High Efficiency Conversion of Lignocellulosics to Sugars for Liquid Fuel Production by the ACOS Process

1988 ◽  
Vol 6 (1) ◽  
pp. 39-60 ◽  
Author(s):  
Laszlo Paszner ◽  
H.J. Cho
Keyword(s):  
Corn Stover ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Ethanol Yield ◽  
Reaction Medium ◽  
Weak Acid ◽  
Liquid Fuels ◽  
Total Biomass ◽  
Oil Reserves ◽  
Biomass Dissolution

Decline of world oil reserves and pollution problems from burning of fossil fuels and lead require that methods for safe alternate liquid fuels be developed. Ethanol is one of the most important alternate liquid fuels since it can be produced readily by fermentation of sugars. Wood and vegetable growth are excellent sources of sugars to support an ethanol fuel economy of significant proportions. Acid Catalysed Organosolv Saccharification (ACOS) is a new means for total biomass dissolution and recover of component sugars and lignin from wood. The process uses an acidified aqueous acetone solution for the high-temperature hydrolysis of biomass. Acetone provides an excellent reaction medium for dissolution of both sugars and lignins and through a transient derivatization of the sugars protects them from further reaction (dehydration) to furfurals and humic substances. Therefore, sugar and lignin recoveries are quantitative. The ACOS process is 700 times faster than the conventional weak acid hydrolysis processes and wood can be dissolved in 30 sec by this process. The lignin is recovered as a low molecular weight powder by-product. This process is applicable to both coniferous and deciduous woods and agricultural residues such as corn stover, straw and bagasse. In case of such residues the ethanol yield can be doubled (straw and corn stover) or tripled (bagasse) compared to what has been obtained from the grain and sugarcane juice so far. Hitherto these residues were merely discarded or burned.

Moving ahead from Hydrogen to Methanol Economy: Scope and challenges

2021 ◽  
Author(s):  
Ankit Sonthalia ◽  
Naveen Kumar ◽  
Mukul Tomar ◽  
Edwin Geo V ◽  
Thiyagarajan S ◽  
...  
Keyword(s):  
Developing Countries ◽  
Crude Oil ◽  
Rural Areas ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Energy Resource ◽  
Liquid Fuels ◽  
Gasoline Engines ◽  
Oil Reserves ◽  
Methanol Economy

Abstract Energy is the driver in the economic development of any country. It is expected that the developing countries like India will account for 25% hike in world-wide energy demand by 2040 due to the increase in the per capita income and rapid industrialization. Most of the developing countries do not have sufficient oil reserves and imports nearly all of their crude oil requirement. The perturbations in the crude oil price, sanctions on Iran and adverse environmental impacts from fossil fuel usage are some of the concern. Therefore, developing countries have started investing heavily in solar and wind power and are considering hydrogen as a future energy resource. Hydrogen is possibly the cleanest fuel and produces only water vapour upon combustion. However, to tap the potential of hydrogen as a fuel, an entirely new infrastructure will be needed for transporting, storing and dispensing it safely, which would be expensive. In the transportation sector, a liquid alternate to fossil fuels will be highly desirable as the existing infrastructure can be used with minor modifications. Amongst the possible liquid fuels, methanol is very promising. Methanol is a single carbon atom compound and can be produced from wide variety of sources such as natural gas, coal, and biomass. The properties of methanol are conducive for use in gasoline engines since it has high octane number and flame speed. Other possible uses of methanol are: as a cooking fuel in rural areas, and as a fuel for running the fuel cells. The present study reviews the limitations in the hydrogen economy and why moving towards methanol economy is more beneficial.

scholarly journals Large Scale Hydrogen Production From Nuclear Energy Using High Temperature Electrolysis

2010 ◽  
Author(s):  
James E. O’Brien
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Oil Sands ◽  
Large Scale ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Liquid Fuels ◽  
Low Grade ◽  
Transportation Fuel ◽  
High Temperature Electrolysis

