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Prof. Timo Kikas
Estonian University of Life Sciences, Institute of Technology, Chair of Biosystems Engineering

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0 biorefining

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Short Biography

Prof. Timo Kikas received his PhD degree from Georgia Institute of Technology, USA in the field of Analytical Environmental Chemistry. He has worked as a researcher in USA, Japan, Finland and Estonia. He has also been a director of Türi College of Tartu University and Study Program manager of Environmental Engineering curriculum at University of Tartu. Presently, he is a Chair Professor of Biosystems Engineering chair in the Institute of Technology of Estonian University of Life Sciences. His main areas of interest include 2nd and 3rd generation bioenergy research, biosensors for environmental monitoring, flow injection analysis and lab-on-valve systems. Prof. Kikas is Editor in Chief of Agronomy Research journal and a guest editor of Energies, a member of the Board of Institute of Technology and the Board of Estonian University of Life Sciences, and national task leader of IEA Bioenergy Task 37 Biogas. Prof. Kikas has been awarded twice with the stipend of Estonian World Council. He is also a recipient of Tartu City Rae Foundation award.

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Journal article
Published: 12 May 2021 in Energies
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Abundant biomass is a potential energy source. However, it possesses several challenges when considered for energy applications. Torrefaction, a thermal pretreatment process can improve the properties of biomass as energy source. This study focused on comparing effect of torrefaction operating parameters on agricultural and wood wastes properties as fuel. The physiochemical properties, composition, moisture-biomass interaction and ash melting behavior were determined. The result show that higher torrefaction temperature and longer residence time increased lignin content, reduced hemicellulose and cellulose content. The moisture uptake of torrefied biomass was reduced in the range 2.47–9.94% compared with raw biomass depending on torrefaction temperature that indicate torrefied biomass was more hydrophobic than raw biomass. The moisture adsorption isotherm curve shows type II isotherm based on the Brunauer-Emmett-Teller’s (BET) classification and was best described by the Oswin model. In addition, torrefaction treatment showed significant influence on the melting behavior of the biomass ash. Especially for agricultural wastes, the fouling tendency shifted from serious range to low range with torrefaction treatment. Torrefaction showed promise for improving fuel characteristics of the studied biomass.

ACS Style

Margareta Cahyanti; Tharaka Doddapaneni; Marten Madissoo; Linnar Pärn; Indrek Virro; Timo Kikas. Torrefaction of Agricultural and Wood Waste: Comparative Analysis of Selected Fuel Characteristics. Energies 2021, 14, 2774 .

AMA Style

Margareta Cahyanti, Tharaka Doddapaneni, Marten Madissoo, Linnar Pärn, Indrek Virro, Timo Kikas. Torrefaction of Agricultural and Wood Waste: Comparative Analysis of Selected Fuel Characteristics. Energies. 2021; 14 (10):2774.

Chicago/Turabian Style

Margareta Cahyanti; Tharaka Doddapaneni; Marten Madissoo; Linnar Pärn; Indrek Virro; Timo Kikas. 2021. "Torrefaction of Agricultural and Wood Waste: Comparative Analysis of Selected Fuel Characteristics." Energies 14, no. 10: 2774.

Journal article
Published: 20 April 2021 in Processes
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During the bioethanol production process, vast amounts of residues are generated as process waste. To extract more value from lignocellulosic biomass and improve process economics, these residues should be used as feedstock in additional processes for the production of energy or fuels. In this paper, barley straw was used for bioethanol production and the residues were valorized using anaerobic digestion (AD) or used for the production of heat and power by combustion. A traditional three-step bioethanol production process was used, and the biomass residues obtained from different stages of the process were analyzed. Finally, mass and energy balances were calculated to quantify material flow and assess the different technological routes for biomass utilization. Up to 90 kg of ethanol could be produced from 1 t of biomass and additional biogas and energy generated from processing residues can increase the energy yield to over 220%. The results show that in terms of energy output, combustion was the preferable route for processing biomass residues. However, the production of biogas is also an attractive solution to increase revenue in the bioethanol production process.

ACS Style

Merlin Raud; Lisandra Rocha-Meneses; Daniel Lane; Olli Sippula; Narasinha Shurpali; Timo Kikas. Utilization of Barley Straw as Feedstock for the Production of Different Energy Vectors. Processes 2021, 9, 726 .

AMA Style

Merlin Raud, Lisandra Rocha-Meneses, Daniel Lane, Olli Sippula, Narasinha Shurpali, Timo Kikas. Utilization of Barley Straw as Feedstock for the Production of Different Energy Vectors. Processes. 2021; 9 (4):726.

Chicago/Turabian Style

Merlin Raud; Lisandra Rocha-Meneses; Daniel Lane; Olli Sippula; Narasinha Shurpali; Timo Kikas. 2021. "Utilization of Barley Straw as Feedstock for the Production of Different Energy Vectors." Processes 9, no. 4: 726.

