Biofuels are produced through controlled biological processes, such anaerobic digestion, yeast fermentation and algal processes and involve the control of liquids and gases to maintain chemistry, for example oxygen concentration and pH levels.
Biofuels can be formed directly from crops grown specifically for that purpose (energy crops) or can be formed indirectly from commercial, domestic, industrial or agricultural waste streams. Flow, pressure and level instrumentation is widely employed within contemporary carbon fixation, such as those that occur in plants or microalgae through the process of photosynthesis. Other examples can be converted via chemical means or biochemical conversion.
Bioethanol is an alcohol made by fermentation, mostly from carbohydrates produced in sugar or starch crops such as corn, sugar cane, etc.