A sustainable biorefinery to convert agricultural residues into value-added chemicals

Table 5 Energy balance of the self-sustaining biorefinery

Energy balance^a	AD	EC process	Fungal fermentation ^b
Energy input (MJ/kg dry feedstock)	−0.16^c	−1.47^d	−3.63^e
Energy output (MJ/kg dry feedstock)	6.95^f	0	0
Net energy (MJ/kg dry feedstock)	6.79	−1.47	−3.63
Overall net energy (MJ/kg dry feedstock)	1.69

All inputs are negative, and all outputs are positive
^a Data were calculated and adjusted based on 1 kg dry animal wastes
^b The fungal fermentation includes unit operations of pretreatment, enzymatic hydrolysis and fungal fermentation
^c The energy input for the AD unit includes both heat and electricity
^d The energy input for the EC unit is 446.65 kJ/L liquid digestate
^e The energy input for pretreatment, enzymatic hydrolysis, fungal fermentation and post-processing is 1.25 MJ/L fermentation broth (unpublished data)
^f The energy output of the AD is the methane energy. Low heating value of methane of 50 kJ/g methane was used for the calculation

ISSN: 2731-3654