Comparative Evaluation of Pyrolysis and Hydrothermal Liquefaction for Obtaining Biofuel from a Sustainable Consortium of Microalgae Arthrospira platensis with Heterotrophic Bacteria

This article presents a comparative evaluation of pyrolysis and hydrothermal liquefaction (HTL) for obtaining biofuel from microalgal biomass (MAB). The research was carried out using biomass of a stable microalgae-bacteria consortium based on Arthrospira platensis. A. platensis was chosen because of its simple cultivation and harvesting. Pyrolysis was carried out at temperatures of 300, 400, 500, and 600 °C with a constant rate of temperature change of 10 °C/min; HTL was carried out at temperatures of 270, 300, and 330 °C. The bio-oil yield obtained by HTL (38.8–45.7%) was significantly higher than that of pyrolysis (up to 21.9%). At the same time, the bio-coal yields using both technologies were almost the same—about 27%. Biochar (bio-coal) can be considered as an alternative strategy for CO2 absorption and subsequent storage since it is 90% geologically stabilized carbon

Renewable energy technologies: enlargement of biofuels list and co-products from microalgae

Microalgae is a perspective feedstock for producing a wide variety of biofuels and co-products with high added value. An alternative to the traditional technology of biodiesel from algae by the transesterification is the technology of hydrothermal liquefaction (HTL). The article presents the results of promising strains screening and directed cultivation of microalgae for the processing by means of variety of technologies and production of valuable co-products. An algorithm for selecting suitable areas for industrial plantations of algae is presented

Estimation of microalgae resource potential for bio-oil production and sustainable rural development in the climatic conditions of Russia (the Republic of Dagestan)

The work is devoted to the estimation of microalgae resource potential for bio-oil production. We propose a method of climate and infrastructural factors spatial analysis for estimations of resource and the possibility of bio-oil production facilities construction in the study region. The resource potential depends on the area of the territory that can be used to produce biomass as feedstock for biofuel production, and equal to the amount of microalgae biomass that can be obtained on this territory. For the case study we selected the territory of the Republic of Dagestan (Russia) and microalgae Arthrospira platensis and Dunaliella salina. As an infrastructural factors, which may reduce the cost of bio-oil production we considered the following sources of cheap material resources and energy: seawater (as a source of macro- and microelements), geothermal water (as low-temperature heat source), CO2 emissions of cement plants and combined heat and power plants (as carbon source and to reduce CO2 emission). The analyses of these factors using the technology of geoinformation systems allowed to find the most suitable territories for microalgae plant allocation and therefore estimate resource potential for biooil production with maximum profit

Renewable energy technologies: enlargement of biofuels list and co-products from microalgae

Microalgae is a perspective feedstock for producing a wide variety of biofuels and co-products with high added value. An alternative to the traditional technology of biodiesel from algae by the transesterification is the technology of hydrothermal liquefaction (HTL). The article presents the results of promising strains screening and directed cultivation of microalgae for the processing by means of variety of technologies and production of valuable co-products. An algorithm for selecting suitable areas for industrial plantations of algae is presented

Comparative Evaluation of Pyrolysis and Hydrothermal Liquefaction for Obtaining Biofuel from a Sustainable Consortium of Microalgae Arthrospira platensis with Heterotrophic Bacteria

This article presents a comparative evaluation of pyrolysis and hydrothermal liquefaction (HTL) for obtaining biofuel from microalgal biomass (MAB). The research was carried out using biomass of a stable microalgae-bacteria consortium based on Arthrospira platensis. A. platensis was chosen because of its simple cultivation and harvesting. Pyrolysis was carried out at temperatures of 300, 400, 500, and 600 °C with a constant rate of temperature change of 10 °C/min; HTL was carried out at temperatures of 270, 300, and 330 °C. The bio-oil yield obtained by HTL (38.8–45.7%) was significantly higher than that of pyrolysis (up to 21.9%). At the same time, the bio-coal yields using both technologies were almost the same—about 27%. Biochar (bio-coal) can be considered as an alternative strategy for CO2 absorption and subsequent storage since it is 90% geologically stabilized carbon

«Языковая конкиста»: колониальные грамматики кечуа как модель культурно-языковой аккультурации

