Biomass thermal pre-treatment for co gasification: CO2 torrefaction

• Main Author: Mohammad Hafizuddin, Mohd Yusoff
• Format: Undergraduates Project Papers
• Language: English
• Published: 2015
• Subjects: Q Science (General); TP Chemical technology
• Online Access: http://umpir.ump.edu.my/id/eprint/12813/1/04.Biomass%20thermal%20pre-treatment%20for%20co-gasification%20CO2%20torrefaction.pdf; http://umpir.ump.edu.my/id/eprint/12813/
• Institution: Universiti Malaysia Pahang

Biomass has been a very reliable alternative for renewable fuel to reduce the use of conventional fuel due to environmental concern and sustainability issue. In order to reduce the emission of the harmful greenhouse gases and to promote sustainable environment, the renewable energy is the perfect solution to achieve the targets. But there are some problems that needs to be overcome before the biomass can be utilised as biochar or biofuel through gasification by using the torrefaction method. Torrefaction of biomass is a pre-treatment process that aims to improve the fuel properties by lowering the moisture content and increasing the energy density at temperature between 200°C to 300°C in either inert or non-inert environment. The objective of this work is to study the effect of CO2 concentration present during torrefaction at temperature 240°C and 280°C. In addition, the impact of torrefaction time was also evaluated at 15 and 30 minutes. In this study, the sample used is empty fruit bunches (EFB) from palm oil mills in Felda Lepar. The torrefaction reactor consists of a vertical stainless-steel tubular reactor equipped with an electrically heated furnace. The experimental apparatus is setup consist of gas tanks, N2 and CO2 that are controlled by regulators and furnace. The gas will be mixed at 0%, 10%, 15%, and 21% value of CO2 while the rest is N2. It was determined that the mass yield is decreased with increased in the CO2 concentration. This suggests the occurrence of oxidative reaction, for example the Boudouard reaction and an enhancement of volatile matter release. The heating value of the torrefied biomass shows an increasing trend, with temperature increased. This is consistent with the findings in the literature, which primarily indicates improved fuel properties. The comparable mass loss at lower temperatures improved fuel properties, makes utilization of carbon dioxide as a torrefaction medium for pre-treating biomass as an attractive technology.