LNG Trains

Figure 2 LNG train size development versus time.

As turbine-driven plants generally cost 2-4 million Euro more than similar plants driven by electric motors the selection of drive will reflect the cost of the plant versus capacity as indicated on Figure 17 showing the regression line for LNG plant cost development versus time (year). Likewise, Figure 18 shows the cost development versus the development of LNG train size [10]. The investment may also reflect various requirements for the liquefaction train and necessary support facilities. 

In contrast to base-load operation peak shaving differs from the large-scale LNG trains that are generally driven by cost of the LNG as a commodity in comparison with alternative fuels available in the market. Peak shaving on the other hand can be justified by the cost of omitted pipeline charges and the reduced capital cost pertaining to pipeline infrastructure [7]. 

Keywords Flaring, Flare Reduction, LNG trains. Purge, Operations, Oil and Gas, Engineering Projects... 

Figure 1. Qatargas LNG Trains and Onplot Flare System.

The LDAR program covers LNG Trains 1 to 7, and equipment / components that are subject to the program inelude pump seals, compressor seals, valves, atmospheric pressure relief devices (PRDs),... 

Based on USEPA Method 21, all applicable components / equipment at the Qatargas 1, Qatargas 2 and Qatargas 3 4 LNG Trains (Trains 1 to 7) are monitored and VOC emissions rates estimated using the EPA Correlation Approach found in USEPA s Protocol for Equipment Leak Emission Estimates (USEPA, 1995) and is applicable to refineries, marketing terminals and oil and gas production operations. The method provides an equation to predict mass emission rate as a funetion of screening value for a particular equipment / component type. 

Abdelkader, Haouari, Sueeessful Start-up of QG Mega LNG Trains , 20th World Petroleum... 

Side studies are often required for major decisions, and a good example is a study of gas versus steam turbines for LNG plants (Reference 5). Indications are that higher capital investment is associated with gas turbine drivers than with steam turbines for liquefaction train service, but that the added capital investment for gas turbines shows... 

The total plant or train main process bottleneck will probably be identified by the licensor, such as the gasifier for a coal gasification train, the main exchanger for a mixed refrigerant LNG plant train, or the cracked gas compressors for an olefin plant. First and foremost, be sure that the licensor has not made the utility area a bottleneck. This can never be allowed since overloaded utilities could repeatedly shut the entire complex down on a crash basis, adversely impacting economics. 

To he economically viable, the LNG option usually requires minimum gas field sizes of 90-130 Gm3, for a train size of 3-4Mt/a over a lifetime of 20 to 25 years. For a production of 10 000 b/day of GTL, field sizes of about 15-20 Gm3 are required over 20 years. Further options to bring stranded gas to market include gas-to-hydrate (which is still basic research) or gas-by-wire technologies. 

Atlantic LNG ConocoPhillips Trinidad/ Tobago Train 1,2, Train 3 Train 4. 2003 2006 Cascade Cascade (In total more than 15) 2x3.4 3.4 5.2 ... 

The breakdown of the investment cost for large-scale LNG plants may vary depending on the plant specification. A representative scope for a typical greenfield plant located to the Middle East for offshore production with an onshore LNG plant having two liquefaction trains shows that the LNG plant per se would account for roughly 50% of the total project, almost... 

The liquefaction train is the novel mixed fluid cascade process (MFCP) patented by Statoil/Linde. It is the first LNG base-load plant ever to employ electric drive for the compressors. Today the Oman plant (Shell) is claimed to be world s most efficient LNG plant as it consumes only 8% of the gas for its operation. When Snohvit goes on stream (2006) it is expected to become even more efficient as it will consume only 5% of the feed gas for the liquefaction. This means that Snohvit will constitute the most efficient LNG plant ever. The high efficiency is attainable much owing to the low temperature of the ambient air and the cooling water in the artic region. 

Figure 18 LNG plant cost versus train capacity [10]...

The current, global LNG production is almost 120 MTPA provided by 69 liquefaction trains. Furthermore, there are 120 satellite facilities. The distribution is 39 satellite and 55 liquefaction facilities in the United States, and 81 satellites and 14 liquefaction facilities in the remaining countries. Owing to the deregulation of the natural gas industry, the construction of LNG facilities in the United States has increased, and the prevailing role of LNG facilities is changing from peak shaving to base-load for the supply of natural gas year round [7,8],... 

Gas liquefaction plants of new design that allows single-train operation (about 2.5-3 million tons per year or more) as opposed to earlier designs that required two trains (about 2.1-2.5 million tons each, 4.5-5 million total per plant). Other advances in LNG technologies (e.g. transportation and re-gasification) have also contributed to lowering the delivered cost of LNG ... 

Application To produce ammonia from natural gas, LNG, LPG or naphtha. Other hydrocarbons—coal, oil, residues or methanol purge gas— are possible feedstocks with an adapted front-end. The process uses conventional steam reforming synthesis gas generation (front-end) and a medium-pressure (MP) ammonia synthesis loop. It is optimized with respect to low energy consumption and maximum reliability. The largest single-train plant built by Uhde with a conventional synthesis has a nameplate capacity of 2,000 metric tons per day (mtpd). For higher capacities refer to Uhde Dual Pressure Process. 

Intercormection of steam utility between LNG plants/trains to eliminate redimdant standby boilers. 

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