Abstract
The aim of the paper is to present a relatively new technology – hydrothermal carbonization (HTC) of municipal sewage sludge. The HTC process was conducted in a stainless steel, Zipperclave Stirred Reactor, with a volume of 1000 ml, equipped with a MagneDrive Agitator. The control panel provides a programme which regulates the heater temperature and mixer speed. The main parameters of the process were temperature (~200°C), pressure (~1.5 MPa) and residence time (4, 7, 10, and 12 h). In order to understand the process, the physical, chemical, thermal, and structural characteristics of the solid product, hydrochar, was investigated. Therefore, the ultimate and proximate analyses, and HHV for raw material and obtained hydrochar are presented. The majority of carbon, of the initial present carbon, remained within hydrochar. TA analysis was used to detect the initial and final temperature for the combustion of raw material and hydrochar. This technique is very useful for predicting the combustion characteristics of carbonaceous material. When considering the use of hydrochar as a solid fuel, more energy can be derived from hydrochar than from e.g. incineration of waste, and its carbon emission should be less significant. Therefore, HTC can be an environmentally beneficial technique for the combustion process.
Highlights
In recent years, the rapid population growth, urbanization and industrialization have caused a significant increase in the amount of sewage sludge
Sewage sludge with a moisture content of 85% was stored at 4 C and later used in hydrothermal carbonization (HTC) experiments
The proximate analysis of the sewage sludge and hydrochars were determined according to European Standards
Summary
The rapid population growth, urbanization and industrialization have caused a significant increase in the amount of sewage sludge. The development of new utilization methods of sewage sludge is an urgent problem which needs to be solved [1-3]. The most common disposal of sewage sludge is landfilling, farming applications and incineration. Sewage sludge can be treated as a potential energy resource despite containing a high level of pollutants. European and Polish legislation concerning sewage sludge treatment has become very restrictive in imposing the rapid development of thermal methods of sewage sludge utilisation (Figure 1). There are several thermal technologiesfor utilisingmunicipal sewage sludge to obtain useful forms of energy through the correct pretreatment. One promising option is the hydrothermal carbonizationprocess, which is an effective way to densify the energy content of sewage sludge without the prior drying process
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