Journal article
Published: 12 January 2021 in Polymers
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Waste banknote paper is a residue from the banking industry that cannot be recycled due to the presence of ink, microbial load and special coating that provides protection against humidity. As a result, waste banknote paper ends up being burned or buried, which brings environmental impacts, mainly caused by the presence of heavy metals in its composition. To minimize the environmental impacts that come from the disposal of waste banknote paper, this study proposes to produce value-added products (bioethanol and biogas) from waste banknote paper. For this, the effect of ink and pretreatment conditions on bioethanol and biomethane yields were analyzed. Waste banknote paper provided by the Central Bank of Iran was used. The raw material with ink (WPB) and without ink (WPD) was pretreated using sulfuric acid at different concentrations (1%, 2%, 3%, and 4%) and the nitrogen explosive decompression (NED) at different temperatures (150 °C, 170 °C, 190 °C, and 200 °C). The results show that the use of NED pretreatment in WPD resulted in the highest glucose concentration of all studies (13 ± 0.19 g/L). The acid pretreatment for WPB showed a correlation with the acid concentration. The highest ethanol concentration was obtained from the fermentation using WPD pretreated with NED (6.36 ± 0.72 g/L). The maximum methane yields varied between 136 ± 5 mol/kg TS (2% acid WPB) and 294 ± 4 mol/kg TS (3% acid WPD). Our results show that the presence of ink reduces bioethanol and biogas yields and that the chemical-free NED pretreatment is more advantageous for bioethanol and biogas production than the acid pretreatment method. Waste banknote paper without ink is a suitable feedstock for sustainable biorefinery processes.

ACS Style

Omid Yazdani Aghmashhadi; Lisandra Rocha-Meneses; Nemailla Bonturi; Kaja Orupõld; Ghasem Asadpour; Esmaeil Rasooly Garmaroody; Majid Zabihzadeh; Timo Kikas. Effect of Ink and Pretreatment Conditions on Bioethanol and Biomethane Yields from Waste Banknote Paper. Polymers 2021, 13, 239 .

AMA Style

Omid Yazdani Aghmashhadi, Lisandra Rocha-Meneses, Nemailla Bonturi, Kaja Orupõld, Ghasem Asadpour, Esmaeil Rasooly Garmaroody, Majid Zabihzadeh, Timo Kikas. Effect of Ink and Pretreatment Conditions on Bioethanol and Biomethane Yields from Waste Banknote Paper. Polymers. 2021; 13 (2):239.

Chicago/Turabian Style

Omid Yazdani Aghmashhadi; Lisandra Rocha-Meneses; Nemailla Bonturi; Kaja Orupõld; Ghasem Asadpour; Esmaeil Rasooly Garmaroody; Majid Zabihzadeh; Timo Kikas. 2021. "Effect of Ink and Pretreatment Conditions on Bioethanol and Biomethane Yields from Waste Banknote Paper." Polymers 13, no. 2: 239.

Journal article
Published: 27 November 2020 in Processes
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The aim of this paper is to study the effect of reinking and pretreatment of waste banknote paper on its usability in the bioethanol production process. To this end, the tensile strength of worn banknote paper was first studied at different pH values. The sample with the lowest tensile strength was considered for the next sections. In the deinking process, NaOH at different concentrations (1%, 2%, 3%, and 4%) and in combination with ultrasonic treatment was applied. After deinking the pulp, two acidic and alkaline chemical pretreatments with concentrations of 1%, 2%, 3%, and 4% were used independently and in combination with ultrasonic. Enzymatic hydrolysis, following fermentation with Scheffersomyces stipitis, and crystallinity measurements were used to confirm the efficiency of the pretreatments. RSM Design Expert software was used to determine the optimal values by considering the three variables—enzyme loading, ultrasonic loading, and contact time for waste paper deinked (WPD) and waste paper blank (WPB) pulps. The results indicated that repulping was the most efficient at pH = 2. In deinking, the highest brightness was obtained using 3% NaOH in combination with ultrasonic. Between the acid and alkaline pretreatment, the acid treatment was more appropriate according to the resulting sugar concentration and weight loss. XRD tests confirmed that the lowest crystallinity index was obtained in the sample pretreated with 4% sulfuric acid in combination with ultrasonic. The highest sugar concentration in the enzymatic hydrolysis step was 92 g/L for WPD and 81 g/L for WPB. For the fermentation at 96 h, the highest ethanol concentration and process efficiency achieved were 38 g/L and 80.9% for WPD and 31 g/L and 75.04% for WPB, respectively. Our research shows that the deinking process can widen the utilization potential of waste banknote paper in biorefinery processes.

ACS Style

Omid Yazdani Aghmashhadi; Ghasem Asadpour; Esmaeil Rasooly Garmaroody; Majid Zabihzadeh; Lisandra Rocha-Meneses; Timo Kikas. The Effect of Deinking Process on Bioethanol Production from Waste Banknote Paper. Processes 2020, 8, 1563 .

