Novozymes explores seaweed-to-ethanol in India

By Kris Bevill | February 03, 2012

Novozymes has entered into a one-year exploratory research agreement with India’s Sea6 Energy to develop a process to convert seaweed to ethanol. As part of the agreement, Novozymes will focus on the development and manufacturing of enzymes for the conversion process. Sea6 Energy, a company created by researchers at the Indian Institute of Technology Madras to develop large-scale biofuels production from seaweed, otherwise known as macroalgae, will share its knowledge of offshore seaweed cultivation technology.

The agreement with Sea6 Energy marks Novozymes’ first venture into seaweed-to-ethanol conversion. GS Krishnan, regional president-India, Novozymes South Asia, said the company elected to explore seaweed’s potential for ethanol production because it offers a natural complement to the company’s other biomass-to-ethanol projects. Seaweed presents unique benefits as a biofuel feedstock in that it is one of the fastest growing plants in the world, it requires no irrigation or fertilizers and it does not need to be cultivated on arable land. Additionally, more than half of the dry mass in seaweed is sugar, offering great potential for high yields. Seaweed also lacks lignin, which could make it easier for producers to break down the plant material in order to reach the fermentable sugars.

Seaweed also possesses a unique compositional element which could pose a challenge for researchers who are seeking a cost-effective conversion process. “Compared to land-based carbohydrate polymers, which mostly consist of glucose and xylose, the carrageenan [the substance extracted from seaweed] is a highly sulfated galactose polymer which might/might not cause difficulties in processing,” Krishnan said. Bakers yeast is used to assimilate glucose and can also be used in the same manner for galactose, according to Krishnan, but the conversion rate is slower.

While this is Novozymes’ first look at seaweed’s potential for biofuels production, other companies have been researching its possibilities for several years. In 2010, Norway-based oil and gas production giant Statoil formed a three-year partnership with California’s Bio Architecture Lab Inc. to develop ethanol-to-seaweed production using a consolidated bioprocessing technology. That agreement called for pilot- and demonstration-scale facilities to be housed in Norway, where the companies would utilize native seaweed acquired from coastal salmon farms, with Statoil providing funding and management for the seaweed cultivation activities. BAL is providing the technological expertise for the project.

Krishnan said the various conversion technologies now being developed by firms for seaweed conversion will be non-competing because they each focus on seaweed substrates specific to certain regions of the world. “While some groups are working with green seaweed or brown seaweed, we are experimenting on red seaweed,” Krishnan said. “The red seaweed is cultivated in tropical areas, like India, and consequently the productivity of the red seaweed is higher.” Krishnan stressed that while its research is in the very early stages, Novozymes will likely develop a flexible bioprocessing conversion process for the seaweed, which will enable it to optimize each step of the process individiually. “The process engineering is aiming at a flexible process as currently [used] in first-generation ethanol processing, taking advantage of the optimal conditions for the degradation of the carrageenan-to-galactose optimizing pH, temperature and enzyme performance,” he said. “The fermentation is possibly conducted at a separate step, optimizing the fermentation conditions. This provides much more freedom to optimize and develop the next generation of enzymes as the process matures.”

While seaweed has been farmed for centuries in parts of the world, it is typically cultivated in areas with calm, shallow waters, according to the company. Sea6 Energy has developed proprietary structures that will allow seaweed to be cultivated in rougher waters, opening the potential for vast new areas of seaweed farms along coastlines that otherwise would not be available for the practice. Sea6 Energy is currently trialing cultivation technology in partnership with fishing communities around the coastal areas of South India. “We are excited about our partnership with Novozymes and look forward to developing an efficient enzymatic process to convert seaweed to sugar,” Sea6 Energy Chairman Shrikumar Suryanarayan said in a news release. “Combined with Sea6 Energy’s offshore seaweed cultivation expertise, these conversion technologies will offer a scalable and sustainable alternative to expensive and polluting fossil fuels, while providing employment to coastal communities and energy security for our country.”