Microalgae biorefinery alternatives and hazard evaluation

Biodiesel production based on microalgae and using carbon dioxide as feedstock constitutes an attractive biofuel alternative. Technology development and process optimization are necessary to minimize the overall production cost. Moreover, in the framework of process sustainability, social and environmental impacts should include process safety aspects. In this context, the objective of this work is to develop a biodiesel production process based on microalgae and the subsequent estimation of the associated risks, thus contributing to more sustainable and safe processes. The biodiesel biorefinery is optimized, taking into account alternative configurations for algae cultivation and lipid extraction. Algae cultivation options are open ponds and tubular photobioreactors. Regarding lipid extraction, dewatering and subsequent n-hexane extraction, and combined ethanol/n-hexane extraction are the studied alternatives. Numerical results showed that open ponds and n-hexane extraction provide maximum net present value. However, n-hexane consumption dramatically rises, and industrial hazards have not been considered in the optimization process. To overcome this issue, a preliminary hazard analysis is carried out to identify hazardous materials and operations. Event trees are formulated to derive the frequencies of different accident scenarios, further determining the consequences. The major consequences of accidents involve toxic releases of high quantities of n-hexane. By comparing the proposed alternatives, this work aims to highlight the need to consider not only economic but also safety and environmental objectives in the development of a biodiesel production project.The authors are grateful for the financial support provided by CONICET and the Spanish MICINN under projects CTQ2013-48280-C3-1-R and CTM2014-57833-R. J. Pinedo would also like to thank the financial support provided by “Becas Iberoamérica JPI España 2014”

Pilot-scale biofiltration at a materials recovery facility: The impact on bioaerosol control

This study investigated the performance of four pilot-scale biofilters for the removal of bioaerosols from waste airstreams in a materials recovery facility (MRF) based in Leeds, UK. A six-stage Andersen sampler was used to measure the concentrations of four groups of bioaerosols (Aspergillus fumigatus, total fungi, total mesophilic bacteria and Gram negative bacteria) in the airstream before and after passing through the biofilters over a period of 11 months. The biofilters achieved average removal efficiency (RE) of 70% (35 to 97%) for A. fumigatus, 71% (35 to 94%) for total fungi, 68% (47 to 86%) for total mesophilic bacteria and 50% (-4 to 85%) for Gram negative bacteria, provided that the inlet concentration was high (103–105 - cfu m�3), which is the case for most waste treatment facilities. The performance was highly variable at low inlet concentration with some cases showing an increase in outlet concentrations, suggesting that biofilters had the potential to be net emitters of bioaerosols. The gas phase residence time did not appear to have any statistically significant impact on bioaerosol removal efficiency. Particle size distribution varied between the inlet and outlet air, with the outlet having a greater proportion of smaller sized particles that represent a greater human health risk as they can penetrate deep into the respiratory system where gaseous exchange occurs. However, the outlet concentrations were low and would further be diluted by wind in full scale applications. In conclusion, this study shows that biofilters designed and operated for odour degradation can also achieve significant bioaerosol control in waste gas

Meeting the U.S. renewable fuel standard: a comparison of biofuel pathways

The production of renewable energy is undergoing rapid development. Ethanol primarily derived from corn and biodiesel made from recycled cooking oil and agricultural grains are established sources of renewable transportation fuel. Cellulosic ethanol production is increasing substantially, but at a rate below expectations. If future renewable fuel projections are to be accomplished, additional sources will be needed. Ideally, these sources should be independent of competing feedstock use such as food grains, and require a minimal footprint. Although the uses of algae seem promising, a number of demonstrations have not been economically successful in today‟s market. This paper identifies efforts being conducted on ethanol and biodiesel production and how algae might contribute to the production of biofuel in the United States. Additionally, the feedstock and land requirements of existing biofuel pathways are compared and discussed

CLINICAL EXPERIENCE AND REHABILITATION OF AMPUTEE MILITARY SERVICE MEMBERS AT THE CENTER FOR THE INTREPID AT BROOKE ARMY MEDICAL CENTER (BAMC): PART 1 – OCCUPATIONAL THERAPY REHABILITATION SERVICES

This lecture will discuss the clinical experiences and provision of rehabilitation services for amputee military service members at the Center For the Intrepid located at Brooke Army Medical Center (BAMC) Fort Sam Houston, Texas. This is part one of a series illustrating the prosthetic services, rehabilitation and research currently underway at BAMC. Case presentations will be utilized to illustrate the team approach to provide clinically appropriate amputee rehabilitation. This cohesive effort includes surgical considerations, early prosthetic fittings, long-term prosthetic care, rehabilitation services, case management, physiological and social support services. Protocols for advanced prosthetic training will be presented with emphasis on various prosthetic componentry. Advancements in the rehabilitation of the military amputee at the Center For the Intrepid will be discussed in detail to include functional capacity evaluations, drivers training, and firearms training simulator. A case study that involves an individual who sustained a dominant upper extremity transhumeral amputation with total loss of vision will also be discussed. In addition, current and future clinical research studies that involve individuals who have sustained upper extremity loss and who are undergoing rehabilitation at the Center For the Intrepid will be highlighted