From acid-esterified biodiesel to pyrolysis biofuel: distillation that meets ultra-low sulfur targets

Introduction - one train for many feeds

Biodiesel producers increasingly work with acid-esterified biodiesel and pyrolysis biofuels - both can carry sulfur and cold-flow issues that complicate compliance. Sulzer’s distillation addresses cold-flow and purity; when paired with adsorption, it reliably delivers <10 ppm sulfur.

What makes these feeds challenging?

Acid-Esterified biodiesel

Residual contaminants and sulfur species can carry through post-reaction, requiring robust finishing to meet ultra-low sulfur requirements.

Pyrolysis biofuel

Complex, variable compositions and color bodies demand strong separation and polishing for consistent, compliant biodiesel.

Distillation + adsorption: the compliance pathway

• Distillation: produces winter-grade biodiesel, very low monoglycerides, and better color; typically <15 ppm sulfur

• Adsorption Add-On: guaranteed <10 ppm sulfur, no impact on distilled biodiesel, better color, common and affordable adsorbent, USD 28-33/ton treated

Full process envelope (for real-world feedstocks)

• Methanol-Water-Biodiesel Separation (acid esterification routes)

• Fatty Acids Removal for acid-esterified biodiesel

• Biodiesel-Glycerin Separation, Biodiesel Washing, Biodiesel-Water Separation

• Biodiesel Drying and Glycerin Drying

• Glycerin-Fatty Matter Separation

• Methanol Recovery (highest recovery and purity)

• Glycerin Refining to USP and Glycerin to Propylene Glycol options

Typical distilled biodiesel specs

• Monoglycerides: ≤ 0.2 wt%

• FFA: ≤ 0.25 wt%

• Moisture: <100 ppm

• CSFT: ≤ 300 s

• Sulfur: <15 ppm (distillation) or <10 ppm (with adsorption)

FAQ - feedstock & compliance

Q1: can you handle high-sulfur bio-intermediates?

A: Yes. Distillation reduces sulfur and adsorption polishing guarantees <10 ppm.

Q2: what if our winter spec is demanding?

A: distillation removes fractions that precipitate in the cold, producing winter-grade biodiesel.

Q3: will adsorption change my FAME’s properties?

A: no - it does not impact the distilled biodiesel.

Q4: do you provide testing before we commit?

A: Yes - testing facilities are available to validate your feed and target specifications.

Q5: how do we procure and operate the system?

A: choose ISBL, skid, or custom scope; static separation means no rotating separation equipment is required.

Q6: are references available?

A: Yes - reference plant in operation and a long reference list.

Need <10 ppm sulfur on a complex feed? We’ll configure the right distillation + adsorption polishing train for your case. Start a technical review →