The efficiency advantage of the ZR-LNG process may be utilised in 2 ways. On capital sensitive projects, the more efficient ZR-LNG scheme permits installation of smaller, lower powered compression/driver equipment. This effectively trades the efficiency advantage of the process for a lower installed cost.
For larger projects however, there is considerable benefit in securing maximum LNG output from the compressor driver, the normal capacity limiting equipment item in liquefaction configurations. In this area, arising from its high energy efficiency, ZR-LNG demonstrates its most compelling commercial advantage over other mid-scale processes.
All things being equal (e.g. compressor/driver size and efficiency and an overall economically matched process equipment configuration) the capacity output from a ZR-LNG scheme will realise a higher plant capacity for an equivalent installed compression power than either SMR or dual expander nitrogen schemes. This higher throughput translates into increased cash flows. This is demonstrated in the graphical presentation of cumulative NPV shown below for monetisation of a 2 TCF offshore gas field using four nominal one million tonne per annum trains driven by an LM6000 gas turbine. Not only does ZR-LNG achieve higher financial returns, it does so in a reduced timescale. For FLNG scenarios, redeployment of the plant to another stranded field would be possible, further widening the ZR-LNG commercial advantage indicated in the graph.
Basic parameters associated with the above graph are:
System capex including integrated field development and FLNG facility $3.9 billion
Sales Gas Price $10/mil BTU
Debt : Equity ratio 70 : 30
Loan interest rate 8%
Loan repayment period 7 years
Tax rate 30%