AMA Style

Omid Yazdani Aghmashhadi, Ghasem Asadpour, Esmaeil Rasooly Garmaroody, Majid Zabihzadeh, Lisandra Rocha-Meneses, Timo Kikas. The Effect of Deinking Process on Bioethanol Production from Waste Banknote Paper. Processes. 2020; 8 (12):1563.

Chicago/Turabian Style

Omid Yazdani Aghmashhadi; Ghasem Asadpour; Esmaeil Rasooly Garmaroody; Majid Zabihzadeh; Lisandra Rocha-Meneses; Timo Kikas. 2020. "The Effect of Deinking Process on Bioethanol Production from Waste Banknote Paper." Processes 8, no. 12: 1563.

Journal article
Published: 26 November 2020
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ACS Style

Timo Kikas. Comparison of different pretreatment methods on degradation of rye straw. 2020, 1 .

AMA Style

Timo Kikas. Comparison of different pretreatment methods on degradation of rye straw. . 2020; ():1.

Chicago/Turabian Style

Timo Kikas. 2020. "Comparison of different pretreatment methods on degradation of rye straw." , no. : 1.

Journal article
Published: 21 October 2020 in Processes
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Results from an investigation of the mechanical size reduction with the Szego Mill™ as a pretreatment method for lignocellulosic biomass are presented. Pretreatment is a highly expensive and energy-consuming step in lignocellulosic biomass processing. Therefore, it is vital to study and optimize different pretreatment methods to find a most efficient production process. The biomass was milled with the Szego Mill™ using three different approaches: dry milling, wet milling and for the first time nitrogen assisted wet milling was tested. Bioethanol and biogas production were studied, but also fibre analysis and SEM (scanning electron microscope) analysis were carried out to characterize the effect of different milling approaches. In addition, two different process flows were used to evaluate the efficiency of downstream processing steps. The results show that pretreatment of barely straw with the Szego Mill™ enabled obtaining glucose concentrations of up to 7 g L−1 in the hydrolysis mixture, which yields at hydrolysis efficiency of 18%. The final ethanol concentrations from 3.4 to 6.7 g L−1 were obtained. The lowest glucose and ethanol concentrations were measured when the biomass was dry milled, the highest when nitrogen assisted wet milling was used. Milling also resulted in an 6–11% of increase in methane production rate during anaerobic digestion of straw.

ACS Style

Merlin Raud; Kaja Orupõld; Lisandra Rocha-Meneses; Vahur Rooni; Olev Träss; Timo Kikas. Biomass Pretreatment with the Szego Mill™ for Bioethanol and Biogas Production. Processes 2020, 8, 1327 .

AMA Style

Merlin Raud, Kaja Orupõld, Lisandra Rocha-Meneses, Vahur Rooni, Olev Träss, Timo Kikas. Biomass Pretreatment with the Szego Mill™ for Bioethanol and Biogas Production. Processes. 2020; 8 (10):1327.

Chicago/Turabian Style

Merlin Raud; Kaja Orupõld; Lisandra Rocha-Meneses; Vahur Rooni; Olev Träss; Timo Kikas. 2020. "Biomass Pretreatment with the Szego Mill™ for Bioethanol and Biogas Production." Processes 8, no. 10: 1327.

Review
Published: 17 September 2020 in Energies
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Lignin is a natural polymer, one that has an abundant and renewable resource in biomass. Due to a tendency towards the use of biochemicals, the efficient utilization of lignin has gained wide attention. The delignification of lignocellulosic biomass makes its fractions (cellulose, hemicellulose, and lignin) susceptible to easier transformation to many different commodities like energy, chemicals, and materials that could be produced using the biorefinery concept. This review gives an overview of the field of lignin separation from lignocellulosic biomass and changes that occur in the biomass during this process, as well as taking a detailed look at the influence of parameters that lead the process of dissolution. According to recent studies, a number of ionic liquids (ILs) have shown a level of potential for industrial scale production in terms of the pretreatment of biomass. ILs are perspective green solvents for pretreatment of lignocellulosic biomass. These properties in ILs enable one to disrupt the complex structure of lignocellulose. In addition, the physicochemical properties of aprotic and protic ionic liquids (PILs) are summarized, with those properties making them suitable solvents for lignocellulose pretreatment which, especially, target lignin. The aim of the paper is to focus on the separation of lignin from lignocellulosic biomass, by keeping all components susceptible for biorefinery processes. The discussion includes interaction mechanisms between lignocellulosic biomass subcomponents and ILs to increase the lignin yield. According to our research, certain PILs have potential for the cost reduction of LC biomass pretreatment on the feasible separation of lignin.

ACS Style

Isa Hasanov; Merlin Raud; Timo Kikas. The Role of Ionic Liquids in the Lignin Separation from Lignocellulosic Biomass. Energies 2020, 13, 4864 .

AMA Style

Isa Hasanov, Merlin Raud, Timo Kikas. The Role of Ionic Liquids in the Lignin Separation from Lignocellulosic Biomass. Energies. 2020; 13 (18):4864.