Hydrogen can be produced from water splitting with relatively high efficiency using high-temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high-temperature process heat. When coupled to an advanced high temperature nuclear reactor, the overall thermal-to-hydrogen efficiency for high-temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. Demand for hydrogen is increasing rapidly for refining of increasingly low-grade petroleum resources, such as the Athabasca oil sands and for ammonia-based fertilizer production. Large quantities of hydrogen are also required for carbon-efficient conversion of biomass to liquid fuels. With supplemental nuclear hydrogen, almost all of the carbon in the biomass can be converted to liquid fuels in a nearly carbon-neutral fashion. Ultimately, hydrogen may be employed as a direct transportation fuel in a “hydrogen economy.” The large quantity of hydrogen that would be required for this concept should be produced without consuming fossil fuels or emitting greenhouse gases. An overview of the high-temperature electrolysis technology will be presented, including basic theory, modeling, and experimental activities. Modeling activities include both computational fluid dynamics and large-scale systems analysis. We have also demonstrated high-temperature electrolysis in our laboratory at the 15 kW scale, achieving a hydrogen production rate in excess of 5500 L/hr.

scholarly journals Conversion of biomass to biofuels and life cycle assessment: a review

2021 ◽  
Author(s):  
Ahmed I. Osman ◽  
Neha Mehta ◽  
Ahmed M. Elgarahy ◽  
Amer Al-Hinai ◽  
Ala’a H. Al-Muhtaseb ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Biomass Conversion ◽  
Biofuel Production ◽  
Process Efficiency ◽  
Liquid Fuels ◽  
Thermochemical Processes ◽  
Lower Temperature

AbstractThe global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.

scholarly journals Direct Carbon Fuel Cell-Cleaner and Efficient Future Power Generation Technology

2019 ◽  
Vol 6 (1) ◽  
pp. 14-30
Author(s):  
Uzair Ibrahim ◽  
Ahsan Ayub
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cell ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Thermal Power ◽  
Gaseous State ◽  
Thermal Plant ◽  
Direct Carbon Fuel Cell ◽  
Pure Carbon ◽  
Pure Carbon Dioxide

Increasing greenhouse effect due to the burning of fossil fuels has stirred the attention of researchers towards cleaner and efficient technologies. Direct carbon fuel cell (DCFC) is one such emerging technology that could generate electricity from solid carbon like coal and biogas in a more efficient and environmental-friendly way. The mechanism involves electrochemical oxidation of carbon to produce energy and highly pure carbon dioxide. Due to higher purity, the produced carbon dioxide can be captured easily to avoid its release in the environment. The carbon dioxide is produced in a gaseous state while the fuel used is in a solid state. Due to different phases, all of the fuel can be recovered from the cell and can be reused, ensuring complete (100%) fuel utilization with no fuel losses. Moreover, DCFC operates at a temperature lower than conventional fuel cells. The electric efficiency of a DCFC is around 80% which is nearly double the efficiency of coal thermal plant. In addition, DCFC produces pure carbon dioxide as compared to the thermal power plant which reduces the cost of CO2 separation and dumping. In different types of DCFCs, molten carbon fuel cell is considered to be superior due to its low operating temperature and high efficiency. This paper provides a comprehensive review of the direct carbon fuel cell technology and recent advances in this field. The paper is focused on the fundamentals of fuel cell, history, operating principle, its types, applications, future challenges, and development.

Expression of serpins by Clostridium thermocellum and simultaneous saccharification of lignocellulosic biomass to enhance ethanol production

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8662-8676
Author(s):  
Maria Mushtaq ◽  
Muhammad Javaid Asad ◽  
Muhammad Zeeshan Hyder ◽  
Syed Muhammad Saqlan Naqvi ◽  
Saad Imran Malik ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Wheat Straw ◽  
Corn Stover ◽  
Rice Straw ◽  
Clostridium Thermocellum ◽  
Ethanol Yield ◽  
Biofuel Production ◽  
Yeast Fermentation ◽  
Second Generation Bioethanol ◽  
Simultaneous Saccharification

