Synthetic gas from coal

This is a report on the basic work done in the laboratory to develop the catalysts for the methanation of synthetic gas from coal, and it also reports on the development of an applicable kinetic system. This report does not include any of the subsequent pilot plant test work. 

Coal gasification production of synthetic gas from coal. 

Oil/fuel industry > Hydrogen addition to heavy oils > Upgrading of bitumen from oil sands > Producing synthetic gas from coal... 

One of the casualties of the budget cutting by OMB was reported to be funds for the commercial application of synthetic gas from coal. The original spending request was 224 million and the OMB slashed this to zero. Secretary Schlesinger asked that 98 million be restored. The final outcome is not known as of January 20, 1979. 

Forecasted natural gas availability from 1971 to 1990 indicates the Nations supply will he inadequate to meet projected demand. Domestic production is expected to peak at about 25 trillion cubic feet (Tcf) in the mid-seventies and decline slowly thereafter, while demand could reach 46 Tcf in 1990. Supplemental sources of gas, including pipeline imports, liquefied natural gas, synthetic gas from coal, and gas from Alaska, will be required to ameliorate indigenous supply deficiencies. Expected volumes of gas from these supplemental sources may total 4.6 and 11.5 Tcf annually by 1980 and 1990, respectively, and by 1990 could provide about 40% of the Nations gas consumption. Nevertheless, total gas supply wiU be insufficient to meet projected demand, and a continuing supply-demand imbalance is expected. 

M. E. Frank and B. K. Schmid, "Economic Evaluation and Process Design of a Coal—Oil—Gas (COG) Refinery," paper presented at Symposium on Conceptual Plantsfor the Production of Synthetic Fuels From Coal, AIChE 65th Annual Meeting, New York, Nov. 26, 1972. 

Until the end of World War II, coal tar was the main source of these aromatic chemicals. However, the enormously increased demands by the rapidly expanding plastics and synthetic-fiber industries have greatly outstripped the potential supply from coal carbonization. This situation was exacerbated by the cessation of the manufacture in Europe of town gas from coal in the eady 1970s, a process carried out preponderantly in the continuous vertical retorts (CVRs), which has led to production from petroleum. Over 90% of the world production of aromatic chemicals in the 1990s is derived from the petrochemical industry, whereas coal tar is chiefly a source of anticorrosion coatings, wood preservatives, feedstocks for carbon-black manufacture, and binders for road surfacings and electrodes. 

Depending on the product and sales arrangement, the revenues calculation can take from a few man-hours to many man-months of effort. For instance, determining the price for a synthetic fuel from coal can be done in a very short time, based on the cost of service. However, if the price is tied to the price of natural gas or oil, the task becomes very difficult, if not impossible. On the other hand, determining the sales growth and selling price for a new product requires a great deal of analysis, speculation, market research, and luck, but projections can be made. 

The major chemical difference between natural gas, crude oil, and coal is their hydrogen-to-carbon ratios. Coal is carbon-rich and hydrogen-poor, so to produce a synthetic liquid or gas from coal requires an increase in the hydrogen-to-carbon ratio. Coal s ratio of about 0.8 has to be raised to 1.4 to 1.8 for a... 

Coal, oil shale, and tar sand are complex carbonaceous raw materials and possible future energy and chemical sources. However, they must undergo lengthy and extensive processing before they yield fuels and chemicals similar to those produced from crude oils (substitute natural gas (SNG) and synthetic crudes from coal, tar sand and oil shale). These materials are discussed briefly at the end of this chapter. 

Gasification technologies offer the potential of clean and efficient energy. The technologies enable the production of synthetic gas from low or negative-value carbon-based feedstocks such as coal, petroleum coke, high sulfur fuel oil, materials that would otherwise be disposed as waste, and biomass. The gas can be used in place of natural gas to generate electricity, or as a basic raw material to produce chemicals and liquid fuels. 

Table 3.11 summarises the current projections of the production of unconventional oil, including synthetic fuels from coal and gas, until 2030. Today, unconventional fuels account for around 2% of world oil production of 81 Mb/day. Their future will depend on the oil price. If prices stay at relatively high levels, unconventional fuels could reach between 2.6 and 5.5 Gb (7 and 15 Mb/day) in 2030. According to the IEA (2006) WEO Reference Scenario, total oil production in 2030 will amount to 42.3 Gb (116 Mb/day). Hence, unconventional fuels would make up between 6% and 13% of total oil production in 2030, of which around one-third comes from oil sands. Unconventional fuels are not a silver bullet they can briefly delay the maximum rate of oil production, however, the global decline of production cannot be prevented in the short to medium term, if demand for oil continues to surge. 

