Transitioning towards Net-Zero Emissions in Chemical and Process Industries : A Holistic PerspectivePeter Glavič
, Zorka Novak-Pintarič
, Helena Levičnik
, Vesna Dragojlović
, Miloš Bogataj
, 2023, pregledni znanstveni članek
Opis: Given the urgency to combat climate change and ensure environmental sustainability, this review examines the transition to net-zero emissions in chemical and process industries. It addresses the core areas of carbon emissions reduction, efficient energy use, and sustainable practices. What is new, however, is that it focuses on cutting-edge technologies such as biomass utilization, biotechnology applications, and waste management strategies that are key drivers of this transition. In particular, the study addresses the unique challenges faced by industries such as cement manufacturing and highlights the need for innovative solutions to effectively reduce their carbon footprint. In particular, the role of hydrogen as a clean fuel is at the heart of revolutionizing the chemical and process sectors, pointing the way to cleaner and greener operations. In addition, the manuscript explores the immense importance of the European Green Deal and the Sustainable Development Goals (SDGs) for the chemical industry. These initiatives provide a clear roadmap and framework for advancing sustainability, driving innovation, and reducing the industry's environmental impact, and are a notable contribution to the existing body of knowledge. Ultimately, alignment with the European Green Deal and the SDGs can bring numerous benefits to the chemical industry, increasing its competitiveness, promoting societal well-being, and supporting cross-sector collaboration to achieve shared sustainability goals. By highlighting the novelty of integrating cutting-edge technologies, addressing unique industrial challenges, and positioning global initiatives, this report offers valuable insights to guide the chemical and process industries on their transformative path to a sustainable future.
Ključne besede: net zero, energy, process industries, emissions, climate, chemicals, biomass, waste, cement, metals
Objavljeno v DKUM: 19.02.2024; Ogledov: 33; Prenosov: 0
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Energy source replacement in a thermal power plantMatej Fike
, Andrej Predin
, 2022, izvirni znanstveni članek
Opis: In Slovenia, approximately one third of electricity is produced in thermal power plants. Electricity prices have risen sharply recently. There are several reasons for this. One of them is the large increase in the price of CO2 coupons that thermal power plants have to buy, since they emit large amounts of greenhouse gas into the environment during the production of electricity. Emissions of the greenhouse gas CO2 are the result of burning fossil fuels, in this case coal. We want to use renewable energy sources to replace fossil fuels and reduce greenhouse gas emissions. More than half of Slovenia is covered with forest, and as a result, wood biomass energy represents a great energy potential. One possibility is the use of wood biomass in a classic thermal power plant for the production of electricity. This contribution presents the energy potential of Slovenian forests, before evaluating the replacement of the energy source in the existing coal-based thermal power plant with wood biomass. It has been discovered that there is enough wood biomass in Slovenia, and that all the electricity that is currently produced from coal can be produced from wood biomass. The cost of wood biomass is higher than the cost of coal. By changing the energy source, we save on the purchase of CO2 coupons. Therefore, the use of wood biomass represents an economically justified energy source for the production of electricity.
Ključne besede: wood biomass, thermal power plant, electricity production
Objavljeno v DKUM: 30.10.2023; Ogledov: 259; Prenosov: 5
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Private forest owner willingness to mobilise wood from dense, small-diameter tree standsMatevž Triplat
, Satu Helenius
, Ruben Laina
, Nike Krajnc
, Thomas Kronholm
, Zdenka Ženko
, Teppo Hujala
, 2023, izvirni znanstveni članek
Opis: Forests are a source of renewable biomass, and their utilisation will play a vital role in the transition towards a climate-neutral economy. Small-diameter tree management could contribute to this transition via providing renewable biomass for sustainable uses and fostering tree growth towards long-lifecycle bioproducts. The utilisation of small-diameter trees in the EU is still low since new technologies and work models are required to make the operations economically profitable, environmentally sound, and socially attractive. The supply of biomass from small-diameter tree stands is dependent on forest owners with diverse perceptions on their forests and diverse ownership objectives. However, there is scarce research on forest owner perceptions on small-diameter tree management, which encompasses home consumption, self-active work, and commercial forestry services. A survey in four EU countries was designed to identify the main factors affecting the motivation of forest owners to mobilise biomass from small-diameter stands. Factor and clustering analyses were used to identify four forest owner segments: weakly-engaged traders, well-being seekers, self-active profit-seekers, and well-informed service users. The willingness to utilise biomass from small-diameter tree stands and participate in the market was shaped by forest owner knowledge of forestry, economic and socio-cultural motivations, and sensitivity to service offerings. Forest owner preferences for market participation are heterogenous, and thus different policy implementation approaches are needed and proposed.
