口流体相连的再循环制冷剂管线;
g)与第二制冷区通路出口流体相连的液化气态材料管线;
h)与上述液化气态材料管线流体相连并具有减压液化材料出口的膨胀器;
i)入口与上述减压液化气态材料出口流体相连并具有闪蒸气体出口和液化气态材料出口的分离器;
j)入口与上述闪蒸气体出口流体相连并具有加热闪蒸气体出口的加热区;和
k)与上述加热闪蒸气体出口流体相连并具有与第二制冷区通路流体相连的再循环闪蒸气体出口和第二闪蒸气体出口的闪蒸气体压缩机。
8.权利要求7的系统,其中,所述步骤k)中的压缩机包含许多压缩机。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102628635A (zh) * 2012-04-16 2012-08-08 上海交通大学 带凝华脱除co2的气体膨胀天然气带压液化工艺

Families Citing this family (46)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0120272D0 (en) * 2001-08-21 2001-10-10 Gasconsult Ltd Improved process for liquefaction of natural gases
US6530240B1 (en) * 2001-12-10 2003-03-11 Gas Technology Institute Control method for mixed refrigerant based natural gas liquefier
US6622519B1 (en) * 2002-08-15 2003-09-23 Velocys, Inc. Process for cooling a product in a heat exchanger employing microchannels for the flow of refrigerant and product
US7014835B2 (en) 2002-08-15 2006-03-21 Velocys, Inc. Multi-stream microchannel device
RU2382962C2 (ru) * 2004-08-06 2010-02-27 Бп Корпорейшн Норт Америка Инк. Способ сжижения природного газа (варианты)
US20060260330A1 (en) 2005-05-19 2006-11-23 Rosetta Martin J Air vaporizor
US20080134717A1 (en) * 2006-11-14 2008-06-12 Willem Dam Method and apparatus for cooling a hydrocarbon stream
US8066023B2 (en) * 2007-04-10 2011-11-29 Black & Veatch Corporation System and method for collecting and increasing the pressure of seal leak gas
US8650906B2 (en) * 2007-04-25 2014-02-18 Black & Veatch Corporation System and method for recovering and liquefying boil-off gas
EP2165138A2 (en) * 2007-07-12 2010-03-24 Shell Internationale Research Maatschappij B.V. Method and apparatus for cooling a hydrocarbon stream
US9254448B2 (en) 2007-09-13 2016-02-09 Battelle Energy Alliance, Llc Sublimation systems and associated methods
US9574713B2 (en) 2007-09-13 2017-02-21 Battelle Energy Alliance, Llc Vaporization chambers and associated methods
US9217603B2 (en) 2007-09-13 2015-12-22 Battelle Energy Alliance, Llc Heat exchanger and related methods
US9243842B2 (en) * 2008-02-15 2016-01-26 Black & Veatch Corporation Combined synthesis gas separation and LNG production method and system
US10132561B2 (en) * 2009-08-13 2018-11-20 Air Products And Chemicals, Inc. Refrigerant composition control
CN101782308A (zh) * 2009-08-26 2010-07-21 成都蜀远煤基能源科技有限公司 煤气化装置来原料气甲烷深冷分离装置的换热系统
US10113127B2 (en) 2010-04-16 2018-10-30 Black & Veatch Holding Company Process for separating nitrogen from a natural gas stream with nitrogen stripping in the production of liquefied natural gas
WO2012075266A2 (en) 2010-12-01 2012-06-07 Black & Veatch Corporation Ngl recovery from natural gas using a mixed refrigerant
EP2597406A1 (en) 2011-11-25 2013-05-29 Shell Internationale Research Maatschappij B.V. Method and apparatus for removing nitrogen from a cryogenic hydrocarbon composition
WO2013087571A2 (en) 2011-12-12 2013-06-20 Shell Internationale Research Maatschappij B.V. Method and apparatus for removing nitrogen from a cryogenic hydrocarbon composition
CA2858756C (en) 2011-12-12 2020-04-28 Shell Internationale Research Maatschappij B.V. Method and apparatus for removing nitrogen from a cryogenic hydrocarbon composition
JP2015501917A (ja) 2011-12-12 2015-01-19 シエル・インターナシヨネイル・リサーチ・マーチヤツピイ・ベー・ウイShell Internationale Research Maatschappij Beslotenvennootshap 極低温の炭化水素組成物から窒素を除去するための方法と装置
EP2604960A1 (en) 2011-12-15 2013-06-19 Shell Internationale Research Maatschappij B.V. Method of operating a compressor and system and method for producing a liquefied hydrocarbon stream
CN102445052A (zh) * 2011-12-16 2012-05-09 南京林业大学 一种用于零散气源点的沼气液化工艺及装置
CN102538389A (zh) * 2011-12-19 2012-07-04 中国海洋石油总公司 一种应用于基荷型天然气液化工厂的混合制冷剂预冷系统
CN102564061B (zh) * 2011-12-19 2014-06-11 中国海洋石油总公司 一种应用于基荷型天然气液化工厂的双级混合冷剂循环液化系统
US10139157B2 (en) 2012-02-22 2018-11-27 Black & Veatch Holding Company NGL recovery from natural gas using a mixed refrigerant
US10655911B2 (en) * 2012-06-20 2020-05-19 Battelle Energy Alliance, Llc Natural gas liquefaction employing independent refrigerant path
US9479103B2 (en) 2012-08-31 2016-10-25 Shell Oil Company Variable speed drive system, method for operating a variable speed drive system and method for refrigerating a hydrocarbon stream
US11408673B2 (en) 2013-03-15 2022-08-09 Chart Energy & Chemicals, Inc. Mixed refrigerant system and method
US11428463B2 (en) 2013-03-15 2022-08-30 Chart Energy & Chemicals, Inc. Mixed refrigerant system and method
CA2907444C (en) 2013-03-15 2022-01-18 Douglas A. Ducote, Jr. Mixed refrigerant system and method
EA030308B1 (ru) 2013-04-22 2018-07-31 Шелл Интернэшнл Рисерч Маатсхаппий Б.В. Способ и установка для производства потока сжиженных углеводородов
EP2796818A1 (en) 2013-04-22 2014-10-29 Shell Internationale Research Maatschappij B.V. Method and apparatus for producing a liquefied hydrocarbon stream
EP2869415A1 (en) 2013-11-04 2015-05-06 Shell International Research Maatschappij B.V. Modular hydrocarbon fluid processing assembly, and methods of deploying and relocating such assembly
US10563913B2 (en) * 2013-11-15 2020-02-18 Black & Veatch Holding Company Systems and methods for hydrocarbon refrigeration with a mixed refrigerant cycle
US9709325B2 (en) 2013-11-25 2017-07-18 Chevron U.S.A. Inc. Integration of a small scale liquefaction unit with an LNG plant to convert end flash gas and boil-off gas to incremental LNG
US9574822B2 (en) * 2014-03-17 2017-02-21 Black & Veatch Corporation Liquefied natural gas facility employing an optimized mixed refrigerant system
EP2977431A1 (en) 2014-07-24 2016-01-27 Shell Internationale Research Maatschappij B.V. A hydrocarbon condensate stabilizer and a method for producing a stabilized hydrocarbon condenstate stream
EP2977430A1 (en) 2014-07-24 2016-01-27 Shell Internationale Research Maatschappij B.V. A hydrocarbon condensate stabilizer and a method for producing a stabilized hydrocarbon condenstate stream
DE102014012316A1 (de) * 2014-08-19 2016-02-25 Linde Aktiengesellschaft Verfahren zum Abkühlen einer Kohlenwasserstoff-reichen Fraktion
US20160061517A1 (en) * 2014-08-29 2016-03-03 Black & Veatch Holding Company Dual mixed refrigerant system
EP3032204A1 (en) 2014-12-11 2016-06-15 Shell Internationale Research Maatschappij B.V. Method and system for producing a cooled hydrocarbons stream
CN105651001B (zh) * 2016-02-25 2018-05-22 上海尧兴投资管理有限公司 适用于不同温度甲烷气的液化系统以及利用该系统液化甲烷气的方法
US10663220B2 (en) * 2016-10-07 2020-05-26 Air Products And Chemicals, Inc. Multiple pressure mixed refrigerant cooling process and system
US20190056175A1 (en) * 2017-08-21 2019-02-21 GE Oil & Gas, LLC Refrigerant and nitrogen recovery

