Coffee Waste: Trash to Treasure

Who doesn't love coffee? Whether it's a good day or a tough one, coffee is always there for us, giving us comfort and company. But did you know that even our favorite drink can harm the environment?

 In this era of globalization, the coffee industry is a major global player following petroleum and generates substantial toxic solid waste. Every year, the coffee sector produces over 10 million tons of waste worldwide including husks, pulp, mucilage, silverskins, and spent coffee grounds (SCGs), stemming from harvesting, processing, roasting, and brewing. In these substances, Spent Coffee grounds are the most prevalent byproduct constituting 0.6 tons per ton of coffee. When these coffee grounds are sent to the landfill for anaerobic decomposition they further release methane, a greenhouse gas which contributes to global warming and hinders the ecological balance. 

 Moreover, for each cup of coffee consumed, approximately one square inch of rainforest is destroyed, leading to chemical buildup in soils, and loss of forest shade causing adverse effects on land and aquatic wildlife. Exploitative practices, particularly in sun-grown coffee production, have led to massive deforestation, with rainforest coverage decreasing from 15% to just 6% of the Earth's surface since the 1950s. The heavy use of fertilizers in coffee cultivation results in nitrate leaching into water sources, leading to oxygen depletion and aquatic life loss. Coffee waste contains high levels of organic compounds, such as caffeine and tannins leading to soil degradation by altering pH levels and nutrient balance and making the soil unfit for further usage. But there's hope on the ground!! With numerous advancements in the scientific field, we can convert our favorite beverage waste into trash and make it the favorite beverage for the environment too!

Here are four eco - friendly products that we can make from coffee waste:

1. Biofuel: To turn coffee waste into biofuel, we start by treating the spent coffee grounds with acid or alkali to break them down. This step helps make the sugars in the grounds easier to ferment. Then, we use fermentation to turn these sugars into ethanol, a type of biofuel. Another method is processing the grounds into polysaccharides, which can also be turned into ethanol. Special treatments like popping can further boost the amount of ethanol we get. For specifications such as turning coffee oils into biodiesel, we use a process called transesterification. Despite some challenges, like high energy use, with the right methods, coffee waste can become a valuable source of biofuel.

2. Biosugars: To make biosugars from coffee waste, we first treat the coffee grounds with ethanol and special enzymes to break them down. Then, we ferment the mixture to create biosugars like D-mannose and manno-oligosaccharides. This process is eco-friendly because it uses safe chemicals and recycles ethanol. With these methods, we can produce valuable biosugars from coffee grounds that would otherwise go to waste.

3. Methane Storage: According to research by Scientist Christian Kemp by heating used coffee grounds with potassium hydroxide, a material is created that can effectively absorb methane. This simple and affordable process provides a sustainable solution for reducing greenhouse gas emissions. Moreover, this innovative material can also store lithium ions for use in batteries and offers flexibility in designing storage for methane in vehicles. 

4. Home Decor: Startups like IDA Eco-Decor are using coffee waste by processing it to make home decor mandala art plates, countertops, and furniture that are sustainable and reliable to use. 

To conclude, these eco-friendly products represent just a glimpse of the innovative ways we can repurpose coffee waste and contribute to a more sustainable future. By transforming spent coffee grounds into biofuel, biosugars, methane absorbers, and even stylish home decor items, we not only mitigate environmental harm but also unlock new economic opportunities. So, let’s utilize our educational journeys to build many more innovative solutions like these for reducing coffee waste from the environment. 

References:
[1] Lee, Y. G., Cho, E., Maskey, S., Nguyen, D., & Bae, H. (2023, April 18). Value-Added Products from Coffee Waste: A Review. Molecules. https://doi.org/10.3390/molecules28083562

[2] Lower, E. B. K. A. C. T. R. S. A. B. H., & Lower, E. B. K. A. C. T. R. S. A. B. H. (n.d.). 2.2 A Bitter Brew- Coffee Production, Deforestation, Soil Erosion and Water Contamination. Pressbooks. https://ohiostate.pressbooks.pub/sciencebites/chapter/a-bitter-brew-coffee-production-deforestation-soil-erosion-and-water-contamination/