October 24, 1995
In several previous columns, I’ve written about the emergence of “industrial ecology,” an approach to basing the design of industrial ecosystems on the design of natural ecosystems, where waste essentially does not exist–one organisms waste is another organism’s food. And I’ve written about the related concept of “zero emissions”–which has grown up enough to have a Zero Emissions Research Institute in Tokyo, but which is still dismissed out of hand, in my informal polling, by a fair number of thoroughly intelligent academics and industrialists.
In the next few columns, we’ll step away from theory and have a look at practice. How are these ideas being applied–profitably–in operating companies?
ZERI, for example, is developing projects for the utilization and recycling of agro-industrial solid and liquid wastes, including a biomass refinery which separates and recycles plant biomass wastes (e.g. green biomasss, bagasse, sisal industrial wastes) and their products (used newsprints) for fiber, protein and chemicals.
Beermaking offers a perfect example of the opportunity, according to ZERI director Gunter Pauli (former CEO of the Belgian firm Ecover). Pauli projects that using all brewery waste –spent grain, CO2, waste heat and waste water (10 liters of water per liter of beer)–in an integrated biosystem can generate seven times more nutrients for human consumption and four times more jobs. “This proves economists wrong who claim that higher productivity leads to less jobs,” Pauli notes. “Here we have more output, the same amount of input (in raw materials) and more jobs while boosting the return on investment.”
Pauli cites Namibian Breweries located in Windhoek, in Southern Africa, which has decided to build a new brewery with a payback period of less than one year on upfront investment of approximately 400,000 US$. The reasons: a zero waste strategy. For example, the brewery will use its spent grain in two ways: to cultivate mushrooms, a cash crop which today is only imported into the country (expected revenue: 150,000 to 200,000 US$ per annum) and to raise earthworms. Earthworms? Think of them as excellent chicken feed–a unique opportunity, considering that currently all chicken feed, and even the chickens, are imported. Chicken manure (and local cattle manure) produces methane to generate all the steam needed in the brewery, savings another 50,000 to 80,000 US$ a year. Wastewater is treated by a multi-species aquaculture treatment system stocked with 6-8 types of fish, and covered with floating gardens producing flowers and vegetables.
The integrated system approach has broad applications in food and fiber industries, in both developing countries and advanced economies. For example, sugar from sugar cane commands a price of US$315/ton. One ton of sugar generates one ton of bagasse. One ton of bagasse contains 48% fiber, and today this one ton of fiber commands a price of US$ 800 if it meets the specs of the pulp and paper industry. Yet today in Brazil 95% of all bagasse is incinerated. “The opportunities,” Pauli observes with classic understatement, “are vast.”
In a more industrially ‘upscale’ example, the Tigney Organic Material Refinery in Canada has developed a patented process to dissociate the lignin and xylan that binds cellulose into a matrix in wood, straw, bagasse and other woody materials.
Typical cellulose extraction systems render xylan and lignin into unusable waste products, though there are many valuable applications for xylan and lignin — nature’s second and third most abundant organic materials. For example, according to Tigney, xylose from xylan) can substitute for glucose from starch as the fermentation base in large scale biotechnology applications. Xylose in turn can be converted to a natural sweetener, used in Trident sugarless gum for its tooth decay preventive qualities.
The residue from these extractions is cellulose, which can be produced is a continuous range from high strength fibers for papers to very pure cellulose suitable for food, fiber, film, pharmaceutical and bioconversion applications, with varying yields of the associated lignin and wood sugars. According to Tigney, the process is significantly cleaner than conventional pulp-to-cellulose processes, because the “cracking” process uses heat rather than chemicals, and the extraction processes uses only mild caustics of hand soap strength. The key to the design: all the components of the starting material end up as product.
These systems may not be perfect, and they may not have reached the zero emissions goal. (Tigney’s report didn’t describe their energy systems, for example.) But the commitment to move toward zero provides a powerful design constraint that, if well implemented, serves the bottom line.
This new, and in some ways very old, approach to production opens up a host of possibilities, not only for individual companies but also for clusters of companies. New businesses alliances may emerge to realize the potential of moving beyond waste management and recycling to “there are no wastes, only products”.
And the potential is not limited only to biologically based companies. Next week we’ll look at zero emissions strategies in the steel and chemicals industries, and at the emerging notion of “ecological industrial parks”.