Steam Biomass Gasification - Effect of Temperature

2016 ◽  
Vol 832 ◽  
pp. 49-54 ◽  
Author(s):  
Marek Baláš ◽  
Martin Lisý ◽  
Jiří Pospíšil
Keyword(s):  
Negative Impact ◽  
Common Knowledge ◽  
Calorific Value ◽  
Biomass Gasification ◽  
Transformation Process ◽  
Effect Of Temperature ◽  
Producer Gas ◽  
Gaseous Fuels ◽  
Gasification Process ◽  
The Impact

Gasification is one of the technologies for utilization of biomass. Gasification is a transformation process that converts solid fuels into gaseous fuels. The gaseous fuel may be subsequently applied in other technologies with all the benefits that gaseous fuels provide. The principle of biomass gasification is a common knowledge. It is thermochemical decomposition oof the fuel in presence of gasification agent. Heat from the endothermic reaction is obtained by a partial combustion of the fuel (autothermal gasification) or the heat is supplied into a gasifier from the outside (allothermal gasification). Oxygen for the partial combustion is supplied in the gasification medium. Quality, composition and amount of the producer gas depend on many factors which include type of the gasifier, operating temperature and pressure, fuel properties (moisture content) and type and amount of gasification medium. Commonly, air, steam and oxygen and their combinations are used as a gasification medium. Every kind of gasification agents has its significant advantages and disadvantages.Research and analysis of the gasification process must pay special attention to all operating parameters which affect quality and amount of the producer gas that is the efficiency of the conversion itself. Composition of the producer gas, calorific value, and content and composition of impurities are especially observed as these are the basic characteristics directly affecting subsequent application of the gas. Steam addition has a significant impact on gas composition. Steam decomposition into hydrogen and oxygen, and their subsequent reactions increases amount of combustibles, hydrogen, methane and other hydrocarbons. Steam addition in the gasification also affects amount and composition of tar and has a negative impact on heat balance.Energy Institute at the Brno University of Technology has a long tradition in research of biomass gasification in atmospheric fluidized bed reactors. Air was used as a gasification medium. This paper describes our experience with gasification using a mixture of air and steam. We analysed the whole process and in this paper we wish to describe the impact of temperature on outputs of the process, especially temperature of leaving steam and temperature of gasification reactions.

scholarly journals Torrefaction of Agricultural Residues: Effect of Temperature and Residence Time on the Process Products Properties

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Katarzyna Jagodzińska ◽  
Michał Czerep ◽  
Edyta Kudlek ◽  
Mateusz Wnukowski ◽  
Marek Pronobis ◽  
...  
Keyword(s):  
High Performance ◽  
Calorific Value ◽  
Barley Straw ◽  
Effect Of Temperature ◽  
Gas Chromatography Mass Spectrometry ◽  
Toxicity Tests ◽  
Main Compound ◽  
Flame Ionization ◽  
Polycyclic Aromatic ◽  
The Impact

Abstract To date, few studies on the potential utilization of agricultural residue torrefaction products have been performed. Thus, torrefaction product characterization aimed at its potential utilization was performed. Wheat–barley straw pellets and wheat–rye chaff were used in the study. The impact of the torrefaction temperature (280–320 °C) on polycyclic aromatic hydrocarbons (PAHs) content in the biochar and noncondensable gas (noncondensables) composition was investigated. The impact of the torrefaction time (30–75 min) on the composition of the condensable volatiles (condensables) and their toxicity were also studied. The torrefaction process was performed in a batch-scale reactor. The PAH contents were measured using high-performance liquid chromatography (HPLC), and the noncondensables composition was measured online using a gas analyzer and then gas chromatograph with flame ionization detector (GC-FID). The condensables composition and main compound quantification were determined and quantified using gas chromatography–mass spectrometry (GC/MS). Three toxicity tests, for saltwater bacteria (Microtox® bioassay), freshwater crustaceans (Daphtoxkit F magna®), and vascular plants (Lemna sp. growth inhibition test), were performed for the condensables. The PAHs content in the biochar, regardless of the torrefaction temperature, allows them to be used in agriculture. The produced torgas shall be co-combusted with full-caloric fuel because of its low calorific value. Toxic compounds (furans and phenols) were identified in the condensable samples, and regardless of the processing time, the condensables were classified as highly toxic. Therefore, they can be used either as pesticides or as an anaerobic digestion substrate after their detoxification.

