Second Generation

First Generation and Second Generation Biofuels are essentially the same thing, however, first generation come from food sources and second generation do not. Some major sources of second generation biofuels are: wood chips, stalks, and various types of grasses. They are converted in many different ways. The two main ones are pyrolysis and cellulolysis.

Pyrolysis

Pyrolysis is adding extreme heat to prarie grasses and plant material wastes. Pyrolysis does not make ethanol but it does make bio crude which can be turned into fuel after removing bio-chemicals.

Cellulolysis

Cellulolysis is the process which takes woods and grasses and turns them into ethanol. The first step in this six step process is to seperate the cellulose from the ligin seal and the crystaline structure which inhibit cellulolysis. Then the sugar has to be broken down in order to be fermented. This can be done with chemicals which either may make fermentation less efficent, or they later need to be seperated. Another way to break down the sugar is with enzymes, but this method is not very cost effective. However bacteria can be genetically modified to aid in this step and make the breakdown more efficient. After that the sugar is fermented into alcohol. The alcohol is then dehydrated and then denatured.

Enzymes

An enzyme is a chemical that can be naturally found and is used to speed up the breakdown of certain things. Researchers have now discovered new enzymes that allow them to easily break down certain types of biomasses that are otherwise more difficult to breakdown. This is what helps companies be able to breakdown the tough cell wall of plant stems. Also the enzymes could help breakdown cardboard and even shells of insects and other animals.