Redundent Equipment / or spare for future use or demolish/keep ?

[mrtangent]

I have a question on what peoples "typical" practice is for redundant equipment in plant.

On our site, we have decommissioned some plants and left them as they stand because it has been thought that at some time we may want to re-commission them. To be honest this has not always been our finest hours - we have tended to leave them in a poor state of repair making if difficult and painful to re-commission.

Our "internal standard" actually states we should demolish a plant if it is not used for 6 months - which we don’t follow and raise waivers for. This is because if we can use the plant for another product it would be wastefully of money to demolish then rebuild again.

This discrepancy tends to cause internal friction - the plant does not want to spend money to remove equipment but from a house keeping perspective and "we must do this because we say we should do this" type of mentality. I tend to see positives on both sides of that argument.

So to cut to the chase,

"What is your experience of this"

My main reason is I am working on a new project for a new column. This is next to an existing column, which will become redundant (too small). But as our product mix changes we may have a need for the column. SO I'm looking for people to share their experiences please!

 

[jay165]

Most plants that I've worked in or visited leave the shutdown equipment where it is unless it's in the way of the new equipment and the facility has limited space. I've seen some companies place the equipment (vessels and exchangers mostly) under N2 pressure to limit internal corrosion. In fact, Dow Chemical did this for years at their Oyster Creek refinery before the equipment was sold.

I've never heard of anybody demolishing equipment "just because it's there". After all, some bright young engineer will figure out a way to use that equipment to make more $$ for your company!

 

[pmureiko]

What is the IRR or NPV on demoing equipment? You can factor in some value for intangibles such as safety or environmental when calculating these. If it has a good IRR or is positive NPV go ahead, otherwise leave it there.

Also be careful when recommissioning used equipment. Its condition has probably deteriorated over long periods of time from neglect, and it may be unusable or unsafe to operate.

I wonder is the effort and expense Dow spent maintaining their equipment was recovered when they finally sold the equipment.