Hardware

Overview

The device encapsulates the solution our team tries to alleviate. The diagram illustrates a solution that captures atmospheric CO₂ using modified cyanobacteria grown in BG-11 medium within transparent, sterilizable glass culture bottles (Fig. 1). All components within the device are sterilized before use. The growth medium is added to each bottle without displacing the headspace for gaseous exchange, and the lids are then closed. The bottles will be positioned above a light source, similar to the one depicted in the diagram; however, the design of the light source can vary depending on the consumer's needs. The team has chosen to place the white light beneath them so that the upward direction illumination will travel through the liquid. The white light, as described, will prompt ppsbA1 and subsequent photosynthesis. To provide CO₂, a gas cooling and filtration unit will be used to cool and remove contaminants from the incoming CO₂, which will be piped through sterile tubing into inlets secured at the top of the bottle, dispersing air into small bubbles throughout the culture. The CO₂ that needs to undergo the cooling and detoxification process exceeds the temperature range (110–170 °C) and contains contaminants, according to the U.S. Environmental Protection Agency, which, before any carbon-capture unit, exceeds the zone of tolerance for cyanobacteria to survive and reproduce. The cyanobacterial CCM is expected to pull in HCO₃^- , and RuBisCO will fixate CO₂, which will enter back into the atmosphere as oxygen released into the atmosphere (Power Plants and Neighboring Communities | US EPA, 2025).

The device should be maintained in a medium temperature range (25-30° C). Visual inspections will be allowed, as the vessels are clear and permit observation of coloration, turbidity, and the rate of bubbling. Subsequent adjustments can be made, in addition to CO₂ and light, to prevent growth from foaming. The main components include four clear glass bottles with screw lids, BG-11 growth medium with modified cyanobacteria, a white light source from below, sterile tubing, and a gas cooling/filtration unit. The effectiveness stems from its confined space, illuminated from below, and transparent photobioreactor, which provides carbon dioxide fixation, maintaining constant active metabolism and carbon capture as biomass.

Carbon dioxide will enter the containers with the liquid cyanobacteria from the filter system. As CO₂ enters the modified cyanobacteria liquid culture, it is absorbed by the cyanobacteria and fixed through CCM, facilitating enhanced carbon capture. As a result, oxygen will be released from the containers and into the pipes, and the CO₂ sensor will detect a lower concentration of carbon dioxide.

Figure 1: The Device – CO₂llectors

Intended Customers

The device is designed for use by power producers seeking a practical and low-risk entry point to the biological fixation of CO₂. Due to the advice given by Mr. Cheng in a specialist meeting, the focus of our intended customers has shifted from low-incentive SMEs to large factories with existing bioscrubbers, as we are unable to compete with current practices. Our device is mounted directly onto the carbon dioxide output source of a factory, cools and filters the contaminated CO₂ before bubbling the pure component back into high-density cyanobacterial cultures illuminated from below for enhanced uptake, and results in continuous conversion from CO₂ to not only quantifiable biomass but also the dissolved inorganic carbon that can be vented safely into the headspace. With modular bottles and manifolds, operators are empowered to perform multiple parallel lines, enhancing light penetration through the manual adjustment of each light source below the devices. This enables a power producer to ramp up while maintaining control. As such, there are two primary uses for plant operators: (1) a compliance pathway and credits via quantifiable mass balance data (inlet CO₂, off-gas, biomass creation) and (2) the ability to turn a fraction of emissions into profitable streams of biomass without impacting existing generating assets.

Setup instructions

1. Adding the cyanobacteria culture
   1. Carefully pour the BG-11 medium with cyanobacteria into a sterilized glass container.
   2. Do not fill the container completely; leave headspace for gas exchange.
   3. Close the lid tightly to maintain sterility.
2. Setting up the light source
   1. Raise the containers by putting them on a higher surface.
   2. Place the light source on a flat surface below the containers, allowing it to project light upwards.
3. Setting up the CO₂ sensor
   1. Attach the sensor to the CO₂ filter system to measure the initial CO₂ concentration
   2. Stick another CO₂ sensor at the end of the pipeline to measure the final CO₂ concentration
4. Conditions
   1. Place the device in a moderate temperature environment (25-30° C). Avoid high heat, as it can kill or stress the culture
   2. Keep the system away from heavy metals or toxic chemicals that affect the pH of cyanobacteria.
   3. Maintain a stable pH in the containers by removing carbon dioxide contaminants. Sudden pH shifts can disrupt cyanobacteria’s survival.
   4. Connect the CO₂ delivery system
   5. The device should have a pipe connection point at the top of the container
   6. Take the other end of the pipe from the CO₂ filter system (which ensures that the CO₂ entering is clean and free of contaminants)
   7. Insert it into the designated inlet at the top of the device so that filtered CO₂ can be gently bubbled into the medium. This supplies inorganic carbon for photosynthesis

