What are two environmentally sound ways that industries currently use to take care of by-products ?

Question

What are two environmentally sound ways that industries currently use to take care of by-products ?

Answer 1

Hot water/steam from power stations is generally regarded as a by-product, since their main product is electricity. In too many cases it is simply thrown away in massive cooling towers. The most environmentally sound way of using it is to pipe it into a local community heating grid. This is often referred to as co-generation [1] (although that covers micro-generation systems as well).

"Copenhagen operates the largest district heating grid in Europe. Currently an area including 1.2 million inhabitants is supplied with district heating; 65% of the buildings are connected to the district heating grid. For 2002 a hook-up rate of 95% is being strived for. The district heating is almost exclusively produced through cogeneration of heat and power." [2]

A second by-product of fossil fuel burning power stations is carbon dioxide. This is usually released straight into the atmosphere, with potentially catastrophic results. Many people are looking at ways to capture and store this CO2. The technologies are grouped under the heading Carbon Capture and Storage [3].

In Holland they have taken a slightly different approach. They are using both the waste heat and the CO2 to improve the productivity of greenhouses near the power station. [4]