Oil and biomass

Of the many factors which influence product yields in a fluid catalytic cracker, the feed stock quality and the catalyst composition are of particular interest as they can be controlled only to a limited extent by the refiner. In the past decade there has been a trend towards using heavier feedstocks in the FCC-unit. This trend is expected to continue in the foreseeable future. It is therefore important to study how molecular types, characteristic not only of heavy petroleum oil but also of e.g. coal liquid, shale oil and biomass oil, respond to cracking over catalysts of different compositions. 

More recently, the chemical industry has seen the need to look beyond petroleum to processes for converting nonpetroleum materials to feedstocks (1,15). These processes, all fuel-oriented but having feedstock potential in varying degrees, usually deal with coal-derived liquids, shale oil, and biomass. 

Figure 3 illustrates the relationship of anthracite, bituminous and snbbituminons eoals, hgnite, fuel oil, and biomass in terms of the atomie hydrogen-to-carbon (H C) and oxygen-to-carbon (0 C) ratios. This type of diagram... 

Approximately 50% of the world s syngas production is based on natural gas. (The other 50% is based on coal, heavy oil, and biomass.) The numbers given in the literature differ, so this is only a rough estimation based on figures given for... 

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). 

Because oil and gas ate not renewable resources, at some point in time alternative feedstocks will become attractive however, this point appears to be fat in the future. Of the alternatives, only biomass is a renewable resource (see Fuels frombiomass). The only chemical produced from biomass in commercial quantities at the present time is ethanol by fermentation. The cost of ethanol from biomass is not yet competitive with synthetically produced ethanol from ethylene. Ethanol (qv) can be converted into a number of petrochemical derivatives and could become a significant source. 

The market penetration of synthetic fuels from biomass and wastes in the United States depends on several basic factors, eg, demand, price, performance, competitive feedstock uses, government incentives, whether estabUshed fuel is replaced by a chemically identical fuel or a different product, and cost and availabiUty of other fuels such as oil and natural gas. Detailed analyses have been performed to predict the market penetration of biomass energy well into the twenty-first century. A range of from 3 to about 21 EJ seems to characterize the results of most of these studies. 

Several biomass species have been found to contain oils and/or hydrocarbons (Table 13). It is apparent that oil or hydrocarbon formation is not limited to any one family or type of biomass. Interestingly, some species in the Euphorbiaceae family, which includes Hevea bra liensis form hydrocarbons having molecular weights considerably less than that of natural mbber at yields as high as 10 wt% of the plant. This corresponds to hydrocarbon yields of about 3.97 mVhm2-yr(25bbl/hm2-yr). 

Table 13. Oil- and Hydrocarbon-Producing Biomass Species Potentially Suitable for North America ...

The MTG process was developed for synfuel production in response to the 1973 oil crisis and the steep rise in crude prices that followed. Because methanol can be made from any gasiftable carbonaceous source, including coal, natural gas, and biomass, the MTG process provided a new alternative to petroleum for Hquid fuels production. New Zealand, heavily dependent on foreign oil imports, utilizes the MTG process to convert vast offshore reserves of natural gas to gasoline (59). 

E. J. Soltes and T. A. Milne, eds.. Pyrolysis Oils from Biomass Producing Analy ng and Upgrading, ACS Symposium Series 376, American Chemical Society, Washington, D.C., 1988. 

Supercritical fluid solvents have been tested for reactive extractions of liquid and gaseous fuels from heavy oils, coal, oil shale, and biomass. In some cases the solvent participates in the reactions, as in the hydrolysis of coal and heavy oils with water. Related applications include conversion of cellulose to glucose in water, dehgnincation of wood with ammonia, and liquefaction of lignin in water. 

Human interaction with the global cycle is most evident in the movement of the element carbon. The burning of biomass, coal, oil, and natural gas to generate heat and electricity has released carbon to the atmosphere and oceans in the forms of CO2 and carbonate. Because of the relatively slow... 

United States in 1998) from coal (56%), nuclear (20%), natural gas (11%), hydro (8%), oil (3%), biomass (1.5%), geothermal (0.2%), wind (0.1%), and solar (0.02%). Recently, wholesale and some retail markets have been unbundled, allowing competitors to sell electrons with the monopoly utility or municipality providing the transmission service. Open-access restructuring gives customers choices and creates a commodity market in which the lowest-cost electricity wins market share at the expense of higher-cost alternatives. 

Robert Boyle, an Irish chemist noted for his pioneering experiments on the properties of gases, discovered methanol (CH3OH) in 1661. For many years methanol, known as wood alcohol, was produced by heating hardwoods such as maple, birch, and hickory to high temperatures m the absence of air. The most popular modern method of producing methanol, which IS also the least costly, is from natural gas (methane) by the direct combination of carbon monoxide gas and hydrogen in the presence of a catalyst. Methanol also can be produced more expensively from oil, coal, and biomass. 

Gas turbine and combined cycle (gas and light fuel oils) Thermal power plant (coal, lignite, wood and biomass)... 

Furthermore, the biocatalysts will be even more important with the shift of the raw materials from oil to biomass. Since biomass is a mixture of various multifunctional compounds, chemo-, regio-, and enantioselective catalysts will be... 

The actual energy content of even dried biomass is typically in the range 14-17 GJ tonne" , this being roughly one-third that of oil and significantly less than natural gas (55 GJ t" ), the most calorific fuel commonly used. 

The use of renewable resources for manufacturing specific performance and speciality chemicals, and for fibres to replace synthetic ones, is growing. The driver for this is improved cost/performance. In order to have a major impact on the amount of oil and gas used there is a need to convert biomass into new, large-scale basic feedstocks such as synthesis gas or methanol. Many technical developments in separation science as well as improvements in the overall yield of chemicals are required before renewable feedstocks can compete effectively with oil and gas, but the gap will continue to narrow. 

Separation of the aqueous, oil, and biocatalyst (solid/biomass paste) phases ... 

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