scholarly journals Development of a brine treatment strategy for enhancing geothermal energy production and associated raw material extraction

2021 ◽  
Author(s):  
Valentin Goldberg ◽  
Daniel Winter ◽  
Fabian Nitschke ◽  
Diego Morata ◽  
Joachim Koschikowski ◽  
...  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alberto Palma ◽  
Javier Mauricio Loaiza ◽  
Manuel J. Díaz ◽  
Juan Carlos García ◽  
Inmaculada Giráldez ◽  
...  

Abstract Background Burning fast-growing trees for energy production can be an effective alternative to coal combustion. Thus, lignocellulosic material, which can be used to obtain chemicals with a high added value, is highly abundant, easily renewed and usually inexpensive. In this work, hemicellulose extraction by acid hydrolysis of plant biomass from three different crops (Chamaecytisus proliferus, Leucaena diversifolia and Paulownia trihybrid) was modelled and the resulting solid residues were used for energy production. Results The influence of the nature of the lignocellulosic raw material and the operating conditions used to extract the hemicellulose fraction on the heat capacity and activation energy of the subsequent combustion process was examined. The heat power and the activation energy of the combustion process were found to depend markedly on the hemicellulose content of the raw material. Thus, a low content in hemicelluloses resulted in a lower increased energy yield after acid hydrolysis stage. The process was also influenced by the operating conditions of the acid hydrolysis treatment, which increased the gross calorific value (GCV) of the solid residue by 0.6–9.7% relative to the starting material. In addition, the activation energy of combustion of the acid hydrolysis residues from Chamaecytisus proliferus (Tagasaste) and Paulownia trihybrid (Paulownia) was considerably lower than that for the starting materials, the difference increasing with increasing degree of conversion as well as with increasing temperature and acid concentration in the acid hydrolysis. The activation energy of combustion of the solid residues from acid hydrolysis of tagasaste and paulownia decreased markedly with increasing degree of conversion, and also with increasing temperature and acid concentration in the acid hydrolysis treatment. No similar trend was observed in Leucaena diversifolia (Leucaena) owing to its low content in hemicelluloses. Conclusions Acid hydrolysis of tagasaste, leucaena and paulownia provided a valorizable liquor containing a large amount of hemicelluloses and a solid residue with an increased heat power amenable to efficient valorization by combustion. There are many potential applications of the hemicelluloses-rich and lignin-rich fraction, for example as multi-components of bio-based feedstocks for 3D printing, for energy and other value-added chemicals.


2021 ◽  
pp. 016224392110345
Author(s):  
James Maguire

This paper explores an informal acoustic method developed by a group of industrial geologists working in geothermal energy landscapes in the southwest of Iceland. Through a series of ethnographic descriptions, this paper renders the work these geologists carry out in sonic terms, emphasizing how they use their bodies as sonic detectors in the production of geological evidence. Sound, the paper argues, is what allows geologists to make the intractable problem of volcanic cooling doable. It does this by differentiating two forms of evidence. Primary evidence, which ends up as data in geological reports, and secondary sonic evidence, which is what establishes that this primary evidence is, in fact, evidence. The paper introduces the concept data echoes as a way to think about how sound articulates between these evidential protocols. As echo, sound works as an outside, which, while remaining external to official protocols of knowledge production, nevertheless helps to constitute distinctions that are meaningful to the production of those categories. As data echoes through the various moments of data capture, analysis, and model building, sound’s temporal form helps to predict the time frame of volcanic cooling, as it affects both the immediate energy production scenarios and the long durée of volcanic time.


2019 ◽  
pp. 23-34
Author(s):  
Sheila Genoveva Pérez-Bravo ◽  
Ana María Mendoza-Martínez ◽  
Maria del Refugio Castañeda-Chávez ◽  
Luciano Aguilera-Vázquez

The energy demand of the world population is increasing due to population growth and technological development. The current energy base is a generator of CO2 emissions, the most abundant and main greenhouse gas responsible for global warming, as well as pollutants, sulfur oxides and nitrogen oxides. The environmental deterioration and the increase in fossil fuel prices make it necessary to investigate less aggressive energy sources with the environment at competitive costs in the market. Biofuels are an alternative for energy production due to their origin in the short carbon cycle, their emissions are considered almost zero, including biodiesel and bioethanol. The latter can be obtained from microalgae rich in carbohydrates and lipids, easy to grow in short periods of time. The objective of this research is to summarize the findings made about the existence of useful microalgae as raw material to produce biofuels in Mexican territory. An exhaustive review of the literature was carried out, which contributed to estimate the microalgal diversity in the country and its lipid contents as well as carbohydrates, with different species of the genera Chlamydomonas, Chlorella, Scenedesmus, Desmodesmus being found mainly.


2012 ◽  
Vol 41 ◽  
pp. 80-85 ◽  
Author(s):  
Xianbiao Bu ◽  
Weibin Ma ◽  
Huashan Li

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