12 replies to this topic

[Lorendrix]

Hi everybody, I need some help in estimating capital costs of an insulated pipeline for CO2 transport. Basically I have to transport liquid CO2 from a CO2 liquefaction plant to an intermediate storage near the shore. The length of the pipeline will be around 50 Km, the flow rate will be around 3 Mtonne/year,the CO2 transport condition will be around -50°C and 6-7 bar (density of about 1150 kg/cum) and the area selected is in the surrounding of the Rotterdam harbor so mainly cultivated land or grassland. I guess the diameter will be smaller than an equivalent (same flow rate) HP pipeline because of a higher density but the insulation will increase the total cost.

However I don t need a really accurate estimation since in the end the specific cost of this pipeline will be quite small compared with the rest of the transport chain. Can anyone help me?
Thanks in advance.

Cheers,

Lorenzo

[Zauberberg]

For evaluating different kinds of insulation, I would recommend you 3E Plus software, developed by NAIMA (North America Insulation Manufacturers Association). It is free for download at:

http://www.pipeinsul...4/download.html

I haven't looked into your process data - Art Montemayor would probably give you the best possible advice when liquid CO2 transportation and storage are concerned.

[Art Montemayor]

Lorenzo:

One doesn’t design equipment on the basis of yearly flow rates. Besides I have no idea of what your units mean (“Mtonne/year”). This could be thousands, mega, or million tonnes. Please be specific and define your terms.

You don’t define the basis of your scope of work. Are you required to transport a certain mass flow rate of CO₂ or are you required to specifically transport it (and receive it) at the saturated conditions of -50 ^oC? It makes a BIG difference on how you approach a practical solution to the problem. If you have to transport it at -50 ^oC in an underground pipeline in the Nederlands you have a serious design problem related to keeping the product at those conditions.

If you are only charged with transporting 3 million tonnes/year (3,000,000,000 kg/year = 500 tonne/hr – based on 6,000 hrs/yr), at whatever condition is deemed more appropriate, then you should explore transporting the CO₂ under the following practical cases:

• As a saturated liquid at 18.3 bara & -22 ^oC; or
• As a supercritical fluid.

Give us your specific basic data and scope of work. Then we can look at what you have and comment accordingly.

Await your response.

[Lorendrix]

Dear Art,

first of all thank you for your answer.

Regarding the quantity Mtonne is Mega tonne (sorry to be not clear). Basically my research is a techno economic analysis of the CO2 transport chain via ship. The ship transport condition are the one specified in the last message, so -52°C and 6.5 bar. In order to reach this specification I have simulated a liquefaction plant (with Aspen plus). Regarding the pipeline length I have still to decide but it will be in the range of 10 to 50 Km. The CO2 purity will be higher than 99% because it comes from a post combustion capture process (only CO2 and water)and the water is dried at ppm level in the liquefaction or in the compression process.

At the moment I am concentrating on estimating costs in order to transport CO2 from the capture unit to the intermediate storage that is near the shore. At this point my case study is set to evaluate three different possibilities:

• In the first option I assume that capture unit, liquefaction plant and int.storage are in the same area so no additional costs have to be added.
• In the second case the capture unit is assumed far away from the shore and liquefaction and storage near the shore. In this case CO2 will be compressed and transported as supercritical, and afterward liquefied by an external refrigeration cycle at the transport specifications.
• Finally the third case is capture unit and liquefaction plant close to each other but far away from the shore. In this case after the liquefaction process the CO2 is at the final specification, so I would need to transport it with a pipeline at that conditions (-50 and 6,5 bar) if it is possible. This could make sense since in this option you don t need to compress CO2 first and after to liquefied it with an refrigeration cycle but you just liquefied it at the final condition in the plant (saving in capital costs). Also, for the pipeline transportation you can use a pump instead of compressor as CO2 is liquid at that conditions, saving in power and cost.

Therefore I'd like to figure out if this solution could be a realistic one (in terms of design feasibility) and if it could be considered cost effective (basically if insulation costs are not so high to overcome the economical advantages just described).

