Show HN: Vanilla JavaScript refinery simulator built to explain job to my kids
by fuelingcurious | 2026-03-11 16:56:51+00:00
Hi HN,
I’m a chemical engineer and I manage logistics at a refinery down in Texas. Whenever I try to explain downstream operations to people outside the industry (including my kids), I usually get blank stares. I wanted to build something that visualizes the concepts and chemistry of a plant without completely dumbing down the science, so I put together this 5-minute browser game.

Here's a simple runthrough: https://www.youtube.com/watch?v=is-moBz6upU. I pushed to get through a full product pathway to show the V-804 replay.

I am not a software developer by trade, so I relied heavily on LLMs (Claude, Copilot, Gemini) to help write the code. What started as a simple concept turned into a 9,000-line single-page app built with vanilla HTML, CSS, and JavaScript. I used Matter.js for the 2D physics minigames.

A few technical takeaways from building this as a non-dev:
* Managing the LLM workflow: Once the script.js file got large, letting the models output full file rewrites was a disaster (truncations, hallucinations, invisible curly-quote replacements that broke the JS). I started forcing them to act like patch files, strictly outputting "Find this exact block" and "Replace with this exact block." This was the only way to maintain improvements without breaking existing logic.

* Mapping physics to CSS: I wanted the minigames to visually sit inside circular CSS containers (border-radius: 50%). Matter.js doesn't natively care about your CSS. Getting the rigid body physics to respect a dynamic, responsive DOM boundary across different screen sizes required running an elliptical boundary equation (dx * dx) / (rx * rx) + (dy * dy) / (ry * ry) > 1 on every single frame. Maybe this was overkill to try to handle the resizing between phones and PCs.

* Mobile browser events: Forcing iOS Safari to ignore its default behaviors (double-tap zoom, swipe-to-scroll) while still allowing the user to tap and drag Matter.js objects required a ridiculous amount of custom event listener management and CSS (touch-action: manipulation; user-select: none;). I also learned that these actions very easily kill the mouse scroll making it very frustrating for PC users. I am hoping I hit a good middle ground.

* State management: Since I didn't use React or any frameworks, I had to rely on a global state object. Because the game jumps between different phases/minigames, I ran into massive memory leaks from old setInterval loops and Matter.js bodies stacking up. I had to build strict teardown functions to wipe the slate clean on every map transition.

The game walks through electrostatic desalting, fractional distillation, hydrotreating, catalytic cracking, and gasoline blending (hitting specific Octane and RVP specs).

It’s completely free, runs client-side, and has zero ads or sign-ups. I'd appreciate any feedback on the mechanics, or let me know if you manage to break the physics engine. Happy to answer any questions about the chemical engineering side of things as well.

For some reason the URL box is not getting recognized, maybe someone can help me feel less dumb there too.
https://fuelingcuriosity.com/game