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Carbon Extraction & Graphitization Systems (CEGS)

Price depends on configuration and options, starting at $103,150.
CEGS Operating Manual

Load a pretreated sample into an inlet port, select your process from a drop-down menu, click Start, and you can walk away. The system notifies you by email or text message when it's ready for another sample.

Once the reactor bank is full of completed samples, the graphite is easily unloaded for packing into accelerator targets. After receiving new dessicant and iron catalyst, a short automatic procedure prepares the reactors for another batch of samples. Total human effort averages less than 5 minutes per sample.

CEGS 12X viewing inlet ports from left
The CEGS 12X features 12 graphite reactors and inlet ports. (Open image in new tab for best resolution. Click on image to open Product Browser with project pricing and additional model-specific information.)
a bank of six CEGS inlet ports

Quick-change inlet port adapters allow the CEGS to easily accept organic, carbonate, and gas samples. Stepped-temperature combustion is built-in. Any fraction can be analyzed or discarded independently of the others.

A column of hot quartz media, loaded directly into the combustion tube, ensures that all carbon is fully oxidized. A 20-micron frit and a 10-micron stainless steel screen prevent particulate intrusion into the vacuum system. The fan-cooled stainless steel trap immediately above the combustion chamber captures room-temperature condensable combustion gas products. These measures work to keep the inlet port and the rest of the vacuum system clean for years of service.

Annotated cross-section view of inlet port configured for combustion
Annotated view of Process Section

The Process Section's task is "quantitative purification." It captures essentially all of the sample's carbon (typically > 99%) while at the same time rejecting or removing everything else.

Each Aeon CEGS offers fully automated process control, with stepped combustion, carbon dioxide collection, purification, measurement and reduction to graphite integrated into a single, seamless process.

The operator simply loads the samples into the configurable inlet ports and enters the sample data into the system computer, selecting the desired process for each sample. Once the "Start" button is clicked, the system automatically executes the selected process for each sample in sequence, and notifies the operator by text or email when the run is complete.

The CEGS 12X is capable of processing twelve organic samples in a 24-hour period. Throughput for digested carbonates and gas samples can be higher, potentially up to 24, depending on sample sizes, process selection, and operator availability.

The sample enters the Process Section as a mixture of gases from an inlet port. The coil trap collects the condensable gases from the mixture, while allowing the incondensable gases to be evacuated away. The collected condensables are then transferred to the variable temperature coldfinger, which sublimes only the carbon dioxide (CO2) into the Measurement Chamber, where it is quantified.

Throughout the CEGS, "Freeze-Thaw" coldfingers (FTCs) use liquid nitrogen to transfer gases from chamber to chamber. The FTCs are managed by a reliable, efficient liquid nitrogen and compressed-air delivery system. FTCs have two stable temperatures: When liquid nitrogen is present, they are frozen at -196 °C, and when it is not, they are thawed at approximately room temperature.

Aeon's variable-temperature coldfinger (VTC) is unique in that its temperature can be controlled and held stable in 1-°C increments over its entire operating range of approximately -190 to 50 °C. Its controller provides excellent precision and stability, which enables the quantitative isolation of specific gases by their distinctive phase change properties.

Aeon's Variable-temperature coldfinger
The Variable-temperature coldfinger accurately maintains any programmed temperature between -190 and 50 °C.
a bank of six graphite reactors with FTCs
This graphite manifold section contains six individual graphite reactors.

The Measurement Chamber forwards the pure, quantified sample CO2, or an aliquot of it, to one of the graphite reactors for reduction. Here the gas is converted to solid carbon, "graphite", using hydrogen and iron powder as a catalyst. Once the CO2 and hydrogen are received, each graphite reactor operates autonomously. This permits the system to carry on processing other samples, while the reduction takes place.

A small amount of iron powder in the tip of the horizontal culture tube is heated by the reactor furnace lowered over it. Magnesium perchlorate chips placed in the bottom of the vertical culture tube absorb the water produced by the reduction reactions. A tiny pressure sensor in the back of the tee monitors reaction progress. The vertical "perchlorate" tube also functions as a coldfinger, to transfer the CO2 into the reactor (FTC not shown. The reactor furnace is raised and the FTC lowered to provide service access, as fresh tubes, iron, perchlorate, and O-rings are needed for each sample.

a bank of six graphite reactors with FTCs
The graphite reactors are based on a similar model first developed at UC Irvine.
CEGS 6X, featuring 6 graphite reactors and 6 inlet ports

Every radiocarbon lab is unique. So, Aeon's CEGS are available in numerous configurations. A smaller lab with modest throughput might prefer the original CEGS 6x1, which features six graphite reactors and one inlet port.

The CEGS 6X, with 6 graphite reactors and 6 inlet ports, provides a mid-range solution that reduces the frequency of operator visits.

CEGS 12X featuring 12 graphite reactors and 12 inlet ports

A large facility needing to process up to 24 organic samples per day might opt for the CEGS 12X, with its 12 graphite reactors and 12 inlet ports.

A researcher that frequently analyzes very old (> 35 ka) or small (< 50 μg C) samples will prefer a low-level (LL) system. The low-level option features all metal-sealed valves in the sample path, vastly reducing the amount of Viton in the system. The minimized gas loads from permeation and outgassing permit quantitative handling of samples as tiny as 5 micrograms of carbon.

