Project goal: To design a 25,000-gallon direct potable wastewater-reuse system for Biosphere 2. Directly treating wastewater to produce potable drinking water is known as “toilet to tap” and is the basis of this project, which aims to make Biosphere 2 as close as possible to 100 percent self-sustaining in terms of drinking water. The equipment was designed to treat the pathogens present in the water and to remove any harmful chemicals, solids or elements. The design incorporates an aerobic plug flow reactor, sludge-removal techniques, reverse osmosis, and ultraviolet and chlorine disinfection to achieve the potable water quality guidelines specified by the Environmental Protection Agency. The process was also designed to be economically feasible for Biosphere 2.

Project goal: To design a facility for large-scale manufacture of cancer immunotherapy drug bevacizumab. Immunotherapy treats cancer by using the body’s immune system to attack cancerous cells. Monoclonal antibodies such as bevacizumab can stimulate this immune response. Bevacizumab treats glioblastoma as well as colorectal, lung, kidney, cervical and ovarian cancers by inhibiting the growth of new vascular tissue. In the United States, over half a million people are diagnosed with these types of cancer every year. Bevacizumab is produced in a cascade of bioreactors charged with recombinant Chinese hamster ovary cells that proliferate and produce the antibodies, which are secreted into the extracellular medium. The secreted antibodies are purified using a process that involves centrifugation, affinity chromatography, ion exchange chromatography, and ultra-filtration. The final purified antibodies are freeze-dried and packaged in vials for shipment to healthcare providers.

Project goal: To develop a system that can treat effluent wastewater produced by hydraulic fracturing.Effluent wastewater produced by hydraulic fracturing, or fracking, often contains high levels of salts, toxic metals, and radioactive particles. Treating this toxic wastewater so that it can be responsibly reused or disposed of in a cost-effective and environmentally safe manner is a hurdle that gas companies must overcome. The design uses membrane distillation and crystallization in a system that can be easily transported and implemented for on-site treatment of fracking effluent. The treatment process will be able to generate 2,000 cubic meters of distilled water daily from effluent containing total dissolved solid levels that often exceed 100,000 parts per million.

Project goal: To design a nearly carbon-free application to grow approximately 3 million pounds of mushrooms per year. Recent developments in the field of medicinal mushrooms have shown that two species, commonly known as turkey tail and lion’s mane, are linked to possible cancer treatments, increased immune system function, and enhanced brain and liver function. Both mushroom species are grown in a commercial atrium containing a humidifier and drip system to maximize growth. Nearly all the water used in this process goes to the growth of the mushrooms, while any excess is reused and filtered using reverse osmosis.The used mushroom substrate, which is made primarily of straw, is exposed to the cellulase enzyme, which breaks down the substrate into simple sugars that can be fermented into bioethanol. The process has been shown to be sustainable and economically efficient.

Project goal: To design a solar energy plant that uses directed sunlight to produce electricity with zero emissions. The plant uses sustainable technology and renewable energy to produce electricity. The design includes solar arrays that direct sunlight to heat molten salt in a closed pipe circuit. The molten salt passes through a heat exchanger that transfers the heat to carbon dioxide. The super-critical carbon dioxide is used to spin a turbine, creating usable electricity. This system does not use water in any form for electricity generation, and can operate during the night due to a storage system that retains the heat of the molten salt.

Project goal: To design a high-efficiency brewery-distillery hybrid that produces 10,000 barrels of beer and 3,000 cases of whiskey annually. The advantages of this hybrid are reduced energy and water consumption. The plant uses novel mash-filtration techniques to achieve nearly 100 percent yield of fermentable sugars from grains, which reduces raw material demand. Water is recycled through a reverse osmosis unit for alcohol production,ensuring quality of product and minimizing equipment downtime. The heat exchanger network is optimized to reduce heat duty requirements. The distillation column is designed to achieve maximum alcohol output while automatically separating the volatiles, products and waste. The hybrid brewery-distillery process maximizes use of equipment, water and raw ingredients to increase the combined output of beer and whiskey while minimizing environmental impact.

Project goal: To design an alkylation unit that produces 5,000 barrels of alkylate per day from a common olefin feedstock found in oil-processing plants. This process converts light hydrocarbons (four-carbon chains)to a heavier hydrocarbon (eight-carbon chain), which is a preferred stock for blending high-octane gasoline to be used in airplanes and automobiles. The reactor and auxiliary units are to be placed in an existing refinery, so footprint and safety requirements are considered in the design. Sulfuric acid is used as a catalyst to run the process at reasonable operating conditions for a large-scale plant. Hydrofluoric acid can also be used, so a cost and safety comparison between the two was conducted. The first reactant for this process, butylene, is commonly created in the separation of crude oil. Typically, lighter hydrocarbons are unusable in fuel blending due to their low boiling point, so heavier molecules are created to output a higher quantity of valuable product from the refinery. By reacting butylene with isobutane via a sulfuric acid catalyst, the two molecules combine to form an eight-carbon hydrocarbon generally referred to as octane, which is sent to a different area of the plant for blending into a variety of fuels. Most of this process was simulated in Aspen Plus software and checked against best industry practices. The project also analyzed and accounted for economics, safety,and environmental impact.

Project goal: To design a distributed generation fuel cell system to replace the fraction of energy that the University of Arizona currently purchases from Tucson Electric Power. The design reacts methane and hydrogen in a reformer to produce hydrogen for the fuel cells’ feedstock and carbon dioxide as a byproduct. The hydrogen and carbon dioxide are fed to a pressure-swing adsorption column, which removes carbon dioxide, and the pure hydrogen is fed to the fuel cells. The process uses a solid-oxide fuel cell that reacts oxygen and hydrogen across a cadmium cathode to produce water and electricity, which is then fed to the University of Arizona’s power grid. Heat from the carbon dioxide is recovered by heating up the air feed to the fuel cell using a heat exchanger. The addition of fuel cells around campus allows the University to be powered by green energy while reducing its electricity bill. The water produced as waste is reused in the heating and cooling system for the fuel cells.

Project goal: To create temporary disaster-relief housing from re-purposed post-consumer cardboard. The design of the shelter includes water-and fireproofing features that can withstand inclement weather and environmental hazards. The construction material is formed via pulping of recycled cardboard, which incorporates the removal of particulates, adhesives and pulp fibers that do not meet strength requirements. After cleaning and refining, the pulp is dried, rolled and formed into new paperboard, which is chemically treated to improve its resistance to water and fire. The paperboard sheets are then laminated into corrugated building blocks for the final shelter design. The engineered product is lightweight and allows rapid and cost-effective transportation to wherever it is needed. The use of post-consumer waste as a building material creates an inexpensive and environmentally benign means of providing shelter to those displaced by natural disasters and conflict.

Project goal: To design an expansion of the Greenfield Water Reclamation Plant that doubles processing capacity, increases efficiency, and minimizes expansion cost while maintaining the quality of the discharged water. The facility is rated at an average daily flow of 16 million gallons per day, or MGD, with a maximum hourly flow of 48 MGD. The expansion designed will handle an average daily flow of 30 MGD and a maximum hourly flow of 90 MGD. The plant’s current design allows it to meet current water quality standards, but its efficiency was improved during this expansion by making the facility more user-friendly, and by reducing the maintenance costs. The team used a decision matrix to find an optimum design for each of the three objective areas, and suggested additional water-treatment technologies that could make the facility easier to operate.