Garbage collection isn’t the typical go-to career for a young intellectual. Meet the exception: Tom Szaky, 27, who dropped out of Princeton to turn mounds of trash into piles of cash. He is the cofounder of TerraCycle, a company that turns waste into products for the home and garden.

While Szaky cares deeply about the environment, he happily admits that he also loves to make money. His company gives equal weight to saving the planet and making giant profits—a rare combination in the business world. In fact, TerraCycle turns the traditional manufacturing process on its head. Instead of using virgin matter to make products that later become trash, the company uses waste as its raw material, turning it into products from household cleaners to office supplies—a process called upcycling. The company’s flagship product, TerraCycle Plant Food, is made from food waste, packaged in used soda bottles and shipped in misprinted boxes dumped by other companies. “It eliminates the very idea of garbage,” Szaky says. It doesn’t get any greener than that.

The company’s approach is paying off, with $6.5 million in sales in 2008 and twice that anticipated for 2009. This year brings other big changes, including expansion into Brazil and England, the launch of a reality show called Garbage Moguls on National Geographic Channel, and the release of Szaky’s first book, Revolution in a Bottle ($15; Portfolio Trade).

TerraCycle had humble beginnings. As a Princeton student in 2001, Szaky took note of a friend’s compost heap that used worms to recycle food scraps into fertilizer. Where others only saw poop, Szaky saw a way to build a business while making a difference. Today, TerraCycle partners with major brands such as Nabisco and Frito-Lay, which pay to have their products’ waste transformed into sellable items. Empty Capri Sun pouches become tote bags, and misprinted Oreo wrappers are turned into notebooks. More business for TerraCycle means less waste in landfills.

“I could do this for my whole career,” Szaky says. “It’s so infinite. I’d only quit if I got bored, and I just don’t see how I could at this point.”