Kaushlendra Singh

Anaerobic Digestion of Poultry Litter: A Review

Poultry litter is an excellent example of how a source of organic nutrients became an expensive problem in concentrated poultry producing areas due to nutrient imbalance at the farm and regional scale resulting in water quality impairment in some watersheds. Recently, anaerobic digestion technology, which is a proven solution for waste reduction and energy production for dairy, swine, and other organic wastes, has been proposed for poultry litter utilization. Although anaerobic digestion is widely studied for many organic and agricultural wastes, it is less understood for poultry litter (combination of manure, spilled feed, feathers, and bedding material). This review presents a detailed analysis of anaerobic digestion of poultry litter in terms of technology and optimization techniques, goals of poultry litter disposal, and economics. The review suggests that anaerobic process does not fulfill the goal of poultry litter nutrient disposal problems. While selecting any alternative option for a given region, one must consider the goals of poultry litter disposal for that area.

Pyrolysis Characteristics of Forest Residues Obtained from Different Harvesting Methods

Although forests promise an abundant supply for residue biomass for biorefining and biopower applications, heterogeneity generated in residue due to collection methods or selection process (limb, top, and understory etc.) may influence biofuel production in both the thermochemical and fermentation pathways. This article focuses on effects of collection methods on the fuel properties, thermochemical decomposition behavior, and properties of pyrolysis bio-oil and char. Forest residues studied in this research include: clean wood chips (CW), horizontal grinder material (GM), pre-commercially thinned biomass chips (PC-chips), biomass chips produced from pine limbs and tops (T-chips), and biomass chips produced from hardwood understory stems and pine limbs and tops (TU-chips). All biomass samples were characterized by measuring bulk density, moisture, chemical composition (cellulose, hemicellulose, lignin, ash, and extractives), energy density, proximate analysis (moisture, fixed carbon, volatile matter, and ash), and ultimate (C, H, N, S, O) analysis. Pyrolysis was performed on partially dried biomass samples to produce char and bio-oil. The yields of pyrolysis products were calculated. Char was characterized by proximate and ultimate analysis, energy density, and iodine number; and, bio-oil was characterized by pH, viscosity, ultimate analysis, energy density, and water content. In addition, fixed carbon yields, char carbon efficiency, and energy conversion efficiency of char were also calculated. Results showed that the GM had the highest ash content (5.9%) and the lowest energy density (17.03 MJ/kg) among all forest residues evaluated. TU-chips had higher concentration of extractives which resulted in an additional decomposition peak at 300°C beyond the main peak which appeared at 370°C responsible for decomposition of cellulose and hemicelluloses in thermogravimetric analysis. Results from this study showed no significant difference in char and bio-oil yields in the various forest residues evaluated; however, GM char which was large in ash content, because of contamination by soil inclusion had lower heating value and adsorption capacity. All residues evaluated produced bio-oil with similar fuel properties.

Effect of fractionation on fuel properties of poultry litter.

In raw form, poultry litter has certain drawbacks for both energy production and fertilizer. These include high ash content and moisture content, a corrosive nature, low heat content, and low nutrient content. Fractionation divides poultry litter into a fine, nutrient rich fraction and a coarse, energy rich fraction. In this research, poultry litter was divided into coarse and fine fractions using a #20 screen. The following analyses were performed on the raw poultry litter and its coarse and fine fractions: higher heating value, proximate, ultimate, compositional, mineral, thermogravimetric (TGA), and differential scanning calorimeter (DSC) analysis. Preliminary results show that the coarse fraction from screen #20 is potentially a much better feedstock for energy production than whole litter. The results of this study may be directly applied to the poultry industry to promote value added utilization of litter and to improve the efficiency of energy producing industries using poultry litter as feedstock.

Effect of Fractionation and Pyrolysis on Fuel Properties of Poultry Litter

Abstract Raw poultry litter has certain drawbacks for energy production such as high ash and moisture content, a corrosive nature, and low heating values. A combined solution to utilization of raw poultry litter may involve fractionation and pyrolysis. Fractionation divides poultry litter into a fine, nutrient-rich fraction and a coarse, carbon-dense fraction. Pyrolysis of the coarse fraction would remove the corrosive volatiles as bio-oil, leaving clean char. This paper presents the effect of fractionation and pyrolysis process parameters on the calorific value of char and on the characterization of bio-oil. Poultry litter samples collected from three commercial poultry farms were divided into 10 treatments that included 2 controls (raw poultry litter and its coarse fraction having particle size greater than 0.85 mm) and 8 other treatments that were combinations of three factors: type (raw poultry litter or its coarse fraction), heating rate (30 or 10 °C/min), and pyrolysis temperature (300 or 500 °C). After the screening process, the poultry litter samples were dried and pyrolyzed in a batch reactor under nitrogen atmosphere and char and condensate yields were recorded. The condensate was separated into three fractions on the basis of their density: heavy, medium, and light phase. Calorific value and proximate and nutrient analysis were performed for char, condensate, and feedstock. Results show that the char with the highest calorific value (17.39 ± 1.37 MJ/kg) was made from the coarse fraction at 300 °C, which captured 68.71 ± 9.37% of the feedstock energy. The char produced at 300 °C had 42 ± 11 mg/kg arsenic content but no mercury. Almost all of the Al, Ca, Fe, K, Mg, Na, and P remained in the char. The pyrolysis process reduced ammoniacal-nitrogen (NH4-N) in char by 99.14 ± 0.47% and nitrate-nitrogen (NO3-N) by 95.79 ± 5.45% at 500 °C.

