Bias correction of regional climate model simulations for hydrological climate-change impact studies: Review and evaluation of different methods

Effectiveness of a densification process to create strong and durable bonding in densified products such as pellets, briquettes, and cubes can be determined by testing the strength (i.e., compressive resistance, impact resistance, and water resistance), and durability (i.e., abrasion resistance) of the densified products. These tests can indicate the maximum force/stress that the densified products can withstand, and the amount of fines produced during handling, transportation, and storage. In this article, the procedures used for measuring the strength and durability of the densified products are discussed. The effects of constituents of the feed such as starch, protein, fiber, fat, lignin and extractives; feed moisture content; feed particle size and its distribution; feed conditioning temperature/preheating of feed; added binders; and densification equipment variables (forming pressure, and pellet mill and roll press variables) on the strength and durability of the densified products are reviewed. This article will help select process parameters to produce strong and durable densified products from new biomass feedstocks or animal feed formulations. Guidelines for developing standards on criteria for the acceptance levels of strength and durability of the densified products are presented.

Factors affecting strength and durability of densified biomass products.

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=2959&context=usdaarsfacpub

Comparison of dilute acid and ionic liquid pretreatment of switchgrass: Biomass recalcitrance, delignification and enzymatic saccharification.

Torrefaction is a mild pyrolysis, which has been explored for the pretreatment of biomass to increase the heating value and hydrophobicity. Due to its potential applications for making torrefied pellets, which can be used as a high quality feedstock in gasification for high quality syngas production and as a substitute for coal in thermal power plants and metallurgical processes, torrefaction and densification have attracted great interest in recent years from both academia and bioenergy industry. This paper provides a comprehensive review of research progresses in this area, drawing on major contributions from two major research groups of the authors on torrefaction and densification at Canada and Taiwan as well as literatures. It is revealed that torrefaction of various biomass species and their major components, lignin, cellulose and hemicelluloses have been extensively studied in thermogravimetric apparatus (TGA) under both inert (N 2 ) and oxidative (O 2 , H 2 O) environments to elucidate the weight loss as a function of temperature, particle size and time. It was found that the higher heating value and saturated water uptake of torrefied biomass were a strong function of weight loss, which represents the degree of torrefaction. When torrefied sawdust is compressed into torrefied pellets, more mechanical energy is consumed and higher die temperature is required to make torrefied pellets of similar density and hardness as regular pellets. Simple economics analyses based on laboratory scale experimental data showed that because of the potential savings from pellets transport, handling and storage logistics, the overall cost for torrefied pellets can be lower than regular pellets in European market for both European and Canadian pellets. The gasification could be improved in terms of both energy efficiency and syngas quality because of the removal of oxygenated volatile compounds from torrefied biomass.

A state-of-the-art review of biomass torrefaction, densification and applications

Zero Energy Building: A Review of Definitions and Calculation Methodologies

Compaction characteristics of barley, canola, oat and wheat straw

Grinding experiments were conducted on non-treated and steam exploded barley, canola, oat and wheat straw using a forage chopper and a hammer mill (screen sizes of 30, 6.4, 3.2 and 1.6 mm) to determine specific energy requirements, and geometric mean particle size and distribution of ground material. The bulk density of non-treated biomass was significantly higher than bulk density of steam exploded agricultural biomass. For non-treated agricultural straw, the particle density of canola and oat straw significantly increased with a decrease in hammer mill screen size from 30 to 1.6 mm. The particle density of steam exploded barley and oat straw was significantly higher than non-treated straw, except for barley at 6.4 mm hammer mill screen size. The particle density of steam exploded canola straw was not statistically different from non-treated straw. The chopper consumed highest (3.15 ± 0.09 kWh t −1 ) and lowest (1.96 ± 0.33 kWh t −1 ) specific energy to chop barley and canola straw, respectively. The highest and lowest specific energy was consumed by wheat (42.57 ± 2.04 kWh t −1 ) at 1.6 mm and canola (1.46 ± 0.30 kWh t −1 ) straws ground using 30 mm hammer mill screen size, respectively. For steam exploded agricultural biomass, the highest and lowest specific energy was consumed by oat (33.18 ± 3.10 kWh t −1 ) at 1.6 mm and canola (2.69 ± 0.26 kWh t −1 ) straws ground using 6.4 mm hammer mill screen size, respectively. Specific energy required by hammer mill to grind non-treated and steam exploded barley, canola, oat and wheat straw showed a negative power correlation with hammer mill screen sizes.

Grinding performance and physical properties of non-treated and steam exploded barley, canola, oat and wheat straw

Rapid and cost effective quantification of lignocellulosic components (cellulose, hemicelluloses and lignin) of agricultural biomass (barley, canola, oat and wheat) is essential to determine the effect of various pre-treatments (such as steam explosion) on biomass used as feedstock for the biofuel industry. Fourier Transformed Infrared (FTIR) spectroscopy was considered as an option to achieve this objective. Regression equations having R 2 values of 0.89, 0.99 and 0.98 were developed to predict the cellulose, hemicelluloses and lignin compounds of biomass, respectively. The average absolute difference in predicted and measured cellulose, hemicellulose and lignin in agricultural biomass was 7.5%, 2.5%, and 3.8%, respectively.

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Quantitative Analysis of Lignocellulosic Components of Non-Treated and Steam Exploded Barley, Canola, Oat and Wheat Straw Using Fourier Transform Infrared Spectroscopy

The ability of a variable displacement pump to respond to a control signal is a critical factor in assessing the dynamic performance of the circuit in which the pump is located. The need for a comprehensive dynamic response model of the pump is necessary if new techniques for control are to be realized. This paper presents a mathematical model, based on fluid mechanics considerations, of a variable displacement pump modulated by a hydraulic control signal. Many of the coefficients in the model depend on the pump model. In this study, a Vickers No. PVB5 pump is used. The describing equations are complex, nonlinear, and comprehensive in the initial model. Some nonlinear terms are simplified using linear approximations without significantly affecting accuracy. The model is subjected to a simulated pressure control signal and the output of the swash plate rotary displacement compared to an experimentally generated displacement time trace. The model and the experimental results show a good correlation.

Greg Schoenau

Papers

Compaction characteristics of barley, canola, oat and wheat straw

Grinding performance and physical properties of non-treated and steam exploded barley, canola, oat and wheat straw

Quantitative Analysis of Lignocellulosic Components of Non-Treated and Steam Exploded Barley, Canola, Oat and Wheat Straw Using Fourier Transform Infrared Spectroscopy

Dynamic Analysis of a Variable Displacement Pump

Gasification of refuse derived fuel in a fixed bed reactor for syngas production.