Bioethanol production from pineapple peels waste by heat treatment and enzyme hydrolysis: An eco-friendly and economical method

2021 ◽  
Vol 16 (12) ◽  
pp. 64-71
Author(s):  
Jambulingam Kiruthika ◽  
A. Sathya ◽  
T. Sharvika

Bioethanol is a renewable energy source with reduced CO2 emission and a better alternate for fossil fuels. The production of bioethanol using low cost agricultural wastes such as fruits waste always remains a better solution for the present environmental and energy problems. The present study focusses on the production of bioethanol from pineapple peel wastes by simultaneous scarification and fermentation process in a completely eco-friendly manner and economical manner. The fruit wastes are rich sources of sugars and can be utilized for the production of second generation fuel. Initially, cellulase producing potent bacterial isolate was isolated from soil sample collected from fruit market (Uzhavar Santhai), R.S. Puram, Coimbatore district, Tamilnadu, India. Further, the bacterial isolate was identified by 16S rDNA sequencing and the sequence was submitted in GenBank with the accession number MW227436. The phylogenetic tree was constructed and the bacterial isolate was identified as Bacillus cereus strain JK79. Pineapple peel waste was processed, heat pretreated and was utilized for enzymatic saccharification with crude cellulase enzyme to hydrolyze cellulose into simple sugars. The enzyme hydrolyzed content was allowed to undergo fermentation simultaneously (Simultaneous saccharification and fermentation) utilizing Saccharomyces cerevisiae to produce bioethanol. The yield of bioethanol was determined by potassium dichromate method. About 10.07 g/l of bioethanol was obtained by fermenting the enzymatically hydrolyzed pineapple peel waste using Saccharomyces cerevisiae. The production of bioethanol was confirmed by GC-MS.

Author(s):  
Numchok Manmai ◽  
Yuwalee Unpaprom ◽  
Ramaeshprabu Ramaraj ◽  
Keng-Tung Wu

The use of fossil fuels, as well as the environmental issues associated with their burning, has pushed for the development of clean, renewable energy sources. Biofuels made from lignocellulosic biomass are considered a carbon-neutral and sustainable method. As the demand for non-petroleum fuels grows, more attention will be placed on developing a cost-competitive liquid transportation biofuel like ethanol. This study was conducted to produce bioethanol utilizing the SHF (separate hydrolysis and fermentation) technique from corn stove lignocellulose. Pretreatment with sodium hydroxide at various concentrations was also studied. The influence of enzymatic saccharification, fermentation time, and substrate concentration on sugar yield and, eventually, ethanol production was investigated. Fermentation was carried out by using the enzymatically saccharified hydrolysate and monoculture of Saccharomyces cerevisiae. The results reveal that pretreatment with 2% NaOH followed by 48 hours of hydrolysis produced the maximum bioethanol production (30.21 ±0.13 g/L). This study findings indicated that alkali-pretreated corn stove might be used as a feedstock for bioethanol production, reducing reliance on fossil fuels.


2020 ◽  
Vol 21 (13) ◽  
pp. 1304-1315
Author(s):  
Junmei Zhou ◽  
Lianghong Yin ◽  
Chenbin Wu ◽  
Sijia Wu ◽  
Jidong Lu ◽  
...  

Objective: Alkaline Carboxymethyl Cellulase (CMCase) is an attractive enzyme for the textile, laundry, pulp, and paper industries; however, commercial preparations with sufficient activity at alkaline conditions are scarce. Methods: High CMCase-producing bacterial isolate, SX9-4, was screened out from soil bacteria, which was identified as Flavobacterium sp. on the basis of 16S rDNA sequencing. Results: The optimum pH and temperature for CMCase reaction were 8.0 and 55°C, respectively. Alkaline CMCase was stable over wide pH (3.0-10.6) and temperature (25-55°C) ranges. Enzyme activity was significantly inhibited by the bivalent cations Mn2+ and Cu2+, and was activated by Fe2+. To improve the alkaline CMCase production of SX9-4, fermentation parameters were selected through onefactor- at-a-time and further carried out by response surface methodologies based on a central composite design. Conclusion: High CMCase production (57.18 U/mL) was achieved under the optimal conditions: 10.53 g/L carboxymethylcellulose sodium, 7.74 g/L glucose, 13.71 g/L peptone, and 5.27 g/L ammonium oxalate.


