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Category: Energy

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

Rifka Aisyah Leave a comment

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

Rifka Aisyah 5 Comments

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

Difference between Base Load, Peak Load, and Load Following Power Plant

Rifka Aisyah 1 Comment

Yesterday I had a discussion about our current project. The discussion was actually not only limited to that topic, however a topic in general: power plant. When one has plan to build a power plant, he must know operational profile of the power plant. Is it used for base load, peak load, or follower load ? What does it mean?

In this picture I show you the difference between those three. Read More

calculation holding time of LNG in storage tank

Predicting Holding Time of LNG in Storage Tank Without Venting

Rifka Aisyah Leave a comment

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

Rifka Aisyah 2 Comments

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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Cold-keeping system (http://docplayer.net/7352415-Curacao-cng-lng-terminal-feasibility-study.html)

LNG Recirculation Requirement

Rifka Aisyah 1 Comment

In LNG receiving terminal, where LNG is pumped from LNG carrier to onshore LNG storage tank, we have to provide one line to intermittently circulate LNG through unloading lines. This is called LNG recirculation line or keep-cool line.  The function of this line is maintain cryogenic condition of the unloading line during holding mode. Unloading activity is conducting intermittently. Sometimes we need to wait for a week or even a month to the next LNG unloading. During this time, there is a possibility of increasing temperature in the line. To prevent that, we need to circulate LNG in unloading line. Read More

Typical Process Diagram for Small LNG Regasification (Part 2)

Rifka Aisyah 2 Comments

As mentioned in part 1, small LNG regasification facility typically consists of LNG unloading facility (which can be flexible hose or marine loading arm), LNG storage tank, LNG sendout pump, ambient air vaporizer, and metering. In part 1 we already discussed about LNG unloading facility and LNG storage tank. In this part I want to share the rest of them.

LNG Sendout Pump

LNG sendout pump is used to increase pressure of LNG before being sent to vaporizer. In LNG facility, there are two most common type of pump: submerged centrifugal pump and reciprocating pump.

Submerged centrifugal pump is used when LNG flowrate is high but the pressure in low to medium. Meanwhile reciprocating pump is used when the flow is low but the pressure is high. Read More