Final Report - Ohio Department of Transportation

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$Page 1 of 8 Traffic Survey Report 12/29/2006 file://X:\TC\Traffic ...$

of the windrows for aeration. The combined emissions amount to 0.01 MTCE/ton of YWC (metric ton carbon equivalent per ton of yard waste compost), but given the estimates of carbon storage using yard waste compost, there is estimated to be a net carbon flux of -0.05 MTCE/ton of YWC (where a negative sign denotes carbon storage) (USEPA 2006). However, this estimate fails to account for the CO2 that is released as the yard waste becomes compost and as the compost decomposes. The reality is that, although some fraction of the original yard waste organic matter may be incorporated into new plant growth at the point of compost application, the vast majority of the yard waste carbon will ultimately be released as CO2. There are also several issues involving potential biological and chemical contamination of yard waste compost since the original feed stock often contains diseased plant matter, animal feces and residuals of yard and garden chemicals. Research investigating the effect of pesticides such as 2,4-Dichlorophenoxyacetic acid (2,4-D) in yard waste composts has been conducted. Michel et al. (1995) found that only 47% of added 2,4-D was mineralized (i.e. experienced complete biodegradation). They also found that less than 1% of added carbon was present in water from the mature compost, signifying a small potential of leaching problems from windrows. This also implies that the chemicals remain in the compost product. However, Muller et al. (1996) found that thermophilic microorganisms are able to degrade many types of pollutants. Typical yard waste composting enters this thermophilic phase once the active respiration of mesophiles raises the internal pile temperature (Fogarty and Tuovinen 1991). The degree to which composting manages biological and chemical yard waste contamination remains an open question. Another issue surrounding yard waste composting is the establishment of a standard for compost maturity. Yard waste compost maturity is not the same as stability. Stability measures the resistance of further degradation of the compost, and is determined by oxygen uptake rates or carbon dioxide evolution rates. Maturity describes the effectiveness of compost used for a specific function (e.g. mulch for landscaping versus a soil amendment for vegetable crops). The effectiveness of various tests varies depending on the feedstock source and end use of the compost. Tests have been proposed based on C:N ratio, inorganic N concentrations, and cation exchange capacities (Sullivan and Miller 2001, Brewer and Sullivan 2003). 15
1.5 Pyrolysis and Carbonization Pyrolysis is a general term for the thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen. There are numerous ways in which the process can be configured and run. The version of pyrolysis applied in this research (often referred to as carbonization) involves the heating of biomass in the absence of oxygen for the purpose of recovering a relatively pure carbon. “Fast” carbonization is believed to be most effective for maximizing production of off gas products. “Slow” pyrolysis is believed to be more effective at maximizing the production of char (Williams and Besler 1996). Shredding biomass before pyrolysis often increases the efficiency of the process, as smaller volume particles increase the rate of biomass heating and byproduct release. The type of reactor configuration used also dictates the amount of grinding needed (Demirbas 2007, Bridgwater 2000, 2003). Fast pyrolysis reactor types include fluid bed, ablative, circulating fluid bed, entrained flow, rotating cone, and transported bed reactors. Slow pyrolysis is undertaken with fixed beds, multiple hearths and rotary kilns (Bridgwater and Peacocke 2000, Williams and Besler 1996) Ablative reactors have the capacity to handle minimally ground yard waste, where fluid bed reactors can require particle sizes of 6 mm. In using these reactors, most experiments have been designed to derive transport fuels from the input biomass, either as additives or as transport fuels on their own (such as biodiesel) (Bridgwater 2003). 1.6 Asphalt Binder Tests The Asphalt Institute reports that both AASHTO and ASTM test methods are used for evaluation of performance grade (PG) asphalt binders in Ohio. These tests include determination of specific gravity (ASTM D 70), flash point (AASHTO T 48), rotational viscosity (AASHTO T 316), and dynamic shear (AASHTO T 315) on the original binder. Tests are also performed on residues from the rolling thin film oven test (RTFOT) and final pavement (PAV). The Asphalt Institute’s required specifications for the state of Ohio (current as of May 2008) have been attached as Appendix A. There are several more sophisticated tests that could (and possibly should) be used (e.g. the SUPERPAVE asphalt binder suite of tests) to characterize the properties of bitumen derived from yard waste. However, they will be of limited value without a detailed basis of comparison. Therefore, it is recommended that the highest priority be given to 16
Page 1: Final Report Bioasphalt from Urban
Page 4 and 5: Credit This document was prepared i
Page 6 and 7: List of Figures, Tables and Notatio
Page 8 and 9: 1. Introduction The research projec
Page 10 and 11: Fig. 1 - Nutrient Poor Oxisol (left
Page 12 and 13: Table 2 - Examples of Feed Stocks T
Page 14 and 15: CWRU’s carbonization reactors fal
Page 16 and 17: Table 3 - Results of Initial Carbon
Page 18 and 19: The results of the growth studies w
Page 20 and 21: The Shell Oil Company has experimen
Page 24 and 25: implementing the tests for which OD
Page 26 and 27: (8) Apply YWC to a sufficient volum
Page 28 and 29: Fig. 10 -Yard Waste Brush Pile (Oak
Page 30 and 31: 3.3 Testing Methods Drying - To mea
Page 32 and 33: Fig. 16 - Sealed Carbonization Reac
Page 34 and 35: interior temperature of the furnace
Page 36 and 37: Fig. 22 - Maple Samaras Before Carb
Page 38 and 39: 3.4 Data Analysis In order to calcu
Page 40 and 41: 2009 Buckeye Fruit 10.37 51.64 37.9
Page 42 and 43: 2010 Rhododendron Leaves 57.36 18.9
Page 44 and 45: Fig. 26 - Improvement of Byproduct
Page 46 and 47: One task of the research project wa
Page 48 and 49: Table 10 - National Asphalt Organiz
Page 50 and 51: Table 15 - Composting Organizations
Page 52 and 53: had a significant aqueous fraction.
Page 54 and 55: Bishara, S.W.,Robertson, R.E. and M
Page 56 and 57: Ji-Lu, Z., (2007), “Bio-oil from
Page 58 and 59: Terrel. R.L. (1980), “Evaluation
Page 60: Appendix A - The Asphalt Institute

Final Report - Ohio Department of Transportation

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