A two-stage enzymatic ethanol-based biodiesel production in a packed bed reactor

Area of Science:

• Biocatalysis and Enzyme Engineering
• Chemical Process Development
• Renewable Energy Technologies

Background:

• Biodiesel production often involves transesterification and esterification steps.
• Enzymatic routes offer advantages in selectivity and milder reaction conditions.
• Packed bed reactors are suitable for continuous enzymatic processes but require optimization for multi-step reactions.

Purpose of the Study:

• To develop and evaluate a two-stage enzymatic process for fatty acid ethyl ester (FAEE) production in a packed bed reactor.
• To optimize reaction conditions for transesterification and esterification stages using immobilized lipases.
• To assess the feasibility of scaling up the process for industrial biodiesel production.

Main Methods:

• A two-stage enzymatic process was simulated in a packed bed reactor using immobilized lipases (NS 88001 and Novozym 435).
• Transesterification (stage 1) and esterification (stage 2) were catalyzed sequentially with intermediate separation of by-products (glycerol and water).
• Process productivity and adherence to European biodiesel specifications were evaluated.

Main Results:

• The first stage achieved a maximum productivity of 2.52 kg FAEE/(kg catalyst·h), comparable to stirred tank reactors.
• The second stage successfully produced biodiesel meeting European specifications.
• The overall two-stage process demonstrated a productivity of 1.56 kg FAEE/(kg catalyst·h).

Conclusions:

• The developed two-stage enzymatic process in a packed bed reactor is effective for producing high-quality FAEE biodiesel.
• The study addressed scale-up challenges and proposed options for continuous operation.
• This enzymatic approach offers a viable alternative for sustainable biodiesel manufacturing.