As the global demand for sustainable waste treatment technologies grows, energy, syngas, and biochar production from waste emerges as a promising solution to mitigate climate change. This study explores the potential of carbon credits and environmental sustainability for biochar production through various thermochemical treatment approaches of wood as a representative waste type. Three distinct cases are evaluated: Case 1, involving traditional pyrolysis with syngas post-combustion; Case 2, incorporating partial syngas combustion; and Case 3, utilizing renewable energy-powered hot “inert” (non-oxidizing) gases. The results demonstrate that Case 1, despite producing biochar, falls short in terms of sustainability due to high CO₂ and NOₓ emissions during the syngas combustion phase, which counteract the carbon sequestration benefits of biochar and disqualify it from carbon credit eligibility. In contrast, Case 2 offers a practical intermediate solution by reducing emissions and improving energy efficiency while producing valuable syngas for biofuel and chemical production. Case 3 represents the most sustainable option, utilizing hot inert gases from renewable sources such as solar or wind energy and releasing no CO₂ or NOₓ, thus offering a zero-emission solution. By integrating syngas reforming and renewable energy, both Case 2 and Case 3 significantly enhance the potential for carbon credit generation and align with circular economy principles. However, it is crucial to consider not only the CO₂ emissions directly generated by the core thermochemical and chemical processes in Waste-to-X conversion, reforming, and recycling but also the emissions associated with producing the chemicals and materials required for these operations. Addressing these indirect contributions is vital to accurately evaluate the full carbon credit potential of Waste-to-X solutions and to ensure they deliver meaningful climate benefits. This study underscores the importance of adopting advanced, holistic approaches to achieve authentic carbon-neutral biochar production, thereby contributing to climate change mitigation, enhancing resource efficiency, and offering strong economic incentives for sustainable and clean climate technologies.
Ahmad Saylam (Sat,) studied this question.