lfolsin
Chemical
- Mar 15, 2006
- 1
Combined Air Separation
To study LNG regasification process in terms to improve its thermodynamic efficiency I have simulated a process model that can-be utilized to integrate Air Separation Unit (ASU) with LNG Regasification.
The results of this simulation are seemed promising.
I compared the simulated ASUR process flow diagram with existing Integrated Regasification Process (IRP), which combines regasification with LPG and Power Production.
(IRP technology was described in ‘’Hydrocarbon Engineering Journal’’ (October issue 2003))
Comparison was made based on following indexes.
SFC - specific fuel consumption as kWh/one ton of total products output (Total product output is sum of delivered gas and by products)
TDE – thermodynamic efficiency in % that is based on exergy balance calculation
OEE – overall energy efficiency in %, which is estimated as following expression: OEE =100*(Products (HHV) + Power output)/(Feed HHV + Power input)
These indexes were calculated for ASUR as results of process model simulation, for IRP they were based on provided material heat balance data.
The results are following:
ASUR simulated model
SFC – 200kWh/t
TDE – 33%
OEE – 98.8%
IRP mass heat balance based estimation
SFC – 1000kWh/t
TDE – 28%
OEE – 97.2%
So these indexes for ASUR process model shows better outcomes.
CAPEX expectations based on main equipment costs have also been estimated for these process options.
The relation between equipment costs CP and annual gross profit GP
(CP /GP) was used as numerical measure for processes comparison.
In order to have the same basis for the comparison the Integrated Regasification unit capacity was decreased to the same value as ASUR combined plant.
Decreasing capacity of Integrated Regasification Process unit for four times down (similar to that as for ASU combined process), gives reduction of equipment costs as about 2.3.
So ASUR (CP /GP) is estimated as 0.21$/$.
And (CP /GP) for four times reduced capacity Integrated Regasification unit is: 0.25$/$.
This estimation shows the ASUR combined process can have even lower pay back period compare to IRP.
The positive fact of combination LNG regasification and Air separation is also that the energy consumption per one Nm3 of cryogenic liquid air products (LIN and LOX) can be considerably cut down.
Usually modern Air separation units (those are dedicated to liquid cryogenic LOX and LIN production) take about 0.7kWh per one total Nm3 of these products.
Combination ASU and LNG regasification, according to simulated model shows, the power requirements are expected to be about 0.3 kWh per one total Nm3 of LOX and LIN, that is more than double lower.
What do you think colleagues about perspectives of such technology?
Where can I find information about existing combined LNG regasification processes? (It seems to me not many sources about this subject).
If somebody interested with it I would like to discuss these issues all comment are welcomed.
To study LNG regasification process in terms to improve its thermodynamic efficiency I have simulated a process model that can-be utilized to integrate Air Separation Unit (ASU) with LNG Regasification.
The results of this simulation are seemed promising.
I compared the simulated ASUR process flow diagram with existing Integrated Regasification Process (IRP), which combines regasification with LPG and Power Production.
(IRP technology was described in ‘’Hydrocarbon Engineering Journal’’ (October issue 2003))
Comparison was made based on following indexes.
SFC - specific fuel consumption as kWh/one ton of total products output (Total product output is sum of delivered gas and by products)
TDE – thermodynamic efficiency in % that is based on exergy balance calculation
OEE – overall energy efficiency in %, which is estimated as following expression: OEE =100*(Products (HHV) + Power output)/(Feed HHV + Power input)
These indexes were calculated for ASUR as results of process model simulation, for IRP they were based on provided material heat balance data.
The results are following:
ASUR simulated model
SFC – 200kWh/t
TDE – 33%
OEE – 98.8%
IRP mass heat balance based estimation
SFC – 1000kWh/t
TDE – 28%
OEE – 97.2%
So these indexes for ASUR process model shows better outcomes.
CAPEX expectations based on main equipment costs have also been estimated for these process options.
The relation between equipment costs CP and annual gross profit GP
(CP /GP) was used as numerical measure for processes comparison.
In order to have the same basis for the comparison the Integrated Regasification unit capacity was decreased to the same value as ASUR combined plant.
Decreasing capacity of Integrated Regasification Process unit for four times down (similar to that as for ASU combined process), gives reduction of equipment costs as about 2.3.
So ASUR (CP /GP) is estimated as 0.21$/$.
And (CP /GP) for four times reduced capacity Integrated Regasification unit is: 0.25$/$.
This estimation shows the ASUR combined process can have even lower pay back period compare to IRP.
The positive fact of combination LNG regasification and Air separation is also that the energy consumption per one Nm3 of cryogenic liquid air products (LIN and LOX) can be considerably cut down.
Usually modern Air separation units (those are dedicated to liquid cryogenic LOX and LIN production) take about 0.7kWh per one total Nm3 of these products.
Combination ASU and LNG regasification, according to simulated model shows, the power requirements are expected to be about 0.3 kWh per one total Nm3 of LOX and LIN, that is more than double lower.
What do you think colleagues about perspectives of such technology?
Where can I find information about existing combined LNG regasification processes? (It seems to me not many sources about this subject).
If somebody interested with it I would like to discuss these issues all comment are welcomed.