Components and parts

1. Transparent glass container and lid
   1. Transparent material for visibility and light penetration
   2. Store the BG-11 medium with modified cyanobacteria
2. Modified liquid cyanobacteria
   1. Contains modified cyanobacteria in BG-11 liquid medium to fix CO₂ photosynthetically
   2. Cyanobacteria will absorb the carbon dioxide and use it for photosynthesis (RuBisCO), producing oxygen as a byproduct
   3. The liquid medium ensures active growth of the cyanobacteria
3. White light source
   1. White light induces the ppsbA1 promoter, facilitating HCO₃^- uptake and carbon fixation efficiency of cyanobacteria
   2. The light sources will be placed beneath the glass containers, which are elevated on shelves, projecting light upward
4. Pipe
   1. To inject the carbon dioxide from the carbon dioxide filter into the liquid
5. CO₂ sensor
   1. The sensor will be dedicated to measuring the initial and final carbon dioxide concentration for industrial companies to align with the ECG

General safety

• Sterility maintenance: Always sterilize the glass container, lid, and pipe before inoculating cyanobacteria into the liquid BG-11 medium to prevent contamination by foreign microorganisms that could outcompete or interfere with cyanobacterial growth and survival.
• Assurance on bacterial and medium containment: Keep the lid tightly sealed and check all pipe connections to ensure there is no leakage of genetically modified cyanobacteria into the surrounding environment. Any spills should be immediately disinfected with 70% ethanol to prevent environmental contamination (Graziano et al., 2013).
• Management of light source beneath the cyanobacteria: Provide continuous white light at controlled intensities (30–100 µmol photons m⁻² s⁻¹) to support photosynthesis and activate the ppsbA1 promoter without overheating (Tamoi & Shigeoka, 2021). Ensure light fixtures are insulated and positioned to prevent electrical hazards in contact with the liquid medium.

Waste disposal and reuse of the device

All waste generated from the cyanobacterial carbon-capture device must be treated as biosafety level 1 (BSL-1) biological waste, in accordance with Taiwan’s Regulations on the Management of Pathogenic Microorganisms and Waste Disposal Act administered by the Environmental Protection Administration (Taiwan Environmental Protection Administration [EPA], 2023). To ensure the thorough inactivation of viable cells, the liquid culture medium containing genetically modified Synechococcus elongatus must be autoclaved at 121°C for 15 to 20 minutes before disposal (WHO, 2020). The autoclaved culture can be cooled and neutralized after sterilization and then released into the appropriate waste system. According to Taiwan’s Standards for Waste Treatment, solid materials that have come into contact with the modified bacteria (in the case, cyanobacteria), such as tubing, filters, containers, and disposable gloves, should be immersed in 10% sodium hypochlorite (bleaching) for at least half an hour before being disposed of in sealed biohazard bags (Regulations of New and Existing Chemical Substances Registration, 2021). These processes reduce the likelihood of inadvertent release or gene transfer into the environment.

Additionally, the device, constructed from sterilizable glass and reusable materials, can be safely reused after exhaustive decontamination. All glass parts and pipelines should be cleaned with 70% ethanol and then autoclaved after use to eliminate residual biological matter and maintain sterility for future use (Graziano et al., 2013). In accordance with Taiwan EPA's General Industrial Waste Disposal Guidelines, any broken or non-sterilizable parts (such as deteriorated seals or tubing) must be disposed of by authorized hazardous waste contractors (Management Regulations for the Import and Export of Industrial Waste, 2025). This waste management procedure guarantees environmental compliance and biological safety by combining chemical disinfection, autoclaving, and sterilization, minimizing the potential risk of contamination in the device.

References