Modification and extension of anaerobic digestion model No.1 (ADM1) for syngas biomethanation simulation: From lab-scale to pilot-scale.

1 – Microbial synthesis reaction zone; 2 – Gas-liquid mixing zone; 3 – Aeration buffer zone; 4 – Gas-solid–liquid separation zone; 5 – Liquid circulating tube; 6 – Import of organic mixture; 7 – Gas inlet; 8 – Sludge discharge zone; 9 – Aerator; 10 – Uniform water distribution device; 11 – Gas-phase stabilization zone; 12 – Gas circulating pipe; 13 – Gas outlet. • ADM1 was modified and extended for syngas biomethanation simulation. • ADM1_modified was established based on lab-scale reactors and R2 all > 0.86. • Pilot-scale reactor data was used for model validation. • Gene sequencing and model simulation obtained similar methanogenic pathway results. The Anaerobic Digestion Model No.1 (ADM1) was extended for simulation of syngas biomethanation from lab-scale to pilot-scale, with the development of the gas–liquid mass transfer, the inhibition equations, and the biochemical reaction of CO and H 2. In the lab-scale reactor, after increasing the syngas flow rate and syngas loading, the syngas conversion efficiency into methane increased from less than 68% to over 95%. The ADM1_modified was developed based on lab-scale data, and the simulation values fitted the experimental results well with R2 values higher than 0.86. The data from the pilot-scale reactor was then used for model validation, and methane production (MP) predictions matched well with the measured data (R2 > 0.83). Methanogenic pathways were further explored and compared by using high-throughput 16S rRNA gene sequencing and the ADM1_modified simulation, and the results from the two methods were highly similar. The established ADM1_modified could be used to describe or predict the syngas biomethanation process macroscopically and microscopically. [ABSTRACT FROM AUTHOR]