Trust, Ethnicity and Integrity in East Africa: Experimental Evidence from Kenya and Tanzania

2017 ◽  
Vol 2 (1) ◽  
pp. 88-123 ◽  
Author(s):  
Dominic Burbidge ◽  
Nic Cheeseman
Keyword(s):  
Ethnic Diversity ◽  
Negative Impact ◽  
Common Knowledge ◽  
Individual Level ◽  
Trust Games ◽  
Negative Effect ◽  
Experimental Games ◽  
The Individual ◽  
The Impact ◽  
First Time

AbstractPolitical economy comparisons of Kenya and Tanzania have often found the political salience of ethnicity to be far higher in the former than the latter, with a negative impact on intercommunal trust. This difference has tended to be explained on the basis of the different kinds of leadership that the two countries experienced after independence. However, these findings have typically been demonstrated using aggregate or survey data. This paper assesses the salience of ethnicity at the individual level for the first time, deploying monetized two-round trust games in urban Kenya and Tanzania. The experimental games isolate the comparative impact of common knowledge of ethnicity and integrity among a quasi-random selection of 486 citizens. Verifying previous findings, we observe higher levels of trust and trustworthiness in Tanzania as compared with Kenya. Further, in comparison with Kenya, any shared knowledge of ethnic identities in Tanzania leads players to transfer fewer resources, while common knowledge that both players are “honest” led to higher transfers there than in Kenya. These results provide robust evidence of higher levels of trust in Tanzania, and of the negative effect in that country of common knowledge of ethnicity on levels of cooperation. The findings demonstrate the way in which political context can shape the impact of ethnic diversity, and encourage further experimental research that looks at the intersubjective dynamics of social cooperation.

scholarly journals A Comprehensive Literature Review of Thermochemical Conversion of Biomass for Syngas Production and Associated Challenge

2019 ◽  
Vol 38 (2) ◽  
pp. 495-512
Author(s):  
Ghulamullah Maitlo ◽  
Rasool Bux Mahar ◽  
Zulfiqar Ali Bhatti ◽  
Imran Nazir
Keyword(s):  
Fossil Fuels ◽  
Fixed Bed ◽  
Biomass Gasification ◽  
Gaseous Product ◽  
Gas Production ◽  
Thermochemical Conversion ◽  
Producer Gas ◽  
Syngas Production ◽  
Gasification Process

The interest in the thermochemical conversion of biomass for producer gas production since last decade has increased because of the growing attention to the application of sustainable energy resources. Application of biomass resources is a valid alternative to fossil fuels as it is a renewable energy source. The valuable gaseous product obtained through thermochemical conversion of organic material is syngas, whereas the solid product obtained is char. This review deals with the state of the art of biomass gasification technologies and the quality of syngas gathered through the application of different gasifiers along with the effect of different operating parameters on the quality of producer gas. Main steps in gasification process including drying, oxidation, pyrolysis and reduction effects on syngas production and quality are presented in this review. An overview of various types of gasifiers used in lignocellulosic biomass gasification processes, fixed bed and fluidized bed and entrained flow gasifiers are discussed. The effects of various process parameters such as particle size, steam and biomass ratio, equivalence ratio, effects of temperature, pressure and gasifying agents are discussed. Depending on the priorities of several researchers, the optimum value of different anticipated productivities in the gasification process comprising better quality syngas production improved lower heating value, higher syngas production, improved cold gas efficiency, carbon conversion efficiency, production of char and tar have been reviewed.

Experimental Study on Continuous Gasification Characteristics and Mechanism of Pine with Air/Steam

2011 ◽  
Vol 145 ◽  
pp. 199-203
Author(s):  
Jing Yu Ran ◽  
Chai Zuo Li ◽  
Li Zhang
Keyword(s):  
Experimental Study ◽  
Kinetic Parameters ◽  
Experimental Studies ◽  
Calorific Value ◽  
Biomass Gasification ◽  
Gas Production ◽  
Action Mechanism ◽  
Furnace Temperature ◽  
Equivalent Ratio ◽  
Gasification Process

