Hydrothermal liquefaction of wet pectin residues into renewable biocrude

Overview

This technology converts wet pectin-production residues, including spent citrus peels, into renewable biocrude using hydrothermal liquefaction (HTL). HTL operates in pressurized hot water, eliminating the need for energy-intensive drying that typically limits the economic viability of wet biomass conversion. The process transforms a costly disposal stream into a renewable energy product while potentially generating marketable co-products.

The biocrude can be upgraded into renewable fuels or serve as a source of industrial chemicals. Solid carbon and mineral-rich fractions may be evaluated as adsorbents or soil amendments, and the aqueous phase can be assessed for nutrient recovery or biological treatment. A continuous or modular HTL unit could be integrated downstream of existing pectin separation operations, offering a pathway to circular resource utilization within existing production facilities.

Technical specifications

The process begins with simple screening and slurry homogenization of wet residues, followed by treatment in pressurized hot water. Key process variables include temperature, residence time, solids loading, and catalyst selection. Process conditions are adjusted based on feedstock variability in moisture, ash, carbohydrate, acid, and mineral content, enabling robust operation across different feedstocks, seasons, and production campaigns.

Key features:

• Direct conversion of high-moisture biomass without drying or extensive purification
• Feedstock flexibility through adaptive condition optimization
• Multiple product streams: biocrude, solid carbon, mineral-rich fractions, and aqueous phase
• Potential for downstream integration with existing separation operations
• Modular or continuous reactor configurations

Technology readiness level

The technology is currently at bench scale, with laboratory reactors (50 mL and 1 L) available for process screening and validation. An 18-month staged program is proposed to advance the technology: feedstock characterization across seasonal samples, parameter screening, validation at larger bench scale with mass and energy balance closure, and assessment of biocrude upgrading and co-product applications. The final stage defines feedstock specifications and an implementation roadmap for continuous pilot demonstration. Commercial and pilot-scale HTL systems provide a credible pathway toward TRL 5–9 deployment.