An Integrated Systems Model for Sustainably Managing Dairy and Food Wastes

New York is the third largest dairy state in the U.S with approximately 625,000 dairy cows, generating over 15 million tons of manure annually. Current manure management and disposal practices (storage and land application) can result in significant methane emissions and environmental damage to river basins and lakes. Furthermore, over 4 million tons of food wastes are landfilled every year in the state. Food waste degradation represents the 3rd largest source of anthropogenic methane emissions in the US. To tackle this problem, New York State passed the ‘Food Donation and Food Scraps Recycling’ law (effective January 2022), requiring producers of more than two tons of food waste per week to redirect their wastes from landfills. This represents an opportunity for the potential commercialization of novel energy and resource recovery techniques to reduce the environmental impacts of current waste disposal methods via new revenue streams. An integrated biorefinery system, consisting of Anaerobic Digestion, Hydrothermal Liquefaction and Biomethanation Power-to-gas technologies, is a promising approach to efficiently convert biomass wastes and recover energy in the form of Renewable Natural Gas, biocrude oil and hydrochar. In this study, a Geographic Information System model was developed to evaluate the variations in technical, economic, and environmental performance of hypothetical biorefineries treating agricultural and food wastes across New York, thereby serving as a fundamental decision tool for policy makers and industry involved in distributed energy and waste management systems.

 

Link to Project:   An Integrated Systems Model for Sustainably Managing Dairy and Food Wastes | AIChE

Primary Category

Associated Content

GIS model MATLAB code

About

  • The model is used to visualize a biorefinery’s techno-economic performance and its associated environmental impacts across New York State. The model allocates spatially distributed biomass waste feedstocks into a centralized biorefinery and computes the life cycle techno-economic (NPV, LCOE, energy production) and sustainability (net GHG emissions, GHG abatement costs) metrics across the entire value chain (feedstock transportation, feedstock processing, renewable fuel production and distribution into the natural gas grid, waste byproduct disposal) for various biorefinery configurations. Biorefinery performance is illustrated through various outputs, including: spatial maps, NPV curves, GHG emissions breakdown charts, feedstock mixture composition, carbon credits integration, discounted cash flows. The model allows user-specified inputs to reflect local/regional market prices, feedstock availability and types, process conditions and policy regulations. The model serves as a fundamental decision tool that informs climate policy and technology options to accelerate the deployment of biorefineries and enable effective decarbonization.

RAPID Content File Info

  • Files include 3 MATLAB scripts (to run the model), 13 MATLAB functions for the various modeling components (process modeling, techno-economic analysis, GHG life cycle assessment, spatial modeling) and 4 data files.
      • Integrated_biorefinery_model.m: Script used to run the model for a specified biorefinery location.
      • Spatial_optimization.m: Script used to run the model across NYS and visualize the biorefinery spatial performance.
      • Distributed_biorefinery_case.m: Script used to run the model for a set of x distributed biorefineries across NYS.
      • Latlondist.m: Function that computes the distance between two locations with known coordinates
      • waste_allocation_updated.m: function that allocates the feedstocks into a centralized biorefinery given a specified biorefinery location and buffer radius
      • WWTPintegration_waste_allocation.m: function that computes (i) the amount and types of feedstocks redirected to existing WWTPs in NYS, and (ii) the waste feedstocks that will be redirected to biorefineries
      • waste_allocation_post_WWTP.m: similar to waste_allocation_updated.m, but uses the updated feedstock data generated by WWTPintegration_waste_allocation.m
      • macromolecular_conversion.m: function that computes the feedstock mixture characteristics (protein, carbohydrates, lipids, inserts concentration etc.) given the individual flow rates of each feedstock going into the biorefinery
      • AD_kinetic_model.m: function that computes AD methane generation, biogas composition and digestate composition based on the feedstock mixture composition
      • HTL.m: function that computes biocrude oil, hydrochar, CO2 and aqueous phase generation from digestate hydrothermal processing. Also includes heat exchanger design calculations.
      • Power_to_Gas.m: function that computes hydrogen, electrolyzer capacity, hydrogen production, biomethane production, electrolysis operating hours etc.. based on AD and HTL CO2 flow rates, and electrolyzer mode of operation.
      • RNG_injection_infrastructure.m: function that computes the pipeline development and construction costs as well as the pipeline pumping costs (between biorefinery and NG grid injection point).
      • cost_estimation.m: function that computes the capital costs and annual operating expenditures of the biorefinery given the size and capacity of the equipment
      • revenues_estimation.m: function that computes revenues from the different product streams
      • DCF.m: discounted cash flow model to compute economic performance metrics such as the net present value and levelized cost of energy
      • carbon_emissions.m: function that computes the biorefinery system’s life cycle net GHG emissions
      • Wasteproducers_spatialdata.xlsx: database showing the location and waste throughput (ton/week) for different types of waste producers. Source: NYS P2I ‘Organic Resource Locator’ database (2018) https://www.rit.edu/affiliate/nysp2i/organic-resource-locator. Also includes data on NYS wastewater treatment plants (i.e. treatment capacity, biosolids production). Source: NYDEC (2020) https://data.ny.gov/Energy-Environment/Wastewater-Treatment-Plants/2v6p-juki
      • Wasteproducers_spatialdata_combined_WWTP.xlsx: database showing the location and waste throughput (ton/week) for different types of waste producers (not including wastewater treatment plants). Source: NYS P2I ‘Organic Resource Locator’ database, 2018.
      • NYS_2019_average_LBMP.xlsx: file showing the hourly electricity wholesale prices for NYS in 2019. Source: NYISO (2019) https://www.nyiso.com/energy-market-operational-data
      • NG Compressor Stations.xlsx: data file showing the location of compressor stations along the NYS NG grid. Sources: NYS GIS clearinghouse (https://gis.ny.gov/gisdata/inventories/details.cfm?DSID=315), US EIA (https://www.eia.gov/maps/layer_info-m.php) and ArcGIS (https://www.arcgis.com/home/item.html?id=e52cc3c9f0c9473da9729c48f65b68c8)

Content File

Licensing Info

Not Applicable

Acknowledgment for Software

  • All software was developed by Cornell Researchers using MATLAB

User Base

Keywords

Corresponding Author(s)

Jefferson W. Tester, jwj54@cornell.edu

Nazih Kassem, nk644@cornell.edu

Licensing

Not applicable

Acknowledgment

  • This material is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Advanced Manufacturing Office Award Number DE-EE0007888.