The Efficiency of Nitrogen and Flue Gas as Operating Gases in Explosive Decompression Pretreatment

As the pretreatment process is the most expensive and energy-consuming step in the overall second generation bioethanol production process, it is vital that it is studied and optimized in order to be able to develop the most efficient production process. The aim of this paper was to investigate chemical and physical changes in biomass during the process of applying the explosive decompression pretreatment method using two different gases—N2 and synthetic flue gas. The explosive decompression method is economically and environmentally attractive since no chemicals are used—rather it is pressure that is applied—and water is used to break down the biomass structure. Both pre-treatment methods were used at different temperatures. To be able to compare the effects of the pretreatment, samples from different process steps were gathered together and analysed. The results were used to assess the efficiency of the pretreatment, the chemical and physical changes in the biomass and, finally, the mass balances were compiled for the process during the different process steps of bioethanol production. The results showed that both pre-treatment methods are effective in hemicellulose dissolution, while the cellulose content decreases to a smaller degree. The high glucose and ethanol yields were gained with both explosive pretreatment methods at 175 °C (15.2–16.0 g glucose and 5.6–9.0 g ethanol per 100 g of dry biomass, respectively).

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A Review of Potential of Lignocellulosic Biomass for Bioethanol Production in Kenya

Asian Journal of Chemical Sciences ◽

10.9734/ajocs/2020/v8i219039 ◽

2020 ◽

pp. 34-54

Author(s):

John Odhiambo Otieno ◽

Fredrick Onyango Ogutu

Keyword(s):

Lignocellulosic Biomass ◽

Treatment Process ◽

Efficient Production ◽

Bioethanol Production ◽

Major Drawback ◽

Major Barrier ◽

Treatment Methods ◽

Advantages And Disadvantages ◽

Research Technology ◽

Pre Treatment

Lignocellulosic biomass is the earth’s most abundant and renewable resource, and, lignin is its strongest component. The lignocellulosic biomass has a potential to produce bioethanol for both domestic and industrial use. The presence of lignin in the biomass, however, hinders the processing and production of bioethanol from the biomass. Hence, to enhance the chances of bioethanol production from the lignocellulosic biomass, lignin has to be pre-treated. The pre-treatment process efficiently separates the interlinked complex components. During the pre-treatment process, the strong lignin component that is highly resistant and a major barrier to solubilization is broken down by hydrolysis of cellulose and hemicellulose. Pre-treatment of lignocellulosic biomass is therefore, necessary to make it more susceptible to microorganisms, enzymes, and pathogens. The initial pre-treatment approaches include physical, physicochemical, and biological methods. The major drawback of this pre-treatment process is its cost implications, as it’s very costly. Studies suggest that even though it’s a costly affair, the pre-treatment methods, however, have a significant impact on the efficient production of ethanol from biomass. Situation Analysis: Bioethanol production from lignocellulosic biomass has mostly been undertaken in Brazil, USA, China, and India. In Kenya, however, little research on bioethanol production from lignocellulosic biomass has been done and adopted. The present review paper seeks to outlay the benefits of bioethanol production from lignocellulosic biomass, the composition of lignocellulosic biomass, its properties, different pre-treatment methods alongside advantages, and, disadvantages, and challenges encountered during bioethanol production. This review eventually will be of great assistance to researchers while developing bioethanol from different lignocellulosic biomass. Research, technology adaption/adaptation, and policy targeted at growing bioethanol industry, could enable Kenya to grow her bioethanol industry.

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Study of wheat straw delignification in a rotary-pulsation apparatus

Acta periodica technologica ◽

10.2298/apt2051103s ◽

2020 ◽

pp. 103-110

Author(s):

Larysa Sablii ◽

Oleksandr Obodovych ◽

Vitalii Sydorenko ◽

Tamila Sheyko

Keyword(s):

Wheat Straw ◽

Production Technology ◽

Raw Materials ◽

Hydrolytic Enzymes ◽

Bioethanol Production ◽

Second Generation Bioethanol ◽

Pulsation Apparatus ◽

Rotary Pulsation Apparatus ◽

Solid Water ◽

Pre Treatment

This paper presents the results of studies of isolation lignin and hemicelluloses efficiency during the pre-treatment of wheat straw for hydrolysis in a rotary-pulsation apparatus. The pre-treatment of lignocellulosic raw materials for hydrolysis is a necessary step in the second-generation bioethanol production technology. The lignocellulose complex is destroyed during this process, and this allows hydrolytic enzymes access to the surface of cellulose fibers. The pre-treatment is the most energy-consuming stage in bioethanol production technology, since it usually occurs at high temperature and pressure for a significant time. One of the ways to improve the efficiency of this process is the use of energy-efficient equipment that allows intensifying heat and mass transfer. An example of such equipment is a rotary-pulsation apparatus, which are effective devices in stirring, homogenization, dispersion technologies, etc. The treatment of wheat straw in a rotary-pulsation apparatus was carried out under atmospheric pressure without external heat supply at solid/water ratios of 1:10 and 1:5 in the presence of alkali. It was determined that the treatment of the water dispersion of straw at ratio of 1:10 due to the energy dissipation during 70 minutes leads to the release of 42 % of lignin and 25.76 % of easily hydrolyzed polysaccharides. Changing the solid / water ratio from 1:10 to 1:5 leads to an increase in the yield of lignin and easily hydrolyzed polysaccharides to 58 and 33.38 %, respectively.

