Aligned with Sustainable Development Goals (SDGs) 2 (zero hunger) and 15 (life on land), soil health, especially in arid or semi-arid regions, is critically important. To address this crisis, sustainable solutions focused on biomass valorization are essential. This study focusses on guayule bagasse. The guayule plant (Parthenium argentatum Gray), a native perennial shrub of northern America (Mexico/Chihuahua desert), has an 18-month to 2-year harvest cycle. It produces three major bioproducts: guayule latex/rubber, guayule resin, and guayule bagasse (app. 85% of the plant). The economic value of guayule bagasse is crucial for the successful market transition of guayule latex and resin. Therefore, PFD of a lab scale pyrolyzer was fabricated to produce biochar (carbon rich source) from guayule bagasse. The conversion of guayule bagasse to biochar will not only help to trap carbon for a long period of time (~100years) but also when applied to the soil helps to improve soil health and hence crop production. Due to the novelty of the bagasse, preliminary bagasse pyrolysis studies used factorial design at 443℃ for 45 mins. Heating rate (1-10℃/min) and nitrogen flow rate (40-200 mL/min) were varied. Optimal conditions (5℃/min, 40 mL/min) yielded 35% biochar, 26% bio-oil, 39% syngas, and biochar CEC of 20 cmol/kg. The pH values of biochar were found to be between 7.3 – 10.5. R² values between 0.7- 0.8 indicated acceptable variance. Heating rate was significant (p<0.05), but nitrogen flow rate was not (p>0.05). Further optimization will be done using Box Behnken in Design Expert 13.0, investigating relationships between carbon yield, biochar yield, CEC, and variables: heating rate (5, 7, 10℃/min), holding time (30, 45, 60 mins), and pyrolytic temperature (325, 443, 562 ℃) at constant nitrogen flow rate (40 mL/min). Biochar characterization (O/C, H/C, BET, SEM, FTIR) and soil amelioration for growing lettuce (Lactuca sativa) will follow.
