Acid and Alkali Pre-treatment Effects on CO2 Assisted Gasification of Pine Wood

2021 ◽  
pp. 1-20
Author(s):  
Jinhu Li ◽  
Kiran Raj Goud Burra ◽  
Zhiwei Wang ◽  
Xuan Liu ◽  
Ashwani K. Gupta

Abstract Biomass gasification in CO2 is a promising thermochemical pathway to help assist with growing issues of CO2 in the environment. However, high reaction temperature requirement and low reaction rate is limiting its development. To resolve these issues, the effect of acid and alkali pre-treatment on the pyrolysis and CO2-gasification of pine wood was examined using a semi-batch reactor. The temporal behavior of syngas components, energy, and their yield, and energy efficiency was quantified. Results showed that while acid pretreatment of biomass with lower alkali and alkaline earth metals (AAEMs) content was beneficial for the CO and syngas yield, the alkali pretreatment with higher AAEM content showed the opposite trend. In contrast, the CO2 assisted gasification of alkali pretreated biomass improved the CO and syngas yield due to catalytic influence of AAEM on the Boudouard reaction, while the acid washed biomass yielded the lowest syngas yield. During gasification, the syngas yield, energy yield and overall energy efficiency were enhanced by 83.44 %, 44.64 % and 44.58 %, respectively using alkali treatment. The results revealed that alkali pre-treatment is an effective catalytic incorporation pathway to improve the syngas, energy output, and reactivity to CO2 gasification.

Energetika ◽  
2018 ◽  
Vol 64 (2) ◽  
Author(s):  
Oleksandra V. Tryboi

The purpose of the paper is to identify the most energy efficient value chains using solid biomass of specially grown energy crops and the most significant parameters affecting their energy efficiency and environmental sustainability. The methodology of Life Cycle Assessment (LCA) was used to determine the energy efficiency of value chains of heat production from energy crops. According to the methodology, the scope of the product system includes the raw material cycle of growing energy crops and the subsystem of transformation with production of thermal energy. Cumulative energy demand and energy yield coefficient were chosen as energy efficiency indicators. The product system was compared with a similar one using natural gas. The non-renewable energy yield coefficient was used to define how many times the energy output was bigger than the input of non-renewable energy. Assessment was conducted for two energy crops: Miscanthus as a typical representative of specially grown grassy energy crops and willow as a typical representative of specially grown woody energy crops. The growing of energy crops in Ukraine for the subsequent production of biofuel in the form of chips and their combustion in biofuel boilers are energetically effective with a maximum transportation distance of 400 km for Miscanthus chips and 180 km for willow chips.


2018 ◽  
Vol 40 (2) ◽  
pp. 56-64
Author(s):  
O.V. Tryboi

The results of the life cycle assessment of heat production from willow chips of Salix Viminalis L. are presented. Energy efficiency and greenhouse gas emissions reduction are estimated. The influence of the most significant parameters is analyzed and optimal relationships are determined to ensure maximum energy efficiency and environmental sustainability. The purpose of the paper is to define the energy efficiency and environmental sustainability of bioenergy value chain for heat production from willow chips of Salix Viminalis in Ukraine. The methodology of Life Cycle Assessment (LCA) was used, according to which, the scope of the product system includes the feedstock cycle of willow Salix Viminalis L. cultivation and harvest, and the subsystem of willow chips conversion to heat in a 500 kW biomass boiler. Cumulative energy demand and energy yield coefficient were chosen as energy efficiency indicators. The product system was compared with the similar one using natural gas. Non- renewable energy yield coefficient was used to define how many times the energy output was bigger than input of non- renewable energy. An acceptable value for renewable energy installations and systems is to receive twice as much energy output as was spent of non-renewable energy, however the recommended value assumed in the work is to receive a 5 times more energy output compared to non-renewable energy input. As an environmental sustainability indicator, a reduction of GHG emissions was used. The acceptable level of GHG emissions reduction was chosen at a level of 60% for the whole life cycle from cultivation-to-heat, compared to traditional heat production in gas boilers. Results of the assessment identified that the most significant parameter affecting energy efficiency and environmental sustainability is transportation distance. The growing of willow Salix Viminalis L. in Ukraine for the subsequent production of biofuel in the form of chips and its combustion in biofuel boilers is environmentally sustainable with a maximum transportation distance of 390 km and energy efficient with a maximum transportation distance of 180 km.


