Test condition 121% of design
123
16
14
At ow rates exceeding design Gas o -spec. operation
H S sample value (ppm) Gas through the contactor
115
12
+21%
108
10
Base case Stable on-spec. operation
100
8
6
92
H S spec.
4
85
2
STT installation
77
0
Figure 5 The technology enabled the operator to increase natural gas production capacity by more than 20% while keep- ing H₂S levels within specified limits
Deployment in AGRU applications The operator of a natural gas treatment facility using Sulfinol-X gas processing technology wanted to debottle- neck the sour gas absorber but was concerned that upgrad- ing the unit would be expensive and disrupt operations. Previous attempts to increase natural gas throughput had led to H₂S levels exceeding regulatory limits, confirming the limits of the existing absorber (see Figure 5 ). The retrofit aimed to increase gas processing capac- ity in the AGRU with minimal Capex by leveraging STT technology. By optimising the column hydraulic limits, the new technology maximised existing solvent loop margins, allowing full utilisation of current equipment without mod- ifications. The retrofitting design parameters are summa- rised in Table 1 . As part of the upgrade, 21 conventional trays were removed and replaced with just nine STT trays, significantly improving efficiency. The new trays were installed using the existing tray support rings, eliminating the need for hot work on the pressure vessel. Additionally, a new solvent inlet
distributor was introduced to enhance flow distribution and handle the increased feed gas flow. A new mesh demister was installed to improve gas-liquid separation. Deploying STT together with Sulfinol-X solvent increased natural gas production capacity while keeping H₂S levels within specified limits. The retrofitted AGRU handled up to 121% of baseline flow rates, while the rich solvent loading increased from 0.46 to 0.51 mol acid/mol amine, remain- ing within the industry standard limits. The regeneration system maintained solvent leanness using the available reboiler capacity of existing hardware. The new technology is expected to achieve even higher capacity, but limited feed gas availability prevented further testing. The total pressure drop across the new trays – including the mixing boxes, gas inlet ports, and swirl devices – was, in fact, reduced by approximately 0.2 bar compared to conven- tional trays. This reduction boosted the plant’s gas capacity, which may be especially beneficial for source fields that are expected to experience declining pressures. Table 2 summa - rises the results from the STT retrofit.
Summary of the real-world deployment objectives vs achieved results
Objective
Result
Achieved. The new technology baseline results demonstrated significantly lower H₂S slip compared to conventional tray baselines. The overall mass transfer of nine STT trays surpassed that of 21 conventional high-capacity trays. Achieved. At a peak feed gas rate of 158 MMSCFD (surpassing the design feed rate of 156 MMSCFD), STT effectively treated the gas, exceeding target specifications while maintaining stable tray hydraulics with no foaming, vibrations, or pressure drop issues. Achieved. The liquid carryover was minimal; no solvent was detected downstream even during start-up. Achieved. Pressure drops across the contactor were consistently low during a two-week run. Despite the initial poor quality of the amine solvent, foam incidents remained infrequent, indicating that the swirl tubes effectively destabilise and break down foam. Achieved (qualitative). The panel operator feedback was positive, suggesting fewer set-point interventions per shift.
Improved mass transfer rate per tray (higher tray efficiency)
Increased gas processing capacity
Reduced solvent losses
Reduced foaming
More robust operation
Table 2
43
PTQ Q3 2025
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