Waste to Carbon: Influence of Structural Modification on VOC Emission Kinetics from Stored Carbonized Refuse-Derived Fuel

The torrefaction of municipal solid waste is one of the solutions related to the Waste to Carbon concept, where high-quality fuel—carbonized refuse-derived fuel (CRDF)—is produced. An identified potential problem is the emission of volatile organic compounds (VOCs) during CRDF storage. Kinetic emission parameters have not yet been determined. It was also shown that CRDF can be pelletized for energy densification and reduced volume during storage and transportation. Thus, our working hypothesis was that structural modification (via pelletization) might mitigate VOC emissions and influence emission kinetics during CRDF storage. Two scenarios of CRDF structural modification on VOC emission kinetics were tested, (i) pelletization and (ii) pelletization with 10% binder addition and compared to ground (loose) CRDF (control). VOC emissions from simulated sealed CRDF storage were measured with headspace solid-phase microextraction and gas chromatography–mass spectrometry. It was found that total VOC emissions from stored CRDF follow the first-order kinetic model for both ground and pelletized material, while individual VOC emissions may deviate from this model. Pelletization significantly decreased (63%~86%) the maximum total VOC emission potential from stored CDRF. Research on improved sustainable CRDF storage is warranted. This could involve VOC emission mechanisms and environmental-risk management

Testing Poultry Dust Mitigation Practices

Cage-free chicken farms are prone to significant amounts of dust in the air due to the disturbance of the litter (bedding) on the ground. We needed to develop a physical test system and Standard Operating Procedure (SOP) that is able to capture and record dust samples. So the client is able to test different litter management practices, vegetable oil, for example, to minimize the amount of dust airborne in cage-free chicken farms. The ideal amount of litter management treatment is unknown. This must be solved to help lower the amount of dust that is airborne in cage-free chicken farms. A high amount of dust in the area from the disturbed bedding will cause the air quality in the barn to be very poor. High dust concentrations result in harmful effects on not only the health of chicken production employees but also the birds. Many poultry production companies over the United States are implementing different litter management practices to try and reduce the airborne dust due to the ban of battery cages for raising poultry in some states. Michigan, Ohio, Washington, and California have bans on battery cages. This results in many more poultry farms in the states listed above to turning to cage-free farms

Modeling solid-phase microextraction of volatile organic compounds by porous coatings using finite element analysis

Experimental optimization of analytical methods based on solid-phase microextraction (SPME) is a complex and labor-intensive process associated with uncertainties. Using the theoretical basics of SPME and finite element analysis software for the optimization proved to be an efficient alternative. In this study, an improved finite element analysis-based model for SPME of volatile organic compounds (VOCs) by porous coatings was developed mainly focussing on the mass transport in coatings. Benzene and the Carboxen/polydimethylsiloxane (Car/PDMS) coating were used as the model VOC and a porous SPME coating, respectively. It has been established that in the coating, volumetric fractions of Carboxen, PDMS, and air are 33, 42 and 24%, respectively. Knudsen diffusion in micropores can slow down a mass transport of analytes in the coating. When PDMS was considered as the solid part of the coating, lower root-mean-square deviation of the modeling results from experimental data was observed. It has been shown that the developed model can be used to model the extraction of VOCs from air and water samples encountered in a typical SPME development method procedure. It was possible to determine system equilibration times and use them to optimize sample volume and Henry\u27s law constant. The developed model is relatively simple, fast, and can be recommended for optimization of extraction parameters for other analytes and SPME coatings. The diffusivity of analytes in a coating is an important property needed for improved characterization of existing and new SPME polymers and analytical method optimization

Chemical-Sensory Characterization of Dairy Manure Odor Using Headspace Solid-Phase Microextraction and Multidimensional Gas Chromatography Mass Spectrometry-Olfactometry

