Microalgae dewatering is a major obstruction to industrial-scale processing of microalgae for biofuel production. The dilute nature of harvested microalgal cultures creates a huge operational cost during dewatering, thereby, rendering algae-based fuels less economically attractive. Currently there is no superior method of dewatering microalgae. A technique that may result in a greater algal biomass may have drawbacks such as a high capital cost or high energy consumption. The choice of which harvesting technique to apply will depend on the species of microalgae and the final product desired. Algal properties such as a large cell size and the capability of the microalgae to autoflocculate can simplify the dewatering process. This article reviews and addresses the various technologies currently used for dewatering microalgal cultures along with a comparative study of the performances of the different technologies.

No abstract

No abstract

No abstract

Ammonia production has traditionally been based on large-scale plants. The thrust toward large-scale production to gain economic advantages has overshadowed the benefits that could be derived from small-scale production plants. Additionally, the ammonia industry consumes a major chunk of global fossil fuels, which also burdens the planet with greenhouse gases. To effectively counter these issues, this study investigates the production of ammonia from biomass. Processes based on biomass plants are usually small-scale and are limited by biomass supply. To ensure sustainable ammonia production, this study tries to highlight the techno-economic advantages that result from small-scale ammonia plants based on biomass feedstock. This paper proposes a new process that takes inputs from a relatively old, natural gas based process (leading concept ammonia) specifically designed for small-scale ammonia manufacture and couples it with a recently developed dual fluidized bed technology for biomass feedstock. Two different flowsheet configurations are simulated rigorously and compared to gain a better understanding of the process. The flowsheets are optimized, and energy integration is performed to provide a wider insight. The life cycle assessment calculations that are carried out using ASPEN Plus simulation results and ecoinvent databases predict a CO 2 emissions reduction of 54−68% when compared to conventional ammonia plants.

No abstract

No abstract

No abstract