Chicago/Turabian Style

Isa Hasanov; Merlin Raud; Timo Kikas. 2020. "The Role of Ionic Liquids in the Lignin Separation from Lignocellulosic Biomass." Energies 13, no. 18: 4864.

Review
Published: 11 September 2020 in Energies
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Bioethanol production from lignocellulosic biomass is still struggling with many obstacles. One of them is lignocellulosic inhibitors. The aim of this review is to discuss the most known inhibitors. Additionally, the review addresses different detoxification methods to degrade or to remove inhibitors from lignocellulosic hydrolysates. Inhibitors are formed during the pretreatment of biomass. They derive from the structural polymers-cellulose, hemicellulose and lignin. The formation of inhibitors depends on the pretreatment conditions. Inhibitors can have a negative influence on both the enzymatic hydrolysis and fermentation of lignocellulosic hydrolysates. The inhibition mechanisms can be, for example, deactivation of enzymes or impairment of vital cell structures. The toxicity of each inhibitor depends on its chemical and physical properties. To decrease the negative effects of inhibitors, different detoxification methods have been researched. Those methods focus on the chemical modification of inhibitors into less toxic forms or on the separation of inhibitors from lignocellulosic hydrolysates. Each detoxification method has its limitations on the removal of certain inhibitors. To choose a suitable detoxification method, a deep molecular understanding of the inhibition mechanism and the inhibitor formation is necessary.

ACS Style

Nikki Sjulander; Timo Kikas. Origin, Impact and Control of Lignocellulosic Inhibitors in Bioethanol Production—A Review. Energies 2020, 13, 4751 .

AMA Style

Nikki Sjulander, Timo Kikas. Origin, Impact and Control of Lignocellulosic Inhibitors in Bioethanol Production—A Review. Energies. 2020; 13 (18):4751.

Chicago/Turabian Style

Nikki Sjulander; Timo Kikas. 2020. "Origin, Impact and Control of Lignocellulosic Inhibitors in Bioethanol Production—A Review." Energies 13, no. 18: 4751.

Journal article
Published: 01 September 2020 in Environmental and Climate Technologies
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One of the possible choices as a biomass for lignocellulosic bioethanol production are different perennial grasses. Cultivating this type of biomass has many advantages in terms of natural diversity and landscape protection. In this study, mixture of red clover and timothy grass was used as a feedstock to investigate its potential as a substrate for bioethanol production. Traditional three step bioethanol production process was used in combination with NED pretreatment. The results show at all pretreatment temperatures similar glucose concentrations and hydrolysis efficiencies, which varied from 4.3 to 5.1 g/l and 15.2 % to 17.7 %, respectively. The ethanol yield, on the other hand, decreased as the pretreatment temperature increased. However, the mass balance revealed that when using this kind of feedstock, 3.3-4.0 g ethanol could be produced from 100 g of biomass. The overall efficiency and yield of the process was lower than expected due to pretreatment, which might not have been suitable for soft biomass.

ACS Style

Merlin Raud; Timo Kikas. Perennial Grasses as a Substrate for Bioethanol Production. Environmental and Climate Technologies 2020, 24, 32 -40.

AMA Style

Merlin Raud, Timo Kikas. Perennial Grasses as a Substrate for Bioethanol Production. Environmental and Climate Technologies. 2020; 24 (2):32-40.

Chicago/Turabian Style

Merlin Raud; Timo Kikas. 2020. "Perennial Grasses as a Substrate for Bioethanol Production." Environmental and Climate Technologies 24, no. 2: 32-40.

Journal article
Published: 16 April 2020 in Industrial Crops and Products
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Cellulosic biomass has been widely used as a feedstock for biofuel applications due to its low-cost, renewability and abundance. However, the production of liquid biofuels is still costly and inefficient mainly due to the recalcitrant structure of lignocellulosic biomass. It requires expensive pretreatment methods to break down the plant cell wall, and efficient enzymes capable of hydrolysing cellulose into glucose. One possible solution to make bioethanol production cost-effective and, at the same time, increase the energy output from the biomass is genetic engineering. Genetic modification has been reported as an effective strategy to increase productivity, biomass yields and specific traits of various agricultural plants. This paper provides an overview of the potential of cereal-based agricultural waste as a feedstock for bioethanol production. It focuses on the progress of different techniques used in genetic modification (transgenesis, cisgenesis mutagenesis and conventional breeding) to genetically engineer plant cell wall. Utilization of genetic modification of cereal plants is proposed as a solution to high costs and low yields of bioethanol production from cereal-based agricultural waste.

ACS Style

Lisandra Rocha-Meneses; Jorge A. Ferreira; Maryam Mushtaq; Sajjad Karimi; Kaja Orupõld; Timo Kikas. Genetic modification of cereal plants: A strategy to enhance bioethanol yields from agricultural waste. Industrial Crops and Products 2020, 150, 112408 .

AMA Style

Lisandra Rocha-Meneses, Jorge A. Ferreira, Maryam Mushtaq, Sajjad Karimi, Kaja Orupõld, Timo Kikas. Genetic modification of cereal plants: A strategy to enhance bioethanol yields from agricultural waste. Industrial Crops and Products. 2020; 150 ():112408.

