Renewable materials are those which can be manufactured or generated quickly enough to keep pace with how fast they are used up. Non-renewable materials, including materials for energy sources, are those which take a long time to renew and are generally used faster than they can be regenerated. Renewable materials can be made from natural products or synthetically produced, and often include recycled products.
Renewable materials are sustainable materials, which means, according to the Rutgers University Center for Sustainable Materials, these materials do not use up non-renewable resources. They can also be produced in high enough volume to be economically useful. Biopolymers are one such renewable material. A biopolymer is a naturally occurring polymer, such as carbohydrates and proteins. Some examples of biopolymers are cellulose, starch, collagen, soy protein and casein. These raw materials are abundant and biodegradable, and are used to make diverse products such as adhesives and cardboard.
Rapidly Renewable Materials
Rapidly renewable materials are plant-based materials that can be replenished within a period of 10 years or less. Bamboo and cork are rapidly renewable materials used to create flooring materials for homes and office buildings. Bamboo is commonly used instead of woods such as oak, which is a relatively slow-growing tree. Although oak is technically a renewable resource, it takes many years for an oak tree to mature compared to bamboo.
Polylactic acid, or PLA, is a biopolymer derived from corn. The corn is first milled to extract its dextrose, a simple sugar. The dextrose is fermented in vats, much like brewing beer, except the final product is lactic acid. This lactic acid is then converted into long-chain polymers to create PLA, which can be used to make clear food containers for the food service industry, as well as cups, lids and even bioplastic cutlery. Products made from PLA are totally renewable and can be composted.
Recycled glass is another renewable resource. According to the EPA, 90 percent of recycled glass gets reused to make new glass products. Recycled crushed glass, called cullet, is mixed in with raw materials to produce new glass. Cullet is less expensive than raw materials and uses less energy to melt. Recycled glass can be used to make new containers, or used as material for kitchen counters. Low-quality cullet is used in manufacturing decorative tiles, roadbed aggregates and insulation products.
Nonrenewable Energy Sources
Oil is a nonrenewable material that is used in the manufacture of many kinds of energy products, including gasoline and diesel fuel. Natural gas, which includes several types of gas--including methane, propane and butane--is often produced as a byproduct of oil wells. Liquefied petroleum gas, oil shale and tar sands are other nonrenewable energy materials. Only 15 percent of the energy used in the world come from renewable sources, but rising concerns about running out of energy sources are pushing the development of solar, wind, geothermal and other environmentally-friendly methods of energy production.
Renewable Energy Sources
Renewable energy sources are those that can be replenished easily and are nonpolluting. Solar power, wind, water, geothermal and biomass are examples of renewable energy sources. Although they do not pollute, dams built to harness the power of water can alter the flow of rivers and affect fish and other animals that migrate.