Thermal characterisation of microalgae under slow pyrolysis conditions

Grierson, Scott; Strezov, Vladimir; Ellem, Gary; Mcgregor, Ross; Herbertson, Joe

doi:10.1016/j.jaap.2008.10.003

Cited by 222 publications

(66 citation statements)

References 14 publications

(14 reference statements)

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“…In the slow pyrolysis of Nannochloropsis at 500 and 600 °C, a significant quantity of methane, from 2 to 5% of the total weight of the feedstock, was observed. Compared to the slow pyrolysis at 500 °C of other species of microalgae [35], the amount of methane ranged from 1 to 2% of the total weight of the feedstock. The recovered heating value of combustible gases from the slow pyrolysis of microalgae was comparable to that of other forms of biomass such as grass (10.0 MJ/kg), wood (16.7 MJ/kg), or rice husk (7.4 MJ/kg).…”

Section: Resultsmentioning

confidence: 93%

Pyrolysis Behaviours of Microalgae Nannochloropsis gaditana

Adamczyk

Sajdak

2017

Waste Biomass Valor

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Section: Resultsmentioning

confidence: 93%

Pyrolysis Behaviours of Microalgae Nannochloropsis gaditana

Adamczyk

Sajdak

2017

Waste Biomass Valor

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“…As well, pyrolysis of sewage sludge has been presented to create a best quality of biochar [78] [79] whereas casein [80] gives an extremely porous product (content of porosity = 20%) using a high nitrogen content (9.02% w/w). Even microalgae have been proved to create great yields (>1/3 by mass) [81]. In addition to traditional pyrolysis procedures for biochar generation, alternate methods have been discovered.…”

Section: Physico-chemical Characterisation Of Biocharmentioning

confidence: 99%

Review Paper: The Fundamentals of Biochar as a Soil Amendment Tool and Management in Agriculture Scope: An Overview for Farmers and Gardeners

Shareef¹,

Zhao²

2017

JACEN

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Improving the soil and biomass with coal is estimated at the international level as a way to enhance soil productiveness, fertility and also to mitigate climate change. Biochar employed to improve land scope and impound carbon, is attracting a great deal of attention. Its characteristics of chemical, physical and biological properties, containing big surface area, CEC (Cation Exchange Capacity), high water-holding capacity, size of pore, volume, distribution, and element composition, affect its recognized influences, particularly on microbial communities. These are discovered in the agriculture lands, lands remediation and composting. However, incomplete information existed about biochar for several farmers or peasants in agriculture scope. Therefore, farmers or peasants and gardeners are facing new opportunities and defiance each day, from feeding global extending and expanding population, whilst meeting severe new emissions requirements, to create more food on fewer land area while reducing their environmental emissions. Widespread application and utilization of biochar in agricultural scope, forestry production, energy, environmental protection and additional areas, has interested awareness by scientists and investigators inside and/or outside the country. The objective of this paper is to provide a guide for the farmers or peasants and gardeners with an essential information about biochar and what the ability of biochar can be achieved in the soil, and which can provide the scientific reference for the biochar application, and to get high yield and good quality of crops in all of different soils.

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“…pyrolysis) of six different microalgae at 500°C was found to be approximately 1 MJ/kg [13]. Because only dry microalgal samples were used in their study, the energy required to evaporate moisture must be considered too.…”

Section: Energy Required For Fast Pyrolysis Of Microalgaementioning

confidence: 99%

“…The conditions and product yields for pyrolysis and HTL processes used in this study are summarized in Table 2. Calculation Specific heat of microalgae According to a scientific report that studied the thermo-chemical properties of six species of microalgae, the specific heat (cp) of microalgae was determined as 1.2 -2 kJ/kg· K [13]. Meanwhile, to calculate the specific heat of microalga from its composition, following assumptions were applied: ash is SiO2 with a specific heat of 733 J/kg· K or 0.175 cal/g·°C , the specific heat of polysaccharides is same as that of glucose (0.3 cal/g·°C ), the specific heat of fatty acids is same as that of stearic acid (0.55 cal/g·°C ), and the specific heat of protein is same as that of quinolone (0.352 cal/g·°C ).…”

mentioning

confidence: 99%

A Comparison of Energy Consumption in Hydrothermal Liquefaction and Pyrolysis of Microalgae

