Dry methane is supplied by a compressor and precooling system to the cooler of a Linde liquid-methane system (Fig. 9.6) at 180 bar and 300 K. The low-pressure methane leaves the cooler at a temperature 6°C lower than the temperature of the incoming high-pressure methane. The separator operates at 1 bar, and the product is saturated liquid at this pressure. What is the maximum fraction of the methane entering the cooler that can be liquefied? The NIST Chemistry WebBook (http://webbook.nist.gov/chemistry/fluid/) is a source of data for methane.

 

Figure 9.6: Linde liquefaction process. Cooler Exchanger Throttle 15 W. 10 Liquid Gas feed