Ključne besede: profili strank, faktorska analiza, gozdarske storitve, upravljavski cilji, biomasa, komunikacijske strategije, customer profiles, factor analysis, forestry services, management objectives, biomass, communication strategies
Objavljeno v DKUM: 10.07.2023; Ogledov: 260; Prenosov: 19
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Hydrothermal processes for conversion of lignocellulosic biomass to value-added compounds : doctoral disertationTanja Milovanović
, 2020, doktorska disertacija
Opis: In this doctorial dissertation subcritical water processes of lignocellulosic biomass to obtain value-added compounds are studied. The doctorial dissertation is divided into four main parts. In the first and second part of dissertation, model compounds (standards of cellulose and sugars and chestnut tannins) were primarly used in order to better understand processes of real biomass material.
The degradation of cellulose and different sugars was performed in batch reactor with subcritical water. The different reaction temperatures and times were used. The main phases, such as water-soluble fraction, acetone-soluble fraction and solid residue were separated and analysed. The analysis of water-soluble phase was done by HPLC equipped with UV and RI detector, while acetone-soluble phase of cellulose was analysed by GC-MS. Total sugar content was determined by the phenol-sulphuric acid colorimetric method. The properties of char, obtained using cellulose as a treated material, such as: specific surface area, pore volume and pore diameter were determined by gas adsorption method. A water-soluble phase mainly consists of sugar monomers and monomer degradation products such as 5-hydroxymethylfurfural (5-HMF), furfural, erythrose, sorbitol, 1,6-anhydroglucose, glycolaldehyde, glycerlaldehyde, 1,3-dihydroxyacetone, pyruvaldehyde, formic, levulinic, lactic, oxalic and succinic acids, while acetone-soluble phase, referred to also as bio-oil, consists of furans, phenols, carboxylic acids, aldehydes, ketones and high molecular compounds. The reaction mechanism of cellulose and sugars in subcritical water has been proposed based on the obtained results. Furthermore, the results from cellulose and sugar hydrothermal degradation were utilized in further work to determine which industrially interesting products could be obtained by hydrothermal processing of paper waste in subcritical water. The optimum conditions ( temperature and reaction time), which gave us the highest yield of base chemicals (furfural, 5-HMF, levulinic acid) were determined.
Sweet chestnut (Castanea Sativa) bark contains high level of tannins and various phenolic compounds which can be utilized in pharmaceutical, cosmetic, nutritional and medical purposes. The sweet chestnut tannins extract and sweet chestnut bark were used as materials highly rich in bioactive compounds for subcritical water processes which are presented in the second part of doctorial dissertation, respectively. The spectrophotometric methods were used to determine total tannins, phenols and carbohydrates content and antioxidant activity. The identified compounds were ellagic and gallic acid, ellagitannins (vescalagin, castalagin, 1-o-galloyl castalagin, vescalin and castalin), sugars (maltose, glucose, fructose and arabinose) and sugar derivatives (5-HMF, furfural and levulinic acid). The results obtained from hydrothermal hydrolysis were compared to results from acid hydrolysis. Finally, the optimization of reaction parameters of subcritical water processes has been done aiming to obtain the product highly rich in ellagic acid.
Subcritical water extraction of horse chestnut (Aesculus hippocastanum) parts such as seeds, seed shell, bark and leaves was described in the third chapter of dissertation. The detected compounds in extracts, such as escins, esculin, fraxin, phenolic compounds (chlorogenic, neochlorogenic and gallic acids) and furfurals (5-hydroxymethyfurfural, furfural, and methylfufrual) are quantified using HPLC.
The last part of dissertation proposes extraction of cocoa shell using green technologies (supercritical CO2 and subcritical water extraction) and also conventional methods (Soxhlet extraction with hexane and extraction with 50 % acetone) to obtain bioactive compounds in order to compare the results. The detected compouns were methylxanthines, phenolic compounds, sugars, fatty acids.
Ključne besede: Subcritical water, biomass, biowaste, extraction, hydrothermal degradation, hydrolysis, bioactive compounds.