Biomass gasification is influenced by many factors, such as temperature, air equivalent ratio, steam/carbon mole ratio, etc. Mostly, these factors are affected each other during the gasification process. It is needed to study the gasification characteristics and the action mechanism of each factor. Firstly, a moving gasification bed is adopted to investigate the biomass gasification characteristics and mechanism in this paper. The pine sample is evenly distributed in a long tray and be sent into the furnace at a certain speed. At the same time, with a furnace temperature, linearly increasing from the entrance to the center of the furnace, the pine sample can be gradually heated up. Based on these, the experimental studies of pine gasification on different ER (air equivalent ratio), S/C (steam /carbon mole ratio) and the temperature T are carried through in this paper. The gas production rule and low calorific value of the syngas have been gotten with heating rate 25°C/min. At last, this paper gets the kinetic parameters of air gasification with different ER. Keywords: Continuous Gasification, Characteristics and mechanism, Pine, Experimental

scholarly journals Optimizing the impact of temperature on bio-hydrogen production from food waste and its derivatives under no pH control using statistical modelling

2015 ◽  
Vol 12 (21) ◽  
pp. 6503-6514 ◽  
Author(s):  
C. Arslan ◽  
A. Sattar ◽  
C. Ji ◽  
S. Sattar ◽  
K. Yousaf ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Hydrogen Production ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Negative Impact ◽  
Glucose Consumption ◽  
Statistical Modelling ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
The Impact

Abstract. The effect of temperature on bio-hydrogen production by co-digestion of sewerage sludge with food waste and its two derivatives, i.e. noodle waste and rice waste, was investigated by statistical modelling. Experimental results showed that increasing temperature from mesophilic (37 °C) to thermophilic (55 °C) was an effective mean for increasing bio-hydrogen production from food waste and noodle waste, but it caused a negative impact on bio-hydrogen production from rice waste. The maximum cumulative bio-hydrogen production of 650 mL was obtained from noodle waste under thermophilic temperature condition. Most of the production was observed during the first 48 h of incubation, which continued until 72 h of incubation. The decline in pH during this interval was 4.3 and 4.4 from a starting value of 7 under mesophilic and thermophilic conditions, respectively. Most of the glucose consumption was also observed during 72 h of incubation and the maximum consumption was observed during the first 24 h, which was the same duration where the maximum pH drop occurred. The maximum hydrogen yields of 82.47 mL VS−1, 131.38 mL COD−1, and 44.90 mL glucose−1 were obtained from thermophilic food waste, thermophilic noodle waste and mesophilic rice waste, respectively. The production of volatile fatty acids increased with an increase in time and temperature in food waste and noodle waste reactors whereas they decreased with temperature in rice waste reactors. The statistical modelling returned good results with high values of coefficient of determination (R2) for each waste type and 3-D response surface plots developed by using models developed. These plots developed a better understanding regarding the impact of temperature and incubation time on bio-hydrogen production trend, glucose consumption during incubation and volatile fatty acids production.

scholarly journals Pemanfaatan gasifikasi batubara untuk unit pengeringan teh

2018 ◽  
Vol 5 (2) ◽  
pp. 443
Author(s):  
Ari Susandy Sanjaya ◽  
S Suhartono ◽  
Herri Susanto
Keyword(s):  
Coal Gasification ◽  
Fixed Bed ◽  
Calorific Value ◽  
Diesel Oil ◽  
Fuel Oil ◽  
Dual Fuel ◽  
Processing Unit ◽  
Producer Gas ◽  
Downdraft Gasifier ◽  
Gasification Process

