Oxygen boiler fuel

Pyrolysis and liquefaction of biomass can be used to produce bio-oils, which are mixtures containing up to 400 compounds including acids, alcohols, aldehydes, esters, ketones and aromatic compounds [31, 42], Bio-oils can be used as boiler fuel or in chemical production. Pyrolysis occurs at 375-525 °C and 1-5 bar in the absence of oxygen. Liquefaction occurs at 250-325 °C and 50-200 bar [31]. 

The most common pressnre vessels in the workplace are boilers and cylinders con-tairring oxygen or fuel gas. A boiler is a closed vessel in which water is heated by combustion of fuel or heat from other sources to form steam, hot water, or high temperature water urtder pressure. 

Combustion controls such as oxygen trim help to maintain optimum operating conditions, especially on gaseous fuels. Instrumentation can give continuous visual and recorded information of selected boiler and plant functions. To be effective, it must be maintained and the data assessed and any required action taken before the information is stored. 

NOTE Under these low hardness but high MU demand circumstances, other risk factors also exist, especially in smaller boilers. Typically, the high MU water demand reduces the FW temperature, which permits the oxygen level to rise and thus requires additional sulfite scavenger to counter the increased risk of corrosion. Also, the requirement for BD is increased as TDS and SS levels also rise, so fuel and other operating costs increase accordingly. 

The chemical products from complete combustion of a hydrocarbon fuel are mainly C02 and H20 (vapor). Combustion of gaseous fuel in air can occur in two different modes - one where fuel and oxygen is mixed during the combustion process, and the other where fuel and air are premixed (gas condensing boilers) and the fuel concentration must be within the flammability limits. In general the premixed situation allows the fuel to burn faster, i.e. more fuel is consumed per unit time. 

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