Featuring high caloric value, clean-burning, and renewability, hydrogen is a fuel believed to be able to change energy structure worldwide. Biohydrogen production technologies effectively utilize waste biomass resources and produce high-purity hydrogen. Improvements have been made in the biohydrogen production process in recent years. However, there is a lack of operational data and sustainability analysis from pilot plants to provide a reference for commercial operations. In this report, based on spectrum coupling, thermal effect, and multiphase flow properties of hydrogen production, continuous pilot-scale biohydrogen production systems (dark and photo-fermentation) are established as a research subject. Then, pilot-scale hydrogen production systems are assessed in terms of sustainability. The system being evaluated, consumes 171,530 MJ of energy and emits 9.37 t of CO₂ eq when producing 1 t H₂, and has a payback period of 6.86 years. Our analysis also suggests future pathways towards effective biohydrogen production technology development and real-world implementation.

The source of raw materials for hydrogen production can be expanded by using vine waste as a substrate. Likewise, the effectiveness of vine waste can also be improved. However, plant parts such as stems and leaves often differ in physicochemical properties, which significantly affects the effectiveness of biochemical transformation. In this research, sweet potato was used as substrate in photo-fermentative hydrogen production (PFHP) to evaluate differences in bio-hydrogen production yield potential and energy conversion efficiency for its stem and leaf. Physicochemical properties were determined using the following techniques: elementary analysis, SEM, and X-ray diffraction. The Gompertz model was adopted to analyze the kinetic parameters, and energy conversion efficiency was calculated. The results showed that stem samples with loose structures produced more hydrogen, with a total cellulose and hemicellulose content of 44.6%, but crystallinity was only 29.67%. Cumulative bio-hydrogen yield of stem was 66.03 mL/g TS, which was 3.59 times higher than that of leaf. An increase of 258.93% in energy conversion efficiency was obtained when stem was used for PFHP. In conclusion, stem samples were more suitable for PFHP than leaf samples.

The insecticidal ingredient in a biogas solution being fully utilized by cation exchange resin to produce slow-release insecticide is of great social value. In this work, the feasibility of ammonia nitrogen in a biogas slurry loaded on resin as a slow-release insecticide was evaluated by studying the effect of adsorption and the slow release of ammonia nitrogen by resin. The effects of the ammonia nitrogen concentration, resin dosage, adsorption time and pH value on the ammonia nitrogen adsorption by the resin were studied. The results showed that the ion exchange resin had a good adsorption effect on the ammonia nitrogen. With the increase of the resin dosage, time and ammonia nitrogen concentration, the adsorption capacity increased at first and then stabilized. The ammonia nitrogen adsorption capacity reached its maximum value (1.13 mg) when the pH value was 7. The adsorption process can be fitted well by the Langmuir isothermal adsorption equation and quasi-second-order kinetic model. Additionally, the release rate of the ammonia nitrogen increased with the increasing sodium chloride concentration. The adsorption capacity of ammonia nitrogen by the D113 (resin type) resin decreased by 15.8% compared with the ammonium chloride solution. The report shows that the ion exchange resin has a good adsorption effect on ammonia nitrogen, which is of guiding significance for expanding the raw materials for slow-release insecticides, improving the utilization rate of biogas slurry and cleaner production of slow-release insecticides from biogas slurry. Additionally, all variables showed statistical differences (p < 0.05).