Size Reduction of Cellulosic Biomass in Biofuel Manufacturing: Separating the Confounding Effects of Particle Size and Biomass Crystallinity

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Meng Zhang ◽  
Xiaoxu Song ◽  
Pengfei Zhang ◽  
Z. J. Pei ◽  
T. W. Deines ◽  
...  
Keyword(s):  
Particle Size ◽  
Metal Cutting ◽  
Milling Process ◽  
Sugar Yield ◽  
Size Reduction ◽  
Cellulosic Biomass ◽  
Future Research ◽  
Transportation Fuels ◽  
Cellulosic Biofuel ◽  
Reduction Methods

Increasing demands and concerns for reliable supply of liquid transportation fuels make it important to find alternative sources to petroleum-based fuels. Cellulosic biofuels provide one such alternative in the short to medium term. Size reduction is the first step for converting biomass into biofuels. In the literature, there are inconsistent reports about the effects of particle size and biomass crystallinity on sugar yield (proportional to biofuel yield). An important reason for this inconsistence is that particle formation in current size reduction methods is not well controlled, causing the effects of these two variables confounded. One paper investigating the confounding effects of particle size and biomass crystallinity using a metal-cutting (milling) process was previously published in this journal. This paper presents a follow-up study. In this study, a lathe was used to produce poplar wood particles with the same crystallinity but different sizes, making it possible to study the effects of particle size on biofuel yield independently without being confounded by the effects of biomass crystallinity. Results showed that, for the three levels of particle size used in this study, sugar yield increased as particle size became smaller. This study also revealed future research opportunities to understand the effects of size reduction and biomass crystallinity in cellulosic biofuel manufacturing.

Size Reduction of Cellulosic Biomass in Biofuel Manufacturing: A Study on Confounding Effects of Particle Size and Biomass Crystallinity

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Meng Zhang ◽  
Xiaoxu Song ◽  
Pengfei Zhang ◽  
Z. J. Pei ◽  
T. W. Deines ◽  
...  
Keyword(s):  
Metal Cutting ◽  
Structural Parameters ◽  
Particle Formation ◽  
Milling Process ◽  
Size Reduction ◽  
Cellulosic Biomass ◽  
Future Research ◽  
Multiple Parameters ◽  
Cellulosic Biofuel ◽  
Reduction Methods

Biofuels derived from cellulosic biomass offer an alternative to petroleum-based liquid transportation fuels. In order to convert cellulosic biomass into biofuels, size reduction is a necessary step along with pretreatment, enzymatic hydrolysis, and fermentation. In the literature, there are inconsistent reports about why size reduction affects sugar yield (proportional to biofuel yield). An important reason for the inconsistence is that particle formation in current size reduction methods is not well controlled, causing effects of some biomass structural parameters confounded. In this study, a metal-cutting (milling) process is used for size reduction of poplar wood, where particle formation can be well controlled to prevent the effects of multiple parameters from being confounded. The results of this study provide explanations for some inconsistent reports in the literature. These results also reveal some opportunities for future research to understand the effects of size reduction on cellulosic biofuel manufacturing.

Size Reduction of Cellulosic Biomass in Biofuel Manufacturing: Effects of Biomass Crystallinity and Particle Size

2011 ◽  
Author(s):  
Meng Zhang ◽  
Xiaoxu Song ◽  
P. F. Zhang ◽  
Z. J. Pei ◽  
T. Deines
Keyword(s):  
Particle Size ◽  
Particle Formation ◽  
Size Reduction ◽  
Cellulosic Biomass ◽  
Future Research ◽  
Cellulosic Biofuels ◽  
Transportation Fuels ◽  
Cellulosic Biofuel ◽  
Reduction Methods ◽  
Petroleum Reserves