Sludge Measurement Using Global Positioning System (GPS) Enabled Sonar Equipped Airboat in a Lagoon

Proper management of animal waste treatment lagoons requires regular sludge surveys of the lagoons. The traditional manual method of sludge survey is unsafe and time consuming. This article presents the effect of sonar unit variables (sensitivity, noise rejection, and surface clarity) on measurements of top and bottom depth of sludge layer in a lagoon using a GPS enabled sonar equipped (model LCX-15M, Lowrance Electronics, Inc, Tulsa, Okla.) remote controlled airboat. Comparisons between airboat measurements and sludge meter readings and the discrepancy between the measurements from the airboat and an instrument from Remediation Resources, Inc. are also discussed. To study the variables, the top and bottom depth of a sludge layer, position and speed of the air boat were measured using a GPS sensor and an ultrasonic sonar in three situations: 1) Statically at single point; 2) Dynamically along two lines; and 3) Dynamically on a lagoon water surface on a random grid. The top and bottom depth of the sludge layer was also measured using a sludge meter method at several points within the cone area for the static location of the transducer. This preliminary study suggested the use of 25% sensitivity level, an inclusion of a correction factor accounting for speed of sound in lagoon water, the steady movement of the boat and the use of a more accurate GPS system (accuracy within inches with DGPS) for future research to measure sludge within acceptable limits.

Wood as an advanced feedstock for bioenergy: scale matters

13 ISSN 1759-7269 10.4155/BFS.12.81

Transforming Solid Wastes Into High Quality Bioenergy Products: Entropy Analysis

Although energy analysis of a pyrolysis system improves the thermal efficiency of the process, it did not account for the quality of energy used and produced from the process. This paper presents the entropy of analysis of converting solid wastes into useable bio-products during pyrolysis. The entropy balance was performed on a continuous flow pyrolysis reactor system using pine pellets as a feedstock at the pyrolysis temperature of 773 K. An interesting conclusion was drawn from the results that the pyrolysis process converted low quality and high entropy biomass into high quality and low entropy energy products char, bio-oil, and gases. The analysis concluded that the both pyrolysis and combustion were the process of low entropy production and most part of the irreversibility or positive entropy production was mainly associated with condenser unit. The high quality energy producing pyrolysis process may be included as part of the future biorefinery.

Co-gasification of Coal and Hardwood Pellets: Syngas Composition, Carbon Efficiency and Energy Efficiency

This paper presents the effect of feedstock mixtures on the composition of syngas produced from a commercially available down-draft gasifier manufactured by All Power Labs (Berkeley, CA). Bituminous coal (Pittsburg seam) and hardwood pellets were used for the experiments. Five types of feedstock mixtures having composition of 100% hardwood pellets, 20% coal-80% hardwood pellets, 50% coal-50% hardwood pellets, 80% coal-20% hardwood pellets and 100% coal were prepared. Air or an air/water mist mixture was used as a gasifying agent and vacuum of 3” water was maintained inside the reactor. Syngas with 20.95% carbon-monoxide and 16.05% hydrogen was produced from the gasification of wood pellets. The hydrogen and carbon-monoxide content in the product gas decreased with an increase of the coal ratio of the mixtures. A significant increase in carbon efficiency was observed with an increase of the coal ratio in the mixtures. Syngas carbon and syngas energy efficiency increased with injection of the mist along with air in the system for the biomass gasification.

Pyrolysis Kinetics of Physical and Chemical Components of Wood using Isoconversion Method

Recently, torrefaction process has been focus of research to transform wood into an energy dense coal-like solid fuel. This paper presents thermo-chemical (torrefaction and pyrolysis) decomposition behavior of hardwood’s physical components (bark, sapwood and heartwood) and chemical component (cellulose, hemicellulose and lignin). Four hardwood species, namely, red oak and yellow-poplar were separated into its bark, sapwood and heartwood components. The wood components were dried and ground to less than 1 mm particle size. The ground samples were tested for calorific value, specific gravity, ultimate analysis, and thermo-chemical decomposition behavior. In addition, thermo-chemical decomposition behavior of cellulose, xylan, and kraft lignin was also tested.

Global Food Security and Sustainability through Agricultural Education and Training

Global food security and outreach training are the topics of this proposed paper. While current data showing the relationship between poverty and food insecurity is alarming, the implementation of AET (agricultural education and training) is a goal that affected countries can address for a brighter future. The presentation will illustrate how successful graduates of AET systems (agricultural education and training) find answers to sustainable food production problems in their home country, how they implemented solutions, and how they provides services and opportunities to rural people. It will use examples of how the involvement of the private sector and introduction of local entrepreneurship in the food chain can be accomplished through training of community members—to achieve food security. Food security depends on a range of conditions, such as overcoming post-harvest losses, sustainability through byproduct utilization for edible food, and use of biomass for bio-energy. In this light, higher educational institutions—particularly Extension Services of a land grant university--hold the keys for capacity building in international situations. By collaborating on projects that enable developing countries to build outreach capabilities, Extension trainers move new data and innovation from the laboratory to the production process. To strengthen skills needed in the food supply chain, Extension experts transfer research and knowledge to local communities, with the aim to improve the structure of agriculture production. Outreach training in the international context also offers unique curricular challenges and opportunities of infusing AET with breakthrough technologies