Global efforts towards decarbonization have led to the rapid evolution of carbon capture and utilization (CCU) technologies. Among these, the chemical synthesis of carbon dioxide into valuable fuels and chemicals offers one of the most promising pathways to achieving Net Zero emissions while building a circular carbon economy.
Transforming carbon dioxide into hydrocarbons not only helps reduce greenhouse gas emissions but also creates an opportunity to replace fossil fuels with synthetic, renewable alternatives. However, CO₂ chemical synthesis is an extremely challenging process, requiring precise flow control, high-pressure operation, and rigorous safety standards.
The SLA5800 Series thermal mass flow controller (MFC) from Brooks Instrument has emerged as a critical technology — providing researchers, engineers, and plant operators with the tools they need to advance CO₂ conversion from lab scale to industrial production.
Why Carbon Dioxide Synthesis is a Growing Field
CO₂ is the most abundant anthropogenic greenhouse gas, with atmospheric concentrations now exceeding 420 ppm. To mitigate its impact, many governments and industries are investing in carbon capture and utilization (CCU) as part of their decarbonization strategies.
One of the most exciting branches of CCU is the chemical transformation of CO₂ into fuels and chemicals. This approach not only removes CO₂ from the atmosphere but also provides a sustainable source of hydrocarbons, reducing reliance on fossil resources.
Common CO₂ Conversion Pathways:
There are several known methods of chemical synthesis of CO and CO2 in useful hydrocarbons:
| Process | Target Products | Key Characteristics |
| Fischer-Tropsch Synthesis | Hydrocarbons | Requires CO as feedstock; CO₂ can be converted to CO via RWGS first |
| Sabatier Reaction | Methane, Water | Highly exothermic requires H₂ and high pressures |
| Reverse Water-Gas Shift (RWGS) | Carbon Monoxide, Water | Converts CO₂ to CO for downstream Fischer-Tropsch or methanol synthesis |
| Electrocatalytic/Photocatalytic Conversion | CO, formate, alcohols, hydrocarbons | Uses electricity or light as energy input |
| Electrochemical CO₂ Reduction | CO, formic acid, ethylene, ethanol | Conducted at ambient temperature and pressure but requires precise gas and liquid flow control |
In recent years, research and development of catalytic reactions to synthesize fuels and alcohols from CO2 has become an active area of public-private-academic collaboration, with investments and grants from governments as well as private and corporate sectors.
The Challenges of High-Pressure CO₂ Chemical Synthesis
Despite its promise, CO₂ chemical synthesis is one of the most technically demanding fields in chemical engineering. The reasons lie in both the physical properties of CO₂ and the operational requirements of the synthesis processes.
1. CO₂ is a Stable, Low-Reactivity Molecule:
CO₂ is a highly stable molecule, with a double bond energy of ~750 kJ/mol. This makes it very difficult to activate without:
- High temperatures (200°C-500°C)
- High pressures (10-300 bar or 1500-4500 psi)
- Catalysts with carefully engineered active sites
- Precise reactant stoichiometry and flow rates
Even small deviations in the CO₂:H₂ ratio or flow stability can dramatically alter:
- Catalyst performance
- Reaction selectivity
- Product yield and quality
2. High-Pressure Gas Handling and Safety:
When high-pressure gases are used as the feed stocks to generate flammable hydrocarbon substances, the environment may be classified as a “hazardous area”. Equipment used in these hazardous areas must have appropriate certifications or high-pressure gas certification.
Hazardous area certification is for equipment where flammable gases, vapors, liquids, or dust may be present. In these environments, ignition sources increase the risk of explosion and fire. Equipment with hazardous area certification is designed and manufactured according to strict standards and is verified by one or more third party approval agencies to be safe for use in hazardous areas. Hazardous area certification is performed in accordance with standards set by the International Electrotechnical Commission (IEC), an international standard, Underwritters Labratories (UL) or other national regulatory agencies.
High-pressure gas certification may be required on equipment that delivers or uses high-pressure gas. By obtaining a high-pressure gas certification, equipment is verified to have the proper design and safety features. This ensures proper handling of high-pressure gases and the safety of personnel and equipment. These hazardous area and high pressure certifications are very important for safety and equipment protection. When working in hazardous or potentially hazardous environments or with high-pressure gas systems, appropriate certifications help to ensure the prevention of accidents and disasters.
3. The Need for Stable, Repeatable Gas Flow:
Successful chemical synthesis requires consistent, reproducible operating conditions. Engineers need flow control devices that deliver:
- High accuracy across the required flow range
- Stable flow under varying inlet and outlet pressures
- Long-term stability to support hours or days of continuous operation
- Low drift to enable scaling up from lab to pilot plant to production
Any instability in flow can result in:
- Variable product yields
- Catalyst deactivation or sintering
- Safety incidents (e.g., overpressure, runaway reactions)
In chemical synthesis research, it is understood that a stable supply of raw materials is essential for experimental reproducibility, reliability, reaction optimization, scale-up and industrial production, safety, and compliance with regulatory requirements.
How Brooks Instrument SLA800 Series Mass Flow Controllers Solve These Challenges
The Brooks Instrument SLA5800 Series MFCs are specifically designed to support high-pressure, high-precision chemical processes, including advanced CO₂ synthesis applications.
Unmatched Pressure Handling Capability
- Standard pressure resistance: 1500 psi
- Maximum pressure resistance: 4500 psi
- Differential pressure capability: up to 4500 psi
This enables safe and stable operation across the entire range of typical CO₂ synthesis processes — from bench-scale catalyst screening to industrial pilot plants.
Wide Flow Range for Versatile Applications
- Flow range: 3 sccm to 2500 slpm: Enables precise control from low flow laboratory testing to high flow industrial reactors
| Challenge | SLA5800 MFC Specifications | SLA5800 MFC Benefits |
| High-pressure operation | .003-200 slpm: 1500 psi/103 bar 100 - 2500 slpm: 1000 psi/70 bar Optional 4500 psi/310 bar on 50 slpm max deviceHydrocarbons |
Handles up to 4500 psi |
| Hazardous area requirements | IECEx, ATEX, UL, PED, KHK | Verified safe for use in environments with flammable gases |
| Need for accurate flow | 3 sccm-2500 slpm | Superior accuracy |
| Reproducibility | 0.20% S.P. | Excellent repeatability and stability |
| Scalability | Three different sizes | Suitable for lab, pilot, and production scales |
High Accuracy and Repeatability
- Excellent flow measurement and control accuracy
- High repeatability for reproducible experiments and process consistency
- Superior long-term sensor stability with low drift — critical for continuous synthesis runs
Certified Safety and Compliance
- Full hazardous area certification: IECEx, ATEX, UL
- High-pressure gas certification: PED, KHK
- Verified safe for use in environments with flammable gases and high-pressure systems
Why Precision Flow Control is Essential for CO₂ Synthesis Success
As CO₂ conversion technologies move from research to commercialization, engineers need flow control solutions that can deliver:
- Safety under hazardous and high-pressure conditions
- Precision to enable optimal reaction performance
- Reliability to support scale-up and continuous operation
Flow Scheme
The Brooks Instrument SLA5800 Series mass flow meter provides exactly that — superior performance and a range of flow and pressure capabilities suitable for applications ranging from relatively large high-pressure CO₂ synthesis pilot plants to small-scale catalyst development and evaluation.