Chicago/Turabian Style

Lisandra Rocha-Meneses; Jorge A. Ferreira; Maryam Mushtaq; Sajjad Karimi; Kaja Orupõld; Timo Kikas. 2020. "Genetic modification of cereal plants: A strategy to enhance bioethanol yields from agricultural waste." Industrial Crops and Products 150, no. : 112408.

Review article
Published: 07 January 2020 in Bioresource Technology
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Torrefaction is one of the pretreatment processes used to overcome the disadvantages of using biomass as a fuel such as low energy density, high moisture, and oxygen contents. The torrefaction increases energy density, hydrophobicity, and reduces grinding energy requirement of biomass. This paper provides a review of the recent advancements in the torrefaction process. The discussion will cover the environmental and economic aspects of the torrefaction process and torrefied pellets, and various applications of torrefaction products. The cost competitiveness of torrefied pellets is one of the major concern of the torrefaction process. Integrating the torrefaction with other processes makes it economically more viable than as a standalone process.

ACS Style

Margareta Novian Cahyanti; Tharaka Rama Krishna Chowdary Doddapaneni; Timo Kikas. Biomass torrefaction: An overview on process parameters, economic and environmental aspects and recent advancements. Bioresource Technology 2020, 301, 122737 .

AMA Style

Margareta Novian Cahyanti, Tharaka Rama Krishna Chowdary Doddapaneni, Timo Kikas. Biomass torrefaction: An overview on process parameters, economic and environmental aspects and recent advancements. Bioresource Technology. 2020; 301 ():122737.

Chicago/Turabian Style

Margareta Novian Cahyanti; Tharaka Rama Krishna Chowdary Doddapaneni; Timo Kikas. 2020. "Biomass torrefaction: An overview on process parameters, economic and environmental aspects and recent advancements." Bioresource Technology 301, no. : 122737.

Review
Published: 01 January 2020 in 2020 ASABE Annual International Virtual Meeting, July 13-15, 2020
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A challenge faced by the Red Meat Processing (RMP) industry in Australia is the quantity of by-products generated at the end of the production chain, which require careful treatment before they can be reutilized or released to the environment. The net result is the additional, and significant, costs to the production chain. However, opportunities for reutilization of such by-products have been identified, including: energy, water extraction, and nutrients. The conversion of bioresources, largely regarded as waste, into value-added by-products is potentially a significant source of income to the industry. This paper identifies and analyses by-products from an Australian RMP facility, and reviews closed-loop concepts for bioresource recovery in order to enhance the energy output and produce value-added by-products from the production chain. For this, a detailed analysis of the different technologies currently available in the market for product extraction was carried out. Recovery or reduction strategies for the production of value-add products and technology applications are proffered, which are applicable to the Australian RMP industry.

ACS Style

Lisandra Rocha Meneses; Peter Harris; Stephan Tait; Diogenes L. Antille; Timo Kikas; Bernadette K. McCabe. Bioresource recovery in the Australian red meat processing industry: a technical review of strategies for increased circularity. 2020 ASABE Annual International Virtual Meeting, July 13-15, 2020 2020, 1 .

AMA Style

Lisandra Rocha Meneses, Peter Harris, Stephan Tait, Diogenes L. Antille, Timo Kikas, Bernadette K. McCabe. Bioresource recovery in the Australian red meat processing industry: a technical review of strategies for increased circularity. 2020 ASABE Annual International Virtual Meeting, July 13-15, 2020. 2020; ():1.

Chicago/Turabian Style

Lisandra Rocha Meneses; Peter Harris; Stephan Tait; Diogenes L. Antille; Timo Kikas; Bernadette K. McCabe. 2020. "Bioresource recovery in the Australian red meat processing industry: a technical review of strategies for increased circularity." 2020 ASABE Annual International Virtual Meeting, July 13-15, 2020 , no. : 1.

Journal article
Published: 29 December 2019 in Sustainability
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This study investigates the potential of different stages of the bioethanol production process (pretreatment, hydrolysis, and distillation) for bioethanol and biomethane production, and studies the critical steps for the liquid and the solid fractions to be separated and discarded to improve the efficiency of the production chain. For this, Napier grass (a fast-growing grass) from Effurun town of Delta State in Nigeria was used and the novel pretreatment method, nitrogen explosive decompression (NED), was applied at different temperatures. The results show that the lowest glucose (13.7 g/L) and ethanol titers (8.4 g/L) were gained at 150 °C. The highest glucose recovery (31.3 g/L) was obtained at 200 °C and the maximum ethanol production (10.3 g/L) at 170 °C. Methane yields are higher in samples pretreated at lower temperatures. The maximum methane yields were reported in samples from the solid fraction of post-pretreatment (pretreated at 150 °C, 1.13 mol CH4/100 g) and solid fraction of the post-hydrolysis stage (pretreated at 150 °C, 1.00 mol CH4/100 g). The lowest biomethane production was noted in samples from the liquid fraction of post-pretreatment broth (between 0.14 mol CH4/100 g and 0.24 mol CH4/100 g). From the process point of view, samples from liquid fraction of post-pretreatment broth should be separated and discarded from the bioethanol production process, since they do not add value to the production chain. The results suggest that bioethanol and biomethane concentrations are influenced by the pretreatment temperature. Napier grass has potential for bioethanol and further biomethane production and it can be used as an alternative source of energy for the transportation sector in Nigeria and other countries rich in grasses and provide energy security to their population.

