Approaching Zero

This article explores different ways to keep carbon emissions to minimum. The pressure of meeting environmental and energy security concerns while also satisfying growing demand requires the current generation to increase, diversify, and optimize the use of energy sources. The alternative to pre-combustion capture approaches, which generally lead to high hydrogen combustion, is to capture the carbon after combustion. Combusting biomass is another approach to achieve low net carbon emissions. Recently, significant interest has emerged in algae as a biomass supply. Some species of algae grow at phenomenal rates, providing a new option for biomass supply. Continued development of advanced combustion methods, materials, and process controls might be expected to increase the potential to follow the load. However, the relative contributions of load following and energy storage are expected to depend on the specific combination of renewable power and fossil fuel backup. Major programs from the US Department of Energy, the European Union, China, India, and other countries are underway, in addition to internal programs at many of the largest energy and petrochemical companies in the world.