Optimisation of sugar and solid biofuel co-production from almond tree prunings by acid pretreatment and enzymatic hydrolysis.

Almond pruning biomass is an important agricultural residue that has been scarcely studied for the co-production of sugars and solid biofuels. In this work, the production of monosaccharides from almond prunings was optimised by a two-step process scheme: pretreatment with dilute sulphuric acid (0.025 M, at 185.9-214.1 â„ƒ for 0.8-9.2 min) followed by enzyme saccharification of the pretreated cellulose. The application of a response surface methodology enabled the mathematical modelling of the process, establishing pretreatment conditions to maximise both the amount of sugar in the acid prehydrolysate (23.4 kg/100 kg raw material, at 195.7 â„ƒ for 3.5 min) and the enzymatic digestibility of the pretreated cellulose (45.4%, at 210.0 â„ƒ for 8.0 min). The highest overall sugar yield (36.8 kg/100 kg raw material, equivalent to 64.3% of all sugars in the feedstock) was obtained with a pretreatment carried out at 197.0 â„ƒ for 4.0 min. Under these conditions, moreover, the final solids showed better properties for thermochemical utilisation (22.0 MJ/kg heating value, 0.87% ash content, and 72.1 mg/g moisture adsorption capacity) compared to those of the original prunings.

Nutrients enriched biochar production through Co-Pyrolysis of poultry litter with banana peduncle and phosphogypsum waste.

Poultry litter (PL) utilisation has been widely studied for production of phosphorus (P) rich biochars. Recent research documented co-pyrolysis of PL with nutrient rich chemical additives like rock phosphate, phosphoric acid and magnesium (Mg) salts for production of P-Mg enriched biochar with improved P use efficiency. However, research is highly scarce on utilisation of waste materials for production of PL biochar enriched in P, potassium (K) and sulphur (S). In this context, present work investigated co-pyrolysis (700°C, 10°C/min, 1h residence time) of PL with banana peduncle (BP) and phosphogypsum (PG) in different w/w ratios (1:1:1, 1:2:1, 1:3:1) of BP-PL-PG for production of K-P-S enriched biochars composites. These biochars mainly showed variations in their K-P-S contents. The K (5.1%) and S (11.35%) enrichment was relatively higher in BP-PL-PG (1:1:1) biochar than PL biochar (K-3.70% and S-0.96%). However, P content was higher in PL biochar (4.48%) and was reduced in biochar composites. The P contents were 3.84, 2.84, and 2.44% in BP-PL-PG (1:3:1), BP-PL-PG (1:2:1) and BP-PL-PG (1:1:1) composites respectively. In biochars, P was present predominantly as Ca-Mg bound form. Furthermore, best fit of second order kinetic model indicated slow-release behaviour of P from biochars and composites. These results highlight the scope of co-pyrolysis of PL with selected wastes for production of multi-nutrients enriched biochars with improved nutrient availability for soil application.