Process design of the piperazine advanced stripper for a 460 MW NGCC

Journal Article · Wed Mar 02 00:00:00 EST 2022 · International Journal of Greenhouse Gas Control

DOI:https://doi.org/10.1016/j.ijggc.2022.103631· OSTI ID:1977183

Suresh Babu, Athreya ^[1]; Rochelle, Gary T. ^[2]

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1. Univ. of Texas, Austin, TX (United States); OSTI
2. Univ. of Texas, Austin, TX (United States)

The Texas Carbon Management Program is conducting a Front-End Engineering Design (FEED) for Piperazine with the Advanced Stripper™ (PZAS™) at a natural gas combined cycle power plant in west Texas. Here, this paper presents the design of the advanced stripper system with an emphasis on the selection of packing type, packing height, column diameter, and heat exchanger size, demonstrates the effect of ambient temperature swing on the regeneration energy requirement, and investigates two alternate process configurations that provide better energy performance than PZAS™. The design uses 2 stripper trains, and each train uses two cold cross exchangers, one hot cross exchanger, a stripper column, a CO₂ exchanger, and a condenser. Each column consists of two sections of random packing with RSR 2 packing at the top and RSR 3 packing at the bottom, with a total packed height of 7.5 m. The cold exchanger was designed with an NTU of 6, the hot exchanger with an NTU of 2, and the CO₂ exchanger with an NTU of 5. At 0.4 rich loading and 0.2 lean loading, this design resulted in a heat duty of 2.85 GJ/tonne CO₂. The heat duty can vary up to 3.1 GJ/tonne CO₂ due to lower rich loading at higher summer temperature, but the absolute steam requirement is 8–15% lower in the summer. An alternate design, PZAS with hot rich bypass, is proposed, which can reduce the equivalent work of stripping by 1.5–3.5% compared to PZAS at low heat exchanger size, due to a reduction in stripper driving force. Using a hot rich bypass increases the vapor fraction of the total rich bypass stream from 0.3 to 1 mol% compared to using the warm rich bypass, which also contributes to a reduction in lost work in the column. PZAS with hot rich bypass outperforms PZAS in energy requirement below a packing height of 15 m, but fails to do so above 15 m of packing due to a column pinch that results in little change in LMTD of the column. PZAS with hot rich bypass has the potential to minimize capital cost in addition to reducing energy requirement as it requires less packing to strip CO₂ than PZAS and requires only one cross exchanger with 8 heat transfer units.

• Research Organization: Univ. of Texas, Austin, TX (United States); University of Texas at Austin, TX (United States)
• Sponsoring Organization: USDOE; USDOE Office of Fossil Energy (FE)
• Grant/Contract Number: FE0031844
• OSTI ID: 1977183
• Alternate ID(s): OSTI ID: 2397333; OSTI ID: 1854423
• Journal Information: International Journal of Greenhouse Gas Control, Journal Name: International Journal of Greenhouse Gas Control Journal Issue: C Vol. 115; ISSN 1750-5836
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
FEED
NGCC
Piperazine
Process configurations
Process design
Stripper