Abstract

A sustainable food supply chain (FSC) is at the nexus of several critical global challenges including hunger, resource scarcity, climate change, poverty, energy security and economic growth. However, managing FSC resources in a sustainable manner is complex and data to support this goal is lacking. This dissertation addressed four knowledge gaps by applying a variety of analytical and experimental tools to the New York State FSC.

First, a cradle-to-grave analysis of the New York State FSC was conducted. Resources leaving the FSC from primary production (post-harvest) through to consumption were defined and characterized. Surveys and literature were used to estimate FSC resources and factors were provided for several sectors and sub-sectors including the Educational sector. Material flows through the utilization pathways in New York State were analyzed. It was estimated that over 3.5 million t/yr of solid resources were generated. Resource utilization pathways including donation were estimated to treat approximately 6% of these resources. An additional 22 million m3/yr of low solid resources primarily from the food processors was also estimated and analyzed.

In the next chapter, climate change impacts of utilization pathways emerging in the State were analyzed. Two comprehensive lifecycle assessments (LCAs) were conducted to assess climate change impacts. The first was based upon primary data collected from the largest on-farm anaerobic digester in the State, which co-digests dairy manure and industrial food wastes. The results showed a net negative climate change of 37.5 kg CO2e/t influent processed when compared to the reference case. Displacement of grid electricity provided the largest reduction, followed by avoidance of alternative food waste disposal options and reduced impacts associated with storage of digestate vs. undigested manure. Sensitivity analysis showed that using feedstock diverted from high impact disposal pathways, control of digester emissions, and managing digestate storage emissions were opportunities to improve climate change benefits. The second LCA was based upon a small-scale, distributed waste-to-ethanol process. This analysis was based upon data from an operating pilot plant facility, co-fermenting industrial and retail FSC resources. The climate change impacts for the processing phase were estimated to be comparable to those associated commercial ethanol production, however when considering the avoidance waste disposal for FSC resources used as feedstock, the result was a net negative impact of 338 kg CO2e/MJ fuel produced.

The following chapter evaluated the potential of several significant New York State FSC resources as feedstock for biogas production. Twenty-four source-separated, commercial substrates from the retail and food processing sector were characterized and tested in bench-scale bio-methane potential (BMP) tests. Substrates were also combined with dairy manure and other substrates to assess synergistic or antagonistic effects associated with co-digestion. Key bio-methane kinetic parameters including bio-methane potential, apparent hydrolysis rate constant and co-digestion indices were reported. Substrates with high fat content demonstrated higher potential for bio-methane generation. Substrates rich in readily hydrolysable carbohydrates and fats showed more complete bio-degradation. Measured bio-methane potential was the product of both of these factors. Bio-methane production of co-digested substrates was close to that of the weighted average of the individual substrates with a slight synergistic bias (-5%/+20% on average). However, co-digestion generally resulted in an increase in apparent hydrolysis rate relative to that predicted by the combination of individual substrates.

Library of Congress Subject Headings

Food supply--Environmental aspects--New York (State); Food waste--Environmental aspects--New York (State); Life cycle costing

Publication Date

4-2016

Document Type

Dissertation

Student Type

Graduate

Degree Name

Sustainability (Ph.D.)

Department, Program, or Center

Sustainability (GIS)

Advisor

Thomas A. Trabold

Advisor/Committee Member

Nabil Nasr

Comments

Physical copy available from RIT's Wallace Library at HD9007.N7 E26 2016

Campus

RIT – Main Campus

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