Sumeng Jia

Bio: Sumeng Jia is an academic researcher from China Agricultural University. The author has contributed to research in topics: Digestate & Anaerobic digestion. The author has co-authored 3 publications.

Comparison of batch and fed-batch solid-state anaerobic digestion of on-farm organic residues: Reactor performance and economic evaluation

Abstract: Batch and fed-batch solid-state anaerobic digestion (SS-AD) of on-farm organic residues including cattle manure, cornstalk, and tomato residues (1:1:1.5, wet basis) were compared under mesophilic condition (35 ± 1 °C). Comparing to batch SS-AD, inoculum was needed in fed-batch was reduced by 60%, but increased cumulative methane yield by 45%. However, the overall daily methane yields in fed-batch SS-AD were 35% lower than that of batch SS-AD. The overall volatile solids (VS) reduction were obtained in fed-batch SS-AD was 12% higher than that in batch SS-AD. Furthermore, the effect of particle size of cornstalk on methane yield of fed-batch SS-AD was investigated. The highest cumulative methane yield of 283.3 L/kg VS feed was achieved in fed-batch SS-AD with cornstalk particle size of 40 mm. However, difference in cumulative methane yields caused by cornstalk particle size of 60 mm, 40 mm, and 10 mm in fed-batch SS-AD was not significant. Economic analysis was conducted to evaluate the economic performance of commercial-scale SS-AD (1,000 m3) under batch, fed-batch, and combine fed-batch and batch system with the annual capacities of 6,400 metric tons (MT), 2,400 MT, and 4,800 MT, respectively. Batch SS-AD system has the highest net present value (NPV, 6.35 million US$) and internal rate of return (IRR, 24.7%) concerning economic analysis. However, batch SS-AD only achieved a slightly higher NPV and IRR compared to the combination of fed-batch and batch SS-AD system. Thus, it is more economical to start reactor with fed-batch SS-AD and later change to batch SS-AD under analysis conditions.

Biochar for agronomy, animal farming, anaerobic digestion, composting, water treatment, soil remediation, construction, energy storage, and carbon sequestration: a review

Abstract: In the context of climate change and the circular economy, biochar has recently found many applications in various sectors as a versatile and recycled material. Here, we review application of biochar-based for carbon sink, covering agronomy, animal farming, anaerobic digestion, composting, environmental remediation, construction, and energy storage. The ultimate storage reservoirs for biochar are soils, civil infrastructure, and landfills. Biochar-based fertilisers, which combine traditional fertilisers with biochar as a nutrient carrier, are promising in agronomy. The use of biochar as a feed additive for animals shows benefits in terms of animal growth, gut microbiota, reduced enteric methane production, egg yield, and endo-toxicant mitigation. Biochar enhances anaerobic digestion operations, primarily for biogas generation and upgrading, performance and sustainability, and the mitigation of inhibitory impurities. In composts, biochar controls the release of greenhouse gases and enhances microbial activity. Co-composted biochar improves soil properties and enhances crop productivity. Pristine and engineered biochar can also be employed for water and soil remediation to remove pollutants. In construction, biochar can be added to cement or asphalt, thus conferring structural and functional advantages. Incorporating biochar in biocomposites improves insulation, electromagnetic radiation protection and moisture control. Finally, synthesising biochar-based materials for energy storage applications requires additional functionalisation.

Waste biomass valorization for the production of biofuels and value-added products: A comprehensive review of thermochemical, biological and integrated processes

Abstract: Waste biomass can be converted to green fuels and value-added products via thermochemical and biological conversion processes. The thermochemical processes endure limitations such as high processing costs due to high-temperature requirements. In contrast, the challenges of biological processes include low product yield and long processing time. Integrating different technologies, especially thermochemical and biological conversion processes, helps to enhance resource utilization and promote a circular economy. The combination of different technologies would help alleviate their limitations. In this respect, the integration of biological processes (e.g., syngas fermentation and anaerobic digestion) and thermochemical processes (e.g., pyrolysis, gasification, hydrothermal carbonization etc.) was the focus of this review. Integrated conversion processes often reduce the environmental impact compared to a standalone process. Hybrid pyrolysis-anaerobic digestion processes are promising from economics and ecological perspectives. However, more studies are required to understand how to effectively recycle and utilize the residue from pyrolysis and other thermochemical processes. Hydrothermal liquefaction (HTL) and pyrolysis are promising bio-oil production. However, HTL-derived oils are characterized by higher heating values and lower oxygen contents. The maturity level of most biological processes for waste biomass valorization is in the range of technology readiness level (TRL) 4–5. In contrast, thermochemical processes are expected to reach a TRL of 9 in the next two decades through detailed research and development. Moreover, the TRL of integrated processes described in the present study should also be assessed to evaluate their maturity and commercialization potential. The study will help researchers and policymakers to identify the knowledge gaps in integrating thermochemical and biological conversion processes. The present review is the first of its endeavor to present the advances, progress, and prospects of combining thermochemical and biological conversion processes for biofuels and value-added chemicals production. Most of the studies available in the literature focus on the advances in thermochemical or biological processes as a standalone conversion pathway despite many possible integration scenarios available. Therein lies the motivation for the present study. The current review is helpful for new researchers and policymakers to acquire the fundamental knowledge and possible pathways to unlock full biomass conversion pathways. Therefore, the authors made a significant effort to explain each conversion pathway in the first few sections before outlining their advantages and limitation. The final section was entirely on the different possible integration scenarios followed by process integration challenges. This study aims to open up the possibility of future research and help researchers identify the knowledge gaps in integrating thermochemical and biological conversion processes.