Pryolytic and kinetic study of Chlorella Vulgaris under isothermal and non-isothermal conditions

Algae are a new potential biomass for energy production but there is limited information on their pyrolysis and kinetics. The main aim of this thesis is to investigate the pyrolytic behaviour and kinetics of Chlorella vulgaris, a green microalga. Under pyrolysis conditions, these microalgae show their comparable capabilities to terrestrial biomass for energy and chemicals production. Also, the evidence from a preliminary pyrolysis by the intermediate pilot-scale reactor supports the applicability of these microalgae in the existing pyrolysis reactor. Thermal decomposition of Chlorella vulgaris occurs in a wide range of temperature (200-550°C) with multi-step reactions. To evaluate the kinetic parameters of their pyrolysis process, two approaches which are isothermal and non-isothermal experiments are applied in this work. New developed Pyrolysis-Mass Spectrometry (Py-MS) technique has the potential for isothermal measurements with a short run time and small sample size requirement. The equipment and procedure are assessed by the kinetic evaluation of thermal decomposition of polyethylene and lignocellulosic derived materials (cellulose, hemicellulose, and lignin). In the case of non-isothermal experiment, Thermogravimetry- Mass Spectrometry (TG-MS) technique is used in this work. Evolved gas analysis provides the information on the evolution of volatiles and these data lead to a multi-component model. Triplet kinetic values (apparent activation energy, pre-exponential factor, and apparent reaction order) from isothermal experiment are 57 (kJ/mol), 5.32 (logA, min-1), 1.21-1.45; 9 (kJ/mol), 1.75 (logA, min-1), 1.45 and 40 (kJ/mol), 3.88 (logA, min-1), 1.45- 1.15 for low, middle and high temperature region, respectively. The kinetic parameters from non-isothermal experiment are varied depending on the different fractions in algal biomass when the range of apparent activation energies are 73-207 (kJ/mol); pre-exponential factor are 5-16 (logA, min-1); and apparent reaction orders are 1.32–2.00. The kinetic procedures reported in this thesis are able to be applied to other kinds of biomass and algae for future works

Pryolytic and kinetic study of Chlorella vulgaris under isothermal and non-isothermal conditions

Algae are a new potential biomass for energy production but there is limited information on their pyrolysis and kinetics. The main aim of this thesis is to investigate the pyrolytic behaviour and kinetics of Chlorella vulgaris, a green microalga. Under pyrolysis conditions, these microalgae show their comparable capabilities to terrestrial biomass for energy and chemicals production. Also, the evidence from a preliminary pyrolysis by the intermediate pilot-scale reactor supports the applicability of these microalgae in the existing pyrolysis reactor. Thermal decomposition of Chlorella vulgaris occurs in a wide range of temperature (200-550°C) with multi-step reactions. To evaluate the kinetic parameters of their pyrolysis process, two approaches which are isothermal and non-isothermal experiments are applied in this work. New developed Pyrolysis-Mass Spectrometry (Py-MS) technique has the potential for isothermal measurements with a short run time and small sample size requirement. The equipment and procedure are assessed by the kinetic evaluation of thermal decomposition of polyethylene and lignocellulosic derived materials (cellulose, hemicellulose, and lignin). In the case of non-isothermal experiment, Thermogravimetry- Mass Spectrometry (TG-MS) technique is used in this work. Evolved gas analysis provides the information on the evolution of volatiles and these data lead to a multi-component model. Triplet kinetic values (apparent activation energy, pre-exponential factor, and apparent reaction order) from isothermal experiment are 57 (kJ/mol), 5.32 (logA, min-1), 1.21-1.45; 9 (kJ/mol), 1.75 (logA, min-1), 1.45 and 40 (kJ/mol), 3.88 (logA, min-1), 1.45- 1.15 for low, middle and high temperature region, respectively. The kinetic parameters from non-isothermal experiment are varied depending on the different fractions in algal biomass when the range of apparent activation energies are 73-207 (kJ/mol); pre-exponential factor are 5-16 (logA, min-1); and apparent reaction orders are 1.32–2.00. The kinetic procedures reported in this thesis are able to be applied to other kinds of biomass and algae for future works.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Evaluation of Oil Palm Biomass Potential for Bio-oil Production via Pyrolysis Processes

The yield and quality of bio-oil obtained from pyrolysis processes depends on many factors, including pyrolysis types, reactor types, operating conditions and biomass property. The objective of this work was therefore to evaluate the potential of oil palm biomass, including oil palm trunk (OPT), oil palm fronds (OPF), oil palm decanter (DC) and oil palm root (OPR) for producing bio-oil via pyrolysis processes. The potential of oil palm biomass was considered in terms of proximate analysis, ultimate analysis, heating value, equivalent heating value, Thermogravimetric analyser (TGA) and lignocellulose content. The results showed that the moisture content of fried samples was in the range of 7.5-10.7% (w.b), which was relatively low and appropriate for pyrolysis. The volatile content of OPT and OPF was higher than 72% (wt.). The carbon, oxygen and hydrogen content of oil palm samples were in the range of 41.5-45.6, 30.7-40.2 and 5.7-5.9% (wt.), respectively. The higher heating value (HHV) of samples was relatively low compared to the HHV of fossil fuels. The OPT and OPF had high cellulose and hemicellulose content, while provided low lignin content compared to the lignin content of DC and OPR. The TGA results showed that thermal decomposition of samples took place within the range of 200–450 °C, which the lignin content affected the thermal decomposition trend. These results revealed that the selected oil palm biomass had relatively high potential for producing bio-oil via pyrolysis processes, particularly the OPT and OPF