The alternative fuels and drive systems available only seem to be viable on the mass market, if the oil price stays above 60 to 70 /bbl for a sustained period. Oil prices peaked above 140 /bbl in summer 2008 and many experts believe that stable oil prices over 100 /bbl could be reached in the next one or two decades. The higher the market prices of fossil fuels, the more competitive low-carbon alternatives will become The principal choice here is between biofuels, electricity and hydrogen, provided that they are produced either from low/zero-carbon feedstock or that the C02 generated during their production is captured and stored. But higher priced conventional oil resources, on the other hand, can also be replaced by high-carbon alternatives such as oil sands, oil shale or synthetic fuels from coal and gas. 

Catalytie synthesis from CO and Hj Natural gas Petroleum gas Distillation of liquid from eoal pyrolysis Catalytic synthesis from CO and Hj Distillation of liquid from wood pyrolysis Gaseous products from biomass gasification Synthetic gas from biomass and coal... 

Methanol was first produced commercially in 1830 by the pyrolysis of wood to produce wood alcohol. Almost a century later, a process was developed in Germany by BASF to produce synthetic methanol from coal synthesis gas. The first synthetic methanol plant was introduced by BASF in 1923 and in the United States by DuPont in 1927. In the late 1940s, natural gas replaced coal synthesis gas as the primary feedstock for methanol production. In 1966, ICI announced the development of a copper-based catalyst for use in the low-pressure synthesis of methanol. 

We will examine three synthetic fuel scenarios and compare their implications regarding sulfur availability with the current and projected market for sulfur to the year 2000. The analysis will consider three production levels of synthetic fuels from coal and oil shale. A low sulfur Western coal will be utilized as a feedstock for indirect liquefaction producing both synthetic natural gas and refined liquid fuels. A high sulfur Eastern coal will be converted to naphtha and syncrude via the H-Coal direct liquefaction process. Standard retorting of a Colorado shale, followed by refining of the crude shale oil, will round out the analysis. Insights will be developed from the displacement of imported oil by synthetic liquid fuels from coal and shale. 

The reaction for the production of the synthetic fuel water-gas from coal is... 

Existing AGR processes envisioned for use in the production of synthetic fuels from coal face unique challenges because these AGR processes were developed primarily in response to the needs of the petroleum and natural gas industries where crude gas mixtures are relatively well-defined. In contrast to crude gas mixtures in the petroleum and natural gas industries, crude coal gasifier gas generally contains much more carbon dioxide, a much higher ratio of carbon dioxide to hydrogen sulfide, and many trace contaminants. The AGR step in synthetic fuels production from coal must be capable of performing two tasks (1) separation... 

The following goals were established at the start of efforts to develop an acid gas removal process more suited to gas cleaning in the production of synthetic fuels from coal, particularly medium BTU and substitute natural gases ... 

For example, the current policy in Washington to keep the energy demand tuned to a zero growth economy - 2% per year or less - means that conventional sources of fuels, particularly coal and natural gas, are currently available in excess and will in the future be available for a number of years longer than previously anticipated. The restraints on the economy will in turn mean that synthetic fuels from coal will not be produced commercially for many years to come. 

The Library of Congress study has these comments on synthetic oil and gas from coal. "For the past several years, there has been renewed interest in converting coal, which is so plentiful, into liquid and gaseous fuels which are not plentiful from domestic sources. The major products under consideration are solvent refined coal (SRC), oil from coal, synthetic natural gas, and medium- and low-Btu gases. The Department of Energy (and its predecessor agency, ERDA), many parts of the Congress and a number of private interests have been involved."... 

N. W. Green, Synthetic fuels from coal, the Garret Process, Clean Fuels from Coal Sym. Inst. Gas Tech., 3, 299 (1975). 

Gas from Coal. Progress toward the development of improved processes to produce high-Btu, synthetic pipeline-quality gas from coal can currently be seen on several fronts. Two large-scale coal gasification pilot plants are currently in operation or under construction and plans to build two others are advancing. The pilot plant in operation is located... 

---