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Bioethanol Production from UK Seaweeds: Investigating Variable Pre-treatment and Enzyme Hydrolysis Parameters

BioEnergy Research ◽

10.1007/s12155-019-10054-1 ◽

2019 ◽

Vol 13 (1) ◽

pp. 271-285 ◽

Cited By ~ 4

Author(s):

Emily T. Kostas ◽

Daniel A. White ◽

David J. Cook

Keyword(s):

Large Scale ◽

Method Development ◽

Reaction Times ◽

Enzyme Hydrolysis ◽

Bioethanol Production ◽

Laminaria Digitata ◽

Treatment Conditions ◽

Water Based ◽

Ethanol Yields ◽

Pre Treatment

Abstract This study describes the method development for bioethanol production from three species of seaweed. Laminaria digitata, Ulva lactuca and for the first time Dilsea carnosa were used as representatives of brown, green and red species of seaweed, respectively. Acid thermo-chemical and entirely aqueous (water) based pre-treatments were evaluated, using a range of sulphuric acid concentrations (0.125–2.5 M) and solids loading contents (5–25 % [w/v]; biomass: reactant) and different reaction times (5–30 min), with the aim of maximising the release of glucose following enzyme hydrolysis. A pre-treatment step for each of the three seaweeds was required and pre-treatment conditions were found to be specific to each seaweed species. Dilsea carnosa and U. lactuca were more suited with an aqueous (water-based) pre-treatment (yielding 125.0 and 360.0 mg of glucose/g of pre-treated seaweed, respectively), yet interestingly non pre-treated D. carnosa yielded 106.4 g g−1 glucose. Laminaria digitata required a dilute acid thermo-chemical pre-treatment in order to liberate maximal glucose yields (218.9 mg glucose/g pre-treated seaweed). Fermentations with S. cerevisiae NCYC2592 of the generated hydrolysates gave ethanol yields of 5.4 g L−1, 7.8 g L−1 and 3.2 g L−1 from D. carnosa, U. lactuca and L. digitata, respectively. This study highlighted that entirely aqueous based pre-treatments are effective for seaweed biomass, yet bioethanol production alone may not make such bio-processes economically viable at large scale.

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Biomass Pre-treatment Methods and Their Economic Viability for Efficient Production of Biofuel

British Biotechnology Journal ◽

10.9734/bbj/2015/18284 ◽

2015 ◽

Vol 8 (2) ◽

pp. 1-17 ◽

Cited By ~ 5

Author(s):

Shivani Bhagwat ◽

Supriya Ratnaparkhe ◽

Anil Kumar

Keyword(s):

Economic Viability ◽

Efficient Production ◽

Treatment Methods ◽

Pre Treatment

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Second generation bioethanol production process via catalyzed steam explosion pretreatment: A computer-aided exergy analysis and heat integration

Indian Journal of Science and Technology ◽

10.17485/ijst/2018/v11i18/122511 ◽

2018 ◽

Vol 11 (18) ◽

pp. 1-7

Author(s):

K. Ojeda-Delgado ◽

�. D. Gonz�lez-Delgado ◽

E. S�nchez-Tuir�n ◽

◽

...

Keyword(s):

Production Process ◽

Steam Explosion ◽

Second Generation ◽

Exergy Analysis ◽

Heat Integration ◽

Bioethanol Production ◽

Second Generation Bioethanol ◽

Steam Explosion Pretreatment ◽

Computer Aided

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Enhanced pretreatment, characterization and utilization of Prosopis juliflora stem for bioethanol production

Management of Environmental Quality An International Journal ◽

10.1108/meq-04-2015-0071 ◽

2016 ◽

Vol 27 (5) ◽

pp. 598-605

Author(s):

S. Sivarathnakumar ◽

G. Baskar ◽

R. Praveen Kumar ◽

B. Bharathiraja

Keyword(s):

Nitric Acid ◽

Alkali Treatment ◽

Prosopis Juliflora ◽

Raw Material ◽

Cellulose Content ◽

Bioethanol Production ◽

Content Type ◽

Pre Treatment ◽

Alkali Hydrolysis ◽

Acid And Alkali Treatment

Purpose –Prosopis juliflora is a raw material for long-term sustainable production of bioethanol. The purpose of this paper is to identify the best combination of pre-treatment strategy implemented on the lignocellulosic biomass Prosopis juliflora for bioethanol production. Design/methodology/approach – Pre-treatment of lignocellulosic material was carried out using acid, alkali and sonication in order to characterize the biomass for bioethanol production. Prosopis juliflora stem was subjected to steam at reduce temperature (121°C) for one hour residence time initially. Further acid and alkali treatment was carried out individually followed by combinations of acid and sonication, alkali and sonication. Sodium hydroxide, potassium hydroxide, hydrochloric acid, sulphuric acid and nitric acid were used with 3 per cent (w/v) and 3 per cent (v/v) concentration under temperature range of 60-90°C for 60 min incubation time. Sonication under 60°C for 5 min and 40 KHz frequency was carried out. Pre-treated sample were further characterised using field emission scanning electron microscope and Fourier transform infrared spectroscopy to understand the changes in surface morphology and functional characteristics. Findings – In sono assisted acid treatment-based method, nitric acid yields better cellulose content at 70°C and removes lignin that even at increased temperatures no burning was observed. Originality/value – The paper adds to the scarce research available on the combination of auto hydrolysis coupled with sono assisted acid/alkali hydrolysis which is yet to be practiced.

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