RESUMEN
Pyrolysis stands out as a highly promising technology for converting biomass. Upgrading the bio-oil to meet the requirements for fuelling internal combustion engines is indispensable. This study evaluates the economic viability of microwave-assisted pyrolysis (MAP) of pine sawdust, followed by bio-oil esterification for the production of biodiesel. Aspen Plus® was used to simulate a facility that processed 2000 metric tonnes of pine sawdust per day. The minimum fuel selling price (MFSP) of biodiesel was established through the use of a discounted cash flow analysis. A life cycle assessment approach was used to evaluate the environmental impact assessment of biodiesel production. Process modelling findings revealed that the pyrolysis section yielded 65.8 wt% bio-oil, 8.9 wt% biochar, and 25.3 wt% NCGs. The biodiesel product yield was 48 wt% of the raw bio-oil, yielding 631.7 tonnes per day of biodiesel. With the cost of methanol playing a significant role, the overall capital investment was $286.1 MM and the total yearly operating expenses were $164.9 MM. The predicted MFSP for biodiesel is $2.31/L, with yearly operational expenses and biodiesel output being the most important factors. The emission from the biodiesel production process resulted in a global warming potential of 70.97 kg CO2eq. With an anticipated MFSP that is competitive with traditional diesel fuel, the study concludes that the method is economically viable. The results underline how crucial it is to optimize crucial process variables in order to increase the process's economic viability.
RESUMEN
This study aims at optimizing the process conditions to extract maximum yields of bio-oil from pine sawdust using microwave-assisted pyrolysis (MAP). Aspen Plus® V11 was used to model the thermochemical conversion of pine sawdust to pyrolysis products, and response surface methodology (RSM) based on a central composite design (CCD) was employed in the optimization of the process parameters. The mutual effects of pyrolysis temperature and reactor pressure on the product distribution were investigated. The findings have shown that the optimal operating conditions for producing the highest amount of bio-oil (65.8 wt%) were achieved at 550 °C and 1 atm. The product distribution of the simulated model was more significantly influenced by linear and quadratic terms of the reaction temperature. In addition, a high determination coefficient (R2 = 0.9883) was obtained for the developed quadratic model. A set of three published experimental results acquired under circumstances comparable to the simulations' operating limitations were used to further validate the simulation results. The process's economic viability was assessed in order to establish the bio-oil minimum selling price (MSP). A MSP of $1.14/L of liquid bio-oil was evaluated. An economic sensitivity analysis has shown that the annual fuel yield, required rate of return, annual income tax, annual operating costs and initial capital investment have a substantial impact on the MSP of bio-oil. It was inferred that using the optimized process parameters may improve the process' competitiveness on an industrial scale due to its better product yields and improved sustainability in biorefineries, as well as assure waste reduction.