2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Jinhu Li ◽  
Kiran G. Burra ◽  
Zhiwei Wang ◽  
Xuan Liu ◽  
Somrat Kerdsuwan ◽  
...  

Abstract Discarded cigarette butts contain polymers, biomass, and a variety of toxins that cause an adverse effect to the human health and environment for years. The cigarette residuals are not recyclable and often get mixed with other kinds of wastes so that much of this waste ends up in landfills. This study investigates the safe disposal of cigarette butts by the thermochemical pathways using pyrolysis and gasification. Mass loss during its thermal decomposition was examined first using a thermogravimetric analyzer. The effect of temperature on the pyrolysis and CO2-assisted gasification was then conducted using a semi-batch reactor with a focus on the flowrate of total syngas and its gas components. Syngas yield, energy recovery, as well as energy efficiency were calculated and compared. The effect of temperature on the CO2 consumption during the gasification process was also examined. The thermal decomposition of cellulose acetate, tar, and wrapping paper were the main contributors during the pyrolysis of cigarette butt. However, the gasification process mainly consisted of the pyrolysis, cracking, and reforming reactions in the gas phase and gasification of char derived from wrapping paper. An increase in temperature enhanced the syngas flowrate, syngas yield, and gas efficiency while decreasing the char yield and reaction time for both the processes. Energy recovery from gasification was higher than pyrolysis due to added CO generation. The maximum syngas energy of 13.0 kJ/g under the gasification condition at 1223 K was 67.2% higher as compared with the pyrolysis. High temperature strongly affected the gasification reaction, while it was negligible at a temperature lower than 1023 K. Complete conversion occurred during gasification at 1223 K that provided only ash residue. The CO2 gasification of cigarette butts provided an effective pathway to utilize 0.5 g CO2/g feedstock at 1223 K to form valuable CO by the Boudouard reaction. Compared with the gasification of other solid wastes, syngas energy yield from cigarette butts was found to be higher than syngas from polystyrene and polyethylene terephthalate. These results support the effectiveness of thermochemical pathways in the rapid conversion of cigarette butts to valuable syngas along with CO2 utilization.


Author(s):  
V. Bereka ◽  
◽  
I. Kondratenko ◽  

The analysis of the known results of processing model aqueous solutions with different types of electric discharge using the AOT technology is carried out. Comparison of the processing efficiency for the decomposition of model pollutants for energy yield criterion (Y), as well as the prospects for further industrial implementation of the technology for the criterion of expected productivity, is carried out. The factors that influence the value of energy output and energy efficiency, in general, are determined. Ref. 17, fig. 2, tables 2.


2014 ◽  
Vol 915-916 ◽  
pp. 871-874 ◽  
Author(s):  
Xian Ping Zeng ◽  
Jin Fa Liu

In this paper, the hemp / cotton / polyester mesh knitted fabric (Han / C / T) is treated by alkali treatment, conventional dyeing and alkali pre-treatment dyeing. We have obtained the conclusion that alkali treatment improves the dyeing effect. Alkali pre-treatment dyeing was done after alkali treatment. The fabric dyeing effect is improved obviously. The optimum process come from orthogonal experiment (dyes 2.5% owf, Na2SO4 :30g/L, Na2CO3:10g/L, liquor ratio (1:50) and 90°C×50 min). Through this optimum process, dyeing effect for hemp / cotton / polyester mesh knitted fabric is close to the pure cotton fabric dyeing effect.


