Effective Use of Dairy Manure Mixed with Sand Bedding for Gasification

2017 ◽  
Vol 60 (1) ◽  
pp. 5-16 ◽  
2005 ◽  
Vol 52 (1-2) ◽  
pp. 525-530 ◽  
Author(s):  
D.H. Zitomer ◽  
T.C. Bachman ◽  
D.S. Vogel

A thermophilic anaerobic digester with ultrafilter (TADU) for solids separation offers potential advantages of higher VS destruction, biomass retention, and pathogen removal. However, potential disadvantages include ultrafilter fouling, decreasing flux, and high VFA concentrations. In this study, a thermophilic anaerobic digester coupled to a sintered titanium, cross-flow ultrafilter was operated for over five months. Dairy manure was digested (HRT of 23 days). The filtrate VFA concentration was low (220 mg/L as HAc), average VS destruction was 49%, and a low average effluent fecal coliform concentration of 102 MPN/100 mL was observed. The low coliform value may be beneficial if dewatered biosolids are used for livestock bedding since low pathogen counts help prevent mastitis. Ultrafilter fluxes of 40–80 L/m2-hr were maintained by cleaning using caustic (3.5% NaOH) followed by water and acid (3% phosphoric acid). Sand from livestock bedding was found to damage the pump and ultrafilter. If TADU were implemented at full scale, then replacing sand bedding with dewatered biosolids should be considered.


2019 ◽  
Vol 9 (13) ◽  
pp. 2703
Author(s):  
Hui Wang ◽  
Horacio A. Aguirre-Villegas ◽  
Rebecca A. Larson ◽  
Asli Alkan-Ozkaynak

Manure characteristics change through processing, including anaerobic digestion (AD). These changes can alter handling of manure during downstream operations. This study analyzed the density, total solids (TS) content, and volatile solids (VS) content of pre-digested and anaerobically digested dairy manure from seven dairy farms in Wisconsin. The density of pre-digested manure increased from 990 to 1065 kg m−3 as the TS level increased from 1.5% to 13.0%. Density and TS for pre-digested manure from facilities using separated solids as bedding were related with a linear model for TS ranging from 1.5% to 13.0% and with a polynomial model for TS ranging from 1.5% to 50%. The model shows that density decreases with an increasing TS content when TS is greater than 8.0%. Manure from dairy facilities that used sand bedding had a VS/TS ratio of 0.87. This ratio was higher than the ratio when manure solids were used as bedding (0.81) and when food waste was incorporated into the digester (0.77). This study also provides a simple methodology to estimate biogas yield by using the density of pre- and post-digested manure.


Energy ◽  
2016 ◽  
Vol 95 ◽  
pp. 187-199 ◽  
Author(s):  
Hyungseok Nam ◽  
Amado L. Maglinao ◽  
Sergio C. Capareda ◽  
David Aaron Rodriguez-Alejandro

Biology ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Haoming Wu ◽  
Yang Wang ◽  
Lei Dong ◽  
Haiyan Hu ◽  
Lu Meng ◽  
...  

Changes in bacterial community, phenotype, metabolic function, and pathogenic bacteria content in recycled manure solids (RMS) were analyzed by 16S rRNA sequencing, Bugbase, picrost2, and qPCR, respectively. The data from RMS bedding were compared to those of sand bedding and rice husk bedding. The results show that the proportion of potentially pathogenic bacteria among the manure flora of RMS after dry and wet separation, after composting, and after sun-cure storage was 74.00%, 26.03%, and 49.067%, respectively. Compared to RMS bedding, the proportion of potentially pathogenic microorganisms in sand bedding and rice husk bedding was higher. The picrust2 analyses show that the level of lipopolysaccharide biosynthesis changed significantly during RMS processing. In addition, the qPCR results show that composting could effectively reduce the detection and quantification of pathogens, except Streptococcus uberis, in RMS bedding. In general, composting is an essential step to improve the safety of bedding materials in the process of fecal treatment. However, at the same time, RMS bedding may increase the risk of mastitis caused by Streptococcus uberis.


2004 ◽  
Author(s):  
Frederick C. Michel ◽  
Jr. ◽  
Jerome Rigot ◽  
Tom Wilkinson and John Pecchia
Keyword(s):  

Author(s):  
Hyungseok Nam ◽  
Amado Maglinao ◽  
Sergio Capareda

Solid manure handling is a major environmental issue confronting animal facilities in the United States. One difficulty in using dairy manure as a fuel source is the presence of sand bedding used for lactating dairy cows. More than 30% of dairy farms use sand beds for a dry and clean environment that prevents bacterial growth [1]. In this study, dairy animal manure obtained directly from waste lagoons was used for the air gasification process. The manure was dried to reduce the moisture down to 5% and a sand separating system was designed to remove some sand bedding materials. Preliminary air gasification experiments showed that the direct use of dairy manure containing 75% ash content, that reflect high sand content, reduced the temperature of the reactor. The study is also aimed at handling unprocessed dairy manure and generating electric power for the on-site use. A high heating value manure is needed to run the gasifier and the produced synthesis gas (or syngas) is fed to an engine coupled with a generator. Some dairy manure gasification work were done using fresh dairy manure. The highest heating value from the dairy manure biomass was found to be 4.5MJ/kg in a fixed-bed gasifier [2]. Another gasification study using a fluidized-bed reactor could produce syngas heating value as high as 4.7MJ/m3 from dairy manure [3]. A bench-scale fluidized bed containing a 3-inch diameter reactor tube with a cyclone and a scrubber was used to gasify dairy manure using air at different temperatures. The sand separated dairy manure used in this study contained approximately 45% ash content. The maximum heating value of the synthesis gas was 3.8MJ/m3 at an operating temperature of 750°C. The syngas will need to be upgraded. To upgrade the synthesis gas heating value, sludge pellets of 18.7MJ/kg were mixed with the dairy manure in different ratios of 10% and 30%. The syngas heating values from mixed manure with sludge pellet were increased to 5MJ/m3 with 10% sludge, and 5.7MJ/m3 with 30% sludge. The sludge used has higher heating value resulting in higher gas HV. The cold gasification efficiency was achieved as high as 36±5% with dairy manure mixed with sludge pellet. At a higher operating temperature, higher efficiency was obtained with increased gas composition of hydrogen and carbon monoxide. This syngas may then be used for power generation as well as possible input gas for the Fisher Tropsch process for liquid biofuel production. The result of the experiments will be a cornerstone for the widespread application of low heating value animal waste for producing high heating value syngas that may be used for electric power generation as a result of various upgrading processes.


Author(s):  
W.A. Carrington ◽  
F.S. Fay ◽  
K.E. Fogarty ◽  
L. Lifshitz

Advances in digital imaging microscopy and in the synthesis of fluorescent dyes allow the determination of 3D distribution of specific proteins, ions, GNA or DNA in single living cells. Effective use of this technology requires a combination of optical and computer hardware and software for image restoration, feature extraction and computer graphics.The digital imaging microscope consists of a conventional epifluorescence microscope with computer controlled focus, excitation and emission wavelength and duration of excitation. Images are recorded with a cooled (-80°C) CCD. 3D images are obtained as a series of optical sections at .25 - .5 μm intervals.A conventional microscope has substantial blurring along its optical axis. Out of focus contributions to a single optical section cause low contrast and flare; details are poorly resolved along the optical axis. We have developed new computer algorithms for reversing these distortions. These image restoration techniques and scanning confocal microscopes yield significantly better images; the results from the two are comparable.


2012 ◽  
Vol 220 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Sandra Sülzenbrück

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.


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