The world faces a dual challenge: increasing energy demand and mounting waste. A recent study published in Circular Economy and Sustainability by Lisandra Rocha-Meneses, Anjana Hari, Muhammad Shahbaz, Abrar Inayat, and Mario Luna-delRisco offers a promising solution through the simulation and optimization of bio-oil, biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, and syngasSyngas, or synthesis gas, is a fuel gas mixture consisting primarily of hydrogen and carbon monoxide. It is produced during gasification and can be used as a fuel source or as a feedstock for producing other chemicals and fuels.   More production from date seeds and tire plastic waste via pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More and co-pyrolysis. This innovative approach not only addresses waste management but also provides alternative biofuel feedstocks for various sectors.

The study utilized Aspen Plus V12 to model the pyrolysis and co-pyrolysis processes, followed by analysis using RSM Design Expert 12 to understand how temperature, pressure, and blending ratios influence product yields. A significant finding was that bio-oil yields are primarily influenced by the tire plastic-to-date seeds blending ratio, regardless of reaction temperature and pressure. The lowest bio-oil yields, ranging from 67 to 72 kg/h, were observed when only date seeds underwent pyrolysis. Conversely, the highest bio-oil yields, between 254 and 286 kg/h, were achieved when only tire plastic was pyrolyzed. This highlights the potential of tire plastic in maximizing liquid fuel production.

However, the picture changes for biochar. When only tire plastic was pyrolyzed, biochar yields were the lowest, at 246 to 264 kg/h. The highest biochar yields, ranging from 264 to 592 kg/h, were obtained from the pyrolysis of date seeds alone, irrespective of reaction temperature and pressure. This suggests a trade-off between bio-oil and biochar production depending on the feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More.

Syngas, a valuable gaseous fuel, also showed interesting trends. The highest syngas yields,428 to 486 kg/h, resulted from the pyrolysis of tire plastic alone at varying temperatures and pressures. The lowest syngas y ield, 284 kg/h, occurred when the tire plastic-to-date seeds blending ratio was 50%. These findings underscore the versatility of co-pyrolysis in generating different valuable products.

The research also delved into the optimal conditions for each product. For bio-oil, a statistically significant positive correlation was found with the tire plastic-to-date seeds blending ratio. Increasing reaction temperatures generally led to higher bio-oil production. For instance, at a reaction pressure of 1 bar, bio-oil yield increased from 72 kg/h (0% blending ratio at 300∘C) to 201 kg/h (100% blending ratio at 500∘C). The highest bio-oil production, 286 kg/h, was achieved at 300∘C, 5 bar pressure, and a 100% blending ratio (tire plastic only).

For biochar, a strong negative correlation was observed with the blending ratio. This means that as the proportion of tire plastic increased, biochar yields decreased. The highest biochar yield of 592 kg/h was obtained at a reaction temperature of 500∘C, 5 bar pressure, and a 0% blending ratio (date seeds only). This outcome aligns with previous research indicating that lower plastic waste ratios positively influence biochar yields.

Regarding syngas, the study showed that while changes in pressure and temperature had a less significant impact, different blending ratios significantly altered yields. The highest syngas yield of 486 kg/h was obtained at 500∘C, 1 bar pressure, and a 100% blending ratio (tire plastic only). This is consistent with other studies that found higher plastic blending ratios lead to greater syngas yields.

The study highlights the potential of co-pyrolysis of date seeds and tire plastic waste as a sustainable strategy for both waste management and alternative fuel production. While pure tire plastic yielded the highest bio-oil and syngas, and pure date seeds produced the most biochar, moderate yields of all products were observed with 50:50 blends. Future work aims to explore higher blending ratios, other feedstock types, and the use of catalysts to further optimize product profiles and yields, ultimately working towards more competitive and environmentally beneficial biofuel production.

Source: Rocha-Meneses, L., Hari, A., Shahbaz, M., Inayat, A., & Luna-delRisco, M. (2025). Simulation and Optimisation of Bio-oil, Biochar, and Syngas Obtained from Pyrolysis and Co-pyrolysis of Date Seeds and Tire Plastic Waste. Circular Economy and Sustainability.