Volume 6, Issue 3
Published: April 5, 2012
Cellulosic ethanol becoming a reality

Biological routes to ethanol depend on fermenting sugar solution, with yeast or other microorganisms, then distilling the ‘beer’ to separate the ethanol. Until now the sugar has come from cane or beet, or from hydrolysing starch from grains, potatoes or other starchy vegetables. This is so-called first generation ethanol and it has served to demonstrate that ethanol is a viable fuel, giving the petroleum industry plenty of experience in transport, storage and blending. Motor manufacturers too have made sure their vehicles are tuned to work well on current blends, and capable of adapting to higher levels of ethanol as it becomes available.

Now though the market is close to the limit of production of first generation ethanol. Using agricultural land to grow fuel crops is having an effect on global food prices and driving land use change around the world, exacerbating the very problem biofuels are designed to reduce. According to US Department of Energy studies, cellulosic ethanol could reduce greenhouse gas emissions (GHG) by 85% compared to petrol. The US renewable fuels standard (RFS2) mandates that 36 billion gallons of renewable fuels be blended into transportation fuels by 2022. Of that, at least 16 billion gallons is required to be cellulosic biofuels.

Cellulose is the most abundant organic compound on earth, and together with hemicellulose and lignin it forms the structure of all plants; cellulose makes up about 40-60% by weight of plant matter, and hemicellulose another 20-40%. Both are natural polymers of sugar, with cellulose based on sugar molecules with six carbon atoms (C6 sugars) primarily glucose and hemicellulose on C5 sugars such as arabinose and xylose.

To read the article in full you have to be a subscriber...
Further Articles in this Issue:
Recently released data shows biodiesel producers in the US throttled back output during the first two months of 2012 after record monthly production reported for December 2011. The production decline follows... [Read more]
The UK’s budget announcement on 21 March saw the Chancellor remaining firm on his decision to increase the tax on used cooking biodiesel. The government policy came in as of 1 April 2012, and increases... [Read more]
US senators are being urged to extend key cellulosic ethanol tax provisions which are due to expire at the end of this year. The Advanced Ethanol Council (AEC) wrote a letter to the Senate Finance Subcommittee... [Read more]
Vivergo Fuels is in the final stages of opening the largest bioethanol production facility in Hull, UK as part of a joint venture with BP, AB Sugar and DuPont. The plant will produce 420 million litres... [Read more]
Oil majors are increasing investments into biofuels as conventional fuel becomes scarcer and the price of oil rises. In a recent report by Pike Research, Shell and BP were named as the two oil companies... [Read more]
The South African government released its Biofuels Industrial Strategy in December 2007. It aims for 2% of final liquid fuels consumption by 2013 which accounts to about 400 million litres. The strategy... [Read more]
Green Fuels’ ethanol project is the single largest investment to happen in Zimbabwe outside mining in the past five years. Green Fuel is also said to be the first large scale ethanol producing factory... [Read more]
Biological routes to ethanol depend on fermenting sugar solution, with yeast or other microorganisms, then distilling the ‘beer’ to separate the ethanol. Until now the sugar has come from cane... [Read more]
After the dramatic events of some years ago, Sierra Leone has now become a democracy. Nevertheless, it remains one of the poorest countries in the world. The development of agriculture and related industries... [Read more]
The successful implementation of RFS2, while marketdriven and therefore not necessarily bankable, has allowed many shuttered facilities to restart production. In 2011, before the FET credit expiration,... [Read more]
It was only a few years ago when a large surplus of quality biodiesel feedstock was available, the political support of biodiesel was unwavering, and demand was at an all time high to find something cheaper... [Read more]
Before biodiesel is ready for blending, the feedstock must be pressed and the oil extracted, and prior to this some cleaning, de-hulling and pulverisation may occur. Firstly, the seeds are sent for cleaning... [Read more]
Ethanol production in 2011 neared 14 billion gallons, according to the Renewable Fuels Association (RFA). This is an increase of 717 million gallons compared to 2010’s production figures. With this... [Read more]