Ethylene from ethane steam cracking capital cost

[Iradah]

Hi all,

I am working on an assignment of estimating the capital and operating cost for ethylene production form ethane by steam cracking. I am working as an intern in a gas company and my supervisor asked for these infomation:
what is the capacity (ethylene production) needed for a commercial plant?
what is the capital cost?
What is the operating cost?
He gave me one week to find out these information, which is not enough to do a full analysis for the flow chart and detailed equipment size and cost.

Can anyone help me of how to get a reliable estimation for what is required?? I am reall getting a hard time!!!!!!!

All thanks

 

[hahor]

Hello Iradah,
1. better than nothing to start with:

http://www.chemweek.com/services/engineering_and_construction/6233.html

2. Look up published data in Engineering & Economics Magazines like "Chemical Engineering" or "Chemical Week" and try to correlate capacity with capital cost; escalate actual capital cost with M&S index to current capital cost.
3. Ask your supervisor what he/she means by “commercial plant” and let him/her come up with at least some hint of plant capacity. Tell your supervisor that the estimating range of your results is +/- 50%.
4. Go to the next pub have a couple of beers and tell everyone that your supervisor is an a$xh0xe since he/she has no idea how to motivate next generation engineers.

Kind Regards,
hahor

 

[Iradah]

Hello hahor,

First thanks for your reply.

Actually, I tried these magazines but I have no subscription to any of the chemical engineering magazines..

I found an analysis made by stanford Research Institute for an ethylene plant by ethane steam cracking but that was in 1967. I tried transfering that to current time by using capacity correlation and the Chemical Engineering Plant Cost Index (I could not find that of M&S). I do not know how reliable these calculations are.
The calculated capital cost was about 98 million $ and my supervisor thinks that this is higher than what it should be??
I found an information saying that Borouge company in UAE has signed a contract of 1.3 billion with another company to build and ethylene plant of 1.5 million ethylene ton/yr. can I use the 1.3 billion as a capital cost?? this will give even higher than the 98 $ I found previously.

I found a website that offers free quotations for such projects. I wrote for them but they emailed me asking for more details without saying what details they are. What details are needed to be supplied to them for preliminary analysis, I don't want them to think that I am not serious??

My supervisor said that by "commercial" he means what is the minimun ethylene capacity of the plant that makes the project profitable and pays back withing 5 years?? He asked also for the amount of ethane required for that capacity of ethylene.
I assumed an amount of ethylene and used the selectivity and conversion found in literature for such reactions and found amount of ethane, but still do not know if this is the minimumn capcity or not because I do not have a complete analysis for the operating cost.

I know that I talked too much, I wanted the image to be clear because I do really need your help.

All thanks.

 

[hahor]

Hello Iradah,
- subscription to Chemical Engineering is for free
- maybe you employer has a Subscription to Chemical Week or could arrange it for you
- a 1967 analysis is definitely too old
- M&S index is published on the “Economic Indicators” page of Chemical Engineering Magazine
- To check if an investment is economical just run an investment analysis (e.g. dynamic investment calculation) … GOOGLE may help
Is your company really in the ethylene gas business ???
Kind Regards,
hahor

 

[dcasto]

There is no size of ethane cracker plant that willpay back in 5 years unless you get the ethane for free and you have a buyer for the ethane that will pay market price.

If you want to be a real smarty-pants (look that term up if you are not familiar), ask you boss to give you the price of ethane and ethylene over the next ten years AND provide the prices for all the co-products (propylene, butylenes and pygas. Then ask if you want the plant to run EP-mix feed or purity ethane. Then ask if there is a market for excess hydrogen and what fuel will be used (ethane or methane).

I suggest you first need to study what an ethane cracker does before you get bogged down.

Shell just announce building such a plant and in the US around Pennsylvannia, there might be some insite on the projected cost and size in the news. Commercial ethylene plants are in the 1 billion pound per year range. Back into the number of gallons per day of ethane feed based on say a 90% conversion rate.