Andmebaasi logo

2021, Vol. 19, Special Issue 1

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/6909

Sirvi

Sirvi 2021, Vol. 19, Special Issue 1 Autor "Blumberga, D." järgi

Nüüd näidatakse 1 - 3 3
  • Pisipilt
    Kirje
    Carbon balance of biogas production from maize in Latvian conditions
    (2021) Bumbiere, K.; Gancone, A.; Pubule, J.; Blumberga, D.
    Production of biogas using bioresources of agricultural origin plays an important role in Europe’s energy transition to sustainability. However, many substrates have been denounced in the last years as a result of differences of opinion on its impact on the environment, while finding new resources for renewable energy is a global issue. The aim of the study is to use a carbon balance method to evaluate the real impact on the atmosphere by carrying out a carbon balance to objectively quantify naturally or anthropogenically added or removed carbon dioxide from the atmosphere. This study uses Latvian data to determine the environmental impact of biogas production depending on the choice of substrate, in this case from specially grown maize silage. GHG emissions from specially grown maize use and cultivation (including the use of diesel fuel, crop residue and nitrogen fertilizer incorporation, photosynthesis), biogas production leaks, as well as digestate emissions (including digestate emissions and also saved nitrogen emissions by the use of digestate) are taken into account when compiling the carbon balance of maize. The results showed that biogas production from specially grown maize can save 1.86 kgCO2eq emissions per 1 m3 of produced biogas.
  • Pisipilt
    Kirje
    Packing materials for biotrickling filters used in biogas upgrading – biomethanation
    (2021) Kusnere, Z.; Spalvins, K.; Blumberga, D.; Veidenbergs, I.
    One of the promising methods of biogas upgrading is biological methanation (biomethanation). During biomethanation process hydrogenotrophic microorganisms use carbon dioxide from biogas and added hydrogen to generate biomethane. Application of biotrickling filter reactors is one of the prospective biotechnologies for methanation where hydrogenotrophic methanogens are immobilized over a material that is used in reactor. Packing materials for biomethanation are critical in terms of hydrogenotrophic methanogens immobilization on the surface of packing material. It acts as support for biofilm growth. Therefore, characteristics of filter material are important parameters that influence the growth of microorganisms and methane production. Factors, such as optimal specific surface area and porosity are important to sustain growth and activity of microorganisms. Optimal particle size and capability to mechanically resist compaction ensures avoiding high pressure drop. Optimal particle size also ensures uniform gas flow as gases distribute through the packing material. This review paper summarizes and compare the characteristics of different packing materials important for biomethanation through ex-situ biotrickling filter reactor systems.
  • Pisipilt
    Kirje
    Prospect on agro-industrial residues usage for biobutanol production
    (2021) Raita, S.; Spalvins, K.; Blumberga, D.
    Climate changes, environmental pollution and resource depletion are one of the numerous major problems humanity faces. United Nations sustainable development goals are aimed at solving these problems. The requirement for affordable, renewable, sustainable, biodegradable and environmentally friendly fossil fuel alternative sources is prompted by the development and advancement of biofuel production technologies. Of the various biofuel alternatives, biobutanol has increased the interests of researchers due to its desirable characteristics such as hydrophobicity, relatively high heating value and energy density, relatively low vapour pressure, etc. Nowadays, sustainable production of the biobutanol depends on the used feedstock source and its pre-treatment method, selected enhancing microorganism strain, acetone–butanol–ethanol fermentation effectiveness and titer of biobutanol. The main research challenges in biobutanol production are an improvement of production efficiency and increasing the financial viability of the technology. This review summarizes the latest results of lignocellulosic components content and fermentable sugars composition in different agro-industrial residues; biobutanol production depending on the Clostridium enhancing strategy, process optimization and selection of substrate. Such analysis provides a better perception of the capability of using agro-industrial residues for biobutanol production efficiency.