DANIELLE MILES

'Greener' plastic recycling uses no water and only half the energy

A Mexican startup has developed a new method of recycling plastic that does away with water and only consumes half the energy of previous systems. At the same time, it produces plastic pellets of equal or better quality,  resulting in an environmentally friendlier process that also promises to be significantly cheaper.

Plastic recycling can turn discarded bottles and other scrap into a myriad of useful objects, helping produce anything from polyester clothes to 3D printing filaments and even diesel. However, it is a long, laborious affair that consumes plenty of resources  –  especially water. Among other things, the plastic needs to be thoroughly washed to get rid of impurities, carefully dehydrated inside an oven, and then water-cooled once again as the newly-formed plastic filaments are cut into small pellets.

According to Marco Adame, the new method that his startup has come up with can produce pellets of equal or better quality using just half of the energy by getting rid of the need for these temperature extremes, while also doing away with the need for water altogether. The system uses special walls that, on contact, are able to both mold the plastic into the desired pellet shape and cool those pellets at the same time.

The energy-demanding dehydration process, which involves temperatures of around 180° C (360° F), had been a necessity so far because, after being washed, the plastic molecules would otherwise attract water to themselves and prevent the plastic from crystallizing properly. Being able to process scrap plastic without water has therefore simplified things considerably.

Adame says that using his technique, the same machines are able to process styrofoam, polystyrene and ABS, which together make up about 90 percent of all plastics. The improved versatility would mean less space would be needed for operation.

The company is now looking to expand the recycling capabilities of its prototype system and to further reduce costs by employing a “green” washing machine for plastics that uses a special biodetergent instead of the more commonly-used lye.

Girl Mountain ’ Rose Wong

Did you know that on a typical day, 32 million children in the U.S. eat cafeteria food? Or that most of these students consume over half of their daily calories at school?

Facts like these motivate us to connect kids to real food, and teach them how to make healthy choices through our sweetgreen in schools program. School cafeterias are one of the biggest areas of opportunity that exist in the battle against childhood obesity. Recently there has been discussion about what constitutes a quality lunch, so we took a look at some typical school meals around the world, and how our own country stacks up.

Italy

Local fish on a bed of arugula, pasta with tomato sauce, caprese salad, baguette and some grapes

Finland

Pea soup, beet salad, carrot salad, bread and pannakkau       (dessert pancake) with fresh berries 

France

Steak, carrots, green beans, cheese and fresh fruit

Brazil

Pork with mixed veggies, black beans and rice, salad, bread and baked plantains

South Korea

Fish soup, tofu over rice, kimchi and fresh veggies

Greece

Baked chicken over orzo, stuffed grape leaves, tomato and cucumber salad, fresh oranges, and greek yogurt with pomegranate seeds

Ukraine

Mashed potatoes with sausage, borscht, cabbage and syrniki (a dessert pancake)

Spain

Sautéed shrimp over brown rice and vegetables, gazpacho, fresh peppers, bread and an orange

USA

Fried ‘popcorn’ chicken, mashed potatoes, peas, fruit cup and a chocolate chip cookie