A future fuel
Cellulosic ethanol is currently on top of the fuel agenda. Provided that the technical and financial hurdles are overcome, within a few years it could turn into the No. 1 advanced biofuel, helping to meet the world’s increasing fuel needs.DATE 2023-11-28 AUTHOR Elaine McClarence
Biofuels have been hailed as a way to provide for the world’s increasing energy needs in a more environmentally friendly way than conventional fossil fuels. The environmental imperative of global warming has given new impetus to the development of these alternative fuels, as has the political issue of a nationally secure energy supply in a world where demand is outstripping supply.
“We think cellulosic ethanol has tremendous potential and is one of the next generation of advanced biofuels,” says Matt Carr, policy director for the industrial and environmental sector at the Biotechnology Industry Organization. “In the US alone it is estimated that we could produce 60 billion gallons of cellulosic ethanol by 2030, which would be around 30 percent of the gasoline demand.”
Cellulosic ethanol is an alternative fuel that can be made from a wide variety of feedstocks (plants not used for human food). This means that cellulosic ethanol could be produced in many parts of the world and be an important fuel resource for countries without significant fossil fuel reserves. It could mitigate the effects of greenhouse emissions and at the same time support rural economic development, Carr explains.
In Canada, Europe and the US, governments and industry are investing significant amounts in commercializing the technology that could make a contribution to our fuel needs, provided that technical and cost hurdles can be overcome. Currently ethanol production using cellulose is three to five times more expensive than other types of ethanol production, but efforts are now focused on lowering the price barriers to its wider use.
Not competing with food
Currently, there are also a number of pilot and commercial demonstration plants in development or in operation in Canada, China, Spain and Sweden. The Iogen Corporation in Canada was the first company to sell cellulosic ethanol commercially, though in small quantities. It aims to scale up that production by 2009.
Though it requires a more complex refining process, cellulosic ethanol contains more net energy and results in lower greenhouse emissions than traditional corn-based ethanol. Equally important is that cellulose ethanol is not competing with food. “Only 1 percent of wheat grown in Europe is used for ethanol production,” says Rikard Krook, market manager, biodiesel, ethanol, sugar and starch at Alfa Laval. Plus, greenhouse gas emissions are reduced by up to 90 percent, compared with fossile fuels, when using cellulose as feedstock.
Wood chips are a suitable raw material for cellulosic ethanol.The agricultural residues are primarily made up of cellulose and “hemicellulose,” which are known as cellulosic materials. Unlike traditional ethanol feedstocks, such as corn kernels, the cellulosic materials contain two major sugars, glucose and xylose, neither of which can be fermented into ethanol by the natural Saccharomyces yeast, the microorganism used by industry to produce ethanol.
Much of the current research effort is focused on developing suitable enzymes to improve the efficiency of the process. Other challenges include scaling up current pilot installations and improving the efficiency of various pre-treatment processes required to prepare the feedstock for further processing.
An infrastructure that can integrate cellulosic ethanol production within the fuel chain is another prerequisite for success. “The biggest challenge is to create an infrastructure to cover the harvesting and transportation to refineries and then getting the fuel to dispensing stations,” says Carr. “We have to collect large quantities of biomass, and the logistics of this need to be worked out.”
That said, Carr points out that the first generation of bioethanol production is already laying the groundwork for success in that respect by creating an infrastructure for ethanol supply. “We are developing more biorefineries that are increasingly efficient,” he says. “It’s only a matter of adapting that infrastructure and expanding it to accommodate much larger volumes.”
In other words, it might only be a matter of time until filling up your car with plant-derived fuel is so commonplace that you don’t think twice about it.
A team for the future
Alfa Laval’s experience with biofuel goes back to the 1970s. The company’s expertise in separation and heat exchange products is well established, and the company is already supplying equipment and expertise to the bioethanol production market.
Since 1998, the demand for its heat exchangers and centrifuges for biofuel production has grown by 10,000 percent. All the information related to cellulosic ethanol and other biofuels is collated centrally so that progress in development is shared throughout the company.
Alfa Laval has a strategy to be at the forefront of developing products tailored to the needs of this industry and is working with a select group of companies to that end, including SEKAB in Sweden and Biogasol, who are pioneering the next-generation technology. SEKAB is the main supplier to the Swedish market and has more than 20 years of experience in supplying ethanol to bus fleets and 15 years of experience in supplying E85 fuel for flexfuel vehicles.
Jan Lindstedt, managing director for SEKAB Industrial Development, says SEKAB is working together with Alfa Laval on the dewatering of lignin, the solid residue from the process, as well as testing and maybe developing suitable heat exchangers for the recycling of the process streams for energy recovery.
SEKAB has set out to prepare the groundwork for future sustainable transport with the help of a long-term sustainable fuel, Lindstedt says. “Our goal is to develop an industrial structure that will enable the supply of knowledge and equipment for the production of cellulose-based ethanol, as well as the construction of production facilities.