Custom CEGS with Tube furnace and flow-through inlets, and dual, toggling coil traps

Some sample types require specialized carbon liberation processes. Examples include DIC water, DOC water, and cosmogenic samples. In such cases, a CEGS can be integrated onto the end of the lab's specialized carbon liberation equipment, to purify, quanitify and graphitize the samples as they arrive.

Aeon's open-source HACS framework enables you to fully automate your existing specialized CO2 production system, and integrate it seamlessly into your CEGS application. Or perhaps your existing system is already automated, using LabVIEW, for example. In cases like this, a very simple text file protocol can hand off the liberated CO2 sample to your CEGS. The two systems can be networked, or often, both systems can run side-by-side on the same host computer.

Key features
  • fully automated (unattended) process control
    • based on Aeon's open-source HACS (Hardware Automation Control System) framework
    • initial system configuration includes built-in process control sequences, appropriate for most common samples
    • sample processes can be created and changed with no programming, using a simple built-in editor
    • automatic logging of all important sample, process, and equipment conditions
    • unique, powerful Data Visualizer utility
      • graph and monitor process progress and conditions live
      • all data is automatically archived for review at any time, even years later
    • all software is open source (GPL 3) and customizable
    • source code and software development environment provided with system
    • specialized, custom software development or assistance is available for purchase (not required)
  • accepts organic, digested carbonate, and sealed gas samples
  • wide sample mass range processed routinely
    • small samples may be graphitized directly, or automatically diluted with 14C-free CO2 to a desired minimum graphite mass
    • the dilution option is configurable, and may be set to trigger automatically based on sample size (or never)
  • low sample cross-talk; blanks and modern samples can be run back-to-back
  • online, stepped-temperature combustion profiles
  • liquid nitrogen traps enable the quantitative capture, isolation and transfer of sample CO2
  • precision, microprocessor-controlled variable temperature coldfinger for cryogenic purification
  • accurate, tuned PID furnace temperature control
  • optimal CO2 sublimation conditions
  • extraction temperature and pressure profiles are recorded for every sample
  • precise CO2 quantity measurement
  • trace sulfur trapping step may be enabled for high-sulfur samples
  • optimal graphitization conditions
    • small graphite reactor volume: ~3 mL
    • precise control of all process gas quantities
        important for ideal reduction H2:CO2 pressure ratio
  • graphitization temperature and pressure profiles recorded for every sample
  • complete graphitization verified by automatic residual pressure check
  • very little inter-sample equipment maintenance required, normally zero
  • minimal manpower requirements: typically less than 5 minutes per sample
  • minimal routine maintenance
Performance specifications
  • graphite reactors: 6 or 12, as configured
  • inlet ports: 1, 2, 6 or 12, as configured
  • sample limitations
    • total mass: 30 μ g to 400 mg
    • carbon content: 30 to 4000 μg C
    • carbon concentration: 0.03% to 100%
    • 14C activity: 0 to 1.3 fM
    • form
      • organic solid or liquid in Aeon combustion tube
      • gas in 6 mm OD x ≤ 150 mm sealed glass ampule
      • gas in septum-sealed vial
  • CO2 collection efficiency: > 97%
  • CO2 transfer efficiency, chamber-chamber: > 97%
  • CO2 quantitification: ± 1 μg C or 1% from ~10 to > 2000 μg C
  • produced graphite: 30 to 1200 μg C
  • graphitization time: 20 to 240 minutes, depending on sample mass
  • graphite yield checked by residual pressure
  • process blank over AMS (aka "system background"): < 0.002 fM (~45,000 years)
  • typical "empty" blank level < 0.5 μg C
  • sample cross-talk: < 1‰ / mg C
  • throughput: ≥ 12 samples / 24 hours
  • ultimate vacuum: < 1e-4 Torr (typ 1e-6 to 2e-5, depends on humidity)
  • system leak-tightness: < 3e-5 Torr L / sec
  • furnace temperature control
    • temperature accuracy: ± 10 °C
    • repeatability: < 1 °C
    • stability (typical drift full cycle): < ± 1.2 °C
  • sample step temperature range (recommended): 70 to 850 °C
      combustion and decomposition temperatures up to ~1200 °C can be used occasionally if needed.
  • variable temperature coldfinger (VTC) for cryogenic purification
    • temperature range: -196 to +50 °C
    • temperature accuracy: ± 2 °C
    • repeatability: < 1 °C
    • stability (typical drift at hold): ± 0.3 °C
  • trace sulfur removal
Every Aeon CEGS purchase includes
  • Delivery, installation, and final adjustments
  • Two days of on-site, hands-on training
  • A starter kit with enough consumable supplies to process about 100 samples
  • One year of (off-site) technical support
The Aeon CEGS requires the following
  • a table or bench with a 122 x 51 cm area of clear surface, capable of supporting 60 kg. The volume above the surface should be empty for a height of about a meter
  • one 120 VAC, 15 A outlet
  • an adjacently-located standard low-pressure Liquid Nitrogen cylinder (pressure-building is not required)
  • compressed air (> 25 psi, ~5 cfm)
  • research-grade, pressure-regulated gas cylinders of H2, O2, and He or Ar
  • a pressure-regulated gas cylinder of 14C-free CO2 (optional, for small-sample dilutions and blank testing)
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