# Macauba (Acrocomia aculeata) as a Bioenergy Platform: Integrated Biodiesel Production and Lignocellulosic Biomass Valorization

## TL;DR

Macauba palm is studied as a sustainable source for biodiesel and biochar, showing potential for efficient bioenergy production.

## Contribution

The study demonstrates the feasibility of using macauba for integrated biodiesel and biochar production with favorable fuel properties.

## Key findings

- Macauba pulp oil is suitable for biodiesel due to high oleic acid content and good fuel properties.
- Up to 90% macauba biodiesel can be blended with fossil diesel without exceeding regulatory limits.
- Pyrolysis of macauba biomass produces biochar with enhanced carbon content and energy density.

## Abstract

Macauba (Acrocomia aculeata) is
a native palm from tropical regions with high potential for integrated
bioenergy and bioproduct applications. This study evaluated the physicochemical
properties of macauba pulp and kernel oils, assessed the production
and fuel properties of biodiesel derived from commercial pulp oil,
and explored the use of macauba lignocellulosic biomass for biochar
production. Pulp oil exhibited a high oleic acid content, which makes
it highly suitable for biodiesel synthesis since oleic acid forms
esters with good oxidative stability, adequate fluidity, and high
combustion quality, resulting in a biodiesel that readily meets fuel
standards. Biodiesel was obtained through a two-step process, and
its blends with fossil diesel (DS10 and DS500: commercially available
fossil diesel fuels containing up to 10 mg kg–1 and
500 mg kg–1 of sulfur, respectively) were evaluated
in terms of density, kinematic viscosity, and heating value. The results
indicate that up to 60% (v/v) methylmacauba biodiesel (MMB) can be
blended with DS10 and up to 90% with DS500 without exceeding regulatory
limits. Additionally, biodiesel production in a continuous tubular
reactor confirmed its technical feasibility, yielding more than 70%
under optimized conditions. Pyrolysis of macauba biomass at 400–600
°C generated biochar with increased carbon content, energy density,
and structural ordering. Biochars derived from extractive-containing
biomass exhibited distinct elemental and energetic profiles compared
with extractive-free samples. These findings reinforce the suitability
of macauba as a versatile and sustainable feedstock for biorefinery
platforms.