large motor plus LCI for cracker compressors
large motor plus LCI for cracker compressors
(OP)
Dear colleagues,
Some crackers in France employ electric driven compressors for charge gas, C3R. TOTAL plant in Gonfreville has a 35MW electric driven CGC.
Why such practice is not so widespread (except in new LNG plants and compression stations))? CAPEX only? Reliability? It seems a very favorable energy balance can be obtained by electric motors (+ LCI) as steam condensation is avoided, lower steam flow during startup is necessary, etc.
have you ever discussed such point in this forum?
Do you know any cracker that is moving in this direction?
regards
Some crackers in France employ electric driven compressors for charge gas, C3R. TOTAL plant in Gonfreville has a 35MW electric driven CGC.
Why such practice is not so widespread (except in new LNG plants and compression stations))? CAPEX only? Reliability? It seems a very favorable energy balance can be obtained by electric motors (+ LCI) as steam condensation is avoided, lower steam flow during startup is necessary, etc.
have you ever discussed such point in this forum?
Do you know any cracker that is moving in this direction?
regards
fabio vincent
www.figener.com.br
RE: large motor plus LCI for cracker compressors
If I am running a gas turbine to generate electricity and I'm willing to spend the capital to recover the waste heat, then using steam is very inexpensive while using the electricity directly to run the compressor has a high opportunity cost (the power can be sold if not used). If I have to burn fuel to generate steam then steam turbines can be quite expensive to operate.
There are situations where I can use gas that would otherwise be vented to run an internal combustion engine, in countries with a carbon tax, the government is paying me to use that fuel instead of venting it, very cheap indeed.
Bottom line of the above discussion is that choice of driver for a particular compression operation in a particular location at a particular time is a complex economic analysis that does not lend itself to rules of thumb. You have to do the analysis honestly, without bias to decide what makes the most economic sense. Once you have that number it is quite appropriate to apply personal, corporate, or regulatory biases to add the consideration of intangibles--with an honest cost breakdown you can determine the cost of indulging in the biases to decide if pandering to them is justified. For example, if the NPV of your electric driven compressor is 80% of the NPV of a gas turbine driven compressor, but adding the turbine would increase the emissions output enough to force the entire plant into a non-attainment status (with accompanying potential for fines, capital expenditure required for other equipment, and bad press) then the lower NPV could easily be justified. In the same example, if the NPV of the electric was 10% of the gas turbine even considering fines and required capital expenditures then accepting the bad press might just be a cost of doing business as you install the turbine.
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: large motor plus LCI for cracker compressors
The project I refer to is a new cracker. The proposed design is to drive the main compressors with condensing steam turbines. However in the entire complex there companies that require process steam and so additional boilers beyond the furnaces steam generators are required. Residual fuel from cracker can be used to generate power in combined cycle and/or in integrated gas turbine (exhaust gases as comburent to furnaces). The point is: the entire cycle is more efficient if the large compressors were motorized (motor + LCI) and steam (produced in the furnaces) could be sent to other companies of the complex. I understand that local energy and fuel costs impact on the viability of any solution. What I could not up to now understand is why there is so few crackers with large motor driven compressors except in France.
Regards
fabio vincent
www.figener.com.br
RE: large motor plus LCI for cracker compressors
The project I refer to is a new cracker within a petrochemical complex. The proposed design is to drive the main compressors with condensing steam turbines. However in the entire complex there are other companies that require process steam and so additional boilers other than the furnaces steam generators are required. Residual fuel from cracker can be used to generate power in combined cycle and/or in integrated gas turbine (exhaust gases as comburent to furnaces). The point is: the entire cycle is more efficient if the large compressors were motorized (motor + LCI) and steam (produced in the furnaces) could be sent to other companies of the complex. I understand that local energy and fuel costs impact on the viability of any solution. What I could not up to now understand is why there is so few crackers with large motor driven compressors except in France. Any idea why?
Regards
fabio vincent
www.figener.com.br
RE: large motor plus LCI for cracker compressors
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: large motor plus LCI for cracker compressors
RE: large motor plus LCI for cracker compressors
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"