Looking forward to hearing from you,

Best,

Lorenzo Nardon

[Art Montemayor]

Lorenzo:

With your submission of additional, needed basic data and scope definition we can now have a clearer picture of what you are proposing to do. We can now make comments directly:

You are leaving out a critical, needed component for this type of “baseload” project. I am very familiar with the CO₂ industry and also with baseload projects, having spent some years in the LNG business. You have left out a key component out of your scope of work – and, consequently, out of your 3 options. You fail to state that your project has an under-pinning: you must be able to load and ship out liquid CO₂ when your ships are available. And your ships MUST always be available in order to keep the capture plant operating and producing on a continuous basis. This are vital requirements for this type of “mega” project because it is so large and costly that it must be project financed and, as such, always be kept fully loaded in order to ensure that the cash flow can be kept positive and service the project debt on a timely basis. To make sure that you comply with the project necessities of keeping the capture plant operating around the clock, you must maintain available and ample storage capabilities for the liquid CO₂ product at the shipping location – whether or not your capture plant and liquefaction facilities are near-by. This is a MUST-HAVE feature of your project – regardless of the transport pipeline necessities.

In your first option description you fail to state that it is located at the ship-out site. This has to be stated because it is the only way you can eliminate the pipeline and the dock-side storage.

In your third option case you fail to take into consideration that you can’t simply liquefy, store and transport liquid CO₂ for 50 kms directly into a ship’s storage compartment. This is not only not practical, it can’t be done in an operable and safe manner. You must have dock-side storage capabilities to receive and load the liquid CO₂.

You also fail to be specific about what type of pipeline you would propose: underground or above ground. I hinted as much in my first post to see if you were thinking in the same light. In order to be practical and realistic, you must consider these two options due to the big effects it would have on any low-temperature insulation requirements for the operation and maintenance of the -50 ^oC product – especially in the shallow water table found in the Nederlands. If your techno economic analysis is to be a serious one, it must take these factors into consideration.

[Lorendrix]

Dear Art,

thanks again. Actually I am completely aware of the need of an intermediate storage facility (also for unloading offshore in some cases) but this will be located in any case near the shore. I just didn t mention before because I though it was irrelevant for the information I need.

So, regarding the first option you are right, it has to be at the ship out site (I didn t explain well before). Regarding the third option that is actually the one I am interested in, it seems to be impractical for high cost of insulation. Anyway I d like to know if there s a method to made a rough estimation of the cost for one low temperature pipeline (both underground or above the ground)to see if this solution could be considered economically feasible (looking into the big picture), and evaluate how the capital costs (and O&M) change over the transport distance. Maybe for short distances, cost for insulation are not so high, and employ an insulated pipeline could be considered convenient. But I have been searching on the web I didn t find any method to estimate the extra cost due to insulation.
I hope you can help me.

Best,

Lorenzo

[Art Montemayor]

Lorenzo:

We now seem to be on the same page. Allow me to emphasize this for your benefit.

You should not initiate this type of study until you have done a conceptual engineering exercise of putting yourself in an investor’s shoes. What would you, as a financial stake holder in this project, demand as security that the project be secure in being able to maintain a continuous and safe operating life? What issues, as an investor, would you rather avoid as too risky and undefined for this project? The technical portion of your analysis forces you to consider the practicality and operability of any possible option and specifically call out those areas that are considered as risks and not recommendable for obvious project engineering and economic considerations. The social and political ramifications of a project of this magnitude cannot be avoided in such a study – in my opinion. I base myself on the fact that there are many social and political factors that can make this type of an investment totally unfeasible and uneconomic. Environmental concerns are an example as well as social constraints. I recommend that you take these factors into consideration when determining if a technical option is considered as a viable option for evaluation. Often, these social-political factors discard some engineering options right at the outset of a project.