Livestock operations are associated with emissions of odor, gases, and particulate matter. The majority of previous livestock odor studies focused on swine operations whereas relatively few relate to dairy cattle. Identifying the compounds responsible for the primary odor impact is a demanding analytical challenge because many critical odor components are frequently present at very low concentrations within a complex matrix of numerous insignificant volatiles. The objective of this study was to describe a chemical-sensory profile of dairy manure odor using headspace solid-phase microextraction (HS-SPME) and multidimensional gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O). Two analytical approaches were used: (1) HS-SPME time-series extractions (from seconds up to 20 hr) followed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analyses, and (2) relatively short HS-SPME extractions (30 min) followed by MDGC-MS-O analyses on selected chromatogram heart-cuts. Dairy manure was collected at research dairy farms in the United States and Israel. Volatile organic compounds (VOCs) resolved from multiple analyses included sulfur-containing compounds, volatile fatty acids, ketones, esters, and phenol/indole derivatives. A total of 86 potential odorants were identified. Of them, 17 compounds were detected by the human nose only. A greater number of VOCs and odorous compounds were detected, as well as higher mass loading, on solid-phase microextraction (SPME) fibers observed for longer extractions with SPME. However, besides sulfur-containing compounds, other selected compounds showed no apparent competition and displacement on the SPME fiber. The use of MDGC-MS-O increased chromatographic resolution even at relatively short extractions and revealed 22 additional odorants in one of the regions of the chromatogram. The two analytical approaches were found to be parallel to some extent whereas MDGC-MS-O can also be considered as a complementary approach by resolving more detailed chemical-sensory odor profiles

Effects of Dietary Treatment on Odor and VOCs Emitted From Swine Manure

Odor and volatile organic compounds (VOCs) emissions associated with swine production facilities are major concerns for the swine industry. Swine manure is one of the major sources of odor from swine operations. Odor control approaches include ration manipulation, improved manure treatment processes, capture and treatment of odorous gases, and improved dispersion. This study was conducted to investigate the effects of a low level of crude protein and low sulfur content in diets of young swine on odor and VOCs emissions from the headspace of swine manure. Small pigs in metabolic stalls were fed twice daily over 28 days with diets containing either 19.36 % crude protein, 7.06 % cellulose and 2,296 mg/kg sulfur (diet B) or 17.83 % crude protein, 6.82 % cellulose and 1,772 mg/kg sulfur (diet H). Three replicate trials were conducted and three pigs were used for each diet. All excreted manure (feces and urine) were collected daily after morning feeding and added to the manure storage vessel designed to hold waste from the same growing pig. Gas samples were collected from the headspace of manure storage container using 85 µm Carboxen/PDMS SPME fibers at the end of each trial and three replicate gas samples were collected for each pig. All samples were analyzed simultaneously for chemicals and odors on a GC-MS-olfactometry system. Statistical analyses were performed to determine the effects on diets on target odorous chemicals and odor. A total of 40 compounds belonging to 14 chemical classes were identified in the headspace of swine manure. A subset of 14 odorous compounds responsible for the characteristic odor of swine manure were selected for statistical analyses. The lower sulfur and crude protein diet was associated with reduced methanethiol (p=0.0686), dimethyl sulfide (p=0.0006), 2,4-dithiapentane (p\u3c0.00001), acetone (p=0.0003), toluene (p=0.0133), 4-methyl phenol (p=0.0745), 4-ethyl phenol (p=0.00004) and skatole (p=0.0002). The total odor (p=0.0262) and some characteristic odors caused by specific gases were also significantly reduced, i.e. ‘sewer’ (H2S) (p=0.0014), ‘acetic’ (acetic acid) (p=0.00001), ‘skunky’ (2,4-dithiapentane) (p=0.0261), ‘onion’ (dimethyl trisulfide) (p=0.0122) and phenolic’ (4-ethyl phenol) (p=0.0168)

Characterization of Livestock Odors Using Steel Plates, Solid Phase Microextraction, and Multidimensional-Gas Chromatography-Mass Spectrometry-Olfactometry

Livestock odor characterization is one of the most challenging analytical tasks. This is because odor-causing gases are often present at very low concentrations in a complex matrix of less important or irrelevant gases. The objective of this project was to develop a set of characteristic reference odors from a swine barn in Iowa, and in the process identify compounds causing characteristic swine odor. Odor samples were collected using a novel sampling methodology consisting of clean steel plates exposed inside and around the swine barn for up to one week. Steel plates were then transported to the laboratory and stored in clean jars. Headspace solid phase microextraction (SPME) was used to extract characteristic odorants collected on the plates. All analyses were conducted on a Gas Chromatography-Mass Spectrometry (GC-MS)-Olfactometry system where the human nose is used as a detector simultaneously with chemical analysis via MS. The effects of sampling time, distance from a source, and the presence of particulate matter (PM) on the abundance of specific gases, odor intensity, and odor character were tested. Steel plates were effectively able to collect key volatile compounds and odorants. The abundance of specific gases and odor was amplified when plates collected PM. The results of this research indicate that PM is major carrier of odor and several key swine odorants. Three odor panelists were consistent in identifying p-cresol as closely resembling characteristic swine odor as well as attributing the largest odor response out of the samples to p-cresol. Further research is warranted to determine how the control of PM emissions from swine housing could affect odor emissions

