Closed Loop Extraction Systems (CLS) 107: Pull/Push Butane Recovery

After running the continuous shower, the liquid butane is pulled off into the gas phase by the recovery pump and pushed into the liquid phase, which then fills back into the recovery cylinder. The push/pull method of recovery requires heating the extraction collection vessel (10) and cooling the recovery cylinder (5). The recovery cylinder can be cooled to -50C if you use a dry ice/ethanol bath, but is not necessary – it just speeds up the recovery. Push/pull is governed by the most useful branch of chemistry – thermodynamics – we’ll explain that at a later time if anyone is interested…

Step 5 – Butane Recovery – heat extraction collection chamber (10) to 85F/30C; cool the recovery cylinder (5) to -4F/-20C; open the purge port (4)
Component #	Component Name	Abbreviation	Open/On	Closed/Off
1	Extraction Column Valve	ECV	x
2	Low Pressure Recovery Manifold	RM2		x
3	High Pressure Recovery Manifold	RM3	x
4	Purge Port	PP	x
5	Recovery Cylinder	RC		x
6	Vacuum Pump	VP		x
7	Recovery Pump	RP		x

Step 5.1 – Butane Recovery – open the recovery cylinder liquid side valve (5) and simultaneously turn on the recovery pump (7)
Component #	Component Name	Abbreviation	Open/On	Closed/Off
1	Extraction Column Valve	ECV	x
2	Low Pressure Recovery Manifold	RM2	x
3	High Pressure Recovery Manifold	RM3		x
4	Purge Port	PP	x
5	Recovery Cylinder	RC		x
6	Vacuum Pump	VP		x
7	Recovery Pump	RP	x

Step 5.2 – Butane Recovery – open the recovery cylinder liquid side valve (5) and simultaneously turn on the recovery pump (7)
Component #	Component Name	Abbreviation	Open/On	Closed/Off
1	Extraction Column Valve	ECV	x
2	Low Pressure Recovery Manifold	RM2	x
3	High Pressure Recovery Manifold	RM3		x
4	Purge Port	PP	x
5	Recovery Cylinder	RC		x
6	Vacuum Pump	VP		x
7	Recovery Pump	RP	x

Step 5.3 – Butane Recovery – recover butane until the pressure gauge reads 10″Hg to 22″Hg
Component #	Component Name	Abbreviation	Open/On	Closed/Off
1	Extraction Column Valve	ECV	x
2	Low Pressure Recovery Manifold	RM2	x
3	High Pressure Recovery Manifold	RM3		x
4	Purge Port	PP	x
5	Recovery Cylinder	RC		x
6	Vacuum Pump	VP		x
7	Recovery Pump	RP	x

As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.