Author(s):  
К.Н. Привалова ◽  
Р.Р. Каримов

Исследования по определению энергетической эффективности пастбищных систем со злаковыми и бобово-злаковыми травостоями проведены в Федеральном научном центре кормопроизводства и агроэкологии им. В. Р. Вильямса. В статье приведены результаты агроэнергетической оценки многовариантных пастбищных систем со злаковыми травостоями, созданными в 1946 году. Даны количественные показатели по сбору обменной энергии, совокупным затратам на её производство, окупаемости затрат в зависимости от системы ведения пастбищ. Изучена эффективность совокупных затрат в виде овеществлённого труда (на семена, удобрения, сельскохозяйственные машины, средства огораживания загонов и прочее) и живого труда (работы трактористов, пастухов и строителей и др.). Обоснована высокая агроэнергетическая эффективность изучаемых пастбищных систем благодаря мобилизации в продукционный процесс природных факторов, долевое участие которых в структуре производства обменной энергии составило 69–84%. Природные факторы, участвующие в продукционном процессе луговых агроэкосистем, характеризуются большим разнообразием. Это не только использование солнечной энергии и азотфиксация бобовыми травами, но и долголетие травостоев, самовозобновление фитоценозов, дерновообразовательный процесс (повышение плодородия почвы), получение дешёвого корма и улучшение здоровья животных при летнем выпасе. Роль возобновляемых природных факторов выявлена на основе балансового метода, принятого в экономике (по разнице сбора обменной энергии и антропогенных затрат). Благодаря ведущей роли природных факторов в структуре произведённой продукции агроэнергетический коэффициент окупаемости совокупных затрат антропогенной энергии (АК) за счёт сбора обменной энергии достигал 3–6 раз в среднем за 45 лет. Разработанные в результате долголетних исследований многовариантные энергосберегающие пастбищные системы обосновывают возможность рекомендовать их производству с учётом применения различного уровня энергозатрат. Ключевые слова: культурные пастбища, системы ведения, долголетние травостои, сбор обменной энергии, совокупные антропогенные затраты, окупаемость затрат. The investigation was conducted at the Federal Williams Research Center of Fodder Production and Agroecology and was aimed at testing energy efficiency of gramineous and legume-gramineous swards. This article presents the results obtained on pasture ecosystems with gramineous planted in 1946. Exchange energy yield, total production costs and economic effectiveness were analyzed. Total production costs comprised costs for seeds, fertilizers, machinery, construction materials, labor, etc. Introduction of natural factors into the production process resulted in higher energy efficiency. Their share amounted to 69–84% in the final exchange energy yield. There are a lot of natural factors that affect grass productivity such as solar energy, nitrogen-fixation, sward longevity and regeneration, soil fertility, low-cost feed production, and livestock health. The value of natural factors was determined according to the balance method (by the difference between exchange energy yield and anthropogenic costs). Since environmental factors had a leading role in the production process, the return rate raised by 3–6 times for 45 years due to exchange energy increase. Therefore, pasture ecosystems developed can be recommended for a large-scale forage production.


2015 ◽  
Vol 46 (2) ◽  
pp. 62
Author(s):  
Remo Alessio Malagnino

Electric production from renewable resources, such as solar photovoltaic (PV), is playing an increasingly essential role in the agricultural industry because of the progressive increase in the energy price from fossil fuels and the simultaneous decrease in the income deriving from farming activities. A central issue in the sustainable diffusion of PV technologies is represented by the actual energy efficiency of a PV system. For these reasons, a performance analysis has been carried out in order to assess the potentials offered by different PV plants within a defined geographical context with the aim of investigating the impact of each component has on the PV generator global efficiency and defining the main technical parameters that allow to maximise the annual specific electric energy yield of an architectonically integrated plant, installed in a dairy house, compared to a ground-mounted plant. The annual performances of three grid connected PV plants installed in the same dairy cattle farm have been analysed: two are architectonically integrated plants - <em>i.e.</em>, a rooftop unidirectional and a multi-field systems (both 99 kW<sub>p</sub>) - and the other is a ground-mounted plant (480 kW<sub>p</sub>). Furthermore, the electrical performances, estimated by the photovoltaic geographical information system (PVGIS), developed by the EU Joint Research Centre, and by an analytical estimation procedure (AEP), developed on the basis of a meteo-climatic database related to the records of the nearest weather station and integrated by the components’ technical specifications, have been compared with the actual yields. The best annual performance has been given by the ground-mounted PV system, with an actual increase of 26% and in the range of 6÷12% according to different estimations, compared to the integrated systems, which were globally less efficient (average total loss of 26÷27% compared to 24% of the ground-mounted system). The AEP and PVGIS software estimates showed a good level of reliability for mean deviations between the annual actual and estimated electrical power yields have been equal to 11.5% for each PV system given the actual irradiation’ s uncertainty during the examined year. The main technical parameters, crucial to maximise the energy yield from a ground-mounted PV system to an integrated one, have been identified in the Tilt and Azimuth angles. Indeed, once a variance of 3÷4% in the global efficiency has been confirmed when the type of PV system is changed, in the case of the unidirectional integrated PV plant, the high roof pitch and the almost South orientation guarantee a solar energy increase up to 18% higher than that obtainable on the horizontal plane and similar to the increase estimated for the ground-mounted generator (+20%). Hence, integrated PV systems, besides reaching the same levels of energy efficiency as those ground-mounted, are also more <em>sustainable</em> than the latter. This is true providing that there are both a suitable orientation and an accurate design, especially to prevent the PV panels’ warming during summer, on an already available surface that is, however, functional to the roof’s architecture.


