Abstract:

For many years,large baseload LNG plants built on land have been the focus of the LNG industry.In recent years the industry has seen many changes which have brought new challenges and required revisiting technology selection considerations.The shale gas boom,the use of LNG as transportation fuel,and the development of liquefaction plants offshore and in arctic area,are few examples of challenges facing the industry.Modern LNG projects have different considerations related to unique feed gas compositions,driver systems and fuel requirements,and operation in an offshore motion environment,and therefore have different requirements for reliability,operability,efficiency and capacity.These new factors affect the technical decisions,and their interactions.This paper will review the key technical features of conventional large baseload plants,and discuss what needs to be re-considered to optimize CAPEX and OPEX and meet modern project needs.In addition,this paper will use two case studies to demonstrate how the right technology selection will ultimately lead to a successful project.

Key words: natural gas, liquefaction, specific power, production, optimization, floating LNG(FLNG), midsize LNG

摘要：

液化天然气(LNG)工业曾经在相当长的一段时间里都把注意力放在陆上大规模基荷型(base-load LNG)液化项目。近几年来,LNG工业开始显现出一些新的发展趋势,如北美的页岩气热、海上天然气资源的开发、使用LNG作为车船用燃料以及在极寒地区建设液化设施等。这些新趋势带来新的挑战,要求人们对工艺技术选择进行谨慎思考。在这个大背景下,最近筹建和在建的新兴LNG项目多具有与传统项目不同的特征,如原料气来源、驱动方式与燃料要求、海洋运动对设备的影响以及外部气候条件等。与此同时,这些项目在可靠性、易操作性、效率和产能等方面也具有不同的要求和侧重点。本文首先对传统基荷型LNG项目在液化工艺技术方面需要考虑的问题进行综述,然后重点论述如何针对新LNG项目优化这些问题以期达到更好的投资回报。以使用2个LNG项目作为案例分析,来展示如何进行正确的工艺技术选择以保证项目成功。

关键词: 天然气, 液化, 单位能耗, 产量, 优化, 浮式液化天然气, 中小型液化天然气