167

based resources (waste, algae and seaweed) are given extra incentives while the usage of conventional biofuels is limited. As 70% of the surface of the earth is covered with oceans and seas it is logic to look into ways to produce biomass in the marine area. Marine biotechnology is used to convert the harvested biomass to energy and industrial chemicals (platform chemicals) in biorefinery processes. These processes are comparable to the processes used to convert land based biomass. But the land based microbes and enzymes are not working well on the marine biomass. Energy production form marine biomass is focussing on 2 separate value chains:  On land cultivation of marine microalgae used to produce biodiesel or sometimes ethanol;  Off shore cultivation of macroalgae (seaweed) to produce ethanol, butanol or methane in a biorefinery. Value chains specific to the energy sector Figure 0.25 Value chain for energy and platform chemicals form macroalgae Figure 0.26 Value chain for biodiesel production form microalgae Potential products areas currently in research and development stage Biofuel production from micro- and macroalgae There are two distinct organisms from which to harness energy from marine biological resources: microalgae and macroalgae (seaweed). Marine algal biomass can produce a range of biofuels including biodiesel, bioethanol, biogas, biomethanol, biobutanol and other biofuels, through the application of marine biotechnology. There are a number of advantages associated with marine algal biofuel production compared to biofuels produced from grain, seeds and other terrestrial commodities such as maize and corn. Microalgae can produce polysaccharides (sugars) and triacylglycerides (fats) that can be used for producing bioethanol and biodiesel. Biofuel production from microalgal tri-acylglycerides is a specific area of interest. Seaweed contains large amounts of polysaccharides and almost no lipids. Therefore, seaweed to energy conversion is similar to the conversion of sugar or corn. Bioethanol and butanol through fermentation are likely products as well as biogas through digestion. The development of both resources is quite different. Microalgae are small organisms that cannot be harvested from the sea but need to be cultivated in a protected environment like a raceway pond or a photo bioreactor. Macroalgae on the contrary can be cultivated and harvested directly form sea. Research for conversion of seaweed to energy and platform chemicals is mostly oriented at the biorefinery concept. In this concept the aim is to produce as many valuable substances from a raw material as possible to maximize the economic efficiency of the process. For seaweed this means 140 Study in support of Impact Assessment work on Blue Biotechnology

168 Publizr Home