Project Overview
Car Filter is a Northern Arizona University Electrical Engineering capstone project focused on evaluating the feasibility of breaking CO₂ into carbon and oxygen using high-voltage electric fields, controlled plasma, elevated temperatures, and other advanced excitation methods.
The project thus far is structured in two major phases:
- Phase I: Characterize the performance and limitations of a Van de Graaff generator (VDG) using a high-voltage liquid divider.
- Phase II: Build a modular, heated, pressure-controlled reaction chamber to study thermally assisted and electrically driven CO₂ dissociation under our controlled lab conditions.
Motivation & Scientific Context
Carbon dioxide is among the most stable small molecules, requiring large energy inputs to break its molecular bonds:
CO₂ → CO + ½O₂ (~290 kJ/mol)
CO₂ → CO + O (~580 kJ/mol)
These bond energies correspond to effective temperatures of roughly 3000–3500 K, meaning that thermal assistance dramatically reduces the electrical energy needed for dissociation.
The Car Filter project investigates whether combining:
- Strong electric fields
- Short-duration plasma discharges
- High-temperature gas conditions
- Controlled pressure environments
Goal: achieve any measurable, repeatable degree of CO₂ breakdown.
System Architecture Overview
The project integrates multiple subsystems to support both Phase I and Phase II experimentation:
- High-Voltage Power
Van de Graaff generator, liquid high-voltage divider, and potential future pulsed-power stages. - CO₂ Handling
Gas regulation and controlled input, transitioning to a sealed, heatable reaction chamber. - Diagnostics
Voltage and current sensing, temperature and pressure monitoring, and future optical diagnostics (e.g., spectroscopy).
Practical Constraints & Realistic Expectations
While high-voltage CO₂ dissociation is theoretically possible, several major challenges exist:
- VDGs have extremely low current throughput, limiting practical energy delivery.
- Open-air CO₂ requires enormous field strengths to meaningfully dissociate.
- Dissociation products readily recombine without controlled thermal and pressure conditions.
- Total energy requirements may exceed any realistic implementation for emissions reduction.
The purpose of this project is to quantify these limitations, investigate controlled-environment improvements, and establish a validated experimental platform for future NAU engineering teams.
