Is natural gas renewable?

What about algae?

Microorganisms are at the forefront of futuristic energy generation. In 2009, the Pacific Northwest National Laboratory, which is part of the U.S. Department of Energy, developed a process called catalytic hydothermal gasification. This process mines huge amounts of natural gas, or biomethane, out of algae. What's even more Earth-friendly about this process is that the carbon dioxide byproduct from burning this biofuel can be recycled. It's used to feed the algae.