Characterisation and Py-GC/MS analysis of Imperata Cylindrica as potential biomass for bio-oil production in Brunei Darussalam

Bio-oil production from renewable sources has been seen as suitable alternative to supply future energy demand. Perennials grasses are currently being developed as a suitable second-generation biofuel feedstock. It has advantages such as rapid growth rate, easy to grow, minimal maintenance and utilise marginal land without competing with food supply. Taking into account of the various challenges attributed to the transformation of second-generation biomass for energy production, this work systematically looks at the ecological perspective and the availability for bioenergy production from Imperata Cylindrica in Brunei Darussalam. Biomass characterisation was carried out to determine the properties and energy content, meanwhile py-GC/MS study was conducted to identify building blocks of value-added chemical from I. cylindrica. The physicochemical properties of feedstock was thoroughly evaluated using thermogravimetric analysis, proximate analysis, elemental analysis, compositional analysis, calorific value, and analytical pyrolysis interfaced with gas chromatograph (Py-GC/MS). Characterisation results indicate that Imperata Cylindrica has a calorific value of 18.39 MJ/kg, with low ash content and high percentage of volatile matter. Py-GC/MS analysis revealed the presence of furfural, 2,3-dihydrobenzofuran, 4-vinylguaiacol, propenylguaiacol, guaiacol and 4-ethylphenol. The fixed-bed pyrolysis experiment of imperata cylindrica showed that the yield of bio-oil increases with the increase of temperature and it reached a peak of 37.16% at 500 °C. These results show that Imperata Cylindrica is suitable as feedstock for bio-oil production via pyrolysis process

Catalytic fast Co-Pyrolysis of sewage sludge−sawdust using mixed metal oxides modified with ZSM-5 catalysts on dual-catalysts for product upgrading

Catalytic fast co-pyrolysis of sewage sludge and sawdust was performed using Py/GC-MS for pyrolytic product upgrades. Metal oxides (NiO and MoO3) and ZSM-5 catalysts had been introduced into single catalytic pyrolysis. The combination of NiO + MoO3 in mixed metal oxides (MMOs) was modified with ZSM-5 under a dual-catalyst with different catalytic layouts. In the pyrolysis process, the metal oxides specifically promoted the formation of phenols, ketones, and furans. ZSM-5 was proven to be more effective in producing aromatic hydrocarbons and phenols and in reducing the oxygenated compounds. The combination of MMOs with ZSM-5 effectively improved product distribution by increasing the production of aromatics and phenols. MMOs promoted the aromatics selectivity of undesirable PAHs (70.5%), however, the addition of ZSM-5 to MMOs appeared to reduce and inhibit the formation of PAHs by 0.85%. The highest yield of aromatics was obtained by the layout of the ZSM-5/MMO dual catalysts layout which was 21.6%. Dual catalysts of MMOs and ZSM-5 in separated layout created promising effects in further increasing the production of aromatic hydrocarbons and phenols compared to the mixture of MMOs modified ZSM-5

Evaluation of Oil Palm Biomass Potential for Bio-oil Production via Pyrolysis Processes

The yield and quality of bio-oil obtained from pyrolysis processes depends on many factors, including pyrolysis types, reactor types, operating conditions and biomass property. The objective of this work was therefore to evaluate the potential of oil palm biomass, including oil palm trunk (OPT), oil palm fronds (OPF), oil palm decanter (DC) and oil palm root (OPR) for producing bio-oil via pyrolysis processes. The potential of oil palm biomass was considered in terms of proximate analysis, ultimate analysis, heating value, equivalent heating value, Thermogravimetric analyser (TGA) and lignocellulose content. The results showed that the moisture content of fried samples was in the range of 7.5-10.7% (w.b), which was relatively low and appropriate for pyrolysis. The volatile content of OPT and OPF was higher than 72% (wt.). The carbon, oxygen and hydrogen content of oil palm samples were in the range of 41.5-45.6, 30.7-40.2 and 5.7-5.9% (wt.), respectively. The higher heating value (HHV) of samples was relatively low compared to the HHV of fossil fuels. The OPT and OPF had high cellulose and hemicellulose content, while provided low lignin content compared to the lignin content of DC and OPR. The TGA results showed that thermal decomposition of samples took place within the range of 200–450 °C, which the lignin content affected the thermal decomposition trend. These results revealed that the selected oil palm biomass had relatively high potential for producing bio-oil via pyrolysis processes, particularly the OPT and OPF