An overall assessment of the technologies in use for the production of renewable fuels and energy

During 1910-1920 ethanol was industrially produced from lignocellulosic raw material. During the past century there were scattered efforts to revitalize similar processes. A significant impulse in R+D occurred in this century. In 2013 a very promising picture had developed: More than a dozen of large demonstration plants (Pioneer size) were under construction or in the start-up stage (See Table). Note, that they were deploying different technological approaches that essentially differed from the first step leading to either the liberation of the pentoses and hexoses from the lignocellulosic matrix or the direct production of syngas, for further processing. The total nameplate capacity of these plants was ca. 350 MGY or 1100 tons/year.

However, no more than 0.3 % of the ethanol nameplate capacity in the USA has been produced in 2015. The long start-ups that these numbers reflect have led to the cancellation of several projects and two companies are under chapter eleven and one already bankrupt. Big companies like Clariant and Dupont are still trying to debug their technologies but so far no signs of scaling up their plants have been hinted in technical publications. The bottom line is that at present the lignocellulosic ethanol is not being produced at competitive costs despite the huge private investment and tax money contributions from different countries, particularly from the USA. This analysis is also applicable to other biofuels from the same origin.

In brief, concerning lignocellulosic biofuels a detailed energy balance of each technological route is required. Besides, a careful analysis of the weak points and bottlenecks of each pathway should be carefully analysed before moving along the very expensive experimental route.

On the other hand, significant advances have occurred in the last few years in the production of electricity from wind and solar sources. It should be noted that for the first time the annual investment (2015) in these areas has been higher than that reported for thermoelectric generation burning coal and natural gas. This is a consequence of: i) Technological advances in the turbine design and novel composites used in the manufacture of wind turbines and ii) The production of thinner photovoltaic silicon films and the simplification of the technique used to make the contacts, now economically printed on the photovoltaic films. Not to be discarded: Solar thermal that offers the great advantage of affordable heat accumulation that allows 24 h operation of the electricity generation unit.

In Argentina there are regions of high insolation and windy areas (e.g. Patagonia). This is the support of the federal government strategy pointing to the development of eolic and photovoltaic parks announced in 2010. This policy was never deployed but now the new government has given a new impulse to this strategic view for the development of renewable energies. Note that a similar strategy has been applied to other Latin-American countries (Chile, Perú, Brasil and Mexico). Consequently, the production of second and third generation biofuels should consider this reference framework.

Table. Pioneer scale cellulosic biofuel projects (2014)

Company	Location	Nameplate Capacity (MGY)
Sundrop Fuels	Alexandria, LA, USA	50
Kior	Natchez, MS, USA	41
Mascoma	Kinross, MI, USA	40
Sunliquid	Bavaria, Germany	36
Abengoa	Hugoton, KS, USA	25
ZeaChem	Boarmand, OR, USA	25
DuPont	Nevada, IA, USA	25
Mossi Ghisolfi	Crescentino, Italy	20
Gran Bio	Alagoas, Brasil	20
Clear Fuels	Collinwood, TN, USA	20
Beta Renewables	Sampson county, USA	20
POET DSM	Emmetsburg, IA, USA	20
INEOS	Vero beach, FL, USA	8 Total 352