which is mainly from fossil fuels,
causes an adverse impact.
However, assuming that rice straw is collected
and used for biogas production, this range of energy consumption
(317–721 MJt−1) only accounts for 10–17% ofthe total input energy
of rice straw anaerobic digestion, which generated a net energy of
3500 (±160) MJt−1 of straw (Nguyen et al., 2016).