Materials Handling & Solids Characterization

Achieving the best process economics

Optimizing and Scaling

The wide range of biomass—whether it is a single feedstock or mixed feedstock—introduces complexities in treating and handling the starting material and resultant products in a process scenario. What works at bench scale may not produce the same results at demonstration and pilot scales.

At ABPDU, our ultimate goal is to optimize processes to avoid problems during scale-up. During downstream polymerization processes, we focus on the specific structures and properties for potential end-user applications. This approach not only helps with quality control, but also allows us to develop the most economical processes.

Understanding Biomass Flow Properties: Changes in Viscosity versus Rheology

The reduced presence of water exponentially increases viscosity of biomass, which poses a number of mass transfer challenges, especially reducing efficacy of enzymes. You can see the drastic change in rheology due to reduced water availability on Avicel®, a form of microcrystalline cellulose.

High Solids Loading

A key feature of biomass is that it is a solid, unlike crude oil. Solids handling is one of the key risk drivers for scale up. Higher solids loading could lead to higher productivity in downstream fermentation processes. At high solids, however, biomass is typically fibrous and hygroscopic and requires special mixing and handling techniques at large-scale.

Performing chemistry on solids is more challenging from a cost and feasibility perspective. At ABPDU, we believe it is critical to obtain a fundamental understanding of the biomass flow properties under various unit operations to evaluate the requirements of mixing and handling techniques for high solid loadings.

Robust Process Design

Rheology of biomass can significantly influence the progress of chemical and biological conversion of biomass to monomeric sugars.

At ABPDU, we utilize extensive rheology to design processes that scale well. The information we obtain helps us balance process economics and quality.

    • Is a fed batch process better than a batch process?
    • How small a particle size is optimum?
    • Can you reduce capital expenditure by using a smaller reactor?
    • What type of pump can we use and what would be its specification?

Our Equipment

Materials Characterization & Solids Handling Options

Measuring Viscosity
Increasing the concentration of the biomass solids during biochemical conversion has a large potential in reducing production costs. These concentrated biomass slurries have highly viscous, non-Newtonian behavior that poses several technical challenges to the conversion process.
Understanding Solids to Liquids Behavior
The reduced presence of water exponentially increases viscosity of biomass, which poses a number of mass transfer challenges, especially affecting the capability of the catalyst. In a high solids slurry, the lack of water requires cellulase enzymes to perform effectively inspite of low water. As biomass is hydrolyzed, absorbed water is released into the newly forming aqueous phase and a drop in viscosity follows. Understanding changes in rheology of high solid slurries can provide several useful insights to improve production of sugars.
Optimizing Enzyme Activity at High Solids Loading
Enzymatic hydrolysis at high solids loadings is key to the scale-up of biochemical conversion processes, because of potentially higher sugar and ethanol titers and low hydraulic loads. However, high solids loading can result in lower conversion of glucan and xylan into fermentable sugars. We use extensive rheology and data analysis to design a highly productive saccharification process.

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