The article is devoted to the role and place of Quechua in colonial Peru, which is the most widely spoken native language in both American continents. A comparative analysis of a number of grammars and dictionaries (including records) written in the 16th‑17th centuries by the representatives of the clergy has become the basic method for recent scientific investigation. Those were the representatives of the clergy who took the most active part in the process of «language conquest» which led to Quechua integration into the intellectual field of Spanish culture and then consequently into the European one. The paper also presents the analysis of the current state of the issue study, which concludes that many points of the problem have not found the proper coverage in science yet. The sources are analyzed on the following points: the attitude of the authors of grammars to the Quechua language; the main goals of writing grammars; their structure and content’s peculiarities; the main cultural and linguistic categories used to describe and analyze the Quechua language in the period under review. The analysis made it possible to come to the following conclusions. Firstly, the attitude of the clergy towards Quechua can be described as ambivalent. Secondly, the main goals of writing can be interpreted as a practical one (mastering the language in order to Christianize the Indians more effectively) and as well as an ideological one (integrating Quechua into the Christian cultural field through its study), although both of them, of course, are interrelated. Thirdly, the analysis allowed us to distinguish the following cultural and linguistic categories that were applied to Quechua: eurocentrism, theoretical and religious orientation. Finally, the main conclusion drawn from the study is that the relationship existed between Spanish and Quechua can be characterized by the term «acculturation»В статье рассматривается роль и место в колониальном Перу народа кечуа – крупнейшего по числу носителей индейского языка в обеих Америках. Ведущим методом исследования стал сравнительный анализ ряда грамматик и словарей (в том числе используется и архивный материал), написанных в XVI–XVII вв. представителями клира. Именно они приняли наиболее активное участие в процессе «языковой конкисты», то есть интеграции кечуа в интеллектуальное поле испанской и, как следствие, европейской культуры. Представлен также анализ современного состояния изученности вопроса, в котором делается вывод, что многие аспекты проблемы еще не нашли должного освещения в науке. Источники проанализированы по следующим аспектам: отношение авторов грамматик к языку кечуа; основные цели написания грамматик; характерные особенности структуры и содержания этих произведений; базовые культурно-языковые категории, с помощью которых описывался и анализировался язык кечуа в рассматриваемый период. В результате проведенного исследования сделаны следующие выводы. Во-первых, отношение клира к кечуа можно охарактеризовать как амбивалентное. Во-вторых, основные цели написания: практическая (овладение языком с целью более эффективной христианизации индейцев) и идеологическая (включение кечуа в орбиту христианского культурного поля посредством его изучения), хотя обе они, конечно, взаимосвязаны. В‑третьих, можно дифференцировать следующие культурно-языковые категории, которые применялись по отношению к кечуа: европоцентризм, теоретичность и религиозная направленность. Наконец, главный вывод, который был сделан по результатам проведенного исследования, заключается в том, что существовавшее взаимодействие между испанским языком и кечуа можно охарактеризовать термином «аккультурация

Direct Study of CO₂ Capture Efficiency during Microalgae <i>Arthrospira platensis</i> Cultivation at High CO₂ Concentrations

Direct study of CO2 capture efficiency during microalgae Arthrospira platensis cultivation at high CO2 concentrations was carried out. Microalgae were grown in a 90 L photobioreactor on Zarrouk’s medium prepared with distilled water. Three 15-day experiments were carried out with different initial CO2 concentrations: 1, 5, and 9 vol.%. During the experiments, both the change in the optical density of the microalgae suspension and the direct change in the CO2 concentration in the chamber were measured. The maximum decrease in CO2 concentration due to the growth of microalgae was 0.10 vol.% (CO2)/day in the experiment with an initial CO2 concentration of 5 vol.%. Growth rate of biomass density was 79.4, 76.3, and 48.4 (mg/L)/day at 1, 5, and 9 vol.% CO2 concentrations, respectively. During the experiment with initial CO2 concentrations of 1 and 5 vol.%., pH of the culture medium was increased, but pH was decreased from 9.2 to 8.8 at 9 vol.%. In general, good viability (high quality of biomass and high rate of its growth) of Arthrospira platensis was established at 1 and 5 vol. (CO2)%, while massive death of Arthrospira platensis cells was observed in the experiment with 9 vol. (CO2)%. Biochemical analysis of the resulting biomass revealed a decrease in the content of lipids and proteins with an increase in CO2 concentration

Direct Study of CO2 Capture Efficiency during Microalgae Arthrospira platensis Cultivation at High CO2 Concentrations

Direct study of CO2 capture efficiency during microalgae Arthrospira platensis cultivation at high CO2 concentrations was carried out. Microalgae were grown in a 90 L photobioreactor on Zarrouk’s medium prepared with distilled water. Three 15-day experiments were carried out with different initial CO2 concentrations: 1, 5, and 9 vol.%. During the experiments, both the change in the optical density of the microalgae suspension and the direct change in the CO2 concentration in the chamber were measured. The maximum decrease in CO2 concentration due to the growth of microalgae was 0.10 vol.% (CO2)/day in the experiment with an initial CO2 concentration of 5 vol.%. Growth rate of biomass density was 79.4, 76.3, and 48.4 (mg/L)/day at 1, 5, and 9 vol.% CO2 concentrations, respectively. During the experiment with initial CO2 concentrations of 1 and 5 vol.%., pH of the culture medium was increased, but pH was decreased from 9.2 to 8.8 at 9 vol.%. In general, good viability (high quality of biomass and high rate of its growth) of Arthrospira platensis was established at 1 and 5 vol. (CO2)%, while massive death of Arthrospira platensis cells was observed in the experiment with 9 vol. (CO2)%. Biochemical analysis of the resulting biomass revealed a decrease in the content of lipids and proteins with an increase in CO2 concentration

From the Cultivation of Arthrospira platensis at an Increased CO2 Concentration to the Bio-Oil Production by Hydrothermal Liquefaction

In this work, the path from the cultivation of Arthrospira platensis at an increased concentration of CO2 to the production of bio-oil by hydrothermal liquefaction (HTL) of the grown biomass is realized. The cultivation was carried out in a 90 L photobioreactor at an initial CO2 concentration of 8 vol.% for 15 days. During the cultivation stage, the optical density for microalgae suspension, pH and chemical composition of nutrient medium were monitored. The grown biomass was separated from the nutrient medium with a 100 µm mesh and then subjected to HTL at 330 °C for 1 h. The biomass growth rate was 82 ± 4.1 mg × L−1day−1 and the pH was in the range from 9.08 ± 0.22 to 8.9 ± 0.24. Biochemical and CHNS analyses were applied for the obtained biomass. The contents of carbohydrates, proteins and lipids in the grown biomass were 38.7 ± 0.4 wt.%, 37.4 ± 0.5 wt.% and 3.8 ± 0.4 wt.%, respectively. Bio-oil yield after the HTL procedure was 13.8 wt.%. The bio-oil composition and properties were determined by GH-MS, TLC-PID and ICP-MS techniques. ICP-MS revealed the contents of 51 metals in bio-oil