Ammonia fibre expansion

Technology
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Technology details
Name:
Category: Pre-processing (Thermochemical processes and technologies)
Feedstock:
Product:

Ammonia fibre expansion (AFEX) is a thermochemical pretreatment that uses volatile ammonia as the main reactant for cellulosic biomass pretreatment. AFEX pretreatment increases the accessibility of polysaccharides to enzymes for hydrolysis into fermentable sugars. These released sugars can be converted into fuels and chemicals in a biorefinery. AFEX offers several advantages over other pretreatments, which include near complete recovery of the pretreatment chemical (ammonia), nutrient addition for microbial growth through the remaining ammonia on pretreated biomass, and not requiring a washing step during the process which facilitates high solid loading hydrolysis.

Feedstock

Origin and composition

Agricultural residues and energy crops

Pre-treatment

Process and technologies

Process

During AFEX pretreatment, liquid ammonia is added to the biomass under moderate pressure (100 to 400 psi) and temperature (70 to 200°C) before rapidly releasing the pressure. Major process parameters are the temperature of the reaction, residence time, ammonia loading, and water loading. The process decrystallises the cellulose, hydrolyses hemicellulose, removes and depolymerises lignin, and increases the size and number of micropores in the cell wall. As a result, the rate of enzymatic hydrolysis increases significantly.[1]

Technologies

Product

After AFEX hydrolysis of lignocellulosic biomass, fermentable sugars are produced. These fermentable sugars can subsequently be converted into fuels (e.g., bioethanol) and chemicals.

Post-treatment

Technology providers

Technology comparison
Company name Country Technology subcategory Technology name TRL Capacity [kg/h] Processable mass [kg] Pressure [bar] Temperature [°C] Ammonia loading [L] Water loading [L] Residence time [h] Feedstock: Food waste Feedstock: Garden & park waste
Michigan Biotechnology Institute (MBI) USA - packed bed AFEX 4-5 1000 - - 100-140 - - 0.25-0.5

Michigan Biotechnology Institute (MBI)

Ammonia fibre expansion provider
General information
Company: Michigan Biotechnology Institute  
Country: USA
Contact:
Webpage: http://www.mbi.org/
Technology and process details
Technology name: packed bed AFEX Technology category: Pre-processing (Thermochemical processes and technologies)
TRL: 4-5 Capacity: 1.000 kg·h-1
Ammonia loading: L Pressure: bar
Residence time: 15-30 min Temperature: 100-140 °C
Other:
Feedstock and product details
Feedstock: Agricultural residues Product:

Open access pilot and demo facility providers

Currently no providers have been identified.

Patents

Currently no patents have been identified.

References

  1. Mosier N., Wyman C., Dale BE., Elander R., Lee YY., Holtzappel M., Ladisch M., 2005: Features of promising technologies for pretreatment of lignocellulosic biomass. Bioresource Technology, Vol. 96, 673-686. doi: https://doi.org/