Grantee Research Project Results

Conversion of crop waste into construction material

EPA Grant Number: SU839850
Title: Conversion of crop waste into construction material
Investigators: Venkatadriagaram, Sundararajan , Lin, Dayong , Orluck, Dylan , Ortiz, Erica , Aoki, Genevieve , Templer, Shawn , de Bleecker, Yann
Current 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 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

Description:

The goal of this research is to develop construction material out of wheat straw, thereby converting straw into a product of higher value. Phase I of the project specifically targets conversion to panels that can replace traditional gypsum-based drywall. The project will develop a drywall substitute that has comparable mechanical, thermal and chemical properties but superior moisture resistance, workability and biodegradability upon disposal.

Objective:

This proposed project develops a two-step process to convert straw into construction material. The first step consists of converting straw into pulp while the second involves converting the pulp into the final construction material. The first step will closely follow the Kraft process for making paper pulp. The second step of converting paper pulp to the final construction material will be customized based on the end product. The project will adopt a rigorous statistical design of experiments methodology to determine the optimal set of operating process parameters to produce a product of the desired mechanical, thermal and chemical properties. It will characterize the environmental impact of the manufacturing process and the product to account for all waste flows, energy flows and material flows in order to obtain accurate comparisons with current methods. It will also re-use the wastes generated from the process so that they can be used as fertilizers.

The project involves conversion of straw which is typically sent as solid waste to landfills into valuable construction material. It also displaces an environmentally impactful and non- biodegradable material with poor workability, and thereby contributes to reduction in solid waste as well as improved safety during installation, repair, tear-down and disposal. Finally, it reduces transportation costs associated with the production and shipping of drywall over long distances as the proposed conversion plants can be developed and commissioned close to farmlands in rural communities. The project will thus provide economic benefits to these communities and will also enable cities and towns in the vicinity to source drywall locally.

The project will be used to provide case studies and problem-based learning in three classes in the Mechanical Engineering and two classes in Chemical Engineering. The results will be presented at the Undergraduate Research Symposium organized annually at the University of California, Riverside, at the annual Southern California Conferences for Undergraduate Research and at the annual Spring Green Expo organized by the Metropolitan Water District of Southern California

Expected Results:

The project will result in a process and a product for converting straw to construction material, specifically drywall. The construction material will have comparable mechanical properties (flexural strength, compressive strength and toughness) and thermal properties (flame resistance and thermal conductivity) as conventional drywall. It will exhibit superior moisture and mold resistance capability as well as have lower environmental impact. The process will be carefully tuned using statistical design of experiments to obtain optimum yield with acceptable environmental impact. The project will yield knowledge regarding the trade-offs that result from the experimental process. The properties of the material will be tested with materials testing facilities available at the University of California, Riverside in the Mechanical Engineering, Chemical Engineering and the Center for Environmental Research.

Contribution to Pollution Prevention or Control: The project reduces the amount of solid waste that is discarded in landfills from two sources: crop waste and construction/demolition waste. By diverting crop waste from landfills, it reduces the release of methane due to anaerobic digestion. Likewise, by reducing the amount of drywall that is discarded from construction or demolition processes, it reduces the possibility of hydrogen sulfide release due again to anaerobic digestion in landfills.

Supplemental Keywords:

Green buildings, green materials, upcycling, resource recycling, reuse, environmentally benign substitute, waste-to-value, sustainable construction

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.