Competition from Nonrenewable Materials

The replacement of timber products by nonrenewable materials is an unfortunate development, since it has been repeatedly shown that the use of timber does have associated environmental benefits compared with the use of nonrenewables (e.g. Marcea and Lau, 1992 Hillier and Murphy, 2000 Bowyer etal., 2003 Lippke etal., 2004). Timber has a lower embodied energy content (and hence a more favourable carbon emission profile) compared to most other building materials and can provide other benefits, such as improved thermal properties. It and the products made from it (in common with other renewable materials) can be used as a repository for atmospheric carbon dioxide. Wood is derived from a renewable resource, albeit potentially an exhaustible one unless it is managed correctly. Disposal of wood can be readily achieved with little environmental impact (subject to how the wood has been treated prior to disposal). 

Unfortunately, one consequence of the ever more stringent controls upon the use of preservatives and upon preservative-treated wood will be the rejection of wood as a construction material. 

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Although hydrogen allows tremendous choices for anode materials and provides good results, the production of hydrogen from nonrenewable sources is still far from being competitive economically. Therefore the sustainable hydrogen from water seems to be a better choice. However, the use of water instead of H2 requires an excellent electrocatalyst. The electrolysis reaction to attain protons at the anode in a PCMR is ... 

However, a number of polymeric (cellulose, lignin) and monomeric (carbohydrates glucose, xylose other materials levulinic acid) materials are available at production costs that make them comparable to many nonrenewable raw materials (15). Strong cost competition would exist from the simpler... 

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