Ammonia fibre expansion

Technology
Technology details
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Ammonia fiber 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

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.

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.

Technology providers

Technology comparison

Company name	Country	Technology category	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
Company 1	[Country HQ location]	[Technology category (if different sub-categories are defined this has to be specified here, the available categories can be found on each technology page under the chapter Process and technologies)]	[Technology name (the "branded name" or the usual naming from company side)]	[4-9]	[numeric value]							●	●
Company 2	[Country HQ location]	[(if different sub-categories are defined this has to be specified here, the available categories can be found on each technology page under the chapter Process and technologies)]	[Technology name (the "branded name" or the usual naming from company side)]	[4-9]	[numeric value]							●	●

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: