Can Our Streets Absorb Greenhouse Gases?

I wrote about driving to work before, wondering if we could cut emissions with sustainable fuels. Now I’m wondering – what about the roads we drive on?

From streets to buildings, concrete is the most widely used material in the world. Concrete is made from sand, crushed rocks, and water and is glued together with cement. Unfortunately, cement factories are some of the largest emitters of greenhouse gases. The emissions come from decarbonizing limestone and the very high temperatures needed to manufacture cement.

Manufacturing a single ton of cement requires the equivalent energy of burning four hundred pounds of coal

Paul Hawken https://www.drawdown.org/solutions/materials/alternative-cement

So, how can we design a more sustainable version of concrete? Imagine a high-tech skyline with remarkable towers and shopping centers. And heat, a lot of heat. This week we are covering an invention from Abu Dhabi in the United Arab Emirates.

Kemal Celik, an assistant professor at NYU Abu Dhabi, researches how to make sustainable cement. He explores using by-products from other industries. Basically, making cement from recycled materials.

There are a lot of desalination plants in the United Arab Emirates to produce drinking water from seawater. A by-product of the desalination process is residual brine. Kemal figured out a way to make cement with the leftover brine. This is how it works:

His invention, reactive magnesium oxide cement, is produced at much lower temperatures than traditional cement. And the best thing? It actually absorbs carbon dioxide during the hardening process and long after it has been mixed into the concrete, making it carbon negative.

Roads and buildings made with it could actually absorb carbon dioxide from the atmosphere over the years and help combat climate change

Kemal Celik, https://nyuad.nyu.edu/en/research/impact/our-research/2018/just-add-salt.html

Another inspiring innovation. Let’s hope we can all drive on roads made from sustainable concrete sometime soon.

Sign up for weekly inspiration right in your inbox

Processing…
Success! You're on the list.

Can Cactus Reduce Global Warming?

Recent posts from the BBC, Futurism and Fronteras about bioplastic made from cactus caught my eye. So let’s explore this!

How does bioplastic help to fight global warming? Plastic is made out of oil. From extracting the oil to manufacturing plastic, greenhouse gases are emitted. After we use plastic, it ends up in the environment or in landfills, where it degrades over hundreds of years, emitting greenhouse gases. Alternatively, plastic trash is burnt which also releases greenhouse gases. Besides that, it releases toxins, harms our oceans and enters our food chain. Project Drawdown estimates that by replacing half our plastic with bioplastic by 2050, 4.3 gigatons of carbon dioxide emissions can be avoided.

So, how do we switch to bioplastic? Previously I wrote about amazing bioplastic solutions from teams all over the world. I covered Notpla’s seaweed pouches from London, and Cove’s PHA bottles from California. This week’s innovation comes from the hot deserts of Mexico.

Imagine a very, very bright green – that’s what cactus juice looks like. Sandra Pascoe Ortiz, a chemical engineering professor from Guadalajara, developed a way to turn this green cactus juice into bioplastic. This is how it works:

She starts by harvesting and peeling cactus leaves. Then she juices and chills the cactus concentrate. After that, the concentrate is mixed with glycerin and wax and finally it is laminated. Sandra has produced bioplastic with different colors, shapes, and flexibility.

What I like most about her approach is that it’s made entirely from renewable resources. She has been researching cactus plastic for over 6 years and says more research needed. Let’s hope we can use her bioplastic one day soon!

Sign up for weekly inspiration right in your inbox

Processing…
Success! You're on the list.

Can Sustainable Air Conditioners Stop Global Warming?

A recent report from the Australian think tank Breakthrough evaluates global warming as existential threat to human civilization. The report says it is essential to build a zero emissions system. Global mobilization is needed quickly to reduce the risk. While reading this I got very scared. But then I asked myself if there was good news as well?

I think the good news is that we know how to reduce greenhouse gas emissions that lead to global warming. In his fantastic book Drawdown, Paul Hawken and a team of over 70 researchers from all over the world list 100 solutions to address global warming.

On place number 1 is refrigeration management, so your air conditioner, fridge, and freezer. The chemicals used to cool the air are greenhouse gases that do harm during production, servicing, when they leak, and especially during disposal. Out of all 100 solutions, refrigeration management can avoid or remove the most amount of greenhouse gases. So let’s look into this. How can we design air conditioners without harmful chemicals?

This week we are highlighting a team from Singapore. Ernest Chua teamed up with three other researchers from the National University of Singapore. Together they are developing an air conditioner that works without harmful chemicals, in fact, it uses water to cool down the air. Here is how it works:

The first step is to dehumidify the air by directing it though a membrane. A nice side effect is that they are able to capture the water, which is almost as pure as bottled drinking water. After that, the dry hot air goes through a water-based evaporative cooler. The cold air is then released to the room.

I’m happy to report that a totally green air conditioner that is chemical free and does not emit heat to the environment is a possibility.

Ernest Chua at his talk at the World Economic Forum 2019

The sustainable air conditioner consumes 40% less electricity and can cool a space as low as 18 °C (64 °F). Ernest and his coworkers are now working on iterating their working prototype. There is huge market for air conditioners worldwide. Unfortunately, with raising temperatures, more and more air conditioners are needed.

What I like most about this project is that is helps in two ways. First, they don’t heat up the environment and second, they don’t use chemical refrigerants. I’m excited about their next steps and hope they are ready to cool down the world soon!

Sign up for weekly inspiration right in your inbox

Processing…
Success! You're on the list.