Fossil fuels such as gasoline coal diesel are nonrenewable sources of fuel and the emission of greenhouse gases as a result of use create incentive to seek alternate sources of clean energy that may be produced in a sustainable manner. Thus biorefinery systems should be established to transform renewable materials such as wood or agricultural crops into extra value goods such as energy and feedstock chemicals in order to support economic sustainability.

Biofuels are fuels obtained from biomass that can be solid liquid or gas. Wood and crops (such as wheat maize and rice) are the two most common kinds of biomass. Another important type of biomass is waste such as food waste manure and so on.

Biodiesel bio-oil bioethanol biohydrogen biogas and methanol are a few examples of biofuels.

In the conversion of biomass to biofuels biological chemical and physicochemical processes are used. The physico-chemical approach is mostly used as a pretreatment method and does not require any chemical alteration of matter. The chemical conversion of biomass alters its chemical structure by the use of heat chemicals catalysts or a mix of the two. The thermochemical technique involves pyrolytic treatment of biomass to yield solid liquid or gaseous compounds that can then be converted to fuels (synthetic biofuels). Various types of pyrolysis gasification and torrefaction are employed to produce gaseous liquid or solid fuels depending on the reaction circumstances.

Fermentation is a biological process that results in the production of ethanol biogas and biohydrogen. The main fermentation process involves the use of microorganisms in a warm and wet environment to turn carbohydrates (sugar etc) into ethanol. Sugar is normally extracted mechanically by crushing and combining sugar-rich crops like sugar cane and sugar beet with water.
This book contains information about the design and application areas of the following biofuels as well as examples of the designs of these compounds derived from biomass.

- Solid biomass thermochemical conversion
- Oil-based biodiesel generation
- Production of biogas from agricultural waste
- Production of bioethanol from biomass
- Production of hydrogen
- Methanol manufacturing