Diesel cars are a popular choice for people looking to buy used cars in Asia, Europe and other regions. Ultimately, diesel cars cost less to maintain, consume less fuel, and have a longer engine life. Although diesel engines emit less pollutants than gasoline engines, they still emit carcinogens, nitrous oxide, and soot. Older models don't even have emissions controls like newer models.
To reduce emissions, diesel vehicles use filters that trap exhaust particles and other pollutants. However, because filters are made of precious metals, they can cost thousands of dollars to replace.
To make replacement filters more environmentally friendly and affordable, a team of engineering students from the Bangladesh Institute of Technology in Dhaka designed a carbon-based version using bamboo. The Green Warriors idea won a US$300 prize for best impact in the IEEE Women in Engineering Big Idea Pitch competition. The goal of the competition is to encourage female engineering students and researchers to become more entrepreneurial as a way to increase the number of female-led technology startups.
“We discovered that older diesel cars had a big impact on CO2 emissions, and we wanted to do something about it,” team leader Tasmiah Afrin said in an email interview.
“Our groundbreaking activated carbon-based filter represents a significant leap forward in environmental and economic efficiency,” added the electrical engineering student. “The filter can quickly and effectively capture carbon-based gases from vehicle exhaust, contributing to immediate improvements in air quality and reduced carbon emissions.”
Carbon-based particulate filter
Diesel engines produce more pollutants than gas engines. Because the particles are so small, they can easily pass through catalytic converters designed to reduce toxic emissions from vehicles. Therefore, diesel particulate filters are installed in the exhaust system, usually at the catalytic converter outlet. The most widely used types force exhaust through a ceramic honeycomb structure coated with a thin layer containing precious metals such as platinum, palladium, or rhodium.
“Our project is based on an air filter modified to allow air to enter the catalytic converter,” Afrin said.
Green Warriors' prototype filter is made from bamboo and uses carbon granules to further reduce emissions.
Activated carbon granules and metal mesh in the absorption chamber form the filter, Afrin says. The gas passes through double or multiple chambers. Their prototype is more aerodynamic and lighter than existing designs used for carbon filters, Afrin says.
“These filters offer a remarkable 5 to 7 percent cost-effectiveness improvement over traditional filters, making them a more cost-effective solution for carbon capture in vehicle exhaust systems,” she says. “Not only is it cost-effective, but it also has an incredible uptake rate. This means the filter can quickly and effectively capture carbon-based greenhouse gases from vehicle exhaust, immediately improving air quality and reducing carbon emissions.”
She believes the team's diesel particulate filters will cost less than current filters, which cost thousands of dollars due to their precious metal content.
filter replacement system
The filters are just one part of the team's vision to reduce vehicle emissions. The students' presentation also included a transportation management system called CarGreenTech and an accompanying smartphone app. Using this app, owners of older diesel cars can purchase replacement filters or prepare for filter installation. Another option is for CarGreenTech to buy old cars, install new filters, and then resell the vehicles. The goal is to extend the life of these older vehicles, Afrin says.
“CarGreenTech is a platform to make existing vehicles more climate positive, providing an all-in-one solution,” says Afrin. “Capture carbon from diesel engine exhaust by utilizing multi-layer activated carbon filters and upcycling old car parts through car buying/selling/upgrading through B2B and B2C solutions.” Motivation for student-led startups
The team also included Ishman Tasnim, Fahmida Sultana Naznin and Nusrat Subah Shakhawat. Tasnim is studying industrial and production engineering, and Naznin is pursuing a degree in computer science and engineering. Shakhawat recently graduated from college with a degree in electrical engineering.
The team's mentor was university lecturer and IEEE member Toufiqur Rahman Shuvo.
The students are all members of the IEEE Student Branch of the Bangladesh Institute of Technology.
“IEEE WIE has a huge impact in motivating student startups like ours,” says Afrin. “Participating in the IEEE WIE Pitch Competition was one of our best decisions. “Thanks to the judges, we were very motivated and even received an award for our work.”
The IEEE WIE competition is sponsored by the IEEE Life Members Committee and Smart WTI, an IoT/artificial water management solutions provider. The company supports initiatives that aim to contribute to a greener and more sustainable future.