Second Generation Bio Fuels Plant Open in Quebec, one coming in Edmonton

From Canadian Company Enerkem
Second-generation biofuels is the term used to refer to the next generation of fuels, which are not produced from plants that are part of the food chain. They are produced from a large base of biomass materials, including waste from urban, forestry, and agricultural sources as well as municipal solid waste.

First-generation biofuels or agrofuels are produced from sugar-rich crops such as corn, sugar cane, and wheat.

Second generation biofuels can be produced from:

• The non-sucrose and non-starch parts of plants, which are often left in the field after harvesting, crushing, or milling (e.g.: bagasse, corn stover, wheat straw, and rice hulls);
• Residual forest biomass (e.g.: thinnings, limbs, tops, needles, sawdust, and bark
  Cellulose is the most important component of these materials, hence the term "cellulosic fuels".Second-generation fuels can also be produced from other carbon-rich waste materials, such as municipal solid waste.
• In this case, only the non-recyclable and non-reusable portion of urban waste is considered. This waste (ultimate residues) is currently landfilled.

Cellulosic ethanol

Cellulose is the most important component of these materials, hence the term "cellulosic fuels".
Second-generation fuels can also be produced from other carbon-rich waste materials, such as municipal solid waste. In this case, only the non-recyclable and non-reusable portion of urban waste is considered. This waste (ultimate residues) is currently landfilled.

Cellulosic ethanol is the best known of the second-generation fuels.

• It is an alcohol that is composed of oxygen, hydrogen, and carbon.

It can be used as industrial ethanol or as ethanol fuel.

Ethanol fuel is a renewable, non-toxic, water-soluble, and highly biodegradable biofuel.

Other second-generation biofuels
Other second-generation biofuels are also emerging, including:

• biomethanol
• dimethyl ether
• synthetic diesel
• synthetic gasoline.
  

Advantages

There are three primary benefits of second-generation biofuels.

1. First, second-generation biofuels reduce greenhouse gas (GHGs) emissions by using waste materials and residues that would otherwise decompose into methane when land-filled. Methane is a greenhouse gas that is 21 times more harmful than CO2. These biofuels further contribute to reducing GHGs by replacing gasoline that is produced from petroleum. According to the US Department of Energy's GREET model, cellulosic ethanol has the potential to reduce GHGs by up to 87 % compared to gasoline.
2. Second, by diversifying our energy sources, second-generation biofuels reduce our dependence on petroleum as our main source of energy.
3. Finally, second-generation biofuels reduce and ultimately eliminate the use of landfill for many waste materials by converting them into fuel for our cars.
   

Technologies
Second-generation fuel-production technologies can generally be divided into two types:

• Enzymatic (or biological) technologies;
• Thermo-chemical technologies.
  

The enzymatic technologies seek to recover and ferment sugars that are found in lignocellulosic (tree and plant) materials. These technologies target forest biomass, particularly less-costly forestry residues, including those produced by saw and paper mills. The challenge of this approach is its ability to recover sugars in these lignocellulosic materials. The sugars are "imprisoned" in complex structures (presence of crystals and lignin, etc.) and it is hard to break down these lignocellulosic materials since nature engineered them to last (which is exactly why we use wood to build houses and other things that we want to last). These technologies aim at recovering the sugars using engineered enzymes to break down the tree and plant material, after which it is possible to hydrolyze the cellulose into glucose, from which ethanol is easily made. Engineering of these new enzymes is still at the research stage.

• Additionally, this approach only applies to very homogenous materials (feedstock that is composed entirely of one type of trees, for instance), since the enzymes and the microorganisms that ferment sugars do not adapt to materials that may fluctuate in chemical composition. Simply put, enzymatic processes are not ready to produce biofuel at market prices and are currently unable to use mixed waste materials to help reduce land-filling.
  

The thermo-chemical technologies, such as Enerkem's, use heat to convert carbon-rich materials into gas.

This gas is then purified so it can be transformed into alcohols such as methanol and ethanol.

It is also possible to produce other fuels, such as synthetic diesel, synthetic gasoline and di-methyl ether as well as chemical products.

Enerkem is one of very few companies that has developed advanced gas purification technology. This allows Enerkem to use heterogeneous (mixed) raw materials that may contain impurities, such as end-wastes that would otherwise be land-filled.

Development phase

Several companies around the world are currently working toward developing technologies for producing cellulosic ethanol on a commercial scale. Other than Enerkem, very few of these companies have arrived at the commercial-demonstration stage.

More @ Enerkem