Objavljeno v DKUM: 16.10.2020; Ogledov: 1446; Prenosov: 150
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Contribution of non-troglobiotic terrestrial invertebrates to carbon input in hypogean habitatsTone Novak
, Franc Janžekovič
, Saška Lipovšek Delakorda
, 2013, izvirni znanstveni članek
Opis: Eleven of the most important terrestrial invertebrate species in Slovenian caves were analyzed for differences in their fresh and dry biomass, energy content and carbon bulk during winter. These data were combined with the species abundance in 54 caves and adits in order to estimate their organic carbon bulk and carbon input into these habitats. In Central European caves, Troglophilus cavicola, T. neglectus, Faustina illyrica, Amilenus aurantiacus and Scoliopteryx libatrix are the most important vectors of carbon between the epigean and hypogean habitats. In contrast to the general assumption, carbon total contribution to caves via dead bodies is only 0.15% of total migratory biomass, and it is not directly available to troglobionts because of infection with entomopathogenic fungi. In winter, together with predated migratory specimens, carbon input does not exceed 0.3% of the total migratory biomass. This situation should be carefully examined in every karstic region inhabited by distinctive fauna.
Ključne besede: biomass, carbon flux, caves, non-troglobiotic species, organic carbon, respiration
Objavljeno v DKUM: 21.12.2015; Ogledov: 1506; Prenosov: 85
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CATALYTIC GENERATION OF HYDROGEN FROM BIOMASS DERIVED LACTIC ACID VIA AQUEOUS PHASE REFORMINGMonika Bosilj
, 2015, magistrsko delo
Opis: Hydrogen production from aqueous phase reforming (APR) of organic acids in aqueous phase and from residue of a biomass decomposition process over 3 wt% Pt/ZrO2 has been studied in the absence and presence of barium ions. The results have been compared with Pt/TiO2, Pt/C and Ni/C catalysts. Having identified barium hydroxide as a promising reagent in combination with Pt/ZrO2 catalyst for the hydrogen production out of organic acids, the method for the lactic acid conversion was extended. Lactic acid (LA) was analysed as a major compound in an aqueous solution after a biomass digestion process with Ba(OH)2.
Gaseous and aqueous products after APR reaction of LA mixture with barium hydroxide were identified by different analytical techniques. Gaseous products consisted mainly of permanent gases such as hydrogen, carbon dioxide and methane. The results showed that mixture of LA in combination with both barium hydroxide and Pt/ZrO2 catalyst had the highest hydrogen production rate and the highest selectivity to hydrogen, whereas low gaseous product amount were observed from mixture of LA and only barium hydroxide or Pt/ZrO2 catalyst. Methane and higher amount of carbon dioxide were detected in gas phase products particular in the presence of Pt/ZrO2 catalyst in the mixture.
Aqueous products consisted mainly of pyruvic acid, acetic acid and salts, such as acetate and propionate. The complete conversion of LA after APR was reached in mixture of LA and Ba(OH)2∙8H2O over Pt/ZrO2 catalyst. Mixture of LA and Ba(OH)2∙8H2O or Pt/ZrO2 catalyst gave lower conversion of LA.
Amount of gaseous products, selectivity to hydrogen and LA conversion were affected by higher reactant mixture concentration. In comparison to low concentrated mixtures, high concentrated mixtures contained larger amounts of barium but the same amount of Pt/ZrO2 catalyst. BET analyses showed much smaller pore volume of spent Pt/ZrO2 catalyst, which was used in APR reaction of high concentrated (1.5 mol/L) mixture. Therefore, lower gas product amounts, lower selectivity to hydrogen and only 63 % conversion of LA were effects of deactivated Pt/ZrO2 catalyst.
The results showed that hydrogen generation from APR of LA and conversion of LA in aqueous phase are hardly influenced by the Pt/ZrO2 catalyst presence, which in combination with barium ions, promotes the catalytic APR reaction.
Ključne besede: biomass, hydrogen production, aqueous phase reforming, lactic acid
Objavljeno v DKUM: 20.02.2015; Ogledov: 1920; Prenosov: 163
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SYNTHESIS OF SUSTAINABLE BIOPROCESSES USING COMPUTER-AIDED PROCESS ENGINEERINGLidija Čuček
, 2013, doktorska disertacija
Opis: This doctoral dissertation, which consists of four substantive wholes, presents several syntheses of sustainable bioprocesses using computer-aided process engineering. In the first part the synthesis of different integrated processes of ethanol production from the entire corn plant is presented. The synthesis of different processes is in the second part further extended to the simplified and more comprehensive synthesis of bioproducts in the whole production supply chain network. Synthesis is based on the generic optimisation model of biomass production and supply chain networks.
In the third part three methods for sustainable development assessment, suitable for multi-criteria optimisation, are presented: method of sustainability indexes, footprints and combined criteria, such as eco- and total profit. Methods are further upgraded with indirect effects in order to measure the unburdening the environment, associated with the use and replacement of environmentally-harmful products. Methods include the direct, indirect and total impacts on the environment.
