Patent ID: 8496733

Claim:
A pressure swing adsorption process for separating a pressurized supply feed gas containing one or more strongly adsorbable component from at least one less strongly adsorbable product gas component in a twelve bed pressure swing adsorption system to produce a continuous stream of product gas enriched in the less strongly adsorbable component and a continuous stream of offgas that is enriched in strongly adsorbable components, wherein the process cycle has four bed-to-bed equalizations steps, four of the beds are in production, and utilizes purge gas of increasing concentrations of the less strongly adsorbable product gas during the purging steps, in accordance to the following cycle chart: Step: Bed# 1 2 3 4 5 6 7 8 1 A1 A2 A3 A4 A5 A6 A7 A8 2 E1′ PP A1 A2 A3 A4 A5 A6 3 E3′ E2′ E1′ PP A1 A2 A3 A4 4 PG1 E4′ E3′ E2′ E1′ PP A1 A2 5 PG3 PG2 PG1 E4′ E3′ E2′ E1′ PP 6 PPG3/ BD2 PG3 PG2 PG1 E4′ E3′ E2′ BD1 7 PPG1 PPG2 PPG3/ BD2 PG3 PG2 PG1 E4′ BD1 8 E3 E4 PPG1 PPG2 PPG3/ BD2 PG3 PG2 BD1 9 E1 E2 E3 E4 PPG1 PPG2 PPG3/ BD2 BD1 10 A7 A8 E1 E2 E3 E4 PPG1 PPG2 11 A5 A6 A7 A8 E1 E2 E3 E4 12 A3 A4 A5 A6 A7 A8 E1 E2 Step: Bed# 9 10 11 12 13 14 15 16 1 E1 E2 E3 E4 PPG1 PPG2 PPG3/ BD2 BD1 2 A7 A8 E1 E2 E3 E4 PPG1 PPG2 3 A5 A6 A7 A8 E1 E2 E3 E4 4 A3 A4 A5 A6 A7 A8 E1 E2 5 A1 A2 A3 A4 A5 A6 A7 A8 6 E1′ PP A1 A2 A3 A4 A5 A6 7 E3′ E2′ E1′ PP A1 A2 A3 A4 8 PG1 E4′ E3′ E2′ E1′ PP A1 A2 9 PG3 PG2 PG1 E4′ E3′ E2′ E1′ PP 10 PPG3/ BD2 PG3 PG2 PG1 E4′ E3′ E2′ BD1 11 PPG1 PPG2 PPG3/ BD2 PG3 PG2 PG1 E4′ BD1 12 E3 E4 PPG1 PPG2 PPG3/ BD2 PG3 PG2 BD1 Step: Bed# 17 18 19 20 21 22 23 24 1 PG3 PG2 PG1 E4′ E3′ E2′ E1′ PP 2 PPG3/ BD2 PG3 PG2 PG1 E4′ E3′ E2′ BD1 3 PPG1 PPG2 PPG3/ BD2 PG3 PG2 PG1 E4′ BD1 4 E3 E4 PPG1 PPG2 PPG3/ BD2 PG3 PG2 BD1 5 E1 E2 E3 E4 PPG1 PPG2 PPG3/ BD2 BD1 6 A7 A8 E1 E2 E3 E4 PPG1 PPG2 7 A5 A6 A7 A8 E1 E2 E3 E4 8 A3 A4 A5 A6 A7 A8 E1 E2 9 A1 A2 A3 A4 A5 A6 A7 A8 10 E1′ PP A1 A2 A3 A4 A5 A6 11 E3′ E2′ E1′ PP A1 A2 A3 A4 12 PG1 E4′ E3′ E2′ E1′ PP A1 A2 where: A1=First Adsorption Step A2=Second Adsorption Step A3=Third Adsorption Step A4=Fourth Adsorption Step A5=Fifth Adsorption Step A6=Sixth Adsorption Step A7=Seventh Adsorption Step A8=Eighth Adsorption Step E1=First Equalization Down E2=Second Equalization Down E3=Third Equalization Down E4=Fourth Equalization Down PPG1=First Provide Purge Gas PPG2=Second Provide Purge Gas PPG3/BD1=Third Provide Purge Gas/First Blowdown BD2=Second Blowdown PG3=Purge using gas from PPG3 step PG2=Purge using gas from PPG2 step PG1=Purge using gas from PPG1 step E4′=Equalization Up (using gas from E4 step) E3′=Equalization Up (using gas from E3 step) E2′=Equalization Up (using gas from E2 step) E1′=Equalization Up (using gas from E1 step) PP=Product Pressurization.