Your third option – a remote capture plant with liquefaction facilities on site plus a long (50 km pipeline) with dock-side storage and loading facilities is the one I will now comment on:

Your have identified a location – the Nederlands. This is an environmental sensitive area for many reasons. The population density is very high. The geography is, as I have stated, subject to a high water table due to its low elevation. This fact dramatically increases the engineering and operability of an underground pipeline. You are also now in an area of feasibly obtaining the land and right-of-way for a long pipeline in a densely populated country. You are most certainly facing a long and extended period of government approval coupled with extensive environmental impact statements. This is a decided and critical risk that could jeopardize the project. You are certainly now contemplating the use of expensire FoamGlas type of insulation with its strict and detailed sealing and insulation mechanical requirements. This technical challenge is a serious one because it entails maintaining an operable pipeline in a world-scale project. You may not be able to justify an underground pipeline without having a second, parallel one as a stand-by due to the recognized reality that you will have to do unavoidable insulation maintenance to the pipeline from time to time and this would shutdown the export of the product and the related project cash flow. An above-ground P/L is certainly more attractive, maintainable, and operable. But it is subject to social and political approval. In such a densely populated, and industrialized area such an exposed P/L would be a transit and communications obstacle and practically un-desirable. In my opinion, it is not credible that such an exposed P/L would be approved within an area such as the Nederlands. So, from a pragmatic standpoint, you are left with the costly U/G version. An U/G pipeline carrying a saturated or sub-cooled liquefied gas in a water-saturated soil is one of the worse Unit Operations I can imagine. The calculations are challenging, but the engineering and implementation are even more demanding and risky. You will certainly have to seriously consider recommending a second, parallel P/L to ensure the project’s viability. You will also entail additional capital and operating costs in supplying subcooling to the product in order to overcome the heat gain that is favored by a water film heat sink surrounding the P/L. Pumping supercooled liquid CO₂ will generate a friction energy – much higher than that when pumping a supercritical product. This means that you must supply additional refrigeration to compensate for this heat gain as well. All this can be calculated with rigorous engineering calculations – but I venture to guess that the obvious answer is that this option is not practical from a risk and capital investment point of view and should be discarded early-on.

I hope I haven’t “busted your balloon” with the above comments. I have tried to be as candid, realistic, and frank as I can in order to give you a “head’s up” on what confronts you as a project. I hope you accept this experience as such and that it serves you in reaching a reasonable and successful engineering study.

[Lorendrix]

Dear Art,

first of all I d like to say that in the former message you didn t hurt me at all since it was clear that you really wanted to help. And of course I am glad to discuss my issues with someone with such big experience in the field.

I am aware that this kind of project are strongly dependent on policy and public opinion, and of course if you need to evaluate the actual feasibility of such huge project you definitely need to take into account this factors. Also, for carbon capture and storage the economic feasibility will strongly depends on how the carbon tax will evolve in time and how the 'learning curve' will influence the cost of the technology in the future. In addition all the logistic aspect of the shipping phase need to be scheduled to make the system work properly.

Unfortunately as you can understand this is huge work and it is impossible to incorporate all these aspect in a single thesis. Therefore what I agree with my supervisor was to focus mainly on the technical and economical feasibility discarding policy and logistic aspect. Basically the purpose of my research is to be a good starting point to an extensive feasibility analysis, so what I want to do is try to identify new solution, weak point and in the end give a quite reliable indication of the specific cost of the chain.

So I would try anyway to evaluate the third option. I know that it will probably be a unrealistic one but if you think about it also option one is actually really difficult to realize since the possibility to have power plant, liquefaction plant, intermediate storage and loading facility in the ship out site is really unlikely in the Rotterdam harbor (even if it s huge). However I think that it could be useful in terms of research literature since this study could actually be applied (with some adjustment)also in other location of the North Sea (in Norway for instance) where maybe installing an above the ground insulated pipeline doesn t create public concern because of a low population density. So again, if you know a rough method to estimate capital cost of an above-ground insulated P/L it would be really helpful for me, at least to get a more concrete idea of the possible cost of the installation and so to compare the different options.

Best,

Lorenzo

[Lorendrix]

Ok probably a method for a rough estimation of capital cost of such pipeline doesn t exist, so I am thinking about another solution for option 3.

