Ultrasonic-Vibration Assisted Pelleting for Cellulosic Ethanol Manufacturing: An Experimental Investigation of Power Consumption

Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Z. J. Pei ◽  
Jonathan Wilson ◽  
Leland McKinney ◽  
...  

Ethanol produced from cellulosic biomass is an alternative to petroleum-based transportation fuels. However, its manufacturing costs are too high for cellulosic ethanol to be competitive. Cellulosic feedstocks have low density, causing their transportation and storage expensive, contributing to high manufacturing costs of cellulosic ethanol. Pelleting can increase the density of cellulosic feedstocks and reduce their transportation and storage costs. Ultrasonic vibration-assisted (UV-A) pelleting is a new pelleting method. Effects of input pelleting parameters (ultrasonic power, pelleting pressure, and particle size) on pellet quality and sugar yield have been studied. However, the effects of these parameters on power consumption in UV-A pelleting have not been studied. Since power consumption directly affects ethanol manufacturing costs, lower power consumption is desirable. The objective of this paper is to study effects of different input parameters (biomass material, particle size, ultrasonic power, and pelleting pressure) of UV-A pelleting on power consumption. Four types of biomass materials (big bluestem, corn stover, sorghum stalk, and wheat straw) were studied. Sorghum stalk consumed the least power. Pelleting pressure, particle size and ultrasonic power significantly affected power consumption of all four materials. Higher ultrasonic power and pelleting pressure resulted in lower power consumption. In addition, this paper also compares power consumption between UV-A pelleting and ring-die pelleting (a traditional pelleting method).

Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Graham Pritchett ◽  
Z. J. Pei ◽  
Meng Zhang ◽  
...  

Ethanol produced from cellulosic materials is an alternative to petroleum-based transportation fuels. However, its manufacturing costs are too high to be competitive at present. Raw cellulosic biomass materials have low density, causing their transportation and handling expensive, contributing to high manufacturing costs of cellulosic ethanol. Pelleting can increase the density of cellulosic biomass and reduce their transportation and handling costs. Ultrasonic vibration-assisted (UV-A) pelleting is a new pelleting method. Earlier studies show that moisture content and particle size have significant effects on pellet quality and sugar yield. However, their effects on power consumption in UV-A pelleting have not been studied. Since power consumption directly affects ethanol manufacturing costs, it is desirable to understand how input variables affect power consumption. The objective of this paper is to study effects of moisture content and particle size on power consumption in UV-A pelleting of wheat straw. Results show that higher moisture content and larger particle size result in higher power consumption.


Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Z. J. Pei ◽  
Graham Pritchett ◽  
Meng Zhang ◽  
...  

Cellulosic biomass is abundantly available in the nature. It is an attractive feedstock to make alternative fuels to petroleum-based transportation fuels. Because of low bulk density and irregular shape, raw biomass materials are difficult to handle, transport, and store. Pelleting can increase the density of cellulosic biomass. Pellets can be easily handled, resulting in reducing their transportation and storage costs. Ultrasonic vibration-assisted (UV-A) pelleting is a new pelleting method. Moisture content, particle size, pelleting pressure, and ultrasonic power are four important input parameters affecting pellet quality and sugar yield (proportional to biofuel yield). However, their effects on power consumption in UV-A pelleting have not been adequately investigated. Since power consumption directly affects ethanol manufacturing costs, it is desirable to understand how input parameters affect power consumption. This paper reports an experimental investigation of power consumption in UV-A pelleting. A 24 factorial design is employed to evaluate the effects of four input parameters (moisture content, particle size, pelleting pressure, and ultrasonic power) on power consumption in UV-A pelleting. Results show that three input parameters (moisture content, particle size, and ultrasonic power) significantly affect power consumption. Higher moisture content, lower ultrasonic power, and larger particle size result in higher power consumption. Only one interaction of two parameters is significant, i.e. with the increase of pelleting pressure, power consumption will increase at the high level of particle size while decrease at the low level of particle size.


Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Shing Chang ◽  
Z. J. Pei ◽  
Donghai Wang

Cellulosic ethanol is an attractive alternative to petroleum-based liquid transportation fuels. However, low density of cellulosic biomass (the feedstock for cellulosic ethanol) causes high costs in biomass logistics and hinders large-scale and cost-effective manufacturing of cellulosic ethanol. Ultrasonic vibration-assisted (UV-A) pelleting can significantly increase the density of cellulosic biomass by compressing raw cellulosic biomass into pellets. Pellet density and durability are two important physical properties of a pellet. In this study, a multiple response surface methodology was employed to optimize the input variables (pelleting time, pressure, and ultrasonic power) in UV-A pelleting of sorghum stalks for simultaneously maximized pellet density and durability. Second-order polynomial models were used to fit the experimental results. Main and interaction effects of the input variables on pellet density and durability were also investigated.


2013 ◽  
Vol 805-806 ◽  
pp. 151-155
Author(s):  
Kang Qi Fan ◽  
Yong Jun Tang ◽  
Yang Fang

Increasing concerns about reliable supplies and envi­ronmental consequences of petroleum-based fuels have made it important to develop sustainable green sources for liquid transportation fuels. One such source is cellulosic biomass. However, high costs associated with transportation and storage of low-density cellulosic biomass has hindered large-scale, cost-effective manufacturing of cellulosic biofuels. Ultrasonic vibration-assisted (UV-A) pelleting can increase biomass density, improve storability, and reduce transportation costs. This paper reviews the state of the art of this technique, covering the effects of different process parameters on pellet quality, pellet charring, pellet crack, and sugar yield. It can be concluded that pellet density increases with an increase in ultrasonic power and pelleting pressure, and with a decrease in biomass moisture content and particle size. However, large ultrasonic power may lead to the charring of cellulosic biomass, which adversely affects the conversion of cellulosic biomass to ethanol. In addition, some problems associated with UV-A pelletingof cellulosic biomass are proposed.


Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Z. J. Pei ◽  
Jonathan Wilson ◽  
Leland McKinney ◽  
...  

Ethanol produced from cellulosic biomass is an alternative to petroleum-based transportation fuels. However, manufacturing costs of cellulosic ethanol are too high to be competitive. Low density of cellulosic feedstocks increases their handling and transportation costs, contributing to high overall costs of cellulosic ethanol manufacturing. Pelleting can increase density of cellulosic feedstocks, reduce transportation and storage costs, and make cellulosic ethanol production more competitive. UV-A (ultrasonic vibration-assisted) pelleting is a new pelleting method (available only in lab scale now). Preliminary research showed that UV-A pelleting could significantly increase pellet density and pellet durability but it has never been compared with other pelleting methods (e.g., using an extruder, a briquetting press or a ring-die pelleting). The objectives of this research are to compare UV-A pelleting with ring-die pelleting in terms of pellet density, pellet durability, energy consumptions of pelleting. The results will be useful to find a better pelleting method for cellulosic ethanol manufacturing.


Author(s):  
Q. Zhang ◽  
P. F. Zhang ◽  
Z. J. Pei

Cellulosic biofuels are becoming an attractive alternative to conventional liquid transportation fuels. Cellulosic biomass is the feedstock for cellulosic biofuel manufacturing. However, high transportation and storage cost of cellulosic biomass due to its low density hinders large-scale and cost-effective manufacturing of cellulosic biofuels. Pelleting processes are used to produce biomass pellets which have higher density and are easier to handle in transportation and storage. Before going through pelleting processes, original cellulosic biomass materials are milled into particles. The particle size is an important input parameter in pelleting processes. Many investigations have been conducted on effects of biomass particle size on pellet quality (in terms of density, durability, stability, and strength). This paper reviews the literature about effects of particle size on pellet quality. Investigated biomass materials, selected range of particle size, utilized milling and pelleting processes are summarized. The approaches to evaluating pellet quality are also reviewed.


