Poultry litter is a useful product as a fertilizer, energy feedstock for thermochemical conversion, and a precursor for synthesis of adsorbents and catalysts. Detailed characterization of baseline properties is necessary for enhanced environmental and economic utilization of this valuable resource. Baseline physicochemical characterization was carried out at two broiler production facilities (Arkansas, PL1, and North Carolina, PL2). Greater concentrations of inorganic nitrogen, phosphorus, and potassium were obtained for PL1, suggesting greater nutrient value compared to PL2. PL2 had greater carbon content and water-holding capacity than PL1. X-ray photoelectron spectroscopy (XPS) of PL1 and PL2 indicated a similarity between litters in terms of the presence of carbon, nitrogen, and oxygen bonds. Both poultry litters had oxygen, nitrogen, sulfur, and phosphorous functional groups, as confirmed by infrared spectroscopy. Time of flight – secondary ion mass spectroscopy of negative ions also indicated similarity of the surface charge distribution between PL1 and PL2. Overall, poultry litters evaluated had similar surface chemistries, with nutrient composition varying based on rearing conditions, which has implications for downstream use in thermochemical conversion and other value-added products.

Rice straw was fractionated with nitric acid in order to avoid the cooking liquor recovery in pulp production from agricultural residue (rice straw). The rice straw treated with 11.03% nitric acid at 90 ℃ for 3hr yields 53.09% pulp. The nitric acid treated rice straw pulp had high amount of lignin and minerals. However, further treatment of nitric acid pulp with low potassium hydroxide reduced the lignin and ash sufficiently as well as the pulp yield. Pulp yield reduced from 53.09 to 34.27%. The papermaking properties of the nitric acid followed by KOH treated pulp showed better quality than the nitric acid pulp. Nitric acid liquor was used several times. Pulp yield decreased in every step of reusing of the nitric acid spent liquor although residual lignin content increased. The final effluent liquor was rich with potassium, nitrogen and biomass that can be used as soil nutrient for cultivation.

Pulping of rice straw was studied using mild nitric acid in mild conditions. Spent nitric acid was chosen as soil nutrient rather than followed by the liquor recovery. The rice straw was treated with 11.03% nitric acid at 90 °C for 3 h, yielded 53.09% pulp. Nitric acid treated rice straw pulp had high residual lignin and minerals. However, further treatment with 7% potassium hydroxide reduced the residual lignin and produced pulp with kappa number 20.36. The papermaking properties of the nitric acid followed by KOH treated pulp showed better quality than the nitric acid pulp. The spent nitric acid liquor was reused repeatedly, pulp yield decreased and residual lignin content increased in each step of spent nitric acid reusing. The spent nitric acid liquor and potassium hydroxide liquor-mixed together to get a neutral effluent liquor which was rich with potassium, nitrogen and biomass. The nutritional capacity of the effluent liquor was assessed by incubation with control soil. The labile form of organic carbon, nitrogen, potassium phosphorous and iron increased in the incubated soil.