A vast array of technologies exist that can produce liquid fuels from coal, oil shale, and biomass resources, that can facilitate enhanced oil recovery from U.S. reservoirs and save millions of barrels per day of liquid fuels in the transportation sector.

There are two basic technologies for producing liquid fuels from coal: Direct and indirect liquefaction. Direct liquefaction produces a synthetic crude that must then be refined to produce gasoline and diesel fuel, whereas indirect liquefaction involves gasification of coal to produce a syngas that is then converted into liquid fuels via Fischer-Tropsch (F-T) synthesis. Indirect liquefaction is a well developed technology and has been used by Sasol to produce liquid fuels from coal for more than five decades. In this study we assume that all of the coal-to-liquid (CTL) plants to be built will utilize indirect liquefaction, which can produce high quality liquid fuels that can supplement or substitute for the fuels now produced from petroleum.

Oil Shales can be produced by mining (surface or underground) with surface retorting or by in-situ processing. Oil shales for surface retorting can be surface mined or deep-mined, and once the shale has been mined, it is heated to convert – or retort -- the kerogen and create shale oil and combustible gases. Numerous approaches to surface retorting have been tested at pilot and semi-works scales. In-situ processing involves heating the resource in-place, underground, and various approaches have been tested, including true in-situ and modified in-situ. True in-situ processes involve no mining: The shale is fractured, air is injected, the shale is ignited to heat the formation, and shale oil moves through fractures to production wells. Modified in-situ (MIS) involves mining below the target shale before heating and requires fracturing the target deposit above the mined area, and the shale is heated by igniting the top of the target deposit. Here we assume that surface retort and true in-situ technologies will be used.

The most promising technology for enhanced oil recovery (EOR) involves the injection of CO2 into the oil reservoir, and the potential for CO2-EOR in the U.S. is increasing continuously with advances in technology. Reservoir modeling, especially for CO2-EOR, has become extremely sophisticated with the increased capabilities of modern computers and with the development of advanced computer codes. The synergism of the advanced technologies allow a far better understanding and control of oil reservoirs, reservoir fluids, and the physics and chemistry of enhanced recovery. CO2-EOR is the “universal” enhanced recovery system, applicable to most reservoirs except the very shallow and the reservoirs with heavier oils, for which thermal technologies are more applicable. DOE estimates that as much as 89 billion bbls of oil could be produced by applying modern and forthcoming advanced CO2-EOR technologies. With more than three decades of experience with the process, companies are becoming more comfortable using CO2-EOR.

Liquid fuels are complex mixtures of hydrocarbons or oxygenated hydrocarbons in the form of ethers or alcohols. The transformation of biomass into these types of compounds involves breaking down the macropolymers of biomass into elemental molecules and then reconfiguring these molecules into the desired fuel compounds. There are two fundamental approaches to this transformation: one is a bioconversion approach and the other uses thermochemical methods. Commercial ethanol and biodiesel liquid fuels production is well established in the U.S., and new pyrolysis and thermal depolymerization techniques are being developed to produce hydrocarbon fuels from cellulosic resources. Large polygeneration carbon-to-liquids plants can process a varied blend of coal, oil shale, and biomass feedstocks into oil. These combination plants first will gasify the carbon-bearing feedstocks and then combine the product gases into liquid fuels using well established Fisher-Tropsch technology.

The technical options for improving light duty vehicle fuel efficiency can be classified into two basic categories: powertrain technologies, which include engines, transmissions, and the integrated starter-generator, and load reduction technologies which include mass reduction, streamlining, tire efficiency, and accessory improvements. Many of these technologies are currently under production, product planning, or continued development. In addition, there are a number of other technologies and initiatives that can be used to reduce petroleum demand in the trucking, airline, marine, and rail transportation sectors. In this study we assumed that, coincident with the crash substitute fuels programs, transportation fuel efficiency will also increase substantially by 2030, and the generic gains likely from transportation efficiency and conservation reduce forecast overall U.S. petroleum requirements. Mass transit, rail, and light rail initiatives were also assumed to be part of the transportation energy efficiency program.