Gradual depletion of world petroleum reserves and increasing environmental impact of greenhouse gas emissions make it urgent to develop sustainable alternatives to petroleum-based transportation fuels. Cellulosic biofuels provide one such alternative in the short to medium term. In order to convert cellulosic biomass into biofuels, size reduction is a necessary step. In the literature, there are inconsistent reports about the effects of particle size and biomass crystallinity on sugar yield (proportional to biofuel yield). An important reason for this inconsistence is that particle formation in current size reduction methods is not well controlled, causing the effects of these two variables confounded. This paper presents an experimental study on size reduction of poplar wood using a lathe, where particle formation could be well controlled to prevent the effects of these two variables from being confounded. In this study, particle size was controlled by different numbers of slots cut on the workpiece. Particles with the same crystallinity but different particle sizes were produced. This will make it possible to study the effects of particle size on biofuel yield independently, and reveal future research opportunities to understand the effects of size reduction in cellulosic biofuel manufacturing.

Effects of Water Soaking on Biomass Particle Size in Cellulosic Biofuel Manufacturing

2012 ◽  
Author(s):  
Hera Wu ◽  
Pengfei Zhang ◽  
Qi Zhang ◽  
Z. J. Pei
Keyword(s):  
Particle Size ◽  
Sugar Yield ◽  
Cellulosic Biomass ◽  
Particle Sizes ◽  
Cellulosic Biofuels ◽  
Transportation Fuels ◽  
Cellulosic Biofuel ◽  
Before And After ◽  
Invasive Method ◽  
Biomass Particle Size

Cellulosic biofuels are an alternative to petroleum-based liquid transportation fuels. However, manufacturing costs of cellulosic biofuels are high partially due to low density and sugar yield of cellulosic biomass. Previous studies show that UV-A pelleting can increase the density and sugar yield of cellulosic biomass. A hypothesis for UV-A pelleting to increase the density and sugar yield of cellulosic biomass is that UV-A pelleting can reduce biomass particle size. To test this hypothesis, biomass particle sizes before and after UV-A pelleting need to be compared. Soaking pellets in water is an efficient and non-invasive method to separate pellets into particles. However, water soaking itself might change biomass particle size. This paper reports an investigation on effects of water soaking on biomass particle size. The biomass particle sizes before and after water soaking are measured and compared. Results show that effects of water soaking on biomass particle size are dependent on the initial particle size (particle size before water soaking) and time period of water soaking.

Size Reduction of Cellulosic Biomass in Biofuel Manufacturing: Effects of Milling Orientation on Sugar Yield

2011 ◽  
Author(s):  
Meng Zhang ◽  
Xiaoxu Song ◽  
P. F. Zhang ◽  
Q. Zhang ◽  
Z. J. Pei ◽  
...  
Keyword(s):  
Experimental Study ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Metal Cutting ◽  
Sugar Yield ◽  
Size Reduction ◽  
Cellulosic Biomass ◽  
Poplar Wood ◽  
Cellulosic Biofuels ◽  
First Time

Cellulosic biofuels can reduce greenhouse gas emissions and the nation’s dependence on foreign oil. In order to convert cellulosic biomass into biofuels, size reduction of biomass is a necessary step. Most related studies in the literature claimed that smaller particles produced higher sugar yields. However, some researchers reported that this claim was not always true. The literature does not have satisfactory explanations for the inconsistence. This paper presents an experimental study on size reduction of poplar wood using a metal cutting process (milling). The results provided one explanation for this inconsistence. It was found for the first time that milling orientation had a strong effect on poplar wood sugar yield. Although smaller poplar particles had a higher sugar yield when they were milled from the same orientation, this trend did not exist for particles milled from different orientations.

