Post-Harvest Logistics and Co-Products

Post-Harvest Logistics and Co-Products

Purpose | Methods | Progress | Research & Results | Team


Post-Harvest Logistics and Co-Products

Guar and guayule are promising crops because they can be used to produce industrial products that have already been shown to be financially feasible: guar gum and hard rubber for tires. The long-term resilience of guar and guayule economies can be improved by developing additional and value-added products from other parts of the plants. For this reason, SBAR researchers in this component focus on co-products from guar protein and hulls, and from guayule resin and bagasse.

Young guar plant freshly cropped from the field ~one month prior to harvest, New Mexico.
Young guar plant freshly cropped from the field ~one month prior to harvest, New Mexico.

Growing guar and guayule in the field is the first part of the path to end-product sales. Since biomass quality is affected by time (time of harvest, storage time and conditions, transportation time), attention must be paid to how harvested biomass is handled between field and processing facility. Guayule rubber in the plant begins to break down after harvest, so there is limited time to get the materials from the field to the extraction plant. Biomass is also bulky and varies from batch to batch, which complicates harvesting, packing, loading and unloading, routing, processing, and selecting transportation mode(s). Post-harvest logistics modeling and testing will allow researchers and practitioners to identify the optimal strategies for harvest and collection levels, storage amounts, and transportation routes to meet demands in economically efficient and environmentally sustainable way.




Biochemical Characterization of Guar and Guayule Bagasse

Guar bagasse, mostly stems, collected from the field

Guar bagasse, mostly stems, collected from the field.

Bomb calorimeter

Bomb calorimeter used to measure bagasse energy content as higher heating value (HHV)

Bagasse refers to the residues from a product extraction from plant biomass, traditionally the fibrous material left over after the extraction of sugar from sugarcane. For guayule, the bagasse consists of the woody stem material left after resin and rubber extraction at the processing facility. For guar, bagasse consists of the plant stem, leaf, and bean pod material left on the field after combine harvesting. Bagasse has several potential applications: direct use as a solid fuel (i.e. guayule bagasse pressed into pellets for combustion in pellet stoves for heat), conversion to a liquid fuel through biochemical or thermochemical methods, return to the soil as soil cover/conditioner for nutrients and organic matter, incorporation into composite materials as a fibrous filler, etc. The characteristics and available amounts of each bagasse provides information about which application will be the most sustainable.

CHNS is the most common form of elemental analysis, and is generally accomplished through combustion. This method allows for the rapid determination of carbon, hydrogen, nitrogen, and sulphur in organic materials. A sample is burned in an excess of oxygen, and various traps collect the combustion products: carbon dioxide, water, nitric oxide, and sulphur dioxide. The masses of these elements can then be used to calculate the composition of the sample.

Characterization consists of several measurements to describe bagasse composition and properties: biochemical content by National Renewable Energy Laboratory methods for moisture, ash, extractives, hemicellulose and cellulose; elemental content by CHNS combustion and by acid digestion/inductively coupled plasma optical emission spectroscopy (ICP-OES); energy content by higher heating value analysis by bomb calorimeter, particle size distribution by sieving, and bulk density. 



Conversion of Guayule Bagasse to Fuels

The baseline use for guayule bagasse is as a solid fuel, to be pelletized at the guayule rubber extraction facility, and then sold for use in pellet stoves. A goal of the SBAR project is to find higher-value energy products that can be made from the bagasse, preferably a liquid fuel such as a hydrocarbon mixture: gasoline, jet fuel (kerosene), diesel, etc.; or one of the shorter-chain oxygenated fuels: ethanol, dimethyl ether, butanol, etc. The yield and quality of the produced fuel depends on the composition of the feedstock, the conversion method, and the reaction conditions. 

