Hydrothermal Carbonisation of Palm Oil Mill Effluent

Hydrothermal carbonisation (HTC) is a thermochemical process that converts organic wastes into a coal-like material named ‘biochar’ or’ hydrochar’. The process involves application of high temperature and pressure to solid biomass in a suspension with water for several hours.
Palm oil refining industry is one of the largest industries in Malaysia. Consequently, the volume of Palm Oil Mill effluent (POME) generated would be massive. This polluting oily waste water always causes environmental issues and requires certain cost for its treatment before discharge. The objective of the project is to verify the potential of HTC process to upgrade or treat POME, to study the effect of temperature, formaldehyde concentration, pH value and feed solid:water ratio towards hydrothermal carbonisation of POME and also the significance of each factor to the quality of hydrochar generation and lastly to select the optimum operating condition. Based on literature review, most researches are commonly done with the solid biomass. However, there are no wide studies on HTC process on waste in sludgy liquid form for example palm oil mill effluent.
In this project, the scope will be focusing on producing hydrochar from POME. The quality of hydrochar will be analysed using Heating Value Analysis, Ash Content Analysis, and Carbon content. Taguchi method is implemented in this project to simplify and reduce the duration required for the project. This method adds the context of quality engineering into the common HTC studies.
The result of the experiment shows that HTC process has high potential to upgrade POME to higher value product. Increasing temperature and humidity reduces yield and ash content but increases heating value and carbon content. Increasing formaldehyde concentration gives positive results to all the parameters. The effect of temperature and formaldehyde concentration is more dominant in HTC process. The suggested operating conditions for HTC process are 270oC, 2.5 wt% Formaldehyde concentrations and 88.05% humidity which is the originally obtained POME.