Hydrocarbon fossil

Biomass, both from residues/wastes and dedicated crops, can be converted not only into bioenergy (electricity, heat) and biofuels for transport but also into bulk chemicals or materials that are nearly equivalent to, or sometimes even better than, those derived from fossil hydrocarbons. 

Biomass is complex in composition, consisting of starch, cellulose, hemicellu-lose and lignin and small amounts of fats. In the past, typically only one of these constituents of the biomass was converted, and the rest discarded. The operations were thus highly inefficient when compared with fossil hydrocarbon refinery. 

Since the industrial revolution mankind has been dependent on fossil hydrocarbon fuel for a very large proportion of total energy needs. Coal was the dominant form until the first half of the twentieth century when fluid hydrocarbons began to make significant inroads due to easier recovery, handling and transportation. Many of the fluid forms also had lower sulphur content than coal and were therefore more attractive from the environmental impact standpoint. 

Typical sulphur content values for various fossil hydrocarbon fuels are shown in Table I. The very high associated sulphur content of many of the deep gas deposits is readily seen. Fortunately, however, this sulphur content is present as relatively easily removed H2S although the presence of such large quantities at elevated temperatures and pressures can pose... 

Meanwhile, many other chemicals have enabled our society to accomplish great technical advances. For example, we have learned to recover fossil hydrocarbons from the earth and use these for heating, for transportation fuels, and for synthetic starting materials. Likewise, synthetic compounds like tetraethyllead, chlorinated solvents, freons, methyl /-butyl ether (MTBE), polychlorinated biphenyls (PCBs), and many others (see Chapter 2) have enabled us to develop products and perform industrial processes with greater efficiencies and safety. However, it has become quite apparent that even such contained applications always result in a certain level of discharge of these compounds to the environment. 

Berkowitz, N. Fossil Hydrocarbons Chemistry and Technology, Elsevier Science, New York, NY, 1997. 

The presence of organic molecules in samples of extraterrestrial matter has been known for more than a century. Some of the greatest chemists of the nineteenth century were involved in the analysis of samples of meteoritic material. They were able to show that carbonaceous chondrites (as they are now named) contain organic molecules. The first to detect carbon in a meteoritic sample was Thenard, in 1806, by analysis of a sample of the Alais meteorite. This result was confirmed in 1834 by Berzelius, who was also the first to detect the presence of water of crystallisation. Working on a sample of the Kaba meteorite, Wohler (1858) confirmed the presence of organic matter, and in a paper dated 1859 said, I am still convinced that besides free carbon this meteorite contains a low-melting point, carbon containing substance which seems to be similar to certain fossil hydrocarbon-like substances... . 

Table 1 1981 proven reserves in fossil hydrocarbons (natural gas excepted f... 

A short account of the origin of the different fossil hydrocarbons is necessary to understand the occurrence of nitrogen compounds and their nature. 

Figure 1 Genesis of nitrogen compounds in fossil hydrocarbons...

Coal Solid fossil hydrocarbon typically composed of from 65 to 75 mass% carbon and about 5 mass% hydrogen, with the remainder oxygen, ash, and smaller quantities of sulfur and nitrogen. 

Despite the general move towards use of fossil hydrocarbon feedstocks, some plant-derived materials have continued to provide economic or technical benefits that ensure they remain the preferred source of raw materials for industry. For example, cotton still accounts for 38% of all textile production due to its airflow- and temperature-regulating capabilities, which are difficult or costly to replicate with man-made fibres. Linseed oil remains a key feedstock in surface coating and linoleum flooring applications. Plant oils are still widely used in the oleochemicals sector, where coconut and palm oils are widely used in detergent... 

The fi C values for the C12-C26 n-alkanes from six chondrites are shown in Figure 4 (Sephton et al, 2001). None of the n-alkanes exhibit either the C-enrichments or systematic isotopic trends that apparently characterize indigenous organic matter in meteorites. Most of the values are similar both in value and in the trends shown within homologous series to variations observed for terrestrial petroleum products or other terrestrial fossil hydrocarbons. These features confirm the long-held suspicion that these molecules are contaminants from the... 

Nevertheless, the world economy remains oil-based and the production of almost the whole range of petrochemical and bulk organic chemical products (with a few exceptions, like methanol, urea, and cyanic acid) is still oriented toward the processing of liquid fossil hydrocarbons as the principal raw materials. Also, the same liquid hydrocarbons dominate in the production of motor fuels and lubricants. However, most if not all of the products traditionally produced from oil can be also obtained from gaseous hydrocarbons, including light alkanes. Unfortunately, up to now their utilization in the chemical industry is not satisfying. 

The production of S worldwide (inclusive of all forms) in 1998 was about 62 Mt, with 40.5 Mt in the form of elemental sulphur (32) produced mainly by refineries (approximately 1/3) (33) and natural gas. This figure is expected to increase to 68.5 Mt in 2003 and then 74.5 Mt in 2008, with 47.8 and 53.1 Mt respectively of elemental S, the proportion of S recovered from fossil hydrocarbon sources increasing steadily. At the present time the zones with the highest S production (inclusive of all forms) are North America which comes far ahead of Asia and Europe (32). 

Hydrogen from Fossil Hydrocarbons and vice versa... 

The GPTRs are therefore at the heart of the geopolitical issues about the optimal management of the resources in fossil hydrocarbon raw materials and in fossil, nuclear or renewable energies. 

Sulfur Recovery From Gases - Recovered sulfur accounts for over 60% of the total world production of elemental sulfur. Most of the recovered sulfur originates from the processing of fossil hydrocarbons, especially natural gas, oil, and coal. In natural gas, sulfur is mainly in the form of hydrogen sulfide, but in oil and coal it is also present as organic compounds such as mercaptans and as sulfides, disulfides, and heterocyclic compounds. 

Fossil hydrocarbons are too valuable as a source of recyclable plastic to be burned for fuel. 

As fossilized hydrocarbons are a finite resource, they must be used as efficiently as possible. To this end, cracking at a refinery seeks to create the most valuable products out of its feedstocks derived from crude oil. This is not limited to fuels such as gasoline. The steam crackers of the petrochemical industry create raw materials for many extremely valuable and useful products such as pharmaceuticals, plastics, solvents, detergents, and adhesives, stretching the use of hydrocarbons for consumers. 

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