Recovery of Value-Added Products from Hydrothermal Carbonization of Sewage Sludge

Abstract

This paper is about the conversion of wet waste stream into valuable products via thermal processing. Hydrothermal carbonization of sewage sludge was carried out at 200 ∘ C and 2.1 MPa in a closed reactor for 1-6 h. Main products were in solid and liquid phases. The resulting hydrochar was shown to have H/C and O/C ratios moving towards natural lignite, improved energetic content, and adsorption property in terms of iodine number. The aqueous solution was found to contain high concentration of plant food nutrients, especially nitrogen and potassium. They may be desirable for subsequent fuel and chemical production as well as applications in agriculture. The study shows that valuable products can be generated successfully from sewage sludge using hydrothermal carbonization.

Hydrothermal carbonization of food waste for nutrient recovery and reuse

“…During the past twenty years, Hydrothermal carbonization (HTC) has received tremendous interest as a potential waste conversion technique that may promote the recovery of valuable resources (Berge et al, 2011;Funke et al, 2013;Goto et al, 2004;Kim et al, 2014;Li et al, 2013;Liu et al, 2013;Parshetti et al, 2013;Saetea and Tippayawong, 2013). HTC is a thermal process that occurs at relatively low temperatures (180-350 °C) in the presence of self-generated pressures.…”

Hydrothermal Carbonization of Biosolids from Waste Water Treatment Plant

“…In recent times, only a few experiments have been performed on hydrothermal carbonization (HTC) of sewage sludge. For example, in one HTC at 200 • C, 2.1 MPa for 1-6 h, the hydrochar yield was 74-81% and depended on the carbonization time [10]. Another HTC on sewage sludge was carried out at 200 • C, 1.5 MPa and residence time of 4, 7, 10, and 12 h [11].…”

“…Another HTC on sewage sludge was carried out at 200 • C, 1.5 MPa and residence time of 4, 7, 10, and 12 h [11]. The higher heating value of the product was 14.73 MJ/kg for residence time of 10 h [10]. Most of the works on HTC has been carried out for longer residence times.…”

TiO2/Carbon Materials Derived from Hydrothermal Carbonization of Waste Biomass: A Highly Efficient, Low‐Cost Visible‐Light‐Driven Photocatalyst

“…This material is a chemically stable, hydrophobic solid product, which has a calorific value similar to that of lignite coal . The hydrochars are regarded as valuable materials for various industrial, environmental, and agricultural applications . Hydrochar is already used as an adsorbent, fuel, supercapacitor material, and as a soil amendment agent .…”

“…[13] The hydrochars are regarded as valuable materialsf or various industrial, environmental, and agricultural applications. [14,15] Hydrochar is already used as an adsorbent,f uel, supercapacitor material, and as as oil amendment agent. [16,17] Recently,t he use of biomass as as ource of carbon for hydrothermalc arbonization has been explored to obtain al ow-costa nd highly efficient carbonaceous material with the delocalized furanicconjugated system.…”