2021 ◽  
Vol 67 (No. 5) ◽  
pp. 45-52
Author(s):  
Gerhard Moitzi ◽  
Reinhard W. Neugschwandtner ◽  
Hans-Peter Kaul ◽  
Helmut Wagentristl

Sustainable crop production requires an efficient usage of fossil energy. This six-year study on a silt loam soil (chernozem) analysed the energy efficiency of four tillage systems (mouldboard plough 25–30 cm, deep conservation tillage 35 cm, shallow conservation tillage 8–10 cm, no-tillage). Fuel consumption, total energy input (made up of both direct and indirect input), grain of maize yield, energy output, net-energy output, energy intensity and energy use efficiency were considered. The input rates of fertiliser, herbicides and seeds were set constant; measured values of fuel consumption were used for all tillage operations. Total fuel consumption for maize (Zea mays L.) production was 81.6, 81.5, 69.5 and 53.2 L/ha for the four tillage systems. Between 60% and 64% of the total energy input (17.0–17.4 GJ/ha) was indirect energy (seeds, fertiliser, herbicides, machinery). The share of fertiliser energy of the total energy input was 36% on average across all tillage treatments. Grain drying was the second highest energy consumer with about 22%. Grain yield and energy output were mainly determined by the year. The tillage effect on yield and energy efficiency was smaller than the growing year effect. Over all six years, maize produced in the no-tillage system reached the highest energy efficiency.  


2015 ◽  
Vol 9 (7) ◽  
pp. 99 ◽  
Author(s):  
Nyoman Puspa Asri ◽  
Diah Agustina Puspita Sari

Synthesis of biodiesel is a strategic step in overcoming energy scarcity and the environmental degradationcaused by the continuous use of the petroleum based energy. Biodiesel as an alternative fuel for diesel engine isproduced from renewable resources such as vegetable oils and animal fats. The main obstacle in the biodieselproduction is the high price of the raw materials, resulting in the price of biodiesel is not competitive comparedto the petroleum diesel. Therefore, the use of waste frying oils (WFO) is one way to reduce the cost of biodieselproduction, because of its availability and low price. In the present work, WFO from California Fried chicken(CFC) restaurants in Surabaya were used as feed stock for the biodiesel production. The experiments wereconducted using three steps of processes: pre-treatment of WFO, preparation of alumina based compositecatalyst CaO/KI/γ-Al2O3 and transesterification of treated WFO. WFO was treated by several types and variousamounts of activated adsobents. The treated WFO was transesterified in three neck glass batch reactor withrefluxed methanol using CaO/KI/γ-Al2O3. The results reveal that the best method for treating WFO is using 7.5%(wt. % to WFO) of coconut coir. Alumina based composite catalyst CaO/KI/γ-Al2O3 was very promising fortransesterification of WFO into biodiesel. The yield of biodiesel was 83% and obtained at 65ºC, 5 h of reactiontime, 1:18 of molar ratio WFO to methanol and 6% amount of catalyst.


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