Grantee Research Project Results

2020 Progress Report: Conversion of crop waste into construction material

EPA Grant Number: SU839850
Title: Conversion of crop waste into construction material
Investigators: Venkatadriagaram, Sundararajan , Lin, Dayong , Templer, Shawn , Ortiz, Erica , de Bleecker, Yann , Aoki, Genevieve , Orluck, Dylan
Institution: University of California - Riverside
EPA Project Officer: Page, Angela
Phase: I
Project Period: November 1, 2019 through October 30, 2020 (Extended to October 30, 2022)
Project Period Covered by this Report: November 1, 2019 through October 31,2020
Project Amount: $24,998
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2019) RFA Text |  Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Sustainable and Healthy Communities

Objective:

The objective of this project is to reuse crop waste, specifically wheat straw, and convert it to a construction material that can provide a substitute for conventional gypsum-based drywall. The wheat straw will be converted using the Kraft process into pulp which will then processed into dry-wall boards. Theresults of this new drywall product will not only be comparable to the traditional drywall, but will have benefits like higher moisture resistance and biodegradability upon disposal. The goal is to provide an environmentally friendly alternative to conventional dry-wall, reuse crop waste and prevent health risks associated with the manufacturing, installation, teardown, and disposal of the traditional drywall. For example, conventional dry-wall produces considerable amount of dust that can be a respiratory irritant. The new wheat straw based drywall will greatly reduce the exposure of drywall dust and eliminate the release of hydrogen sulfide compared to the traditional drywall.

Progress Summary:

The team has completed a detailed process flow diagram (PFD) with simulated results and mathematical modeling and analysis. The design used for this research is based on the Kraft process typically used to turn wood into pulp for paper and particle boards. The team has modified this process to be more environmentally friendly by using potassium hydroxide and ammonia. Though the SuperProDesign simulation, the results of the overall conversion rate percentages are as follows: 100% for Acetic Acid, 100% for Diluted Ammonia, 80.4% for wheat grains, 93.8% for water, and 42.1% of potassium hydroxide (KOH). On a feed basis of approximately 50 tons (45,000kg) of wheat straw, assuming constant inlet water flow rate, the amount of pulp that was produced is about 31,905kg/batch. With about 8387kg/batch of byproduct produced consisting of mostly sugars and proteins. From this, the percent yield of pulp is around 53.9% which is higher than the literature’s value of about 50% yield. The waste streams such as the black liquor can also be processed for valuable materials. At the moment, undergraduate students were prevented access to laboratories due to COVID-19 restrictions. So, no experiments could not be conducted. Laboratory experiments will begin immediately as the materials and equipment needed have been purchased.

Future Activities:

As stated in the Progress Summary/Accomplishments section, laboratory experiments are the next step for the project team once restrictions have been lifted. Once experiments are started, operating parameters like pressures and temperatures will be tested and optimized for the most effective production of pulp. Feed basis will also be considered to get the most optimal percent yield without the quality of the pulp decreasing. Experiments will be conducted under the Standard Operating Procedures for the University of California, Riverside and supervision under the Principal Investigator or Supervisor.

Supplemental Keywords:

green engineering, resource recycling, environmental substitute, waste-to-value, sustainable construction.

Progress and Final Reports:

Original Abstract

2021 Progress Report

Final Report