Inside biodiesel distillation: how we reduce sulfur, lower monoglycerides, and improve cold flow

Introduction - the chemistry behind clean, stable biodiesel

Transesterified biodiesel can carry monoglycerides, moisture, color bodies, and trace sulfur each impacting performance and compliance. Distillation provides a robust thermal separation that refines FAME quality. When needed, adsorption polishing further reduces sulfur to <10 ppm, enhancing stability and compliance margins.

Distillation mechanism - what we remove and why it matters

Cutting monoglycerides to improve cold flow

Monoglycerides precipitate at lower temperatures and can impair CFPP. Distillation separates FAME from higher-melting components, achieving monoglycerides ≤0.2 wt% and winter-grade performance.

Moisture and volatile control

Biodiesel drying plus thermal separation keeps moisture <100 ppm, reducing hydrolysis risk and improving storage stability.

Color improvement and stability

Thermal fractionation also removes color-forming components, improving appearance from yellow to near colorless.

Sulfur reduction pathways

Distillation for acid-esterified and pyrolysis biofuel

These feeds can introduce sulfur species. Distillation reduces sulfur content, with typical <15 ppm results for distilled biodiesel.

Adsorption polishing for ULSD biodiesel

Adding adsorption downstream of distillation achieves guaranteed <10 ppm sulfur with:

• Common, affordable adsorbent

• No impact on distilled biodiesel properties

• Better color in the final biodiesel

• Typical processing cost: USD 28-33/ton treated distilled biodiesel

  
  

Performance snapshot

• Monoglycerides: ≤ 0.2 wt%

• FFA: ≤ 0.25 wt%

• Moisture: <100 ppm

• CSFT: ≤ 300 s

• Sulfur: <15 ppm (distillation)

• Sulfur: <10 ppm guaranteed (with adsorption)

  
  

Process integration that de-risks operations

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

• Methanol Recovery from biodiesel and glycerin (highest recovery rate and purity)

• Glycerin Drying and Glycerin-Fatty Matter Separation

• Methanol-Water-Biodiesel Separation for acid esterification routes

• Fatty Acids Removal and Biodiesel/FAME Fractionation

• No rotating separation equipment → fewer moving parts, lower maintenance

• Post-distillation candle evaporator to maximize FAME yield

  
  

Delivery options and execution

• Full ISBL, skid supply, or customizable scope

• Testing facilities available to validate feedstock, sulfur targets, and CFPP goals

• Guaranteed performance with a long reference list and reference plant in operation

FAQ

Q1: how does distillation improve CFPP?

A: by separating out heavier or higher-melting components (e.g., monoglycerides) that cause crystallization at low temperatures.

Q2: What’s the difference between distillation alone and distillation plus adsorption?A: distillation typically achieves <15 ppm sulfur; with adsorption polishing, sulfur is guaranteed <10 ppm.

Q3: does the adsorption media affect FAME properties?

A: no. The add-on does not impact the distilled biodiesel, and it improves color.

Q4: what about methanol handling?

A: we provide highest methanol recovery rate and highest purity recovered methanol from biodiesel and glycerin streams.

Q5: what equipment philosophy reduces maintenance?

A: Static separation no rotating separation equipment is required.

Q6: can you tailor the scope?

A: Yes - ISBL, skid, or custom scope, backed by testing and guaranteed performance.

Have a challenging feed or sulfur target? Let’s engineer a distillation + adsorption train that meets your specs. Speak to an engineer