The New Role of Process Engineers and Engineering Firms

Chemical process and product design engineers, environmental engineers, and consulting engineering firms can play a pivotal role as industries move toward the Zero Emissions or Zero Discharge paradigm, especially firms whose traditional niche has been to treat waste so that it is benign and acceptable for discharge. The role for these engineers in the twenty‐first century is to transform the effluent of one process to serve as the raw material for another process. The new role is not simply facilitating waste exchange; rather, the new jobs include the following:

• Assessing material flows through the economy and the use of raw materials, water, and energy
• Designing databases with a wider set of information about material flows and manufacturing processes
• Working with design firms to understand the production processes of the industries that produce the wastes
• Designing conversion processes
• Identifying purchasers for converted wastes
• Designing material transfer systems to carry wastes to industries that will use them as feedstock
• Identifying industrial clusters and understanding how to fit diverse industries into a successful industrial cluster
• Designing eco‐industrial parks and negotiating arrangements that are commercially sound and profitable, yet based on good personal relationships; voluntary, and yet in close collaboration with regulatory agencies

What this means for engineering firms is the need for a broader set of engineering skills and services. As can be seen, consulting engineering firms will find that achieving Zero Emissions entails expertise in areas that have not been part of engineering curriculum, or the professional engineer’s exam.

Zero Emissions engineers need to be not only well trained in design for the environment, concurrent engineering, and industrial engineering but also be able to think and design outside the traditional boundaries of the factory to work in terms of industrial clusters.

In the town of Tsumeb in the African desert, Namibian nationals will be implementing Zero Emissions technology at a brewery inaugurated in January of 1997. The three main inputs into beer – grain, water, and energy – are scarce commodities in a developing nation. Brewing uses only 8–10% of the nutrients in grain, consumes 10 L of water for every liter of beer produced, and generally requires imported coal, an expensive and polluting energy source.

The lignin‐cellulose component of spent grain, which makes up 70–80% of its bulk, is indigestible to cattle, but it is easily broken down by the enzymes of mushrooms. It takes 4 T of spent grain to produce 1 T of mushrooms, which are a potentially lucrative cash crop for export, because most southern African nations currently import mushrooms. The protein content of the spent grain – up to 26% – is used by earthworms, which in turn are fed to chickens and pigs. Processing the waste from the animals in a digester could supply all of the vapor energy required for brewing. Brewery wastewater is high in nutrients but is too alkaline for crops. However, it can be used to grow spirulina, which generate up to 70% protein.

The brewery’s thermal waste could heat greenhouses or the brewery. These interrelated industries will form an optimal industrial cluster for increasing the productivity of the brewery’s raw materials in ways that also produce food for humans that is high in nutritional value.