Bioethanol is by far the most widely used biofuel for transportation worldwide and currently the only alternative to gasoline that can be used immediately without having to make any significant changes in the way fuel is distributed. Production of bioethanol from biomass is one way to reduce both consumption of crude oil and environmental pollution. There are different segments of bioethanol based on different kinds of raw materials: simple sugars, starch and lignocellulosic bioethanol. However, the price of the raw materials is highly volatile, which can highly affect the production costs of the bioethanol.
From all the raw materials, lignocellulosic biomass seems to be the best choice for lignocellulosic bioethanol production, due to its great availability and low cost. Arundo donax, or commonly known as giant reed is a lignocellulosic feedstock with high-yieds, low input and low cost requirements, providing biomass for lignocellulosic bioethanol production, thus contributing to the fight against climate change and offering a great investment possibility.
Feedstock controversy of lignocellulosic bioethanol
Lignocellulosic bioethanol is one of the most important sources of advanced biofuels owing to its promising feedstock availability and low production costs. Global bioethanol production accounts for 94% of global biofuel supply. Brazil and the United State are current world leaders owing to the availability of corn crops or sugar cane, which serve currently as a major feedstock in both countries.
According to the Renewable Fuels Association, bioethanol use has significantly increased in the USA from 3.4 to about 4.8 billion gallons already back in 2004–2006. In Brazil, bioethanol production is mainly aimed at satisfying external demand, mostly from the USA or European countries. Current production levels are approximately to 4.5 billion gallons with the potential to replace almost one-third of global gasoline.
The assessment of bioethanol feedstock is an essential factor in improving large-scale commercial production. Substantial problems exist for land availability since the current feedstock used to produce bioethanol is essentially energy crops (sugar cane and sugar beet). Several conflicts arise in the production of lignocellulosic bioethanol owing to increasing competition of land resources for food crops.
Lignocellulosic bioethanol production from sugar cane in Brazil is relatively cheap owing to the governmental support in terms of blending mandates with gasoline which lowered sugar cane costs and created additional demand for bioethanol. The dispute around land use could be easily solved by using crops like giant reed, which not only adapts to marginal and saline lands, but still brings high yields. Not mention the fact that the irrigation of Arundo donax is possible using wastewater, which further reduces the costs of production.
In Europe, bioethanol is obtained from sugar beet crops which are grown by all member states, yielding about 100 l bioethanol / ton sugar beet / hectare. However, according to our own (ArundoBioenergy) estimates, 330 l lignocelluosic bioethanol / ton of Arundo donax / hectare could be gained, which is about three times more compared to sugar beet.
The environmental effects
The environmental impact from the production of fuels is an important factor in determining bioethanol feasibility as an alternative to fossil fuels. Over the long run, small differences in production cost, environmental ramifications, and energy output may have large effects. It has been found that cellulosic ethanol can produce a positive net energy output. The reduction in green house gas (GHG) emissions from corn ethanol and lignoellulosic ethanol compared with fossil fuels is drastic. Corn ethanol may reduce overall GHG emissions by about 13%, while that figure is around 88% or greater for lignocellulosic ethanol. Also, lignocellulosic bioethanol can reduce carbon dioxide emissions to nearly zero.
One of the major reasons for increasing the use of biofuels is to reduce greenhouse gas emissions. In comparison to gasoline, ethanol burns cleaner, thus putting less carbon dioxide and overall pollution in the air. Additionally, only low levels of smog are produced from combustion.
According to the U.S. Department of Energy, ethanol from cellulose reduces greenhouse gas emissions. Carbon dioxide gas emissions are shown to be 85% lower than those from gasoline. Lignocellulosic bioethanol contributes little to the greenhouse effect and has a five times better net energy balance than corn-based ethanol. When used as a fuel, lignocellulosic bioethanol releases less sulfur, carbon monoxide, particulates, and greenhouse gases. Cellulosic ethanol should earn producers carbon reduction credits, higher than those given to producers who grow corn for ethanol, which is about 3 to 20 cents per gallon.