In the last part the methodology for reducing a large number of criteria within multi-objective optimisation to a small number of representative criteria is presented. This method is presented on the case of environmental footprints.
Ključne besede: Biomass energy generation, Supply chain networks, Synthesis of sustainable bioprocesses, Life Cycle Analysis, Sustainability assessment, Multi-objective optimisation, Dimensionality reduction, Representative Objectives Method
Objavljeno v DKUM: 06.05.2013; Ogledov: 2450; Prenosov: 277
Celotno besedilo (4,29 MB)
Preliminary estimation of bryophyte biomass and carbon pool from three contrasting different vegetation typesMahesh Kumar Singh
, Anita Juhász
, Zsolt Csintalan
, Mitja Kaligarič
, Michal V. Marek
, Otmar Urban
, Zoltán Tuba
, 2005, objavljeni znanstveni prispevek na konferenci
Opis: Bryophytes are the primary form of carbon storage in many ecosystems. There is growing consensus within the scientific community that increases in atmospheric carbon dioxide (CO2) enhancing the earth's natural greenhouse effect. Because of the potential effects of these gases on the global enery budget and future elimate, there is an urgent need to quantify terrestrial sources and sinks of carbon. There is more carbon stored in some bryophytes than in any other genus of vascular or non-vascular plants (Clymo & Hayward, 1982). Predicting how the vast stores of carbon in moss-dominated ecosystems will be affected by anthropogenic disturbance is critical for models of global climate change (Post et al., 1982). Bryophytes are a prominent feature of many forest and grassland types, where they can make an important contribution to carbon balance (Delucia, et al., 2003). Tropical montane rain forest, because of their complexity and variety of microhabitats, usually harbors a rich diversity of bryophytes. Even though they are often small and inconspicuous, especially in the lowland forest, they may play a significant role in the forest ecosystem (Frahm, 1994). Similarly, bryophytes in the temperate forest and grasslands are thought to be an important carbon sink (O'Neill, 2000). The objective of this research was to estimate components of the bryophyte biomass and approximate amount of carbon stored in it.
Ključne besede: vegetation, habitats, geoelements, carbon, carbon storage, bryophyte, bryophyte biomass
Objavljeno v DKUM: 07.06.2012; Ogledov: 1798; Prenosov: 134
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Synthesis of regional networks for biomass and biofuel production Hon Loong Lam
, 2010, doktorska disertacija
Opis: This thesis presents two different approaches to the synthesis of regional networks for biomass and biofuel production and supply: Mathematical Programming and Graph Theoretic approach. The optimisation criterion for both approaches is the maximisation of profit.
The first approach is based on a generic optimisation model of biomass production and supply networks. This superstructure approach is based on a flexible number of network layers: plantation, collection using a pre-treatment, process, and consumption. A Mixed Integer Linear Programming (MILP) model has been successfully developed during this work.
However, the solution of this biomass production network model is very challenging due to the large sizes of the networks and the number of interconnections. The huge number of redundant variables reduces model efficiency (time taken to solve the model and the interpretation of the results). This model when representing very large size networks cannot be solved over a reasonable time even by professional mathematical programming software tools. Several model-size reduction techniques are therefore proposed for the solution of large-scale networks. In particular, methods are proposed for (i) reducing the connectivity within a biomass supply chain network by setting the maximum allowable distance between the supply zones to the collection centres, (ii) eliminating unnecessary variables and constrains to reduce the zero-flows in the full model, and (iii) aggregating the network and hence the synthesis process by merging the collection centres.
The network synthesis is also carried out by P-graph (Process Graph) tools. P-graph is a directed bipartite graph, having two types of vertices — one for operating units and another for those objects representing material or energy flows/quantities. In this procedure, firstly a maximum feasible superstructure for biomass production network is generated from which the optimal structure is then selected by the Branch and Bound method. This graph-based method clearly shows where, how, and what kind of material and energy carriers will be transferred from one supply chain layer to another.
In order to test the efficiency of the model, a small regional renewable network problem was solved using both methods. Their performances were tested and the results confirmed the applicability on a regional scale. The proposed model-size reduction techniques were also tested. A large-scale regional case study was created to demonstrate these techniques. The results are very positive and some suggestions for future work are given in the conclusion.
Ključne besede: Biomass and bioenergy network synthesis, Model-size reduction
techniques, Mathematical Programming, MILP, P-Graph
Objavljeno v DKUM: 06.01.2011; Ogledov: 3540; Prenosov: 135
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