2010 ◽  
Vol 64 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Zlatica Predojevic

The use of renewable energy sources (biofuels), either as a component in the conventional fossil fuels, gasoline and diesel, or as a pure biofuel, contributes to energy saving and decrease of total CO2 emission. The use of bioethanol mixed with gasoline significantly decreases gasoline consumption and contributes to environment protection. One of the problems in the production of bioethanol is the availability of sugar and starch based feedstock used for its production. However, lignocellulosic feedstocks are becoming more significant in the production of bioethanol due to their availability and low cost. The aim of this study is to point out the advantages and shortcomings of pretreatment processes and hydrolyses of lignocellulosic feedstocks that precede their fermentation to bioethanol.


2021 ◽  
Vol 850 (1) ◽  
pp. 012008
Author(s):  
N Rajamurugu

Abstract Renewable energy sources become suitable valid options to reduce the dependency on fossil fuels or petroleum products. The International Renewable Energy Agency reports that the world will harvest 40% of energy from renewable energy sources by 2030. Conventional technologies such as solar PV technology, consumes higher capital per unit (kWh) of electricity generation cost significantly higher than the traditional sources. Hence, solar chimney power generation system can be suitable option for generating low cost energy. Solar chimneys are developed and tested by different researchers in enhancing the performance of the system. Studies on the geometric modifications of the collector, and chimney are limited. The aim of this paper is to analyse the experimental data obtained from a divergent solar chimney. Experimentation is carried under sunlight in an open atmosphere. The airflow rates in the chimneys are tested under different collector outlet height. The experimental results showed that a chimney with higher collector openings was performed well than other models. The computational analysis is also carried out using ANSYS Fluent software package which shows that the collector opening of 2.5m is recommended for higher high mass flow rate and system efficiency.


2011 ◽  
Vol 148-149 ◽  
pp. 97-100
Author(s):  
Xu Gang Wang ◽  
Guang Qi Cao ◽  
Zhi Guang Guan ◽  
Zu Yu Zhao

Wind power is an important direction of new energy, which has no pollution, no consuming fossil fuels, and no producing waste, which is widely used at this stage of clean energy. The small stand alone wind power has been paid more and more attention due to its low cost, flexible installation, strong adaptability. This paper introduces the mechanical and electrical structure, which are used in KW level stand alone mode wind turbine automatically track and yaw system. The motion rules and control strategies of the tracking and yaw system are discussed and then the control program flow is provided. The PIC16F873 chip is used as controller for this part in this system. It can fully meet the design requirements, which will reduce costs and increase the system's control ability. This system can automatically track and yaw, according to the wind direction and wind power.


The renewable energy generation initiatives contain a low-cost viable option for the electric consumer worldwide. The efficient methodologies of wind, solar, ocean current, and geothermal power generation are attractive alternatives to fossil fuels. Based on the current condition of the infrastructure, most of the proposed wind energy projects require transmission line upgrades. In some regional impact studies, the existing transmission system may have sufficient capability to handle the power from the planned renewable generating sources. Nevertheless, integrating large amounts of wind power (even small amounts in some areas) will require some form of infrastructure upgrades.


