Up-cycling of wastes through hydrothermal carbonization

In today’s society, waste generation and management is one of the challenges that could potentially be troublesome in the near future. Waste production is heavily affected by growth in economic activities and population. Rapid urbanization and economic development throughout the world ensure constant increase in waste generation. Given the fact that energy is consumed to generate materials, waste production is also associated with energy waste. In this regard, waste-to-energy concept was first establish to tackle this issue by recovering the potential energy within waste using novel technologies. One of these unique and advantageous techniques is Hydrothermal Carbonization (HTC). HTC is one of the advanced waste treatment technologies that allows transformation of organic wastes to fuel (hydrochar) for energy production. In fact, HTC technology is based on the concept of waste-to-energy which improves the effectiveness of organic wastes by transforming them into a quality fuel for energy production. In this study, application of hydrothermal carbonization in renewable energy communities was discussed. In this context, several different energy communities were established in order to utilize hydrochar as a sustainable fuel for energy generation. Utilization of hydrochar was made possible by developing various conversion system based on gasification and combustion technologies. It was found that, hydrothermal carbonization can be implemented in renewable energy communities as long as the cost of hydrochar production could be managed properly. The cost of hydrochar production could vary between 11.11 €/MWh to 59.82 €/MWh, depending on the capacity of waste treatment. To this end, the cost of energy generation could also vary considerably depending on this cost. Thermal energy generation in district heating network was found to be between 0.022 €/kWh and 0.128 €/kWh. Such variations could be observed in other scenarios where depending on the cost of hydrochar production and energy demand, the levelized cost of electricity and heat could vary significantly.