Fourth generation biofuels are derived from specially engineered plants or biomass that may have higher energy yields or lower barriers to cellulosic breakdown or are able to be grown on non-agricultural land or bodies of water. (Citation T-27)

 

 

 

 

 

 

 

 

 

 

In fourth generation production systems, biomass crops are seen as efficient 'carbon capturing' machines that take CO2 out of the atmosphere and ‘lock’ it in their branches, trunks and leaves. Then, the carbon-rich biomass is converted into fuel and gases by means of second generation techniques. Crucially, before, during or after the bioconversion process, the carbon dioxide is captured by utilizing so-called pre-combustion, oxyfuel or post-combustion processes. The greenhouse gas is then geosequestered - stored in depleted oil and gas fields, in unmineable coal seams or in saline aquifers, where it stays locked up for hundreds, possibly thousands of years.

 

‘The resulting fuels and gases are not only renewable, they are also effectively carbon-negative. Only the utilization of biomass allows for the conception of carbon-negative energy; all other renewables (wind, solar, etc) are all carbon-neutral at best, carbon-positive in practice. Fourth generation biofuels instead take historic CO2 emissions out of the atmosphere. The system not only captures and stores carbon dioxide from the atmosphere, it also reduces carbon dioxide emission by replacing fossil fuels.’

(Citation T-26)