Project Goal: Using environmentally friendly options, design, produce and recover energy from food waste in Denver, Colorado.

Fossil fuel-generated electric power leads to increases in greenhouse emissions. Anaerobic digestion is an environmentally friendly process that produces methane, which can be used as fuel to help decrease greenhouse emissions.

In this design, food waste is purified in a separation process and combined with manure to enrich the organic matter. Then the anaerobic digestion process uses two reactors to maintain stability, one that handles the hydrolysis and acidogenic reactions and the other to handle acetogenic and methanogenesis. The resulting main products are methane and carbon dioxide in biogas and liquid forms. The biogas, which has a ratio of 60 methane to 40 carbon dioxide, can be used as a power source. Liquid materials can be used in other ways.

Such an operation can process up to 36 tons of food waste per day to produce 1.3 million cubic meters of methane per day.

Project Goal: Without altering its main functionality, restructure the Gilbert North Water Treatment Plant to improve operation so it accommodates the plant’s emerging issues from population growth.

The city of Gilbert’s water treatment plant recently experienced an increase in total organic content, which results in disinfection byproducts in the clean-water reservoirs. This project assesses four water treatment techniques to determine which consistently reduces high contaminant levels to Environmental Protection Agency standards.

The assessment looked at enhanced coagulation, a combination of ozone/UV and biological activated carbon filters, microsand filtration and nano filtration. These treatment techniques can reduce and sustain the water's total organic content, or TOC, levels to less than 2 mg/L.

A decision matrix considered economics, as well as social and environmental factors, to determine the most cost-effective and reliable method.

Project Goal: Explore the viability of aluminum-air batteries as an alternative to lithium-ion batteries in electric vehicles.

Electric vehicles are a promising alternative to gasoline-powered cars because their operation results in reduced fossil fuel emissions. However, producing the vehicles causes more pollution than producing gasoline-powered cars. This is mainly because of the high environmental cost of mining lithium and producing lithium-ion batteries.

One potential solution is the aluminum-air battery, which has a life cycle that generates fewer emissions. The aluminum ore is much more abundant than lithium and is closer to the earth’s surface. A limiting factor for widespread use of aluminum-air batteries is that they typically are not rechargeable.

To examine its viability in terms of operating voltage and power density, this team developed a primary aluminum-air battery with a nonaqueous AlCl4-/KCl ionic liquid electrolyte.

Project Goal: Develop a process to manufacture a recyclable heating, ventilation and air conditioning filter capable of filtering out dust and allergens with a stretch goal of filtering out the COVID-19-causing coronavirus and other viruses.

An HVAC filter is the first line of defense against dust and other allergens that enter a home. Modern HVAC filters are disposable, and millions end up in landfills then take decades to decompose.

This environmentally friendly filter design uses a decomposable biopolymer, poly butyric acid instead of a synthetic polymer as the main component in the fibers of an HVAC filter. The fibers are thermoplastic polymers molded and set with a melt blower, a non-woven technology. The polymer is then delivered to a conveyor belt at an extremely high velocity, which collects the polymer and prepares it for use in an HVAC system.

In developing the process, the team accounted for manufacturing differences between a biopolymer and synthetic polymer. The use of biodegradable HVAC filters reduces plastic buildup in landfills.

Project Goal: Simulate on an industrial scale the manufacturing and distribution of a COVID-19 vaccine.

Producing and distributing as many vaccine doses as possible is critical to ending the spread of the coronavirus. This project simulates the chemical engineering process for production and distribution of the COVID-19 mRNA vaccine BNT162b2, which is produced by Pfizer and BioNTech, and suggests the best model for production configuration.

To determine the best configuration in terms of cost, safety and environmental impact, the project analyzed manufacturing information released by Pfizer. This resulted in a model for scaled-up industrial equipment such as bioreactors, filtration systems, storage tanks and freezers.

The team carefully considered benefits and drawbacks of multiple configurations and found that the optimal model involved fitting disposable bioreactors to the manufacturing process and having one centrally located plant.