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3690114A (en) * 1969-11-17 1972-09-12 Judson S Swearingen Refrigeration process for use in liquefication of gases
US4033735A (en) 1971-01-14 1977-07-05 J. F. Pritchard And Company Single mixed refrigerant, closed loop process for liquefying natural gas
DE2206620B2 (de) 1972-02-11 1981-04-02 Linde Ag, 6200 Wiesbaden Anlage zum Verflüssigen von Naturgas
US4541852A (en) * 1984-02-13 1985-09-17 Air Products And Chemicals, Inc. Deep flash LNG cycle
US5196260A (en) * 1988-11-19 1993-03-23 Ciba-Geigy Corporation Process for the treatment of fibrous materials with modified organopolysiloxanes and the materials
US5036671A (en) * 1990-02-06 1991-08-06 Liquid Air Engineering Company Method of liquefying natural gas
US5657643A (en) 1996-02-28 1997-08-19 The Pritchard Corporation Closed loop single mixed refrigerant process
TW368596B (en) * 1997-06-20 1999-09-01 Exxon Production Research Co Improved multi-component refrigeration process for liquefaction of natural gas
US5791160A (en) * 1997-07-24 1998-08-11 Air Products And Chemicals, Inc. Method and apparatus for regulatory control of production and temperature in a mixed refrigerant liquefied natural gas facility
US6070429A (en) * 1999-03-30 2000-06-06 Phillips Petroleum Company Nitrogen rejection system for liquified natural gas
US6298688B1 (en) * 1999-10-12 2001-10-09 Air Products And Chemicals, Inc. Process for nitrogen liquefaction

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102628635A (zh) * 2012-04-16 2012-08-08 上海交通大学 带凝华脱除co2的气体膨胀天然气带压液化工艺
CN102628635B (zh) * 2012-04-16 2014-10-15 上海交通大学 带凝华脱除co2的气体膨胀天然气带压液化工艺

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