ACS Style

Lisandra Rocha-Meneses; Oghenetejiri Frances Otor; Nemailla Bonturi; Kaja Orupõld; Timo Kikas. Bioenergy Yields from Sequential Bioethanol and Biomethane Production: An Optimized Process Flow. Sustainability 2019, 12, 272 .

AMA Style

Lisandra Rocha-Meneses, Oghenetejiri Frances Otor, Nemailla Bonturi, Kaja Orupõld, Timo Kikas. Bioenergy Yields from Sequential Bioethanol and Biomethane Production: An Optimized Process Flow. Sustainability. 2019; 12 (1):272.

Chicago/Turabian Style

Lisandra Rocha-Meneses; Oghenetejiri Frances Otor; Nemailla Bonturi; Kaja Orupõld; Timo Kikas. 2019. "Bioenergy Yields from Sequential Bioethanol and Biomethane Production: An Optimized Process Flow." Sustainability 12, no. 1: 272.

Journal article
Published: 01 November 2019 in Environmental and Climate Technologies
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The aim of this study is to analyse from the thermodynamic, environmental and economic point of view an ORC for heat recovery from urban waste, using R245fa as a working fluid on the example of Terceira Island (Azores). The proposed ORC system includes two evaporators, two turbines, a condenser, a pump and a generator. The thermodynamic model is created using the Visual Basic programming language. In order to analyse the influence of pressure, temperature and mass flow on net output, efficiency, and mass flow rate of the power plant, the sensibility analysis is carried out. The results show that from the energetic point of view, urban waste recovery (using an ORC) could be a viable solution on Terceira Island, since the maximum net output produced from this system for a mass rate of 19 727 tonnes is 485 kW. The efficiency of the ORC is 25 %. Environmentally, the incineration of the urban waste produced on the island is a positive solution for these residues since it will reduce the amount of waste deposited in the landfill. However, this project is not economically viable. The losses estimated in this study exceed 500 000 EUR (per year).

ACS Style

Lisandra Rocha-Meneses; Jose Carlos Silva; Sandra Cota; Timo Kikas. Thermodynamic, Environmental and Economic Simulation of an Organic Rankine Cycle (ORC) for Waste Heat Recovery: Terceira Island Case Study. Environmental and Climate Technologies 2019, 23, 347 -365.

AMA Style

Lisandra Rocha-Meneses, Jose Carlos Silva, Sandra Cota, Timo Kikas. Thermodynamic, Environmental and Economic Simulation of an Organic Rankine Cycle (ORC) for Waste Heat Recovery: Terceira Island Case Study. Environmental and Climate Technologies. 2019; 23 (2):347-365.

Chicago/Turabian Style

Lisandra Rocha-Meneses; Jose Carlos Silva; Sandra Cota; Timo Kikas. 2019. "Thermodynamic, Environmental and Economic Simulation of an Organic Rankine Cycle (ORC) for Waste Heat Recovery: Terceira Island Case Study." Environmental and Climate Technologies 23, no. 2: 347-365.

Journal article
Published: 26 September 2019 in Energies
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The production of second-generation ethanol using lignocellulosic feedstock is crucial in order to be able to meet the increasing fuel demands by the transportation sector. However, the technology still needs to overcome several bottlenecks before feasible commercialization can be realized. These include, for example, the development of cost-effective and environmentally friendly pretreatment strategies and valorization of the sidestream that is obtained following ethanol distillation. This work uses two chemical-free pretreatment methods—nitrogen explosive decompression (NED) and synthetic flue gas explosive decompression—to investigate the potential of a bioethanol production sidestream in terms of further anaerobic digestion. For this purpose, samples from different stages of the bioethanol production process (pretreatment, hydrolysis, and fermentation) and the bioethanol sidestream went through a separation process (involving solid–liquid separation), following which a biomethane potential (BMP) assay was carried out. The results show that both factors being studied in this article (involving the pretreatment method and the separation process) served to influence methane yields. Liquid fractions that were obtained during the process with NED gave rise to methane yields that were 8% to 12% higher than when synthetic flue gas was used; fermented and distillation sidestream gave rise to the highest methane yields (0.53 and 0.58 mol CH4/100 g respectively). The methane yields from the liquid fractions were between 60–88% lower than those that were obtained from solid fractions. Samples from the bioethanol sidestream (solid fraction) that were pretreated with NED had the highest methane yield (1.7 mol CH4/100 g). A solid–liquid separation step can be a promising strategy when it comes to improving the energy output from lignocellulosic biomass and the management of the ethanol distillation sidestream.