In your first comment you said that CO2 could be transport as a liquid at 18 and -20 C. I was thinking I can transport CO2 at these specification and after sub-cooling it at the ship out site (before the intermediate storage)to reach the final ship transport condition. Of course I need a good amount of cold energy (about 4 MW) to decrease CO2 at a reasonable temperature before it expands in the flash drum; this is necessary in order to limit at minimum the flash creation (it cannot be recycled). So I should assume the availability of a process that can provide this cryogenic energy (like LNG re-gasification)near the ship out site.

So, do you think this solution could be more realistic? And, what about capital cost estimation of this type of pipeline?

Await your response.

Lorenzo

[Art Montemayor]

Yes, if you do some research on the CO₂ Industry (for example, drop in at a Coca-Cola bottling plant) you will notice that today almost all CO₂ is produced, stored, and transported as a saturated liquid at 18 bara and -20 ^oC. This has been going on for the last 60 years that I know of. So, the technology and the infrastructure is already out there. You can certainly capitalize on that fact and use your own equipment or that of contracted services to do the road transport – if that is what you mean by “I was thinking I can transport CO₂ at these specification”. That means of CO₂ transport is being done all over the world on a daily basis. You don’t have to re-invent the wheel. However, I don’t know how your logistics and quantity of equipment would look. You have not defined the specific product design flow rate on an hourly or daily basis. As I inferred, the yearly rate is for statisticians and politicians – we engineers need an hourly or daily design rate to make an estimate.

Are you proposing a pipeline or road tanker truck transportation? A pipeline can be estimated much as you estimate any piping job – except that you must add the civil and installation work – if you avoid the right-of-way, land, and political/social issues that I previously stated.

If you have done your prerequisite CO₂ processing and liquefaction studies, you probably know that you can’t liquefy CO₂ any lower than its triple point (5.27 bara) and that there are basically two methods used industrially to liquefy CO₂: the high pressure process and the low pressure process.

The high pressure process is the original way used to liquefy CO2 over a century ago. What was done was that the pure CO₂ was compressed in a 3-stage reciprocating compressor to its critical pressure, cooled below the critical temperature with cooling water and the resultant high pressure liquid was adiabatically expanded. The resultant, low temperature vapors were recycled back to the 3^rd stage of compression. The result was a low-temperature product at either 18 or 9.5 bara. This was the type of refrigeration employed by our great-grandfathers to produce solid CO₂ (“Dry Ice”) at -78.8 ^oC. You can do the same thing with your project and there is no need to waste what you call “the flash creation”. ALL FLASH CO₂ VAPORS CAN BE RECYCLED.


The low pressure process is refrigerating 18 bara CO₂ with a refrigerant such as ammonia. The result is the 18 bara saturated liquid. You certainly do not need cryogenic refrigeration. CO₂ liquefaction is very simple and straight forward. It’s a piece of cake.

If you require help in defining the refrigeration cycle for your CO₂ liquefaction, tell me. I can advise you with even a PFD and mass balance – but you have to cooperate and furnish all the required specific basic data and scope of work at one time and not piece-meal it or spoon-feed me with information.

[Lorendrix]

Art,

thanks. My idea was to transport CO2 at -20 and 18 bar via pipeline and since apparently these conditions are quite common it couldn't be so difficult to estimate the cost of that pipeline.

Regarding liquefaction I didn t explain well before. Coming back to the three options I can explain you how I am going to process the captured CO2 to reach the transport specification:

1- First option: liquefaction plant composed by a four compressor train to reach a max pressure of 55 bar. After every compression stage the gas is cooled by seawater heat exchangers (assumed seawater temperature: 10 C) and dried by a flash drum. After the third compression stage water is dried to ppm level (50 ppm with a molecular sieve or TEG). After reaching the highest pressure the gas is condensed again using a seawater heat exchanger. Afterwards the liquid CO2 is sub-cooled by flash gas obtained from the expansion of CO2 at intermediate pressure and finally it s expanded to reach the product specification. This create an open cycle in which the CO2 is used as a refrigerant and after recycled back to the compressor train at the appropriate pressure level. Of course with this configuration all the flash is recycled, also the boil off from intermediate storage because they are assumed to be one close to the other one. See the attached image to have a more clear idea (p.s: red line are work output, yellow are heat duty and blue are water).