Author(s):  
Q. Feng ◽  
W. L. Cong ◽  
M. Zhang ◽  
Z. J. Pei ◽  
C. Z. Ren

As one of the near-to-mid-term alternatives to fossil fuels, cellulosic biofuels can cut greenhouse gas emissions while continuing to meet liquid transportation fuel needs. By processing cellulosic biomass into pellets, density and handling efficiency of cellulosic feedstocks will be improved, resulting in a reduction in transportation and handling costs in biofuel manufacturing. Temperature of biomass during the pelleting process can affect the quality of the pellet. But effects of pelleting variables on biomass temperature during ultrasonic vibration-assisted (UV-A) pelleting are still unknown. This paper reports an experimental investigation on temperature of biomass in UV-A pelleting. It studies the effects of moisture content of the biomass and pelleting variables (ultrasonic power, tool travel distance, and feedrate). The results will be helpful in understanding the effects of ultrasonic vibration on biomass temperature, compaction mechanism, and biofuel conversion.


Author(s):  
P. F. Zhang ◽  
Z. J. Pei

Cellulosic ethanol is one type of renewable energy, and can be used to replace petroleum based transportation fuels. The technologies of converting cellulosic biomass into ethanol are relatively mature. However, the manufacturing costs of cellulosic ethanol are too high to be competitive. Economic analyses of cellulosic ethanol manufacturing have appeared regularly to estimate manufacturing costs of cellulosic ethanol. But the estimated manufacturing costs of cellulosic ethanol have a wide range due to differences in used assumptions. It is very difficult to judge which one is most reliable among the markedly different cost estimates in the literature. This paper reviews the literature on cost estimates in manufacturing of cellulosic ethanol. Cost estimates of each manufacturing process are summarized. Cost components and their data sources are discussed. This review provides a foundation to develop a comprehensive cost model for cellulosic ethanol manufacturing.


Author(s):  
Qi Zhang ◽  
P. F. Zhang ◽  
Timothy Deines ◽  
Z. J. Pei ◽  
Donghai Wang ◽  
...  

Cellulosic biofuels can be used to replace traditional liquid transportation fuels. Cellulosic biomass is feedstock in manufacturing of cellulosic biofuels. However, the low density of cellulosic biomass feedstock hinders large-scale and cost-effective manufacturing of cellulosic biofuels. Another bottleneck factor in manufacturing of cellulosic biofuels is the low efficiency of the enzymatic hydrolysis of cellulosic biomass materials resulting in a low sugar yield. Ultrasonic vibration-assisted (UV-A) pelleting can increase the density of cellulosic biomass feedstocks via combined effects of mechanical compression and ultrasonic vibration of the tool on the cellulosic biomass. Meanwhile ultrasonic vibration may act as a beneficial pretreatment for enzymatic hydrolysis, which can possibly increase the efficiency of hydrolysis and obtain a higher sugar yield. The pressure and the ultrasonic power are important parameters in UV-A pelleting. Their effects on pellet quality (density, durability, and stability) and sugar yield (after hydrolysis) are experimentally investigated.


2012 ◽  
Vol 151 ◽  
pp. 245-249 ◽  
Author(s):  
Yong Jun Tang ◽  
Chun Mu Chen ◽  
Guan Wang

Cellulosic biofuels have been proposed to replace part of traditional liquid transportation fuels. Cellulosic biomass is the feedstock in cellulosic biofuel manufacturing. Costs associated with collection and transportation of cellulosic biomass account for more than 80 percent of the feedstock cost. By processing cellulosic biomass into pellets, density and handling efficiencies of cellulosic feedstock can be improved, resulting in reduction of transportation and handling costs. The pellet temperature is one of the most important parameter in Ultrasonic Vibration (UV-A) pelleting. There is very few literature on the pellet temperature of UV-A pelleting. This paper mainly studied how to on-line measure the pelleting temperature, also, the detailed temperature characteristics of the pellet was obtained. The results are valuable for selecting suitable pelleting parameters and controlling the quality of pellet in UV-A pelleting. Also, the accurate measurement of the pellet temperature is helpful to understand pelleting mechanism, charring, and durability issues.


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