Engineering for Industrial Designers and Inventors

Chapter 9. Sustainability in Design

Grass and weeds are forms of biomass and when burned provide a renewable form of heat energy. One proponent of burning willow weeds claimed this fuel produces a tiny amount of ash. Not really. Even though only a small amount of ash was collected in his heating system, the amount of ash generated was unknown because the combustion system had very ineffective pollution control equipment. It only collected the largest particulates. Therefore, he only saw a little ash in the boiler. Most of the ash went unseen up the exhaust stack and is thought to never have existed. However, it did exist and went out the stack as tiny particulates.

Beyond misunderstanding how fine ash gets produced (and gets deeply inhaled in the lungs), we need to consider other aspects of this renewable fuel source. Do these fuels produce air toxics such as dioxin or mercury? Do they produce nitrous or sulfur oxides? What chemical might be attached to the ash particles? What effect does growing these plants have on soil, or fertilizers on water nitrate levels? What heat source is it displacing, and is this really an improvement in terms of air, water, soil quality? Some level of technical sophistication is required to discuss sustainability fairly.

The word sustainability is commonly seen now but it has been around in different forms for ages. Sustainable design is a holistic approach whereby you consider all activities involved in getting a product into the end user’s hands ...