Science and Coal

Posts Tagged ‘U.S.’

High oil prices and the desire to reduce energy dependence in the United States have brought coal-to-liquid (CTL) technology to the forefront of the discussion about alternative fuel sources. Nearly 100 years old, CTL processes have long been used by countries lacking access to oil, most notably Germany, where production peaked during the 1940s; South Africa, which has been using CTL technology for fuel since the 1950s; and, more recently, China, where the Shenhua Group LLC began trial operation of the world’s first direct CTL facility in December 2008, and intends to eventually produce 1 million tons of coal-based liquid fuel a year. The U.S. Government promoted the development of CTL technologies following the oil shocks of the 1970s, but shelved the projects after the price of oil fell during the 1980s. In the current economic and political environment of the United States, with oil prices surpassing $100 per barrel in summer 2008 and generally projected to rise in the long term, synthetic fuel derived from coal may once again become economically viable, and several projects are in the initial design phase around the country. From an environmental standpoint, however, the carbon dioxide (CO2) emissions produced throughout the lifecycle of coal-based liquid fuel make it a less desirable option.

Turning Coal into Liquid Fuel
Coal can be converted into liquid fuel using several liquefaction processes; these processes can be divided into two general categories. The first category, indirect liquefaction, is a multi-step procedure that first requires the gasification of coal to produce a “syngas.” This syngas is then converted to liquid fuel via two methods: the Fischer-Tropsch process or the Mobil process. In the Fischer-Tropsch process, which is much more common, the syngas is then cleansed of impurities and subjected to further chemical refinement to produce a sulfur-free diesel or gasolinei. The initial syngas can be derived from coal alone, or from a coal / biomass mixture. The process is the same when biomass is included, but the amount of CO2 emitted during the process decreases as the proportion of biomass increases. In the less-common Mobil process, the syngas can be converted to methanol, which is subsequently converted to gasoline via a dehydration sequence. Indirect liquefaction of coal during Fischer Tropsch produces a significant amount of CO2 that is removed from the fuel as a necessary step during the final stages of the process. However, recent research has suggested a modified Fischer-Tropsch method that could significantly reduce CO2 emissions during liquefaction.ii
The second category, direct liquefaction, requires creating a chemical reaction at high temperatures and then using hydrogen gas and a catalyst to produce a liquid fuel. Direct liquefaction usually produces low-quality liquid fuel that is expensive to make compliant with U.S. standards for purity. Therefore, although the process is used in China, it is not a viable option for meeting the United States’ liquid fuel requirements and will not be discussed for the remainder of this brief. Read the rest of this entry »

A large section of the Fifth Estate, that world company of scientists, climbed the Allegheny Mountains to Pittsburgh last week. They knew soft coal, what it was and what could profitably be done with it and were answering the call to the Second International Conference on Bituminous Coal made by President Thomas Stockham. Baker of Carnegie Institute of Technology.

Coal Situation. Of U. S. coal companies, only the Island Creek Coal Co. admits that it is making satisfactory profits. Practically all the rest claim that they are losing money. Certainly most are. They have millions of tons of coal mined and ready .for : sale at low, unprofitable prices. But sales have fallen off. Electricity, gas and oil are supplanting coal. This economic shift is inevitable.

The way to coal profits—President Baker emphasized when he opened last week’s conference—is to teach consumers how to use coal in new ways and to teach coal men how to “unlock the riches that lie hidden” in coal (i.e., to produce synthetic goods).
C-O-H-N & Synthetics. When Carnegie Tech’s President Baker asked Director Edwin Emery Slosson of Science Service to speak at this bituminous coal conference, he did not expect Dr. Slosson “to make any serious contribution to the practical and technical problems” which engaged the attention of the Congress. So Dr. Slosson, learned journalist, made a brilliant survey of synthetic chemistry, in which soft coal is the great raw material. Read the rest of this entry »

Coal dust exposure is directly linked to severity of emphysema in smokers and nonsmokers alike, according to new research from the National Institute for Occupational Safety and Health (NIOSH).

‘In this study we have shown that coal mine dust exposure is a significant predictor of emphysema severity,’ said Eileen Kuempel, Ph.D., a senior scientist at NIOSH and lead author of the study.

The findings, which were reported in the August 1 issue of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine (AJRCCM), highlight a health problem related to a growing industry. In the past 25 years, coal production has nearly doubled worldwide.

Dr Kuempel and colleagues compared lung autopsy results from 722 individuals, including 616 coal miners from West Virginia and 106 non-miners from West Virginia and Vermont. Those from West Virginia were collected from consecutive autopsies from 1957 and 1973 at the Beckley Southern Appalachian Regional Hospital as part of a black lung study. Those from Vermont were taken from consecutive autopsies performed at the University of Vermont between 1972 and 1978. Age at death, race, miner/non-miner status and smoking history were established where possible, and individual exposure to coal dust was estimated using work history data and job-specific dust exposure estimates. Read the rest of this entry »

Coal is the dirtiest of all fossil fuels. When burned, it produces emissions that contribute to global warming, create acid rain and pollute water. With all of the hoopla surrounding nuclear energy, hydropower and biofuels, you might be forgiven for thinking that grimy coal is finally on its way out.

But coal is no sooty remnant of the Industrial Revolution — it generates half of the electricity in the United States and will likely continue to do so as long as it’s cheap and plentiful [source: Energy Information Administration]. Clean coal technology seeks to reduce harsh environmental effects by using multiple technologies to clean coal and contain its emissions.

Coal is a fossil fuel composed primarily of carbons and hydrocarbons. Its ingredients help make plastics, tar and fertilizers. A coal derivative, a solidified carbon called coke, melts iron ore and reduces it to create steel. But most coal — 92 percent of the U.S. supply — goes into power production [source: Energy Information Administration]. Electric companies and businesses with power plants burn coal to make the steam that turns turbines and generates electricity. Read the rest of this entry »