Feedstock production, coal

Coal is used ia industry both as a fuel and ia much lower volume as a source of chemicals. In this respect it is like petroleum and natural gas whose consumption also is heavily dominated by fuel use. Coal was once the principal feedstock for chemical production, but ia the 1950s it became more economical to obtain most industrial chemicals from petroleum and gas. Nevertheless, certain chemicals continue to be obtained from coal by traditional routes, and an interest in coal-based chemicals has been maintained in academic and industrial research laboratories. Much of the recent activity in coal conversion has been focused on production of synthetic fuels, but significant progress also has been made on use of coal as a chemical feedstock (see Coal CONVERSION processes). 

We will consider three processes in more detail to show how the sulfur in the original feedstock material (coal or oil shale) is recovered as elemental by-product sulfur. In this way yields of sulfur per barrel of product can be computed. The three processes will illustrate examples of coal gasification for production of SNG, methanol or indirect liquids, direct liquefaction for production of naphtha and synthetic crude oil and finally, oil shale retorting for production of hydrotreated shale oil. 

HES [Feedstock (Water, Coal, Oil, Gas, Biomass) Electric Energy (Nuclear PP, Renewable PP, Fossil PP), H2 Production (Electrolysis, Reforming, Gasification) H2Utilisation (Fuel Cell, Gas Turbine, Internal Combustion Engine)]... 

Catalysis has made possible the change in the chemical process industry from feedstocks of coal and acetylene, to ethylene. Activation of alkanes is now a major research topic. German industrial scientists led in the coal- and acetylene-based chemical industry developments. Many of the chemical products were for the dyestuffs industry. 

Sasol (Suid-Afrikaans Sintetiese Olie) in South Africa has one of the largest coal gasification production operations in the world with the three plants.1 One plant produces only chemicals and the other plants produce both liquid fuels and chemical feedstocks from coal. In 1994, Sasol s total ammonia capacity was over 500,000 tons per year.54... 

Hydrogen must be chemically separated from some other material. Currently, natural gas is the most common feedstock, but coal is also used. Biomass could be used in the future. The full costs of the production, processing, and purification of these hydrocarbon feedstocks are included in this analysis. When these materials are used to produce hydrogen, the required energy is embedded in the feedstock. (See Chapter 8 and Appendix E for more details.)... 

The committee analyzed several implications relative to domestic resource use. For biomass production, it examined the amount of land that would be required to grow the crops used as feedstocks. For coal-based hydrogen production, it examined the amount of coal that would be used over time. For technologies involving sequestration, it examined the amount of C02 that would be sequestered on a year-by-year basis and the cumulative quantity sequestered. The committee did not try to quantify several other resource use impacts it did not examine the amount of land that would be required for wind farms, production facilities, or distribution infrastructure it did not examine the impacts on water use for steam reforming processes or for biomass production it did not attempt to examine any labor force issues nor did it examine the needs for metals or other materials for fuel cells, electrolyzers, or production facilities, or the number of pipelines, or other infrastructure. 

As the H/C ratio in the feed decreases, the tendency to favor the production of carbon increases. Since the amount of water formed by combustion becomes insufficient, it is therefore necessary to operate in the presence of steam, even at elevated temperature. The thermodynamic calculation shows that, at identical temperatures, an increase in pressure results in larger water requirements and a decrease in oxygen requirements. Simultaneously, the residual methane content increases, and this can be offset by raising the temperature. The highest carbon content feedstocks (residues, coal, biomass) constitute the limit case.. ... 

Land use is another concern. Additional natural gas production, coal mining, and growth of dedicated biomass feedstocks will impact land use, alter topography, or impact ecological systems. Mitigation and reclamation strategies would be required to offset some of these changes. 

Feedstock anthracite coal waste (culm) at 1.4 million tons per year Products 5,000 barrels per day of ultra-clean fuels, 39 MW electricity for export, sulfur, and steam. 

