"Coffee Or Tea? Something Hiding In Your Trash Could Help Save Both From Climate Change"
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India’s Assam state is the largest tea-producing region in the world, mostly because its high hills and regular rainfall. But recently, higher temperatures and erratic rainfall “are choking the once-flourishing plantation industry,” as Al Jazeera reported.
This is also affecting taste, and as professional tea-taster Parag Hatibaruah said, Assam tea is “not as strong, brisk and creamy as it was once.”
RM Bhagat, deputy director of the Tea Research Association, said that over the last 100 years, “we have found that the minimum temperature has risen by 1.5 degree centigrade, and the annual rainfall has reduced by 200 millimetres.” Usually the ambient temperature in the region was below 95 degrees Fahrenheit. Recently, the temperatures have been between 100 and 104 degrees in the shade, and 122 degrees under the sun.
For context, photosynthesis slows down at 95, and above 102, plants stop producing food. At 118 degrees, tea leaves die because they stop breathing.
Gardens in Assam produce about one-sixth of the world’s tea, but more and more areas of Assam are going to tea production in order to meet increasing demand.
To adapt to the changing climate, tea experts recommend increasing the shading in tea plantations, using organic manure, and changing traditional watering systems. Some also recommend switching to hardier, more climate-resistant tea breeds.
But mitigating climate change can also part of the solution. And this is where coffee grounds could come in.
But researchers at the University of Cincinnati used a small school innovation grant to test whether spent coffee grounds could be used to produce biofuels to power automobiles and furnaces.
Yang Liu, Qingshi Tu, and Mingming Lu attempted to convert these wasted grounds bound for the landfill into useful biodiesel and activated carbon. Most biofuel today comes from corn and soybean crops that can be used for other things — the market for spent coffee grounds is essentially nonexistent.
When the researchers began the study in 2010, they gathered their precious material in a bucket from a campus Starbucks. The process involves extracting oil from the coffee grounds to use as biodiesel and glycerin, then drying the grounds themselves to filter impurities in biofuel production. All biofuels must be filtered, often using a multi-step process combining physical and chemical purification to meet the required standards. The remaining grounds can then be burned separately as a form of biomass.
Liu presents the findings to the American Chemical Society’s 246th National Meeting & Exposition this week. Their results show that oil content in the coffee-derived biodiesel meets official biofuel standards.
There is room for improvement in how efficient using the spent grounds to purify the biodiesel actually is, especially compared with commercial products normally used to purify the fuel. The researchers would like to make the process more efficient, but the fact that otherwise-wasted coffee could be used to create biofuel is promising. And compared with fossil fuels, this biofuel seriously cuts the emissions of traditional pollutants.
Around 1 million tons of coffee grounds are thrown out in America each year, and most go into landfills.