Models, wood fuel production

Note that this approach assumes Fl4C = 1.0 and is constant prior to 1950. Actually the 14C/12C of atmospheric C02 did vary with time prior to 1900, mostly reflecting changes in the rate of 14C production in the upper atmosphere. During the Holocene, these variations were less than 10%, and they are documented in the calibration data sets based on 14C measured in known-age wood. Between 1900 and 1950, Eatm declined due to the addition of 14C-free C02 derived from fossil fuels, known as the Suess effect. Modeling of turnover times should use the actual atmospheric 14C inputs to photosynthesis, although it is not as important before 1959 as after. 

Ligno-cellulosic biomass is a resource from which liquid hydrocarbon fuels potentially may be derived. Pyrolyzing the wood yields gas and liquid products, but a relatively large percentage of the original wood carbon can be lost to a low value char by-product. Furthermore, like the model oxygenates described above, the EHI of the pyrolysis liquid products is substantially less than 1. 

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