Limited information is available about potential physicochemical changes that can occur in hydrochar post-production,e.g.during drying and storage.Understanding these changes is crucial not just for shaping future res...Limited information is available about potential physicochemical changes that can occur in hydrochar post-production,e.g.during drying and storage.Understanding these changes is crucial not just for shaping future research plans,but also for future practical applications.Here we studied the effect of moisture(69.2%and 2.4%)and three storage temperatures(−18,4,and 20°C)over a year on selected organic and inorganic compounds in hydrochar produced from the Hydrothermal carbonization(HTC)of digested cow manure.Comparison of the control wet hydrochars(WHs)and dry hydrochars(DHs)showed changes in organic compound composition due to drying.Overall,the total amount of the selected organic compounds was notably greater in WH(15.2 g kg−1 DM)compared to DH(11.8 g kg−1 DM),with variations observed in individual compound concentrations.Drying,however,had no significant influence on the identified inorganic compounds.Storage caused significant changes in both WH and DH,particularly in organic compounds after 12 weeks.Sugars(2-sevenfold),acids(36-371%),and aromatics(58-120%)in stored samples at week 52 were significantly higher than their control values.Changes in the inorganic elements(e.g.,Co,K,Mg,Mn,P,S,Sr,and Zn)occurred faster in WH,with significant differences starting from week 1 compared to their control values,while DH showed fewer changes.Based on these changes in both organic and inorganic content,we recommend the optimal storage conditions for future HTC studies to preserve hydrochar properties.Finally,we discussed potential applications for stored hydrochars,with DH showing greater stability,especially at−18°C,making it suitable for various applications.展开更多
Hydrothermal carbonization(HTC)converts wet biomass into hydrochar and a process liquid,but aromatic compounds in the products have been reported as a roadblock for soil applications as they can inhibit germination,pl...Hydrothermal carbonization(HTC)converts wet biomass into hydrochar and a process liquid,but aromatic compounds in the products have been reported as a roadblock for soil applications as they can inhibit germination,plant growth,and soil microbial activity.Here,we compared HTC and hydrothermal humification(HTH)of cow manure digestate while varying the initial alkaline content by adding KOH.HTH converted 37.5 wt%of the feedstock to artificial humic acids(A-HAs)found in both solid and liquid,twice that of HTC.HTH reduced phenolic and furanic aromatic compounds by over 70%in solids and 90%in liquids.The A-HAs in HTH resemble natural humic acids(N-HA),based on FTIR,UV-vis spectra,and CHN and XRD analysis.The HTH liquid possesses 60%higher total organic carbon(TOC)than HTC.Although one-third of TOC can be precipitated as A-HA,a high TOC concentration remains in the liquid,which is shown to be mainly organic acids.Therefore,we also evaluated the HTC and HTH liquids for anaerobic biomethane production,and found that compared to the original cow manure digestate,the HTH liquids increased methane yield by 110.3 to 158.6%,a significant enhancement relative to the 17.2%increase seen with HTC liquid.The strong reduction in organic acids during biogas production from HTH liquid indicates the potential for converting soluble byproducts into methane,while maintaining high A-HAs levels in the solid product.展开更多
文摘Limited information is available about potential physicochemical changes that can occur in hydrochar post-production,e.g.during drying and storage.Understanding these changes is crucial not just for shaping future research plans,but also for future practical applications.Here we studied the effect of moisture(69.2%and 2.4%)and three storage temperatures(−18,4,and 20°C)over a year on selected organic and inorganic compounds in hydrochar produced from the Hydrothermal carbonization(HTC)of digested cow manure.Comparison of the control wet hydrochars(WHs)and dry hydrochars(DHs)showed changes in organic compound composition due to drying.Overall,the total amount of the selected organic compounds was notably greater in WH(15.2 g kg−1 DM)compared to DH(11.8 g kg−1 DM),with variations observed in individual compound concentrations.Drying,however,had no significant influence on the identified inorganic compounds.Storage caused significant changes in both WH and DH,particularly in organic compounds after 12 weeks.Sugars(2-sevenfold),acids(36-371%),and aromatics(58-120%)in stored samples at week 52 were significantly higher than their control values.Changes in the inorganic elements(e.g.,Co,K,Mg,Mn,P,S,Sr,and Zn)occurred faster in WH,with significant differences starting from week 1 compared to their control values,while DH showed fewer changes.Based on these changes in both organic and inorganic content,we recommend the optimal storage conditions for future HTC studies to preserve hydrochar properties.Finally,we discussed potential applications for stored hydrochars,with DH showing greater stability,especially at−18°C,making it suitable for various applications.
文摘Hydrothermal carbonization(HTC)converts wet biomass into hydrochar and a process liquid,but aromatic compounds in the products have been reported as a roadblock for soil applications as they can inhibit germination,plant growth,and soil microbial activity.Here,we compared HTC and hydrothermal humification(HTH)of cow manure digestate while varying the initial alkaline content by adding KOH.HTH converted 37.5 wt%of the feedstock to artificial humic acids(A-HAs)found in both solid and liquid,twice that of HTC.HTH reduced phenolic and furanic aromatic compounds by over 70%in solids and 90%in liquids.The A-HAs in HTH resemble natural humic acids(N-HA),based on FTIR,UV-vis spectra,and CHN and XRD analysis.The HTH liquid possesses 60%higher total organic carbon(TOC)than HTC.Although one-third of TOC can be precipitated as A-HA,a high TOC concentration remains in the liquid,which is shown to be mainly organic acids.Therefore,we also evaluated the HTC and HTH liquids for anaerobic biomethane production,and found that compared to the original cow manure digestate,the HTH liquids increased methane yield by 110.3 to 158.6%,a significant enhancement relative to the 17.2%increase seen with HTC liquid.The strong reduction in organic acids during biogas production from HTH liquid indicates the potential for converting soluble byproducts into methane,while maintaining high A-HAs levels in the solid product.
