Gasification — the word itself sounds pretty intense. One thinks of something industrial, complex and challenging. In the real world, gasification is one of our oldest and most versatile industrial technologies. At its core, gasification is recycling being performed at the molecular level and this is what makes gasification an ideal technology for programs focused on energy independence.
Unlike most energy technologies, gasification can use virtually any feedstock on the input side of the system. If it contains carbon and hydrogen, it can be gasified. This material is fed into a gasifier where extreme temperature and pressure is applied to break the material down at the molecular level and convert the material to a mixture of gases. The most common of the gases are hydrogen and carbon monoxide (referred to as synthesis gas, or syngas) along with carbon dioxide and various other gases, depending on the feedstock. Once in a gaseous form, scrubbers and distillation columns are used to separate the gases and remove impurities.
The purified gases can then be passed over various catalysts to form new molecules and compounds which are the desired end products. Gasification can be used to manufacture ethanol, methanol, butanol and other alcohols as well as methane gas, synthetic petroleum, dimethyl ether, kerosene, diesel and other gases and liquids. Even the “waste” gases can be used to form marketable products such as fertilizers and chemical feedstocks.
This is why gasification can play a crucial role in achieving energy independence. The same technology can be used to convert feedstocks into fuels even as we make changes in our energy infrastructure. A gasification plant built today can start producing synthetic petroleum products from coal feeds and then adjust to alcohol products at a later date. As more renewable feedstocks from wastes and energy crops become available, the same infrastructure can adapt to use those inputs for whichever fuels we need at the time. And unlike future promises of cellulosic ethanol and hydrogen economies, gasification has been in commercial use for over 180 years.
The following pages consider the viability and potential for constructing a gasification infrastructure capable of producing 10 million barrels per day of synthetic fuels. This infrastructure would be capable of producing over 50% of the liquid fuels used in the United States every year. This target is defined by a variety of studies indicating that over 1 billion tons of renewable biomass can be produced in the United States annually without disrupting food or feed production. Options are also reviewed for increasing that production capacity without increasing feedstock requirements.
By Scott Miller — February 2011