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LNG Regasification Vessel Requirement based on DNV Classification Notes No. 16.3

In previous posts, I shared some of onshore LNG terminal and regasification system. How about offshore LNG regasification system? Does it have any differences with onshore regasification system? In this post, I want to share you practical guidance of offshore regasification vessel from DNV (Det Norske Veritas) Classification Notes No. 16.3. DNV Classification Notes No. 16.3 is applicable for all vessels engages in LNG regasification.

Regasification vessel is intended to regasify LNG then delivered the gas to pipeline gas grid, through a Submerged Turret Buoy or through dedicated export manifold. The Classification Notes specifically explains regasification systems and offloading systems for natural gas through submerged turret buoy offshore or through dedicated gas unloading manifolds. Read More

Economic of comparison vacuum insulated tank and flat bottom tank

Comparison of LNG Flat Bottom Tank and Vacuum Insulated Tank

In previous post (typical process flow diagram of small scale LNG regasification facility), I explained that LNG storage tank played important part in the facility. It is used to stored LNG for certain duration (usually in term of round trip). In small scale LNG regasification facilities, vacuum insulated tank is usually used because the capacity if small. But when the capacity is high, LNG flat bottom tank is used.

In this post I want to share you difference and comparison between LNG flat bottom tank and vacuum insulated tank and give some advice what to choose.

Table below shows comparison of flat bottom storage tank and vacuum insulated tank. Read More

Schematic of LNG single containment flat bottom tank part 2 (EN 1473)

Flat Bottom Storage Tank – Different Types and Its Features

In my third LNG project, I had a chance to meet two different LNG storage tank vendors. One vendor produce vacuum insulated  storage tank (pressurized type) and the other one produce flat bottom storage tank (atmospheric type).

During the meeting I got several terms of  LNG flat bottom storage tank types, such as single containment tank, double containment tank, and full containment tank. What was that?

In this post I want to share you different types of LNG flat bottom storage tank and its special features. Read More

How To Choose LNG Regasification System – AAV, ORV, IFV, and Other Unique Vaporizing Unit

Until now, I’m still dealing with LNG regasification system. I knew now that I don’t quite understand how to choose regasification method. And I understand that technology is getting better, so you have many options which type of regasification to choose, which one is the best.

I’ve studied several type of vaporizers, such as ambient air vaporizer, both natural draft and forced draft, open rack vaporizer, and intermediate fluid vaporizer, using glycol-water or propane. I had a correspondence with several vendors regarding that vaporizers. However, I haven’t encountered with submerged combustion vaporizer or intermediate fluid vaporizer with Rankine cycle. So, I can’t imagine how those vaporizers really work.

In the past, I remembered I encountered with Indirect Fired Water Bath Heater (personally, this term is really long, I can’t easily remember :D). But the application is not to regasify LNG, but to increase temperature of natural gas. In other word, it is gas post treatment after leaving vaporizer.

In this post, I want to share you summary of everything I learned until now about how to choose correct vaporizer for your condition. And I also want to share you some type of unique vaporizers (for me it is unique). Read More

Rollover in LNG Storage Tank

Rollover in LNG Storage Tank

I think reading BS EN 1160 makes my writing ideas grows. As a follow of of this post (LNG Basics: Understanding Its Typical Properties), I want to share you what I read and browsed about Rollover in LNG Storage Tank.

Rollover in one of physical phenomena explained in BS EN 1160, other than Rapid Phase Transition (RPT) and Boiling Liquid Expanding Vapor Explosion (BLEVE).

Rollover refer to process whereby large quantities of gas can be emitted from an LNG storage tank over a short period of time. How this could happen? Read More

calculation holding time of LNG in storage tank

Predicting Holding Time of LNG in Storage Tank Without Venting

In this post, we use vacuum insulated type LNG storage tank when we don’t want to deal with boil-off gas handling. The storage tank have design pressure as high as 6-10 barg. When we store LNG in the LNG, boil-off gas will be generated due to heat leak to tank. Increasing temperature of LNG will increase total volume of LNG and vapor in the tank, thus increasing its pressure.

This phenomena leads to a simple question, “How long can LNG storage tank keep the vapor before PSV works?” Read More

LNG Basics: Understanding Its Typical Properties

For those who starts working with LNG, I recommend to read BS EN 1160 – Installations and equipment for liquefied natural gas – general characteristics of liquefied natural gas. The standard covers almost all LNG characteristics that you need to know, such as properties of LNG, evaporation of LNG, spillage, ignition, containment, and other physical phenomena. I think it will be nice to share some of them in this post.

There are three things at least you need to know about LNG before knowing other things.

lng-basic-properties
lng-basic-properties

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