Renewable resource process sustainability

It should be pointed out that the raw materials for VAM and its related polymers (i.e. ethylene and acetic acid) are produced from fossil resources, mainly crude oil. It is possible to completely substitute the feedstock for these raw materials and switch to ethanol, which can be produced from renewable resources like sugar cane, com, or preferably straw and other non-food parts of plants. Having that in mind, the whole production of PVAc, that nowadays is based on traditional fossil resources, could be switched to a renewable, sustainable and C02-neutral production process based on bioethanol, as shown in Fig. 3. If the vinyl acetate circle can be closed by the important steps of biodegradation or hydrolysis and biodegradation of vinyl ester-based polymers back to carbon dioxide, then a tmly sustainable material circle can be established. 

One of the major factors undermining the sustainability of a production process is the depletion of the resources it uses. A quantification of process sustainability should therefore include a parameter that deals with the sustainability of resource utilization, and the construction of such a parameter begins with defining a quantitative measure for the depletion of an individual resource. One way of doing this is to classify each resource as either renewable or nonrenewable, as was done by De Wulf et al. [36]. The distinction made between renewable and nonrenewable resources is that renewable resources are created at least as fast as they are consumed (e.g., solar energy), while nonrenewable resources are consumed faster than they are created (e.g., crude oil). 

Looking into this matter more carefully, we have come to the insight that the extent to which a process contributes to sustainability can be characterized by three parameters. A first parameter is the thermodynamic efficiency of the process. A second parameter needs to reflect the extent to which use has been made of renewable resources. Finally, a third parameter is needed to indicate the extent to which cycles have been closed. This has been discussed at great length in Section 13.6. 

Halasz, L., G. Povoden, and M. Narodoslawsky, Sustainable process synthesis for renewable resources, Resour, Conserv. Recyc., 44, 293-307 (2005). 

Researchers interested in renewable resources should use the principles listed in Figures 3.1 and 3.2 when designing new processes, products and materials. The principles focus your thinking in terms of sustainable design criteria and have already provided innovative solutions to a wide range of problems, and will ultimately benefit the environment, economy and society (otherwise known as the triple bottom line). 

Since the oil shortages of the 1970s, there has been a sustained search for materials to replace the petroleum-based resins used as durable adhesives for exterior wood products. Such alternatives are considered important, because supplies of petrochemicals for use in the wood industry could again become undependable. Ideally, the source of material for an adhesive would be readily available, possibly from materials already found near or used by wood processing plants, for example, agricultural or wood-based renewable resources. The purpose of this investigation was to explore the use of carbohydrates as constituents in water-resistant adhesives. 

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