Cyanobacteria, or blue-green algae, can be used as host to produce polyhydroxyalkanoates (PHA), which are promising bioplastic raw materials. The most important material thereof is polyhydroxybutyrate (PHB), which can replace the commodity polymer polypropylene (PP) in many applications, yielding a bio-based, biodegradable alternative solution. The advantage from using cyanobacteria to make PHB over the standard fermentation processes, with sugar or other organic (waste) materials as feedstock, is that the sustainability is better (compare first-generation biofuels with the feed vs. fuel debate), with CO2 being the only carbon source and sunlight being the sole energy source. In this review article, the state of the art of cyanobacterial PHB production and its outlook is discussed. Thirty-seven percent of dry cell weight of PHB could be obtained in 2018, which is getting close to up to 78% of PHB dry cell weight in heterotrophic microorganisms in fermentation reactors. A good potential for cyanobacterial PHB is seen throughout the literature.
Part of the book: Algae
This review article summarizes the state of the art in energy efficiency (EE) management in air and rail cargo transportation. After an introduction, explanations and definitions follow around the topic of energy efficiency. The political framework conditions of the European Union (EU) as well as the associated European Union Emissions Trading System are described. In particular, the drive technologies, CO2 emissions, and fuel-saving options are reviewed.
Part of the book: Transportation Systems Analysis and Assessment