Reimagining the Membrane
In recent years, biofuels have become feasible and economically competitive. This has resulted in manufacturing plants that grow microalgae in large open fields or work in tandem with coal plants sequestering carbon dioxide by feeding it directly to an attached algae plant. The US alone has over 50 research institutions and 100 companies working on algae technologies. The existing market uses microalgae facilities as add-ons to existing power plants; however, this is predicted to be a temporary transitional phase before biofuel plants begins to overtake conventional stored fuel sources and large-scale algae fields become more common.
“Your bang for your buck is just bigger because you can really do this on a much smaller amount of land and yet yield, much, much higher biomass.” – Michael S. Atkins, CEO of San Francisco area-based Ocean Technology & Environmental Consulting.
Algae are single-celled organisms that grow in a water medium. They are one of the oldest species on earth, whose history span over 3 billion years, becoming one of nature’s most efficient producers of plant-based oils for energy storage. No other plant-based bio-stock compares to the yields of algae. Microalgae have the capacity of doubling in mass every 24 hours naturally; however, advances in genetic modification have allowed modified species to double in 3 – 4 hours. It’s important to note these modified species require special containment procedures to prevent algae blooms that can devastate local aquatic environments; however, the yields make it extremely economical. A gallon of B100 (biodiesel with 100% algae-based oils) contains 103% the energy content of gasoline and 93% of diesel. It is commonly used as a form of bioremediation of contaminated water supplies. Microalgae can grow in fresh, salt, waste, or polluted water sources. For every gallon of biofuel produced, 1.4 gallons of freshwater is a byproduct. This effectively makes microalgae farming a form of desalinization. The process of biofuel production requires breaking apart the cell wall of the algae through a chemical application or sound waves. 70% is refined into biofuel, the remaining 30% is refined into biomass that can be used in fertilizer, pharmaceuticals, and cosmetics.
What makes microalgae even more special is its ability to store CO2. Scientists have stated that carbon emissions have reached the point of no return as of September 2016, passing the 400 ppm threshold. No one will witness an atmosphere below this concentration within their lifetime. According to economists Gernot Wagner and Martin Weitzman’s book, “The Economic Consequences of a Hotter Planet,” they discuss the importance of carbon sequestration through the “bathtub” analogy. Most of our efforts have been towards shutting off the faucet which, when accomplished, still leaves us with a bathtub full of water that needs to be drained. We need to not only be carbon neutral, but carbon negative. With regards to microalgae carbon sequestration, 100 tons of carbon dioxide is sequestered for every 5,000 – 6,000 gallons of B100 produced.
“There is no stopping global warming… so the key thing now is slowing climate change down enough to make sure we can adapt to it as painlessly as possible.” – Gavin Schmidt, climate scientist and Director of NASA
More recent projects by H.O.R.T.U.S. Eco Studio exhibits the personal interaction between humans and microalgae, one creating the necessary nutrients for the other, revitalizing farming communities in the Swedish Baltic Sea region. Only one architectural precedent currently exists, the BIQ (“Building with Bio-Intelligent Quotient”) House in Hamburg, Germany was constructed in 2013. It hosts a microalgae panel system as the skin of the residential complex. Taking inspiration from these two works, the intent of this research is to produce a functioning façade system comprised of modular, microalgae pods that can be applied to existing facades. By farming algae on a building skin, these units will have the capacity to produce biofuels and reduce dependency on nonrenewable resources.
The microalgae pod project was designed in collaboration with Dr. Kim and Professor Thaddeus at UNCC’s SOA. Dr. Kim specializes in building envelopes and has researched the potential of algae as part of the building envelope for many years. Professor Thaddeus specializes in structural systems. This thesis proposal presents a solution to improve building envelope performance, filter sunlight, generate energy, produce fresh water, reduce lighting needs through bioluminescence, and sequester carbon dioxide and air particulates. The pods shape was also inspired by Erwin Hauer’s undulating wall systems, which comprise of a repeating, curvilinear, textile pattern. This led to the concept of having modular units that hook into each other through a set of curved pins that connect to the shell housing the algae pouch. The gradual curved structure of the pin connections allows the pins to slide in from the side but is unable to disconnect towards the direction of gravity. The shell shape was designed to allow for maximum area for the microalgae growth within the pouch and minimum area for service equipment.
With regards to manufacturing, a set of 3-D printers were built to produce the pods as a series of streamlined parts that can be assembled and replaced easily. While Hauer’s walls are conventionally made of concrete, these units are made of PLA plastic. PLA is made from corn starch, it is 100% recyclable and biodegradable within 3 – 6 months in a composing system. PLA can also be produced from biomass, which would allow the resources being grown to produce additional pod shells, mimicking algae’s cellular division at a much larger scale. Each pod houses a clear PETg plastic pouch manufactured by CNC routing MDF and vacuum forming the sheets over the routed shape. These pouches are where the algae will grow. PETg is also an eco-friendly material and is recyclable. The pods are modeled as hollow components to allow the service equipment to be hidden within the system. Each pod requires four connections, an input of young algae and carbon dioxide, and an output of oxygen and mature algae. Algae’s growth cycles are consistent and the algae can regrow by leaving a small amount behind between growth cycles. Vertical tubes running through the system represent the primary direction of resource movement. Horizontal tubes running across each pod act as an emergency rerouting of resources in the event of pod depressurization. Valve systems are controlled by a series of Arduino units that release a programmed set of resources into each pod. As of the summer of 2018, a single functioning pod unit has been successfully developed.
The project was divided into two separate research endeavors. The first proposal is a full-scale building integration of the pod technologies know as an UPP Rehabilitation program (Urban Power-Plant). This included schematic drawings and concepts for the conversion of a 50,000 sf 19th century commercial building in the heart of Manhattan. It would showcase the ability of the system to be applied to pre-existing buildings, rather than tearing them down to construct new ones. This converted building would house an on-site refinery with over 10,000 microalgae pods covering the surface area of the building exposed to sunlight. It has the potential of producing 174,000 – 208,000 kwh annually which is enough to offset the energy demands of the building and 40+ nearby blocks at the 5,000 kwh range or most of East Village. If the fuel is sold rather than burned, a building of this size would generate over $100,000 in fuel sales annually at current B100 market rates. The system has the potential of covering costs of construction over time, much as solar pays for itself. In addition, the system would sequester 100 tons of carbon and produce 7,000 – 8,400 gallons of fresh water annually. The resources visibly flow around the structural columns, eventually ending up in each pod on the skin of the building, allowing the inhabitants to make the visual connection that the energy developing these pods is what’s powering their laptops and the Big Apple.
The second research direction is a proposal that made semi-finalist in an international green technologies competition for plans of a mock up wall of 84 pods built in UNCC’s community garden. The wall would act as a research base for the environmental engineering department to study biofuel production in a wall system, generating on-site energy and provide biomass fertilizer for the local garden. It would be produced using the university’s manufacturing equipment and be comprised of a fly-ash concrete base supported by carbon fiber pins attached to recycled timber supports. The top would house a water collection system. The wall system would respond to people by releasing nutrients to the pods whenever the proximity sensor was triggered. Its location places it at a primary circulation route on campus and the wall would respond to students walking towards their next class. Such a response provokes the idea that perhaps humanity’s presence could sustain life rather than be a detriment towards it. Designer Robert L. Peters once said, “Design creates culture. Culture shapes values. Values determine the future”. Microalgae could be the key towards a future worth living in.