Size Reduction of Poplar Wood Using a Lathe for Biofuel Manufacturing: A Preliminary Experiment

2011 ◽  
Author(s):  
Xiaoxu Song ◽  
Meng Zhang ◽  
Z. J. Pei ◽  
T. Deines ◽  
Q. Zhang ◽  
...  
Keyword(s):  
Chip Thickness ◽  
Crystallinity Index ◽  
Particle Formation ◽  
Sugar Yield ◽  
Size Reduction ◽  
Formation Mechanisms ◽  
Poplar Wood ◽  
Transportation Fuels ◽  
Cross Section Area ◽  
Reduction Methods

Poplar wood can be used as feedstocks for manufacturing of cellulosic biofuels (e.g., ethanol) as liquid transportation fuels. Producing ethanol from poplar wood involves reducing poplar wood into small particles, hydrolyzing cellulose inside poplar particles to fermentable sugars, and converting these sugars to ethanol. Size reduction is usually done by wood chipping and biomass milling. In the literature on poplar biofuels, there are no reports on particle formation mechanisms or effects of size reduction on sugar yield. One important reason for the lack of such knowledge is that particle formation in current size reduction methods is not well controlled. This paper presents the first attempt to use a lathe to generate poplar particles (or chips) with well controlled mechanisms of chip formation. The objective is to experimentally determine relations among chip thickness, uncut chip cross-section area, shear angle (representing the deformation severity of the chips), crystallinity index, and sugar yield.

An Experimental Investigation on Cellulosic Biofuel Manufacturing: Effects of Biomass Particle Size on Sugar Yield

2011 ◽  
Author(s):  
Pengfei Zhang ◽  
Qi Zhang ◽  
Z. J. Pei ◽  
Linda Pei
Keyword(s):  
Experimental Investigation ◽  
Particle Size ◽  
Enzymatic Hydrolysis ◽  
Crystallinity Index ◽  
Cost Effective ◽  
Sugar Yield ◽  
Cellulosic Biomass ◽  
Experimental Investigations ◽  
Cellulosic Biofuel ◽  
Biomass Particle Size

Biofuels made from cellulosic biomass are an alternative to petroleum-based liquid transportation fuels. A key barrier to cost-effective manufacturing of cellulosic biofuel is low sugar yield in enzymatic hydrolysis. Particle size and crystallinity index of cellulosic biomass are two important parameters in enzymatic hydrolysis. The current literature contains many experimental investigations about effects of biomass particle size on sugar yield. However, particle size, often reduced by ball milling, is correlated with crystallinity index. Changes in particle size usually cause changes in crystallinity index. Therefore, particle size and crystallinity index may have confounding effects on sugar yield. Relations between particle size and sugar yield are not clear. This paper reports an experimental investigation on sugar yields from switchgrass particles produced by three methods: cutting milling, hammer milling, and manual cutting. The particles have different sizes but the same crystallinity index. Results show that there are no significant differences among sugar yields from these particles of different sizes. Particle size within the tested range has no significant effects on sugar yield.

Effects of Ultrasonic Treatments on Cellulose in Cellulosic Biofuel Manufacturing: A Literature Review

2010 ◽  
Author(s):  
P. F. Zhang ◽  
Z. J. Pei
Keyword(s):  
Large Scale ◽  
Morphological Structure ◽  
Degree Of Polymerization ◽  
Sugar Yield ◽  
Cellulosic Biomass ◽  
Cellulosic Biofuels ◽  
Crystallinity Degree ◽  
Transportation Fuels ◽  
Cellulosic Biofuel ◽  
Low Efficiency

Cellulosic biofuels are one type of renewable energy, and have been proposed to replace traditional liquid transportation fuels. Cellulosic biomass is the feedstocks in cellulosic biofuel manufacturing. Cellulose accounts for approximately 30% of the total weight in cellulosic biomass. Glucose, one type of monosaccharide convertible to ethanol, can be obtained by hydrolyzing the polymeric structure of cellulose. Currently enzymatic methods are the most common for the hydrolysis of cellulose. However, the low efficiency of enzymatic hydrolysis increases production cost and hinders the large-scale manufacturing of cellulosic biofuels. Ultrasonic treatments applied on cellulosic biomass were found to improve the efficiency of hydrolysis and subsequently increase the sugar yield of hydrolysis. To understand the effects of ultrasonics on cellulose, investigations have been conducted on the effects on cellulose characteristics caused by ultrasonic treatments during hydrolysis. This paper reviews the effects of ultrasonic treatments on cellulose during hydrolysis in terms of sugar yield and some characteristics of cellulose, such as accessibility, crystallinity, degree of polymerization, and morphological structure.