Perspectives and challenges of on-site quantification of organic pollutants in soils using solid-phase microextraction

This study explores the current state-of-the-art progress toward on-site quantification of organic pollutants in soils with solid-phase microextraction (SPME). In spite of many available methods, only few publications report on-site analyses of soil samples by SPME. To date, the only application of SPME for the on-site quantification of organic pollutants in soil has been devoted to trichloroethylene. The problem of matrix effects limiting quantification by external standard calibration is discussed. Efficiencies of available approaches for decreasing and controlling matrix effects are evaluated and compared. SPME from a soil sample headspace with internal standard calibration was identified as one of the promising approaches to achieve fast, simple, precise, and accurate on-site quantification of a wide range of organic pollutants in soil. Cold-fiber SPME has a significant development potential, because it is capable of providing lowest detection limits together with a minimum matrix effect. Perspectives for future development of the field are outlined

Test Device and Process for Assessment of Smithfield Facility Aging

● Establishing structural objective tests and recommendations for hog production facilities. ● The risks are to the livestock, growers, and Smithfield for potential collapses of hog facilities in NW Iowa. ● We assess our solution to be applicable to a large portion of the hog production industry to quickly and objectively measure truss deterioration and provide detailed monetary and structural guidance to growers

Agriculture Study Abroad program to Poland

The Technology Travel Course (TSM 496) is an elective course that meets the university-wide international perspectives requirement. The course has a curricular home in the department of Agricultural and Biosystems Engineering (ABE), Iowa State University (ISU). It enables instructors to develop and offer a study abroad program structured as a faculty-led trip abroad. This course is also an excellent opportunity for students to learn/compare technology concepts and applications in an international context that is encouraged by the ABE External Advisory Board. The objectives of this paper are to (1) Review the application of TSM 496 to Ag Study Abroad trip to Poland (with cultural trips to Czech Republic, Denmark, Germany, Lithuania, and Ukraine, and to (2) summarize curricular enhancement of student learning objectives (SLOs) and competencies. The course has been offered yearly since 2011, and served 48 students from several majors in Agriculture & Life Sciences and Engineering colleges. The pre-departure course is focused on teaming up ISU students with students at two agricultural universities in Poland. Teams develop comparative projects focused on agriculture with specific emphasis on animal systems production, technology, environment, sustainability, and regulations. Projects are finalized and presented jointly at special Polish-American Student Workshops. The joint project format creates an opportunity to make friends with students in Poland while working on international projects. The scientific part of the program is a mix of field trips to farms, plants, co-ops, lab tours, cultural sites and activities. Students have many opportunities to socialize, get inspired by rich culture, history, science, agro business attitudes and the spirit of change. SLOs are measured with the program surveys. Currently 65 SLOs/competencies are enhanced with 17 provided by this program (26%). In addition, 25 new competencies are gained, a 38% increase to the new total of 90. Students highly rate this learning and often list it as a highlight of their college career thus far. Data analysis of the Program Evaluation Surveys shows high degree of developing student skills, meeting and enhancement of class goals, departmental and college SLOs

Torrefaction of Sewage Sludge: Kinetics and Fuel Properties of Biochars

We propose a ‘Waste to Carbon’ thermal transformation of sewage sludge (SS) via torrefaction to a valuable product (fuel) with a high content of carbon. One important, technological aspect to develop this concept is the determination of activation energy needed for torrefaction. Thus, this research aimed to evaluate the kinetics of SS torrefaction and determine the effects of process temperature on fuel properties of torrefied products (biochars). Torrefaction was performed using high ash content SS at six (200~300 °C) temperatures and 60 min residence (process) time. Mass loss during torrefaction ranged from 10~20%. The resulting activation energy for SS torrefaction was ~12.007 kJ·mol−1. Initial (unprocessed) SS higher heating value (HHV) was 13.5 MJ·kg−1. However, the increase of torrefaction temperature decreased HHV from 13.4 to 3.8 MJ·kg−1. Elemental analysis showed a significant decrease of the H/C ratio that occurred during torrefaction, while the O/C ratio fluctuated with much smaller differences. Although the activation energy was significantly lower compared with lignocellulosic materials, low-temperature SS torrefaction technology could be explored for further SS stabilization and utilization (e.g., dewatering and hygienization)