2- Second option: the CO2 reach the ship out site in supercritical state from a high pressure pipeline (let s say at 100 bar and 20 C) . At this point to reach the product specification I need a refrigeration cycle (I use R22 as refrigerant) to cool down the flow to -45 C. Afterwards the stream is expanded to 6.5 bar in a product drum. Of course some flash is created (only a small quantity, like 2% of the total flow rate) and this cannot be recycle since it should be compressed again but the compression occurs at the capture plant that is far away from the shore (that s what I meant before).

3- Third option: the CO2 is liquefied again with the first liquefaction plant but I set it to reach the -20 C and 18 bar specification. At this point the liquid CO2 is transported via insulated pipeline to the shore. Here I need to reach the product specification before storing it in the storage buffer. So at this point in my opinion using a refrigeration cycle again doesn t make sense because otherwise it would be better to shift again to the second option in which CO2 is transported as supercritical in conventional pipeline with no need of insulation and additional O&M costs. Therefore this option make sense only if I can take advantages of the fact that I have already cooled down part of the LCO2 and so I just need less cooling duty at the dock site. That s why I was thinking of a process that require waste heat like LNG re-gasification to provide the required cooling duty (that should of about 4 Mw). However this will be only an assumption because I won t have to time to analyse an integration system between these two process.

Regarding the first option I could also compress to a lower pressure and use a refrigeration cycle (as you said), however the two process are similar in terms of cost and energy use and in literature the one I use it is suggested for large scale liquefaction. Concerning option two I already have figures for the refrigeration cycle but if you can please send me the information you were talking about it would be helpful anyway. Finally regarding the third option what I d like to understand is whether or not the pipeline transport in liquid phase (18 bar and -22 C) could be considered advantageous in some extend. Otherwise I will just discard this option and concentrate on the first two.

I hope I have been enough clear.

Best,

Lorenzo

Attached Files

•  My system.gif   19.98KB   13 downloads

Edited by Lorendrix, 13 August 2010 - 11:37 AM.

[Art Montemayor]

Lorenzo:

You haven't been clear enough because your GIF/BMP picture is terrible.

Please bear in mind that I'm 73 years old - and even if I was 20 years, your attempt at minimizing your effort and time produces a product that can't be deciphered, has no labels, has no data on it, has no identifications, can't be printed to a larger size, and isn't worth the time to try to understand what it represents. Why are you trying to communicate with a picture, when you can easily draw in Excel and produce a conventional, detailed PFD or P&ID? Kindly submit something that represents an engineering product - not a Simulation Program screen printout. I need process information to understand your liquefaction process.

Is your shipped product at -52°C and 6.5 barA saturated or sub-cooled? What conditions do you want to load your ships at?

[Lorendrix]

Art,

sorry again. It s better if I send you the paper where I found that liquefaction system ('gas conditioning'; at page 350 you can find the clear image). What I did is reproduce the system with Aspen Plus. You can also see at page 249 the compression system that I had also reproduce with Aspen, the one that I will use in option two. Regarding the CO2 condition look at the image at page 12 of the presentation attached. The product will be loaded through loading arms at the product specification (-52 C and 6.5 bar).

Please let me know what you think about the third option as discussed in the former comment. Also, if you can please send me the documentation about refrigeration cycles it would be nice for me in order to compare it with the one I d like to use for option two. My business mail is L.Nardon@ecofys.com

Best,

Lorenzo

Attached Files

•  Gas conditioning.pdf   1.18MB   31 downloads
•  CCS value chains with CO2 shipping.pdf   4.94MB   26 downloads

Edited by Lorendrix, 13 August 2010 - 01:04 PM.