Among the conversion technologies being investigated for guayule bagasse are enzymatic hydrolysis and sugar fermentation, anaerobic digestion, hydrothermal liquefaction, fast pyrolysis, gasification, Fisher-Tropsch synthesis, syngas fermentation, and hydrotreatment/catalytic upgrading. In the first two years, conversion will be studied through literature review and lab-scale experiments; in the last three years, partnerships with companies/organizations will be formed to conduct pilot/demonstration scale experiments to down select conversion technologies to those most ready for commercialization. 

Conversion of guayule bagasse to fuels chart


Model and Algorithm Development for Biomass Supply Chain

A biomass supply chain consists of several operational components: from biomass harvesting and collection, pre-treatment, storage and conversion, to transportation. This research includes the development of system-level logistics models, and the identification and evaluation of alternatives for production, harvest and collection, storage, and transportation routes to meet demands. The model brings biomass production, processing, and conversion to a wholly sustainable bio-economy system, as well as simplifying and streamlining the feedstock logistics. Compared to existing research, this project will improve the efficiency of designed algorithms to obtain the solutions for decision-making, increase the quality and accuracy of optimal solutions, enhance the robustness of decisions for the biomass supply chain, and ensure the flexibility and adaptiveness of models for studying in various scales and different regions.



Progress Made Thus Far

SBAR student – Meshack Audu – in a guar research field at the NMSU Agricultural Science Center in Clovis, New Mexico.
SBAR student – Meshack Audu – in a guar research field at the NMSU Agricultural Science Center in Clovis, New Mexico.

Progress in the first year included: visits to partner field sites and processing facilities; collection of whole plant and post-processing fraction samples; characterization method establishment; training of students and researchers on characterization methods; preparation of literature review articles on biomass transportation optimization models and on biomass conversion methods; separation and identification of known and new compounds in guayule resin; and identification of secondary metabolites in guayule biomass. 



Research and Results

Posters and Presentations

Brewer Research Group SBAR

Fan Research Group SBAR




Post-Harvest Logistics and Co-Products team NM
Team Members: Mostafa Dehghanizadeh, Meshack Audu, Nicolas Soliz, Feng Cheng, Dr. Umakanta Jena, Hengameh Bayat, Dr. Catherine Brewer
Post-Harvest Logistics and Co-Products team AZ
Team Members: Dr. Neng Fan, Feng Cheng, Scott Woolf, Brian Treftz, Dr. Catherine Brewer, Dr. Omar Holguin, Stephanie Willette, Sa’Rae Montoya, Sarah Acquah, Ou Sun

Principal Investigators

Name Affiliation
Catherine Brewer New Mexico State University
Neng Fan University of Arizona
Leslie Gunatilaka University of Arizona
Omar Holguin New Mexico State University
Istvan Molnar University of Arizona

Associated Researchers and Key Personnel

Name Affiliation
Mark DeDecker Bridgestone Americas, Inc.
Jackie Jarvis New Mexico State University
Umakanta Jena New Mexico State University
Chandra Madasu University of Arizona
Alex Muraviyov Guar Resources
Sarocha (Mimi) Pradyawong New Mexico State University
Jaspreet Rekhi University of Arizona
Laura Rodriguez-Uribe New Mexico State University
Bob White Bridgestone Americas, Inc.


Name Affiliation
Matt Armijo New Mexico State University
Meshack Audu New Mexico State University
Hengameh Bayat New Mexico State University
Nico Carrero-Little New Mexico State University
Feng Cheng New Mexico State University
Mostafa Dehghanizadeh New Mexico State University
Travis Le-Doux New Mexico State University
Saba Gill New Mexico State University
Erin Gutierrez New Mexico State University
Sicilee Macklin New Mexico State University
Cesar Martinez-Bejarano New Mexico State University
Sa’Rae Montoya New Mexico State University
Kaavya Polisetti New Mexico State University
Rodrigo Rosalez New Mexico State University
Nicolas Soliz New Mexico State University
Ou Sun University of Arizona
Brian Treftz New Mexico State University
Jacob Usrey New Mexico State University
Stephanie Willette New Mexico State University
Scott Woolf New Mexico State University
April Wright New Mexico State University