ACS Style

Lisandra Rocha-Meneses; Jorge A Ferreira; Nemailla Bonturi; Kaja Orupõld; Timo Kikas. Enhancing Bioenergy Yields from Sequential Bioethanol and Biomethane Production by Means of Solid–Liquid Separation of the Substrates. Energies 2019, 12, 3683 .

AMA Style

Lisandra Rocha-Meneses, Jorge A Ferreira, Nemailla Bonturi, Kaja Orupõld, Timo Kikas. Enhancing Bioenergy Yields from Sequential Bioethanol and Biomethane Production by Means of Solid–Liquid Separation of the Substrates. Energies. 2019; 12 (19):3683.

Chicago/Turabian Style

Lisandra Rocha-Meneses; Jorge A Ferreira; Nemailla Bonturi; Kaja Orupõld; Timo Kikas. 2019. "Enhancing Bioenergy Yields from Sequential Bioethanol and Biomethane Production by Means of Solid–Liquid Separation of the Substrates." Energies 12, no. 19: 3683.

Journal article
Published: 15 May 2019 in Renewable and Sustainable Energy Reviews
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Since the Kyoto protocol, the EU renewable energy policy has been the driving force in research and development of the production and use of biofuels. Therefore, the utilization of biofuels and the scientific research to widen the scope of their commercialization are being increasingly promoted. In this context, we present here an overview of the technological developments that have occurred in the production of different biofuels and their resources with a focus on the lignocellulosic biomass and biofuels derived from it. In the recent years, many technologies have evolved enabling the production of different liquid biofuels from lignocellulosic biomass. Bioethanol production using microbial fermentation, and production of bio-oil using fast pyrolysis process of biomass are some of the most widely researched and promising technologies. The first production plants based on these techniques are already operational. Bioethanol production from lignocellulosic biomass promises a good fuel yield under laboratory scale. However, there are several challenges that need to be tackled before the production process can be commercialized. We provide here an overview of the various possibilities that can be exploited for biofuel production and make recommendations for increasing the production efficiency with a view to improving the overall yield and lowering the production costs.

ACS Style

M. Raud; Timo Kikas; O. Sippula; N.J. Shurpali. Potentials and challenges in lignocellulosic biofuel production technology. Renewable and Sustainable Energy Reviews 2019, 111, 44 -56.

AMA Style

M. Raud, Timo Kikas, O. Sippula, N.J. Shurpali. Potentials and challenges in lignocellulosic biofuel production technology. Renewable and Sustainable Energy Reviews. 2019; 111 ():44-56.

Chicago/Turabian Style

M. Raud; Timo Kikas; O. Sippula; N.J. Shurpali. 2019. "Potentials and challenges in lignocellulosic biofuel production technology." Renewable and Sustainable Energy Reviews 111, no. : 44-56.

Journal article
Published: 14 April 2019 in Energy
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When using the novel N2 explosive decompression pre-treatment, its effect was investigated in relation to the biomass structure and chemical processes during the treatment process. The results that were gained from this testing were compared to those for the widely-used steam explosion pre-treatment method in order to be able to present the advantages in using each method. Both methods are economically and environmentally attractive since only the pressure and water or steam are used to break down the biomass structure. Two pre-treatment methods were used at different temperatures and samples from various process steps were analysed. The results were used to assess the pre-treatment effect and the chemical changes in the biomass and, finally, mass balances were compiled for the bioethanol process at different process steps. The results show that the highest glucose and ethanol yields were obtained by means of the steam explosion pre-treatment method at a temperature of 200°C (24.29g and 12.72g for 100g of biomass respectively), and at 175°C (15.4g and 9.0g for 100g of biomass respectively). At lower temperatures the nitrogen explosion treatment produced better yields.

ACS Style

M. Raud; K. Krennhuber; A. Jäger; T. Kikas. Nitrogen explosive decompression pre-treatment: An alternative to steam explosion. Energy 2019, 177, 175 -182.

AMA Style

M. Raud, K. Krennhuber, A. Jäger, T. Kikas. Nitrogen explosive decompression pre-treatment: An alternative to steam explosion. Energy. 2019; 177 ():175-182.

Chicago/Turabian Style

M. Raud; K. Krennhuber; A. Jäger; T. Kikas. 2019. "Nitrogen explosive decompression pre-treatment: An alternative to steam explosion." Energy 177, no. : 175-182.

Data article
Published: 16 March 2019 in Data in Brief
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This data article ranks 294 countries worldwide with more potential available, of cereal based agricultural residues for bioenergy production. Nine different cereal-based agricultural waste products (barley, wheat, millet, oat, rice, and rye straw, sorghum straw/stalk, and maize cob) are used. The tables and figures are grouped by the most prevalent Köppen-Geiger climate classification (tropical/megathermal, dry (desert and semi-arid), temperate/mesothermal, continental/microthermal), continent and region. The data was collected by the authors from FAO bioenergy and food security rapid appraisal tool (excel-based tools) that uses crop yields and production with 10 years (2005–2014) average annual production to estimate the residue yield (t/ha), by feedstock.

