NOVACAR – Novel low-ash carbon from sludge: Exploration of its properties and performance in technical and environmental applications

Industrial and municipal residual streams such as sludge from pulp and paper mills, anaerobic digestion and sewage treatment are due to their complexity and potentially harmful composition virtually untapped resources.

Current management strategies are insufficient, but one promising strategy is hydrothermal carbonization (HTC), which is ideal for sludges as it requires no feedstock drying. HTC generates a solid (hydro)char, a small amount of gas, and an organic-rich filtrate.

Recently, we discovered that a fourth product spontaneously forms in the filtrate, a self-generated carbon (SGC) with significantly lower ash content than the hydrochar, even when derived from sludge materials.

It also has very promising surface and morphological properties of relevance for environmental and technical applications.The NOVACAR project aims to further explore SGCs and what governs their formation, how it can be enhanced and maximized, and investigate their properties and performance in selected applications (i.e. water treatment and energy storage).

We will evaluate the need for activation and/or functionalization to enhance SGC properties and performance.

Moreover, we will assess the possibilities, challenges, and potential bottlenecks of production of SGCs from industrial and municipal residual streams.

SGC is a new product that forms from the HTC filtrate without energy input, and we believe that it will open a new valorisation route for industrial and municipal sludge materials.