1. Hydrogen Gas and Liquid Nitrogen Production A feasibility study by Green Horizons – Jonah Nelson, Samantha Kunze, Jeff Watson, and Scott Schellenberger Purpose and Methods of Study Conclusions Photobiological The Photobiological method uses algae to produce hydrogen gas. When exposed to an environment lacking in sulfur and copper, algae switch from producing oxygen as waste, to producing hydrogen gas as waste. This is a relatively new process, so it is not yet fully understood or easy to adopt on a large scale. Research is being conducted to enhance the efficiency of this process, such as “turning off” algae reproduction so the Liquid Nitrogen Generation Liquid nitrogen is already mass produced for several industrial processes by compressing air. Because of this, the technology of production has already reached a point of being highly feasible and inexpensive. Liquid nitrogen costs around $0.06 per liter 7 when bought in bulk, and Dewars (liquid nitrogen containers) can cost from $300 to $1000 depending on capacity. However, producing nitrogen is an energy- intensive process and the fuel itself has a low energy density. This means that a lot References Thermo-Chemical Thermo-chemical processes convert hydrocarbons (mostly fossil fuels) to CO and H 2. The CO is then reacted with steam in a water-gas-shift reaction that produces CO 2 and more H 2. Three main processes that use this method include: Steam Methane Reforming (SMR), Partial Water Splitting There are a number of methods that utilize H 2 0. By splitting the water molecule into its component parts, the splitter is able to obtain not only hydrogen but also oxygen. These technologies have been utilized for a long time and they are nearing the theoretical limits of efficiency. The technologies examined in this study were electrolysis (see photo 1 ), thermal decomposition, and the S-I cycle. Of these technologies, the S-I cycle and thermal decomposition (with a catalyst) were the most promising. However, these technologies appear to be out-distanced by the photobiological method. microbes focus more energy on producing hydrogen. It will likely be possible in the future to create vast “algae farms” to massively and efficiently harvest hydrogen gas. In order to fully replace current U.S. gasoline consumption, 10,000 square miles of algae farmland would be required – about 2% of current American cropland. 7 Renewable energy. Pollution-free transportation. Self-sufficient energy production. Green technology is on everyone's mind. Green Horizons produced a feasibility study on the production of two specific renewable energies: hydrogen and nitrogen. This study determines the most feasible means of producing hydrogen and nitrogen so that they can be further developed as energy sources and implemented in future energy technologies. Ranking Criteria: Environmental: side effects of implementation (e.g. pollution) Cost: overall cost of large-scale development Sustainability: capability of long term application Implementation: time required for widespread adoption Oxidation, and Coal Gasification. Of these three, SMR is the most widely used. SMR is currently used to produce 95% 2 of the over 9 million tons of H 2 produced in the US each year 3. It is also the cheapest method 4 of bulk H 2 production to date (~$3.66/kg) 5. As seen in the photo 4, SMR is typically done on a large scale and thus has high efficiency (70% 4 ). SMR would provide a good transition to hydrogen power due to the existing infrastructure and low cost. EnvironmentalCostSustainabilityImplementation 4141 Feasibility ranking chart for thermo-chemical production of hydrogen Feasibility ranking chart for water splitting production of hydrogenFeasibility ranking chart for photobiological production of hydrogen more liquid nitrogen must be produced than petroleum or even hydrogen to extract an equal amount of energy. This is a concern for implementing it as a fluid of propulsion in transportation. Feasibility ranking chart for liquid nitrogen production EnvironmentalCostSustainabilityImplementation 1414 EnvironmentalCostSustainabilityImplementation 3333 EnvironmentalCostSustainabilityImplementation 2222 Honda FCX Clarity – a hydrogen fuel cell powered car and an application for the production methods discussed in this study. 1.Saskatchewan Schools. (2006, June 10). Redox reactions & electrochemistry. Retrieved from http://www.saskschools.ca/curr_content/chem30_05/6_redox/redox3_3.htm 2.United States Department of Energy. (2011). Natural Gas Reforming. Retrieved April 25, 2011, from http://www1.eere.energy.gov/hydrogenandfuelcells/production/natural_gas.html 3.United States Department of Energy. (2010). Today’s Hydrogen Production Industry. Retrieved May 30, 2011, from http://www.fossil.energy.gov/programs/fuels/hydrogen/currenttechnology.html 4.NYSERDA. (n.d.). Hydrogen Fact Sheet. Retrieved May, 2011 from http://www.getenergysmart.org/files/hydrogeneducation/6hydrogenproductionsteammethanereforming.pdf 5.NREL. (2002). Hydrogen Supply: Cost Estimate for Hydrogen Pathways-Scoping Analysis. http://www.afdc.energy.gov/afdc/pdfs/32483.pdf 6.United States Department of Agriculture. (2011). United States Agricultural Fact Sheets. Retrieved April 24, 2011, from http://www.ers.usda.gov/statefacts/us.htm 7.Elert, G. (2007). Price of liquid nitrogen. Retrieved from http://hypertextbook.com/facts/2007/KarenFan.shtml In terms of environmental impact and sustainability, the photobiological process is the best technology. However, the thermo-chemical processes are much more realistic for immediate implementation. The liquid nitrogen generation and water splitting technologies are intermediately ranked. Thus, we suggest a two-step process starting with the more immediately-implementable thermo-chemical processes and transitioning over time to the more environmentally-friendly and sustainable photobiological process.