Coal gasification utilization for tea drying unit. Anticipating the rise of fuel oil, the management of a tea plantation and drying plant has considered to substitute its oil consumption with producer gas (gaseous fuel obtained from gasification process). A tea drying unit normally consumes 70 L/h of industrial diesel oil and is operated 10 hours per day. The gasification unit consisted of a down draft fixed bed gasifier (designed capacity of about 100 kg/h), gas cooling and cleaning systems. The gas producer was delivered to the tea processing unit and burned to heat the drying oil: Low calorific value coal (4500 kcal/kg) and wood waste (4000 kcal/kg) have been used as fuel. The gasification unit could be operated as long as 8 hours without refueled since the coal hopper on the toppart of gasifier has a capacity of 1000 kg. Sometimes, the gasification process must be stopped before coal completely consumed due to ash melting inside the gasifier. Combustion of producer gas produced a pale-blue flame, probably due to a lower calorific value of the producer gas or too much excess air. Temperature of heating-air heated by combustion of this producer gas was only up to 96 oC. To achieve the target temperature of 102 oC, a small oil burner must he operated at a rate ofabout 15 L/h. Thus the oil replacement was about 78%.Keywords:  Fuel oil, Producer gas, Downdraft gasifier, Dual fuel, Calorific value, Burner. AbstrakKenaikan harga bahan bakar minyak untuk industri pada awal 2006 telah mendorong berbagai pemikiran dan upaya pemanfaatan bahan bakar alternatif. Sebuah unit gasifikasi telah dipasang di pabrik teh sebagai penyedia bahan bakar alternatif. Unit gasifikasi tersebut terdiri dari gasifier, pendingin, pembersih gas, dan blower. Unit gasifikasi ini ditargetkan untuk dapat menggantikan konsumsi minyak bakar 70 L/jam. Gasifier dirancang untuk kapasitas 120 kg/jam batubara, dan memiliki spesifikasi sebagai berikut: downdraft gasifier; diameter tenggorokan 40 cm, diameter zona reduksi 80 cm. Bunker di bagian atas gasifier memiliki kapasitas sekitar 1000 kg batubara agar gasifier dapat dioperasikan selama 8 jam tanpa pengisian-ulang. Bahan baku gasifikasi yang telah diuji-coba adalah batuhara kalori rendah (4500 kcal/kg) dan limbah kayu (4000 kcal/kg). Gas produser (hasil gasifikasi) dibakar pada burner untuk memanaskan udara pengering teh sampai temperatur target 102 oC. Pembakaran gas produser ternyata menghasilkan api biru pucat yang mungkin disebabkan oleh rendahnya kalor bakar gas dan tingginya udara-lebih. Temperatur udara pengering hasil pemanasan dengan api gas produser hanya mencapai 96 oC. Dan untuk mencapai temperatur udara pengering 102 oC, burner gas prod user harus dibantu dengan burner minyak 15 L/jam. Jadi operasi dual fued ini dapat memberi penghematan minyak bakar 78%.Kata kunci: Minyak bakar, Gas produser, Downdraft gasifier, Dual fuel, Kalor bakar, Burner. 

Simulation Analysis of the System Integrating Oxy-Fuel Combustion and Char Gasification

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Ruochen Liu ◽  
Martin Graebner ◽  
Remi Tsiava ◽  
Ting Zhang ◽  
Shenqi Xu
Keyword(s):  
Flue Gas ◽  
Simulation Analysis ◽  
Co2 Reduction ◽  
Biomass Gasification ◽  
Integrated System ◽  
Char Gasification ◽  
Gasification Process ◽  
The Government ◽  
Gas Recirculation ◽  
The Impact

Abstract To explore the feasibility of converting hot flue gas into valuable syngas through char gasification process, Aspen Plus is applied to evaluate the performance of the integrated system including oxy-combustion, pyrolysis, gasification, and flue gas recirculation. The impact of feedstock type (reed straw and municipal solid waste (MSW)), feeding rate (0.1–1 t/h), and flue gas recycle ratio (FGR) (10%–30%) is investigated. The economic analysis of the integrated system is also performed. The results indicate that higher oxygen consumption is required for biomass gasification to reach the same temperature as MSW gasification. The gasification temperature is 750 °C–950 °C under 10%–30% FGR. The CO + H2 content in syngas from biomass gasification is slightly higher than that from MSW gasification. For the integrated system, more natural gas (NG) can be saved and more fossil CO2 can be reduced under biomass gasification. When the feedstock input is 1 t/h, the fossil CO2 emission can be reduced by 70% when taking biomass, the CO2 reduction is double of that when taking MSW. The total OPEX cost can be 26% saved by biomass and 62% saved by MSW due to the government subsidy. If CO2 tax is considered, the advantage of biomass for saving OPEX cost will be more obvious.

scholarly journals Optimizing the impact of temperature on bio-hydrogen production from food waste and its derivatives under no pH control using statistical modelling

2015 ◽  
Vol 12 (15) ◽  
pp. 12823-12850 ◽  
Author(s):  
A. Sattar ◽  
C. Arslan ◽  
C. Ji ◽  
S. Sattar ◽  
K. Yousaf ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Negative Impact ◽  
Glucose Consumption ◽  
Statistical Modelling ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
Fatty Acid Production ◽  
The Impact