Utilization of biomass for production of second generation bioethanol was considered as a way to reduce burdens of fossil fuel in Pakistan. The materials wheat straw, rice straw, cotton stalk, corn stover, and peel wastes were used in this experiment. Various parameters, such as acidic and alkali pretreatment, enzymatic hydrolysis by cellulases, and effect of proteases inhibitors on ethanol production, were examined. Fermentation was completed by the yeasts Saccharomyces cerevisiae and Clostridium thermocellum separately, and their ethanol production were compared and maximum ethanol yield was obtained with wheat straw i.e.,11.3 g/L by S. cerevisiae and 8.5 g/L by C. thermocellum. Results indicated that a higher quantity of sugar was obtained from wheat straw (19.6 ± 1.6 g/L) followed by rice straw (17.6 ± 0.6 g/L) and corn stover (16.1 ± 0.9 g/L) compared to the other evaluated biomass samples. A higher yield of ethanol (11.3 g/L) was observed when a glucose concentration of 21.7 g/L was used, for which yeast fermentation efficiency was 92%. Results also revealed the increased in ethanol production (93%) by using celluases in combination with recombinant Serine protease inhibitors from C. thermocellum. It is expected that the use of recombinant serpins with cellulases will play a major role in the biofuel production by using agricultural biomass. This will also help in the economics of the biofuel.

Graphite Electrodes for Hydrogen Production by Acid Electrolysis

2020 ◽  
Vol 1012 ◽  
pp. 158-163
Author(s):  
Oliveira Marilei de Fátima ◽  
Mazur Viviane Teleginski ◽  
Virtuozo Fernanda ◽  
Junior Valter Anzolin de Souza
Keyword(s):  
Hydrogen Production ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Low Cost ◽  
Electric Energy ◽  
Gas Production ◽  
Hydrogen Fuel Cells ◽  
Graphite Electrodes ◽  
Alkaline Electrolysis ◽  
Selection Of

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.

scholarly journals EXERGY-BASED INVESTIGATION OF A COAL-FIRED ALLAM CYCLE

2019 ◽  
Vol 137 ◽  
pp. 01018 ◽  
Author(s):  
Jing Luo ◽  
Ogechi Emelogu ◽  
Tatiana Morosuk ◽  
George Tsatsaronis
Keyword(s):  
Fossil Fuels ◽  
Coal Gasification ◽  
High Efficiency ◽  
Cycle Performance ◽  
Energetic Efficiency ◽  
Component Level ◽  
Lower Efficiency ◽  
Heating Value ◽  
Lower Heating Value ◽  
Lower Heating

Allam cycle is a novel cycle that capitalizes on the unique thermodynamic properties of supercritical CO2 and the advantages of oxy-combustion for power generation. It is a high-pressure supercritical carbon dioxide cycle designed to combust fossil fuels such as natural gas or syngas (from coal gasification systems) with complete CO2 separation at a high-efficiency and zero atmospheric emissions. This semi-closed cycle produces sequestration-ready/pipeline quality CO2 by-product, and thus eliminates the need for additional CO2-capture system. The Coal-fueled Allam cycle is targeted to deliver between 51-52% net efficiency (lower heating value) for coal gasification. In this study, the expected energetic efficiency is verified by simulating the system in Ebsilon professional software and the result showed that the net efficiency of the simulated coal-fired plant is 30.7%, which is significantly lower than the targeted value. The lower efficiency maybe as a result of the missing heat integration in the system, the high power demand of the oxidant compressor and CO2 compressors. And an exergy analysis based on published cycle data is employed, to investigate the cycle performance, identify the sources of the cycle’s thermodynamic inefficiencies at the component level; a sensitivity analysis is also performed to study the effects of selected thermodynamic parameters on the overall performance of the coal-fired Allam cycle.