Yang¹,

Wu²,

Deng³

et al. 2017

Tr Ren Energy

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The energy requirements for converting one tonne (1,000 kg) of Chlorella slurry of 20 wt% solids via fast pyrolysis, microwave-assisted pyrolysis (MAP), and hydrothermal liquefaction (HTL) were compared. Drying microalgae prior to pyrolysis by using a spray drying process with a 50% energy efficiency required an energy input of 4,107 MJ, which is higher than the energy content (4,000 MJ) of raw microalgae. The energy inputs to conduct fast pyrolysis, MAP, and HTL reactions were 504 MJ (50% efficient), 1,057 MJ (~25% efficient), and 2,776 MJ (50% efficient), respectively. The overall energy requirement of fast pyrolysis is theoretically about 1.6 times more than that of HTL. The energy recovery ratios for fast pyrolysis, MAP, and HTL of microalgae were 78.7%, 57.2%, and 89.8%, respectively. From the energy balance point of view, hydrothermal liquefaction is superior, and it achieved a higher energy recovery with a less energy cost. To improve the pyrolysis process, developing drying devices powered by renewable energies, optimizing the pyrolysis process (specifically microwave-assisted), and improving the energy efficiency of equipment are options. IntroductionThermochemical conversion of microalgae can be divided into pyrolysis of dry algae and hydrothermal liquefaction (HTL) of algal slurries [1]. Usually, the microalgal culture has a very dilute concentration of 0.1-1% dry solids. Currently, the proposed harvesting process is using a series of mechanical unit operations to dewater the microalgae media to a level of ~20% dry solids, which is considered as a less energy intensive processing option than completely drying microalgae for pyrolysis purpose. Drying is one of most dominant costs for algae harvest and may account for 30% of the total product costs, and the power consumption was equivalent to 15.8% of the energy of the recovered hydrocarbon [2]. Because of this energy consumption barrier, pyrolysis is considered as a kind of hopeless technologies for microalgae and only limited to laboratory investigations [3]. Meanwhile, researchers also recognized the advantages of the pyrolysis of microalgae (such as higher quality of pyrolytic bio-oil than that of cellulosic biomass) [4] and the merits of pyrolysis technology (such as lower capital cost than HTL) [5,6].This paper provides a simple comparison between the energy consumptions in pyrolysis of microalgae and hydrothermal liquefaction of microalgae. The purpose is not to provide a complete evaluation to these conversion technologies, but to give an idea how the energy consumption impacted the conversion processes of microalgae, and what would be the possible solutions. Methodology MicroalgaeThe composition analysis and properties of Chlorella sp. are summarized in Table 1. An engineered Chlorella sp. was assumed to be grown autotrophically, and had following components: 25% fatty acids, 50% protein, 15% polysaccharide, and 10% ash. For calculation, one tonne (1,000 kg) of Chlorella slurry at 20°C with 20 wt% solids and 80 wt% water (i.e. 200 kg dry alga...

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Thermal characterisation of microalgae under slow pyrolysis conditions

Cited by 222 publications

References 14 publications

Pyrolysis Behaviours of Microalgae Nannochloropsis gaditana

Pyrolysis Behaviours of Microalgae Nannochloropsis gaditana

Review Paper: The Fundamentals of Biochar as a Soil Amendment Tool and Management in Agriculture Scope: An Overview for Farmers and Gardeners

A Comparison of Energy Consumption in Hydrothermal Liquefaction and Pyrolysis of Microalgae

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