Project Goal: Design technology to mitigate lunar dust in astronauts’ cabin environment.

Since NASA’s first lunar landing by humans, it has tried to address the damage to technology caused by the moon’s abrasive electrostatically charged dust. This project focuses on solutions and technologies to mitigate the dust.

The filtration system design uses suction to clean the dust out of the air then pass it through an aerogel-packed bed with a series of high-efficiency particulate air filters. A pump recycles the air through the system to trap more dust particulates. The bottom of the system creates an electrostatic field that attracts the charged lunar dust particles. As the air recycles through the system, the dust that does not get trapped by the packed bed and filters is drawn to the electrostatic field at the bottom of the system.

The design is compact and can be used inside the cabin.

Project Goal: Design a process for an environmentally beneficial fuel additive that can be added easily onto an existing ethanol plant to improve its profitability.

Biofuels come from renewable biological materials, such as ethanol from corn, grass, biomass and algae and diesel from soybeans. Replacing fossil fuels with biofuels or blends can cut down on some aspects of fossil fuel production and use, resulting in decreased conventional and greenhouse gas emissions, exhaustible resource depletion, and dependence on foreign suppliers. The EPA’s Renewable Fuel Standard, or RFS, encourages ethanol manufacturers to produce biofuel additives cost effectively.

Using an existing corn-based, dry mill ethanol plant, this design synthesizes diethyl ether, or DEE, a highly rated biofuel additive. The catalyzed synthesis process requires minimal equipment and energy, reducing initial costs and making it a viable option for an ethanol plant. The project further evaluated profitability based on DEE’s market value and RFS incentives.

Project Goal: Design a process that treats three different types of wastewater for a chemical engineering integration lab at the University of Arizona.

This design will be used in labs to teach UA undergraduate students about wastewater treatment processes.

Wastewater treatment removes contaminants from wastewater through physical, chemical and biological processes and converts the water into an effluent, which is safely returned to the environment. The centralized U.S. waste treatment industry handles about 75% of the commercial wastewater and industrial process byproducts.

This lab treatment system is expected to purify wastewater found in three industries: mining, agriculture and semiconductor. Each type of waste goes through a designated path that includes treatment processes such as reverse osmosis, coagulation/flocculation, filtration and membrane bioreactor technology. The product must comply with EPA and local regulations for potable water.

Project Goal: Design and build a wastewater treatment laboratory for the University of Arizona Chemical and Environmental Engineering Department to use in a novel hands-on course.

The UA Department of Chemical and Environmental Engineering is developing a wastewater treatment laboratory. It will combine several unit operations to purify artificial wastewater for demonstrating classic techniques. The feed streams are modeled after raw water concentrations seen as runoff from common industries in southern Arizona.

The project addresses coagulation, flocculation, gravity filtration and advanced oxidative treatment processes as well as design of the three chemical broths for separation. These were incorporated into a previous team design that uses reverse osmosis and a membrane bioreactor. An interchangeable valve setup varied the order of flow through the subsystems. Separation was characterized by monitoring pH, density, turbidity and electric conductivity throughout the process.

The design included researching, sizing, selecting and building each unit operation and associated equipment so the laboratory can feasibly operate in a safe, cost-effective and environmentally responsible manner.

Project Goal: Separate the components of guayule resin into high-value products, and evaluate their market potential.

Guayule is a desert plant that contains 5% to 7% rubber, primarily in the stalk. It is extracted to make tires. The guayule plant also contains 5% to 9% resin, which can be turned into products to keep the guayule industry economically feasible. Thus, this project explores the separation of the guayule to make marketable products.

The team used ASPEN software to simulate the separation process, including flash and distillation to fraction the resin into terpenes, terpenoids, sesquiterpenes and fatty acids. Resin content varies depending on the environmental conditions under which guayule is grown, and this simulation can be used to predict the required operating conditions depending on the feed composition.

The expected outcome is production of natural products, such as terpenes and terpenoids, which can be sold at approximately $1 a pound.