Fuel Ethanol Production from Wet Oxidised Corn Stover by S. Cerevisiae

2011 ◽  
Vol 343-344 ◽  
pp. 963-967 ◽  
Author(s):  
Zhang Qiang ◽  
Anne Belinda Thomsen
Keyword(s):  
Ethanol Production ◽  
Corn Stover ◽  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Liquid Fraction ◽  
Raw Material ◽  
Wet Oxidation ◽  
Inhibition Effect ◽  
Simultaneous Saccharification

In order to find out appropriate process for ethanol production from corn stover, wet oxidation（195°C，15 minutes）and simultaneous saccharification and fermentation (SSF) was carried out to produce ethanol. The results showed that the cellulose recovery of 92.9% and the hemicellulose recovery of 74.6% were obtained after pretreatment. 86.5% of cellulose was remained in the solid cake . After 24h hydrolysis at 50°C using cellulase（Cellubrix L）,the achieved conversion of cellulose to glucose was 64.8%. Ethanol production was evaluated from dried solid cake and the hydrolysate was employed as liquid fraction . After 142 h of SSF with substrate concentration of 8% (W/V), ethanol yield of 73.1 % of the theoretical based on glucose in the raw material was obtained by S. cerevisiae(ordinary baker’ yeast) . The corresponding ethanol concentration and volumetric productivity were 17.2g/L and 0.121g/L.h respectively. The estimated total ethanol production was 257.7 kg/ton raw material by assuming consumption of both C-6 and C-5. No obvious inhibition effect occurred during SSF. These instructions give you the basic guidelines for preparing papers for WCICA/IEEE conference proceedings.

scholarly journals Catalysts for Emerging Energy Applications

MRS Bulletin ◽  
2008 ◽  
Vol 33 (4) ◽  
pp. 429-435 ◽  
Author(s):  
Bruce C. Gates ◽  
George W. Huber ◽  
Christopher L. Marshall ◽  
Phillip N. Ross ◽  
Jeffrey Siirola ◽  
...  
Keyword(s):  
Natural Gas ◽  
Metal Oxides ◽  
Chemical Transformation ◽  
Fossil Fuels ◽  
Biomass Conversion ◽  
Liquid Fuels ◽  
Porous Solids ◽  
Metal Sulfides ◽  
Energy Applications ◽  
Starting Point

AbstractCatalysis is the essential technology for chemical transformation, including production of fuels from the fossil resources petroleum, natural gas, and coal. Typical catalysts for these conversions are robust porous solids incorporating metals, metal oxides, and/or metal sulfides. As efforts are stepping up to replace fossil fuels with biomass, new catalysts for the conversion of the components of biomass will be needed. Although the catalysts for biomass conversion might be substantially different from those used in the conversion of fossil feedstocks, the latter catalysts are a starting point in today's research. Major challenges lie ahead in the discovery of efficient biomass conversion catalysts, as well as in the discovery of catalysts for conversion of CO2 and possibly water into liquid fuels.

Solar Upgrading of Fuels for Generation of Electricity

2001 ◽  
Vol 123 (2) ◽  
pp. 160-163 ◽  
Author(s):  
Rainer Tamme ◽  
Reiner Buck ◽  
Michael Epstein ◽  
Uriyel Fisher ◽  
Chemi Sugarmen
Keyword(s):  
Gas Turbines ◽  
Large Scale ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Combined Cycle ◽  
Test Facility ◽  
Small Scale ◽  
Start Up ◽  
Efficiency Conversion ◽  
Solar Field

This paper presents a novel process comprising solar upgrading of hydrocarbons by steam reforming in solar specific receiver-reactors and utilizing the upgraded, hydrogen-rich fuel in high efficiency conversion systems, such as gas turbines or fuel cells. In comparison to conventionally heated processes about 30% of fuel can be saved with respect to the same specific output. Such processes can be used in small scale as a stand-alone system for off-grid markets as well as in large scale to be operated in connection with conventional combined-cycle plants. The complete reforming process will be demonstrated in the SOLASYS project, supported by the European Commission in the JOULE/THERMIE framework. The project has been started in June 1998. The SOLASYS plant is designed for 300 kWel output, it consists of the solar field, the solar reformer and a gas turbine, adjusted to operate with the reformed gas. The SOLASYS plant will be operated at the experimental solar test facility of the Weizmann Institute of Science in Israel. Start-up of the pilot plant is scheduled in April 2001. The midterm goal is to replace fossil fuels by renewable or non-conventional feedstock in order to increase the share of renewable energy and to establish processes with only minor or no CO2 emission. Examples might be upgrading of bio-gas from municipal solid waste as well as upgrading of weak gas resources.

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