Gasification feedstocks, potential

Figure 2 deals with potential gasification feedstocks in the contiguous 48 United States. As shown, coal, at about 5000 quads, is by far the largest recoverable fossil fuel. Peat is next at about 750 quads, and then oil shale at about 500 quads. And finally, we have also shown crude oil at about 170 quads to add perspective to the reserve estimates. These estimates, including crude oil, were published by the Institute of Gas Technology (IGT) in late 1977. 

Alternative feedstocks for petrochemicals have been the subject of much research and study over the past several decades, but have not yet become economically attractive. Chemical producers are expected to continue to use fossil fuels for energy and feedstock needs for the next 75 years. The most promising sources which have received the most attention include coal, tar sands, oil shale, and biomass. Near-term advances ia coal-gasification technology offer the greatest potential to replace oil- and gas-based feedstocks ia selected appHcations (10) (see Feedstocks, coal chemicals). 

Synthesis Gas Generation Routes. Any hydrocarbon that can be converted into a synthesis gas by either reforming with steam (eq. 4) or gasification with oxygen (eq. 5) is a potential feedstock for methanol. 

Coal used in power stations has the potential to be partly replaced by fuels derived from pre-treated plastics and paper waste, reducing both dependency on fossil fuels and reliance on landfill. APME reports on a project in the Netherlands which it co-sponsored to develop a substitute fuel from plastics. The environmental assessment of the project compared the environmental impacts of coal substitution with other plastics recovery methods, including gasification in feedstock recycling and energy recovery from plastics waste in cement kilns. The study also compared coal substitution with the generation of power from burning biomass. 

A potential source of particulates is char formed when the biomass feedstock is incompletely gasified. These particles undergo devolatilization and subsequent reactions at gasification temperatures that leave them less reactive than fresh biomass feedstock. They can pass through the gasifier before they are completely gasified, particularly in those configurations with turbulent beds. Char entrained in the product gas also represents unconverted biomass that contributes to lower conversion efficiencies. 

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. 

Briefly, new uses may include improved coke-fuel oil mixtures, feedstock for petrochemical manufacture via gasification, lime kiln fuel for paper mills and as cogeneration fuel at refinery sites. The potential for coke usage with fuel oil is particularly high in Japan, where several industry participants estimate an additional 1.5 million short tons could be consumed annually. 

Various forms of biofuels represent interesting feedstocks for combustion, gasification and pyrolysis processes in power plant technology as a source of CO2 neutral fuels. Biomass has an estimated potential in Germany of about 660 PJ (1 Petajoule = lO Joule). This is equivalent to about 5 % of the annual primary energy consunqrtion in Germany. [10]... 

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