Refinery feedstocks from coal (coal liquids) have not been dealt with elsewhere in this text but descriptions are available from other sources (Speight, 2008, 2011). Once the liquids are produced, the next issue is the means by which these liquids can be refined to produce the necessary fuel products. 

Furnace carbon black is produced from the incomplete combustion of what is called carbon black oil feedstock, which consists of heavy aromatic residue oils. In the United States this oil is commonly the bottoms from catalytic cracker units. They are commonly referred to as cat cracker bottoms and contain relatively low hydrogen content (and conversely high carbon content). In Europe and other locations, the carbon black oil used is commonly a byproduct of high-temperature steam cracking of such products as naphtha, gas condensate, and gas oil to produce ethylene, propylene, and other olefins. Here, no catalysts are used in the cracking process. These types of carbon black oils are mainly unsaturated hydrocarbons. A third source of carbon black feedstock is coal tar, which is commonly used in China to manufacture carbon black. 

Feedstocks are usually either cat cracker bottoms from a petroleum cracking unit or tars from steam cracking for polyethylene production. Coal tars are commonly used as feedstocks to produce carbon black in China. 

Global petrochemical production of platform chemicals derived from fossil-based feedstocks (oil, coal, gas) is estimated to be aroxmd 330 million tons. The initial output is dominated by building blocks and converted into a staggering number of different fine and specialty chemicals with specific functions (Jong et al., 2012). The US Department of Energy listed out chemicals such as 3-Hydroxy-propionic (3-HP) acid and xylitol, to name just two, which are the potential building blocks for the future (Jong et al., 2012). 

Methanol. If methanol is to compete with conventional gasoline and diesel fuel it must be readily available and inexpensively produced. Thus methanol production from a low-cost feed stock such as natural gas [8006-14-2] or coal is essential (see Feedstocks). There is an abundance of natural gas (see Gas, natural) woddwide and reserves of coal are even greater than those of natural gas. 

The term feedstock in this article refers not only to coal, but also to products and coproducts of coal conversion processes used to meet the raw material needs of the chemical industry. This definition distinguishes between use of coal-derived products for fuels and for chemicals, but this distinction is somewhat arbitrary because the products involved in fuel and chemical appHcations are often identical or related by simple transformations. For example, methanol has been widely promoted and used as a component of motor fuel, but it is also used heavily in the chemical industry. Frequendy, some or all of the chemical products of a coal conversion process are not isolated but used as process fuel. This practice is common in the many coke plants that are now burning coal tar and naphtha in the ovens. 

Because of the ovedapping roles of coal in industry, many of the technologies covered here have been developed for synthetic fuel appHcations, but they also have been used or have demonstrated potential for production of significant quantities of chemicals. The scope of an article on coal as a chemical source would not be complete without coverage of synfuel processes, but the focus will be on the chemical production potential of the processes, looking toward a future when coal again may become the principal feedstock for chemical production. 

Many valuable chemicals can be recovered from the volatile fractions produced in coke ovens. Eor many years coal tar was the primary source for chemicals such as naphthalene [91-20-3] anthracene [120-12-7] and other aromatic and heterocycHc hydrocarbons. The routes to production of important coal-tar derivatives are shown in Eigure 1. Much of the production of these chemicals, especially tar bases such as the pyridines and picolines, is based on synthesis from petroleum feedstocks. Nevertheless, a number of important materials continue to be derived from coal tar. 

Approximately 50—55% of the product from a coal-tar refinery is pitch and another 30% is creosote. The remaining 15—20% is the chemical oil, about half of which is naphthalene. Creosote is used as a feedstock for production of carbon black and as a wood preservative. Because of modifications to modem coking processes, tar acids such as phenol and cresyUc acids are contained in coal tar in lower quantity than in the past. To achieve economies of scale, these tar acids are removed from cmde coal tar with a caustic wash and sent to a central processing plant where materials from a number of refiners are combined for recovery. 

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