Abstract. The effect of temperature on bio-hydrogen production by co-digestion of sewerage sludge with food waste and its two derivatives, i.e. noodle waste and rice waste, was investigated by statistical modelling. Experimental results showed that increasing temperature from mesophilic (37 °C) to thermophilic (55 °C) was an effective mean for increasing bio-hydrogen production from food waste and noodle waste, but it caused a negative impact on bio-hydrogen production from rice waste. The maximum cumulative bio-hydrogen production of 650 mL was obtained from noodle waste under mesophilic temperature condition. Most of the production was observed during 48 h of incubation that continued till 72 h of incubation, and a decline in pH during this interval was 4.3 and 4.4 from a starting value of 7 under mesophilic and thermophilic conditions, respectively. Most of glucose consumption was also observed during 72 h of incubation and the maximum consumption was observed during the first 24 h, which was the same duration where the maximum pH drop occurred. The maximum hydrogen yields of 82.47 mL VS−1, 131.38 mL COD−1, and 44.90 mL glucose−1 were obtained from mesophilic food waste, thermophilic noodle waste and mesophilic rice waste respectively. The production of volatile fatty acids increased with an increase in time and temperature from food waste and noodle waste reactors whereas it decreased with temperature in rice waste reactors. The statistical modelling returned good results with high values of coefficient of determination (R2) for each waste type when it was opted for the study of cumulative hydrogen production, glucose consumption and volatile fatty acid production. The 3-D response surface plots developed by the statistical models helped a lot in developing better understanding of the impact of temperature and incubation time.

scholarly journals The Impact of Coal’s Petrographic Composition on Its Suitability for the Gasification Process: The Example of Polish Deposits

Resources ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 111
Author(s):  
Barbara Bielowicz ◽  
Jacek Misiak
Keyword(s):  
Coal Gasification ◽  
Negative Impact ◽  
Vitrinite Reflectance ◽  
Low Rank ◽  
Petrographic Composition ◽  
Gasification Process ◽  
Physico Chemical ◽  
Higher Rank ◽  
The Impact ◽  
Selection Of

In this paper, we discuss the impact of the rank of coal, petrographic composition, and physico-chemical coal properties on the release and composition of syngas during coal gasification in a CO2 atmosphere. This study used humic coals (parabituminous to anthracite) and lithotypes (bright coal and dull coal). Gasification was performed at temperatures between 600 and 1100 °C. It was found that the gas release depends on the temperature and rank of coal, and the reactivity increases with the increasing rank of coal. It was shown that the coal lithotype does not affect the gas composition or the process. Until 900 °C, the most intense processes were observed for higher rank coals. Above 1000 °C, the most reactive coals had a vitrinite reflectance of 0.5–0.6%. It was confirmed that the gasification of low-rank coal should be performed at temperatures above 1000 °C, and the reactivity of coal depends on the petrographic composition and physico-chemical features. It was shown that inertinite has a negative impact on the H2 content; at 950 °C, the increase in H2 depends on the rank of coal and vitrinite content. The physicochemical properties of coal rely on the content of maceral groups and the rank of coal. An improved understanding these relationships will allow the optimal selection of coal for gasification.

scholarly journals Responses of Rice Growth to Day and Night Temperature and Relative Air Humidity—Dry Matter, Leaf Area, and Partitioning

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 521
Author(s):  
Stuerz ◽  
Asch
Keyword(s):  
Leaf Area ◽  
Mass Fraction ◽  
Dry Matter ◽  
Negative Impact ◽  
Effect Of Temperature ◽  
Plant Responses ◽  
Air Humidity ◽  
Night Temperature ◽  
Relative Air Humidity ◽  
The Impact

Asymmetric changes of day and night temperature have already been observed because of Climate Change. However, knowledge on environmental conditions either during day or night serving as trigger for growth processes is scarce. In this study, one rice (Oryza sativa) variety (IR64) was examined to assess the impact of varying temperatures and relative air humidities during day and night periods on biomass, leaf area, and dry matter partitioning between organs. Three different day and night temperature (30/20 °C, 25/25 °C, 20/30 °C) and relative air humidity (40/90%, 65/65%, 90/40%) regimes were established. The effect of relative air humidity on both plant dry matter and leaf area was larger than the effect of temperature, in particular low humidity had a strong negative impact during the night. With high day temperature, the shoot mass fraction increased, whereas the root mass fraction decreased. Specific leaf area increased at high night temperatures and led, along with the high leaf mass fraction at high night humidities, to higher growth rates. The results emphasize the importance of considering relative air humidity when focusing on plant responses to temperature, and strongly suggest that under asymmetric day and night temperature increases in the future, biomass partitioning rather than biomass itself will be affected.

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