2020 ◽  
Vol 1012 ◽  
pp. 158-163
Author(s):  
Oliveira Marilei de Fátima ◽  
Mazur Viviane Teleginski ◽  
Virtuozo Fernanda ◽  
Junior Valter Anzolin de Souza

Nowadays, humanity has become aware of the consequences that the use of fossil fuels entails, and the latest developments in the energy sector are leading to a diversification of energy resources. In this context, researching on alternative forms of producing electric energy is being conducted. At the transportation level, a possible solution for this matter may lie in hydrogen fuel cells. The electrolysis of water is one of the possible processes for hydrogen production, but the reaction to break the water molecule requires a great amount of energy and this is precisely the biggest issue involving this process. In this work, low cost electrodes of 254 stainless steel and electrolytic graphite were used for hydrogen production, allowing high efficiency and reduced oxidation during the process. The selection of these materials allows to obtain a high corrosion resistance electrolytic pair, by replacing the high cost platinum electrode usually employed in the alkaline electrolysis process. The formic acid of biomass origin was used as an electrolyte. It was observed that the developed reactor have no energy losses through heat and it was possible to obtain approximately 82% conversion efficiency in the gas production process.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3559 ◽  
Author(s):  
Alfredo Oliva-Taravilla ◽  
Cristhian Carrasco ◽  
Leif J. Jönsson ◽  
Carlos Martín

The enzymatic hydrolysis of cellulose is inhibited by non-productive adsorption of cellulases to lignin, and that is particularly problematic with lignin-rich materials such as softwood. Although conventional surfactants alleviate non-productive adsorption, using biosurfactants in softwood hydrolysis has not been reported. In this study, the effects of four biosurfactants, namely horse-chestnut escin, Pseudomonas aeruginosa rhamnolipid, and saponins from red and white quinoa varieties, on the enzymatic saccharification of steam-pretreated spruce were investigated. The used biosurfactants improved hydrolysis, and the best-performing one was escin, which led to cellulose conversions above 90%, decreased by around two-thirds lignin inhibition of Avicel hydrolysis, and improved hydrolysis of pretreated spruce by 24%. Red quinoa saponins (RQS) addition resulted in cellulose conversions above 80%, which was around 16% higher than without biosurfactants, and it was more effective than adding rhamnolipid or white quinoa saponins. Cellulose conversion improved with the increase in RQS addition up to 6 g/100 g biomass, but no significant changes were observed above that dosage. Although saponins are known to inhibit yeast growth, no inhibition of Saccharomyces cerevisiae fermentation of hydrolysates produced with RQS addition was detected. This study shows the potential of biosurfactants for enhancing the enzymatic hydrolysis of steam-pretreated softwood.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Hossein Alishah Aratboni ◽  
Nahid Rafiei ◽  
Raul Garcia-Granados ◽  
Abbas Alemzadeh ◽  
José Rubén Morones-Ramírez

Abstract The use of fossil fuels has been strongly related to critical problems currently affecting society, such as: global warming, global greenhouse effects and pollution. These problems have affected the homeostasis of living organisms worldwide at an alarming rate. Due to this, it is imperative to look for alternatives to the use of fossil fuels and one of the relevant substitutes are biofuels. There are different types of biofuels (categories and generations) that have been previously explored, but recently, the use of microalgae has been strongly considered for the production of biofuels since they present a series of advantages over other biofuel production sources: (a) they don’t need arable land to grow and therefore do not compete with food crops (like biofuels produced from corn, sugar cane and other plants) and; (b) they exhibit rapid biomass production containing high oil contents, at least 15 to 20 times higher than land based oleaginous crops. Hence, these unicellular photosynthetic microorganisms have received great attention from researches to use them in the large-scale production of biofuels. However, one disadvantage of using microalgae is the high economic cost due to the low-yields of lipid content in the microalgae biomass. Thus, development of different methods to enhance microalgae biomass, as well as lipid content in the microalgae cells, would lead to the development of a sustainable low-cost process to produce biofuels. Within the last 10 years, many studies have reported different methods and strategies to induce lipid production to obtain higher lipid accumulation in the biomass of microalgae cells; however, there is not a comprehensive review in the literature that highlights, compares and discusses these strategies. Here, we review these strategies which include modulating light intensity in cultures, controlling and varying CO2 levels and temperature, inducing nutrient starvation in the culture, the implementation of stress by incorporating heavy metal or inducing a high salinity condition, and the use of metabolic and genetic engineering techniques coupled with nanotechnology.


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