The Wiley Online Library, Maiden, Mass., USA, this past week published its preview of an upcoming article in Journal of Applied Science magazine detailing how a waste product in the cellulosic ethanol production process (a process known as second generation ethanol production using wood chips, waste, residuals, and plant stalks instead of foodstock sugars such as corn to produce the renewable fuel) can be used to create a biodegradable polymer foam for use in various industries as part of their production process.

Currently, plastic-based polymer foam is often seen as superior because of its strong initial water resistance; however, it is not biodegradable. In response to environmental concerns, in recent years many producers have sought out more sustainable alternatives to plastic-based polymer foam. One popular form that has emerged on the market is the starch based alternative to plastic polymer foam—completely biodegradable, "starch polymer foam." However, starch foam by itself has the disadvantage of also not having enough initial water resistance in many types of manufacturing processes. 

In the past, different additives of varying degrees of biodegradability and cost effectiveness have been added to starch polymer foam in an attempt to make it more water resistant. This new research shows that the natural "leftovers," including lignin from cellulosic biofuel production (where only the wood sugars are used and solid waste is still left behind, often times destined for a landfill, barring a novel and expensive approach to send it through a heat recovery boiler) can be added to starch polymer foam with significant and positive results. 

 

The biomass-starch foam replacement to plastic polymer foam demonstrated in experiments to maintain the same initial water resistance as plastic based foam while still being completely biodegradable. Furthermore, in this process, absolutely no additional additives were required. 

This technology could potentially solve an industrial sustainability issue at the same time it creates a more affordable product and a market loop between the forest/biomass industry and other producers who use plastic or starch polymer foams in their production facilities. Generally, only chemical pulp producers use recovery boilers while many cellulosic ethanol-only production facilities do not. For these plants, it could add to their supply chain instead of towards waste disposal liabilities. 

 

For some of the more select, newer, and more advanced forest production facilities generating pulp based products, cellulosic ethanol, and energy back to the grid from their plants, this option may give these producers a future of added value to any extra cellulosic production (primarily lignin-based) waste that cannot be used in current heat recovery boiler capacity. 

 

Cellulosic ethanol interest, production, and demand continues to expand in many South American countries, Western Europe, and now in the U.S. with the EPA saying it will maintain 15% vs. 10% ethanol blend standards at vehicle fuel pumps, primarily due to an interest in adding capacity through increased production of cellulosic based ethanol.

 

More information can be found online and in the Wiley Online Library abstract.