Sugar Yield Comparison of Wheat Straw Processed by Two Pelleting Methods for Cellulosic Biofuel Manufacturing

2012 ◽  
Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Meng Zhang ◽  
Xiaoxu Song ◽  
Z. J. Pei ◽  
...  
Keyword(s):  
Power Consumption ◽  
Wheat Straw ◽  
Sugar Yield ◽  
Cellulosic Biomass ◽  
Experimental Comparison ◽  
Low Density ◽  
Pellet Quality ◽  
Transportation Fuels ◽  
Cellulosic Biofuel ◽  
Higher Temperature

Biofuels made from cellulosic biomass are an alternative to petroleum-based liquid transportation fuels. However, low density of cellulosic biomass causes high costs in biomass transportation and handling in cellulosic biofuel manufacturing. Such costs can be reduced by pelleting processes that can densify cellulosic biomass. Ultrasonic vibration-assisted (UV-A) pelleting and ring-die pelleting are two pelleting methods. A previous study has compared the two pelleting methods in terms of pellet quality and pelleting power consumption. This paper reports an experimental comparison on sugar yields of wheat straw processed by the two pelleting methods under different combinations of pretreatment variables. Results show that wheat straw processed by UV-A pelleting has higher sugar yield than that processed by ring-die pelleting when the higher temperature and longer time are applied in pretreatment. Under other combinations of pretreatment variables, wheat straw processed by UV-A pelleting has lower sugar yield than that processed by ring-die pelleting.

Supercritical CO2 Pretreatment of Cellulosic Biomass for Biofuel Production: Effects of Biomass Particle Size

2018 ◽  
Author(s):  
Yang Yang ◽  
Timothy Deines ◽  
Meng Zhang ◽  
Ke Zhang ◽  
Donghai Wang
Keyword(s):  
Particle Size ◽  
Corn Stover ◽  
Supercritical Co2 ◽  
Sugar Yield ◽  
Size Reduction ◽  
Cellulosic Biomass ◽  
Biofuel Production ◽  
Particle Size Reduction ◽  
Significant Difference ◽  
Biomass Particle Size

Biofuel derived from cellulosic biomass is a sustainable alternative to petroleum-based fuel. Pretreatment is an essential step in biofuel production because it accounts for more than 20% of the inputs. Furthermore, particle size reduction as a preprocessing step prior to pretreatment exerts a substantial impact on all following processes. Many studies have investigated the effects of biomass particle size on sugar yield after conventional pretreatments of biomass such as alkaline and dilute acid pretreatments. The similar trends have shown that smaller biomass particle size results in higher sugar yield. Supercritical CO2 (SC-CO2) pretreatment has been applied at 1450 psi, 120 °C for 30 mins in this study as a pretreatment method for biofuel production from cellulosic biomass. As a recyclable green-chemistry method, SC-CO2 pretreatment offers many advantages such as no toxic chemicals added and low-cost input. The objective of this study is to understand the effects of particle size on sugar yield after SC-CO2 pretreatment. Three particle size: 1 mm, 2 mm, and 4 mm were used for size reduction of corn stover. Ethanol and water were used as co-solvents to enhance SC-CO2 pretreatment. Analysis of variance (ANOVA) was performed and it is found that, after SC-CO2 pretreatment, the sugar yields differ significantly between 1 mm and 2 mm, 1 mm and 4 mm. In contrast, there is no significant difference between 2 mm and 4 mm after SC-CO2 pretreatment. 1 mm particle produced the highest sugar yield of 0.115 g glucose per 1 g of dry biomass which is 16.62% and 10.39% higher than the 4 mm and 2 mm corn stover biomass produced.

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