Particulate Size of Microalgal Biomass Affects Hydrolysate Properties and Bioethanol Concentration

Effective optimization of microalgae-to-bioethanol process systems hinges on an in-depth characterization of key process parameters relevant to the overall bioprocess engineering. One of the such important variables is the biomass particle size distribution and the effects on saccharification levels and bioethanol titres. This study examined the effects of three different microalgal biomass particle size ranges, 35 μm ≤x≤ 90 μm, 125 μm ≤x≤ 180 μm, and 295 μm ≤x≤ 425 μm, on the degree of enzymatic hydrolysis and bioethanol production. Two scenarios were investigated: single enzyme hydrolysis (cellulase) and double enzyme hydrolysis (cellulase and cellobiase). The glucose yield from biomass in the smallest particle size range (35 μm ≤x≤ 90 μm) was the highest, 134.73 mg glucose/g algae, while the yield from biomass in the larger particle size range (295 μm ≤x≤ 425 μm) was 75.45 mg glucose/g algae. A similar trend was observed for bioethanol yield, with the highest yield of 0.47 g EtOH/g glucose obtained from biomass in the smallest particle size range. The results have shown that the microalgal biomass particle size has a significant effect on enzymatic hydrolysis and bioethanol yield.

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Study on Soot Mass Fraction and Size Distribution in a Direct Injection Diesel Engine Using Particulate Size Mimic Soot Model

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4040993 ◽

2018 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Fadzli Ibrahim ◽

Wan Mohd Faizal Wan Mahmood ◽

Shahrir Abdullah ◽

Mohd Radzi Abu Mansor

Keyword(s):

Particle Size ◽

Size Distribution ◽

Mass Fraction ◽

Size Range ◽

Particle Size Range ◽

Soot Particles ◽

Soot Mass ◽

Particulate Size ◽

The Relationship ◽

Soot Model

Abstract With today's computing technology, research on soot particles using simulation works has become more preferable as a supplementary to the existing experimental methods. The objective of this study is to investigate the effect of different engine load conditions to in-cylinder soot particles formation. This is to clarify the relationship between soot mass fraction (SMF) and size distribution. The first section of the study is conducted by computational analysis using a detailed kinetics soot model, particulate size mimic (PSM), which is based on the concept of the discrete sectional method. The analysis is carried out within closed-cycle combustion environment which is from the inlet valve closing (IVC) to the exhaust valve opening (EVO). The next section is conducted by experimental work deliberately for validation purpose. The total soot mass obtained from the computational work during EVO is comparable to the calculated value by less than 13% error for all of the experimental cases. The soot size distribution measurement indicates that exhaust out particles are dominantly in the dual-mode size range, <10 nm and 11–30 nm. The relationship between the soot mass and size distribution demonstrates that soot mass fraction does not completely rely on soot size distribution as well as particle size range. In most of the cases, particles with the moderate size range (11–60 nm) hold the highest mass fraction during EVO. On the whole, this paper provides significant information that contributes key knowledge to indicate that soot mass fraction is not entirely dependent on soot size distribution as well as particle size range.

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