Oil and gas production handbook An introduction to oil and gas production

 
Figure 15. Optimized cascade process 

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75 
 
The dual cycle mixed refrigerant (DMR), developed by Shell and others, may 
look simpler but the overall design will be similar in complexity as multistage 
compressors are typically needed. It is shown on the left with the C3MR on 
the right for comparison.  
 
Figure 16. Shell DMR and APLI C3MR designs 
 
For small and micro LNG, single cycle designs are often preferred. There are 
literally hundreds of patented solutions, but only a handful of mainline 
licensors, that have solved the challenge of achieving single cycle 
refrigeration. However, this means multiple internal stages in the process 
flow and the heat exchanger itself. The PRICO SMR is shown on the left and 
the Linde LIMUM
®
 (on the right).