The value of pee
Gintare Cerniauskaite
Every day every person produces 1-2 litres or urine. That’s about 10,5 billion litres of urine a day.
This makes 154.061 shipping containers 10 largest container ships put together.
Or 4.200 Olympic swimming pools.
So is it all waste? Or can we use pee for a good purpose?
95% of urine is actually water.
But it also contains, in order of decreasing concentration, urea 9.3 g/L, chloride 1.87 g/L, sodium 1.17 g/L, potassium 0.750 g/L, creatinine 0.670 g/L and other dissolved ions, inorganic and organic compounds.
Since the largest concentration in pee, in addition to water, is urea, this research will focus on this compound.
Worldwide urea demand is 120 million tonns a year.
With over 7 billion people in the world 40% of all urea could be produced only by humans.
Maybe we could even fulfil all our demand, if we collect farm animal urine.
But what would we do with it?
Agriculture
More than 90% of world production of urea is used as a nitrogen-release fertilizer. Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use. Therefore, it has the lowest transportation costs per unit of nitrogen nutrient. Urea is being disolved in water for applications as spray. But in summer urea is often spread as granulles. This must be done just before the rain, so no nitrogen would be lost to atmosphere in a form of amonia gas. Urine can also be used as a source of urea for fetilizing and is just as compatible as manufactured urea. But it must be diluted in water - human urine with a ratio of 1:8 for general use and 1:5 for containergrown annual crops.
Emissions
Urea tank is standard equipment for most new diesel trucks, buses, cars, and sport utility vehicles (SUVs) manufactured in the United States after Jan. 1, 2010. An automotive grade of urea is injected into the vehicles’ exhaust stream to “scrub” nitrogen oxide (NOx) from the diesel exhaust. This is meant for reducing air pollution. In 2010 only 7% of diesel trucks in US used these urea tanks, but by 2011 it doubled and numbers keep increasing. The whole Europe’s truck fleet should be changed (and thus, use urea tanks) by 2020. Mercedes-Benz has actually used this technology for years in their trucks and busses. For the new Mercedes BlueTec models the urea will come in cartridges that will be replaced during normal servicing. However, this new application has increased urea prices, and since it is the main fertilizer for crops, food prices have also been influenced.
Energy
The most prommising application seems to be energy making. Urea has four hydrogen mollecules - twice as much compared to water. For this reason urea is more efficient and could be a low cost alternative to super low-emission systems such as cars, submarines or remote power stations. Dr Shanwen Tao and Dr Rong Lan have edveloped the urea fuel cell that is cheaper and safer alternative to normal hydrogen fuel cells. Plus, urea is renewable material. So how about peeing in your car tank, instead of filling it with gasoline or water?
There are many more appilcations for Urea in different fields: •A stabilizer in nitrocellulose explosives •A component of animal feed, providing a relatively cheap source of nitrogen to promote growth •A non-corroding alternative to rock salt for road de-icing, and the resurfacing of snowboarding halfpipes and terrain parks •A flavor-enhancing additive for cigarettes •A main ingredient in hair removers such as Nair and Veet •A browning agent in factory-produced pretzels •An ingredient in some skin cream, moisturizers, hair conditioners •A reactant in some ready-to-use cold compresses for first-aid use, due to the endothermic reaction it creates when mixed with water •A cloud seeding agent, along with other salts •A flame-proofing agent, commonly used in dry chemical fire extinguisher charges such as the urea-potassium bicarbonate mixture •An ingredient in many tooth whitening products •An ingredient in dish soap •Along with ammonium phosphate, as a yeast nutrient, for fermentation of sugars into ethanol •A nutrient used by plankton in ocean nourishment experiments for geoengineering purposes •As an additive to extend the working temperature and open time of hide glue •As a solubility-enhancing and moisture-retaining additive to dye baths for textile dyeing or printing
Apparently, urea has many applications and even more potential.
With its growing rates in demand, why wouldn’t we get urea from pee?
A research conducted in Japan in 2001 states that urea production uses lots of energy and emits massive amounts of CO2. It predicts “serious environmental problems in Asian region countries in the future�. But a research by other Japanese scientists made in 2008 states that by using energy saving factories, urea production actually reduces greenhouse gas. A lot has changed in those seven years. And new energy saving factories have already been built in Abu Dhabi (UAE) and several other countries. This is not only because of the environmental issues, but mostly due to financial reasons.
Urea is produced from liquid ammonia and carbon dioxide, so it has potential to reduce greenhouse gas (GHG) emission by utilizing carbon dioxide as the feedstock. This is because one ton of urea production requires 0.733 tons of carbon dioxide. When produced in energy saving factory, energy generated to produce urea emits much fewer CO2 than consumed for production. This means that our annual 120 million tons urea demand has potential to reduce global CO2 mission by 7.8 million tons per year.
That’s United States’ and China’s annual emissions put together.
Or a third of all the world’s CO2 emissions.
So manufacturing urea is actually good for environment.
Still, urine could be used for many applications in a household, for experiments or when no synthetic urea is available at hand.
Sources:
Greenpeace Research Laboratories; K. Brigden & R. Stringer “Ammonia and Urea production: Incidents of amonia release from the Profertil urea and ammonia facility, Bahia Blanca, Argentina 2000”; Toyo Engineering Corporation; Y. Kojima, H. Morikawa, E. Sakata “Urea Production Reduces Greenhouse Gas by Energy Saving and Carbon Dioxide Recovery” Toyohashi University of Technology; E. Munawar, M. Ubaura, N. Goto, K. Fujie “Estimation CO2, Non-CO2 GHGs and Other Gas pollutant Emissions of Indonesia’s Urea Fertilizer Factories.” Biology labaratory, Yogyakarta; Yunita Panarisma “Urine ingredient analysis” World Resources Institute; “Environment statistics: CO2 Emissions (most recent) by country”; http://www.nationmaster.com/graph/env_co2_emi-environment-co2-emissions Pure Energy Systems “Urine-Powered battery developped”; http://pesn.com/2005/08/16/9600149_Urine_Power/ Discovery News “Urine: A ‘Clean’ Energy Source”; http://dsc.discovery.com/news/2009/07/08/urine-power.html Inhabitat “Researchers Use Urea to Create Low-Cost Fuel Cells “; http://inhabitat.com/researchers-use-urea-to-create-low-cost-fuel-cells/ Zero “CO2 Recovery Plant to Urea production in Abu Dhabi”; http://www.zeroco2.no/projects/co2-recovery-plant-to-urea-production-in-abu-dhabi EurekAlert! “Urea tanks on diesel trucks -- that’s the law in the United States starting in 2010“; http://www.eurekalert.org/pub_releases/2008-11/i-uto111008.php OECD, ODCE; A. Dean & P. Hoeller “Costs of reducing CO2 emmisions: Evidence form six global models”; http://www.oecd.org/dataoecd/22/11/33957059.pdf Wikipedia “Urine”; http://en.wikipedia.org/wiki/Urine Wikipedia “Urea”; http://en.wikipedia.org/wiki/Urea#Other_commercial_uses Wikipedia “Urea-formaldehyde”; http://en.wikipedia.org/wiki/Urea-formaldehyde_resin
Gintare Cerniauskaite Design Academy Eindhoven 2012