Case study · Geoscience & subsurface studies
Studying six-month reaction kinetics in corrosive media: a custom six-reactor HPHT bench
For a major geoscience research center, IRIAN Mecatronics designed and built a test bench with six independent HPHT reactors. The system simulates long-term biogeochemical processes by maintaining stable, extreme conditions: 150 bar (2175 psi) pressure, 150°C (302°F) temperature, and a corrosive environment with brine and H₂S.
At a glance
- Client
- A major geoscience research center
- Field
- Geochemistry
- Technique
- Kinetic study in a three-phase environment
01 — The research question
How to study reaction kinetics over several months without equipment contaminating the sample?
Studying very slow reaction kinetics, such as fluid-rock interactions in geological storage, requires keeping a sample under stable conditions for weeks or months. In a corrosive environment, the equipment itself becomes a source of contamination: even minor ion leaching or wall effects can skew the analyses and invalidate a time-consuming test. The challenge for this project was to combine several requirements that are rarely met at once: extreme corrosion resistance (high-salinity brine + H₂S), stable HPHT conditions for six months, effective mixing for a three-phase system (solid, liquid, gas), and near-zero dead volume for valid sampling. No off-the-shelf custom HPHT reactor could meet all these requirements simultaneously across six parallel units.
Ensuring a sample remains uncontaminated and representative over a very long period in an extremely corrosive HPHT environment that degrades equipment and skews measurements.
02 — Our approach
The design approach: four choices to ensure measurement reliability
Ensuring absolute chemical inertness
Over six months, even high-grade stainless steel would have suffered from pitting corrosion in the presence of brine and H₂S, contaminating the test. We therefore manufactured all wetted parts from Hastelloy C276. Using a single alloy eliminates any risk of galvanic corrosion and ensures complete chemical inertness.
Ensuring representative sampling
For a kinetic study, any fluid stagnating in a sampling line (dead volume) skews the analysis. Instead of using remote sensors and valves, we integrated all measurement and sampling functions as close as possible to the reaction volume, directly on the reactor head, thereby eliminating dead volumes.
Homogenizing a three-phase system (solid-liquid-gas)
The reactions being studied depended on the interfaces between phases. It was crucial to keep the rock particles in suspension and maximize gas-liquid mass transfer. A powerful, custom-designed mechanical stirring system was developed to ensure the medium's homogeneity and to confirm that the measured kinetics were driven by chemistry, not by physical limitations.
Facilitating parallel operation of six reactors
Managing six long-term tests is demanding. To optimize experimental throughput and safety, we mounted all six reactors on a single frame. This design centralizes control and monitoring on a single interface while facilitating individual access, assembly, and cleaning for each unit.
03 — Technical specifications
| Number of reactors | 6, independently controlled |
|---|---|
| Operating pressure | up to 150 bar (2175 psi) |
| Operating temperature | up to 150°C (302°F) |
| Wetted material | Hastelloy C276 |
| Typical test duration | up to 6 months |
| Liquid medium | Brines with salinity up to 360 g/L |
04 — Other applications
Does your project have similar requirements?
Fine chemicals / catalysis
For studying long-duration reactions (e.g., hydrogenation, synthesis) with a solid catalyst where purity is critical, the principle of a stirred, inert HPHT reactor with low dead volume remains the same. The material (Inconel, Titanium) and certification (ATEX) would change depending on the reactants.
Energy / CO₂ Capture
For testing material aging or solvent efficiency in prolonged contact with supercritical CO₂, a common challenge in custom CCUS reactor systems, and acid gases (H₂S), the need for multiple parallel HPHT vessels, acid corrosion resistance, and stable long-term conditions are directly transferable requirements.
New materials / biomimicry
For synthesizing materials via hydrothermal routes (e.g., zeolites, ceramics), precursors must be kept in suspension at high pressure and temperature. The need for stirred reactors that can withstand extreme pH levels and provide precise thermal control to manage crystallization presents a very similar challenge.
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