Project Entry
Project Description
Our capstone project was a low-cost distillation monitoring system designed to improve safety in small-scale distillation. The goal was to detect the transition between alcohol phases in real time so users would not have to rely on subjective methods such as smell, taste, or discarding a fixed volume. By combining sensing, flow monitoring, and temperature control, we developed a proof-of-concept system that made the distillation process more measurable, repeatable, and safety-focused.
Why This Project Matters
During distillation, methanol is naturally produced as a byproduct of fermentation, particularly in fruit-based alcohols. While small amounts are unavoidable, methanol is highly toxic to humans. When ingested, it is metabolized into harmful compounds such as formic acid, which can cause symptoms including headaches, dizziness, and nausea. In more severe cases, methanol exposure can lead to blindness, organ failure, and even death. What makes it especially dangerous is that symptoms are often delayed, meaning individuals may not realize the severity of exposure until significant damage has occurred.
In small-scale distillation, separating methanol from usable alcohol is often done using subjective methods such as smell, taste, or fixed volume estimates. This can lead to inconsistent results and serious safety risks. This project addresses that gap by introducing a more reliable and accessible approach, using sensors to monitor the process in real time. By making the distillation process more measurable and less dependent on user judgment, the system aims to reduce the risk of methanol poisoning and improve overall safety.
Click to view full code for sensors on GitHub →
Identifying the Problem
We began by focusing on a safety problem in small-scale distillation where methanol is a toxic byproduct, yet many users still depend on informal judgment methods to separate it from usable output. Our objective was to create a safer and more accessible alternative that could monitor the process in real time. From the beginning, the project had to balance three competing priorities that were affordability, usability, and reliable sensing. This meant that any solution had to be practical enough for small-scale use while still providing meaningful performance.
Exploring and Selecting a Sensing Strategy
We explored several possible approaches for methanol detection, including more direct analytical methods, but many were too expensive, complex, or impractical for a low-cost prototype. Our final direction used capacitive and conductive sensing with flow measurement to infer alcohol phase changes indirectly. This was an important design decision as instead of pursuing the most precise laboratory method, we selected an approach that better aligned with the project’s cost and accessibility goals. That trade-off shaped the rest of the design and made the project more realistic as a scalable solution.
Iterating the Prototype
The most important part of the project was iteration. Early versions of the sensing chamber introduced air bubbles, unstable readings, and inconsistent liquid contact with the sensors. To address this, we repeatedly redesigned the P-trap geometry to improve flow behavior and sensor submersion. We also refined the broader system by improving sealing, reducing vacuum-related issues, and integrating flow monitoring to support more stable temperature regulation. My contributions focused on software, testing support, and project deliverables, which meant helping translate test results into clearer system improvements and documenting design decisions throughout the process.
Testing, Results, and Limitations
The final prototype demonstrated that alcohol phase transitions could be tracked in real time using combined sensor outputs and controlled operating conditions. The system achieved temperature accuracy within ±1°C and maintained operation close to the desired setpoint. Testing also showed that the sensing approach could detect meaningful changes corresponding to alcohol transition behavior. Because legal constraints prevented validation with actual methanol-ethanol distillation, we used isopropyl alcohol as a substitute during testing. This limited full real-world validation, but the project still demonstrated that the concept was feasible and worth further refinement.