ACS Style

Lisandra Rocha-Meneses; Thaísa Fernandes Bergamo; Timo Kikas. Potential of cereal-based agricultural residues available for bioenergy production. Data in Brief 2019, 23, 103829 .

AMA Style

Lisandra Rocha-Meneses, Thaísa Fernandes Bergamo, Timo Kikas. Potential of cereal-based agricultural residues available for bioenergy production. Data in Brief. 2019; 23 ():103829.

Chicago/Turabian Style

Lisandra Rocha-Meneses; Thaísa Fernandes Bergamo; Timo Kikas. 2019. "Potential of cereal-based agricultural residues available for bioenergy production." Data in Brief 23, no. : 103829.

Journal article
Published: 13 February 2019 in Energy
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Lignocellulosic biomass is emerging as an important feedstock for biofuel production. Bioethanol is one of the most common liquid biofuels in the transportation sector. However, its production process is still inefficient due to the large quantity of production waste that is left unused after the distillation process. In this paper, the biomethane potential of bioethanol production waste is analysed. The results are compared with the biomethane potential of samples from different stages of the bioethanol production process (pretreatment, hydrolysis and fermentation), and that of untreated biomass. In this study, barley straw is used as a biomass crop and N2 explosive decompression (NED) is applied as a pretreatment method. The results show that bioethanol production waste has higher methane yields (1.17 mol CH4/100 g) than raw barley straw (1.04 mol CH4/100 g). Production waste also has a higher degradation rate (0.252) than untreated material (0.138), and achieves 95% of the maximum methane yield much faster (7.8 days) than untreated samples (22 days). This shows that production waste can be used for further anaerobic digestion (AD) to add value to the bioethanol production chain. NED pretreatment is an effective method of pretreatment.

ACS Style

Lisandra Rocha-Meneses; Merlin Raud; Kaja Orupõld; Timo Kikas. Potential of bioethanol production waste for methane recovery. Energy 2019, 173, 133 -139.

AMA Style

Lisandra Rocha-Meneses, Merlin Raud, Kaja Orupõld, Timo Kikas. Potential of bioethanol production waste for methane recovery. Energy. 2019; 173 ():133-139.

Chicago/Turabian Style

Lisandra Rocha-Meneses; Merlin Raud; Kaja Orupõld; Timo Kikas. 2019. "Potential of bioethanol production waste for methane recovery." Energy 173, no. : 133-139.

Journal article
Published: 28 October 2018 in Industrial Crops and Products
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Lignocellulosic biomass is an attractive feedstock for the production of liquid (eg. biofuel) or gaseous (eg. methane) fuels for the transportation sector. The bioethanol production process still produces a large quantity of production waste following the distillation process. Stillage consists mostly of lignin, hemicellulose, extractives, and yeast and therefore does not have any commercial value. The conversion of bioethanol production waste into gaseous biofuels like biogas or biomethane is a promising solution when it comes to transforming stillage into value-added products, enhancing the value of the biomass, and as a strategy for achieving zero-waste societies. This study aims to investigate the potential of bioethanol production waste for biomethane production. The results are compared with samples from different stages of the bioethanol production process. Milled barley straw (Hordeum vulgare) was used as a feedstock to produce energy in the form of methane, and the flue gas pre-treatment method (with and without bubbling) was applied. The results show that the methane production yield of bioethanol production waste, which has been pretreated with flue gas without bubbling is 5% higher than that of untreated substrate, and can achieve 94% of the methane production of fermented samples. Bioethanol production waste from substrates, which have been pretreated with flue gas with bubbling have a methane production level that is 29% higher than that of untreated materials. The results suggest that methane yields are influenced by the bubbling process. It is reasonable to use bioethanol production waste for the production of energy in the form of methane and to increase the energy output from the biomass.

ACS Style

Lisandra Rocha-Meneses; Anastasia Ivanova; Guilherme Atouguia; Isaac Ávila; Merlin Raud; Kaja Orupõld; Timo Kikas. The effect of flue gas explosive decompression pretreatment on methane recovery from bioethanol production waste. Industrial Crops and Products 2018, 127, 66 -72.

AMA Style

Lisandra Rocha-Meneses, Anastasia Ivanova, Guilherme Atouguia, Isaac Ávila, Merlin Raud, Kaja Orupõld, Timo Kikas. The effect of flue gas explosive decompression pretreatment on methane recovery from bioethanol production waste. Industrial Crops and Products. 2018; 127 ():66-72.

Chicago/Turabian Style

Lisandra Rocha-Meneses; Anastasia Ivanova; Guilherme Atouguia; Isaac Ávila; Merlin Raud; Kaja Orupõld; Timo Kikas. 2018. "The effect of flue gas explosive decompression pretreatment on methane recovery from bioethanol production waste." Industrial Crops and Products 127, no. : 66-72.