What type of small Fuller’s earth diesel purification unit is suitable for removing submicron carbon contamination from marine diesel fuel and restoring its original color?

For a small Fuller’s earth–based polishing unit the CMM-6RL six‑column adsorption diesel polishing machine is the right fit: it’s built for diesel fuel polishing and color restoration using an adsorption column array with Fuller’s earth, runs automatically and its adsorbent can be reactivated multiple times (typically 300–500 cycles). If you need a marine version for low‑viscosity fuels there’s a dedicated CMM‑6RL low‑viscosity marine polishing variant; for larger throughput the same family includes ten‑column units (e.g., CMM‑10RL) that also use Fuller’s earth.

For best results plan mechanical filtration ahead of adsorption and remove free water first — typically with a coarse filter unit (e.g., CMM‑4.0F) and a dehydration stage (e.g., CMM‑1.0CF) — so the adsorbent life and polishing performance are maximized. Note adsorption polishing is excellent for restoring color and removing many dissolved and colloidal contaminants, but if you’re specifically targeting submicron carbon particulates or very heavy contamination you should size pre‑treatment and polishing stages accordingly; I can put together a short checklist (throughput, power, and pre‑treatment needs) if you tell me your flow rate and fuel condition.