Thomas T. Adams

DSC studies to evaluate the impact of bio-oil on cold flow properties and oxidation stability of bio-diesel.

This paper describes the use of Differential Scanning Calorimetry (DSC) to evaluate the impact of varying mix ratios of bio-oil (pyrolysis oil) and bio-diesel on the oxidation stability and on some cold flow properties of resulting blends. The bio-oils employed were produced from the semi-continuous Auger pyrolysis of pine pellets and the batch pyrolysis of pine chips. The bio-diesel studied was obtained from poultry fat. The conditions used to prepare the bio-oil/bio-diesel blends as well as some of the fuel properties of these blends are reported. The experimental results suggest that the addition of bio-oil improves the oxidation stability of the resulting blends and modifies the crystallization behavior of unsaturated compounds. Upon the addition of bio-oil an increase in the oxidation onset temperature, as determined by DSC, was observed. The increase in bio-diesel oxidation stability is likely to be due to the presence of hindered phenols abundant in bio-oils. A relatively small reduction in DSC characteristic temperatures which are associated with cold flow properties was also observed but can likely be explained by a dilution effect.

Anaerobic codigestion of hog and poultry waste

Anaerobic batch tests were performed using hog and poultry wastes in various proportions. Treatments that received both wastes produced higher yields of biogas, up to 200 +/- 30 mL/g volatile solids (VS) destroyed, and methane, up to 130 +/- 20 mL/g VS destroyed, compared to either waste alone.

Rheological characterization of animal fats and their mixtures with #2 fuel oil

To aid in the development of biomass fuels based on waste animal fats, as of yet unpublished rheological properties of these fats and their mixtures with petroleum-based fuels are needed. The viscosities and densities of beef tallow, choice white pork fat, poultry fat and yellow grease were experimentally determined to examine their potential use as fuel substitutes or additives. The viscosities of 30% mixtures of these fats with #2 fuel oil fuel were also examined. Dynamic viscosities of these agricultural oils were measured for shear rates of 0.65– at temperatures between 54.4°C and 85°C. The resulting measurements were fitted to a power law model to obtain values for the consistency coefficient and the flow behavior index. These results indicated pseudoplastic flow behavior for all products, with increasingly Newtonian behavior at higher temperatures and shear rates. The mixtures of these fats with fuel oil exhibited even more encouraging rheological properties very near those of pure fuel oil.

Solid state fermentation of broiler litter for production of biocontrol agents.

Several varieties of heat-sterilized broiler litter with 60% (wet basis, wb) moisture content were substrate in solid-state fermentations to produce biocontrol agents. Litter varieties included litter produced by one flock of broilers from medicated and non-medicated controlled rations, and litter produced by two flocks and four flocks on a single application of bedding material from medicated commercial sources. Litter preparations were inoculated with monocultures of Bacillus thuringiensis serovar japonensis strain Buibui, a pathogen of Japanese beetle larvae (Popillia japonica), or Pseudomonas fluorescens 2-79. B. thuringiensis did not grow in unextracted 1-flock litter nor in water extracted litter, but grew in methanol extracted litter to 5 x 10(10) cell forming units (CFU)/g litter (dry weight, dw) and a spore count of 1 x 10(10) CFU/g litter (dw). B. thuringiensis also grew in unprocessed 2-flock and 4-flock litter, achieving cell counts of 3 x 10(9) and 1 x 10(9) CFU/g litter (dw), respectively, and spore counts of 1 x 10(9) CFU/g litter (dw). P. fluorescens grew in medicated 1-flock litter with no extraction to a cell density greater than 4 x 10(11) CFU/g litter (dw). Bioassays in soil containing over 0.5% (db) litter fermented with B. thuringiensis resulted in over 90% mortality in 21 days for first instars of Japanese beetle when compared to a control treatment using compost without fermented litter. The investigations demonstrate that bacterial biocontrol agents produced via solid substrate fermentations using broiler poultry litter have potential in biocontrol applications in the soil environment.

Bacillus thuringiensis subsp. kurstaki spore production in batch culture using broiler litter extracts as complex media

Abstract Broth for the growth of Bacillus thuringiensis subsp. kurstaki was prepared by extraction of broiler litter with water. Filamentous growth occurred during the first 6 h of fermentation in the full strength and in a 2:1 extract dilution. Of the five dilutions examined, the 2:1 dilution of the extract having a total organic carbon concentration of 1.7 g/l produced the highest spore count, 2.46 × 10 8 spores/ml. SDS-PAGE analysis of spore-crystal protein produced during the fermentation indicated a molecular weight of approximately 135000, suggesting the presence of bacterial insecticidal protoxin. With appropriate pretreatment, broiler litter may be a valuable resource when used as a low-cost complex medium for production of biochemicals.

Respiration in broiler litter slurry surface applied to soil

Abstract Respiration in broiler litter slurry that was surface applied to soil was examined for the purpose of determining the feasibility of enriching closed crop canopies with carbon dioxide. An estimated flux density of 1.11 g CO 2 m −2 h −1 was calculated to be required from a ground source to obtain a maximum average increase in photosynthate of 23% for C 3 plants. Litter, as received from the farm, was stored at 24°C for 72 days in a closed container (approximating conditions for deep stack storage). The stored litter was made into a slurry and stored at 24°C in a closed container for 23 days (approximating conditions in a manure storage pond). When stored slurry, inoculated 10% by volume with fresh litter slurry aged for seven days, was applied to soil at the rate of 0.13 ml cm −2 (12,890 l ha −1 ) an average flux density of 5.32 g CO 2 m −2 h −1 was measured.