The effect of pyrolysis temperature on the characteristics of biochar, pyroligneous acids, and gas prepared from cotton stalk through a polygeneration process

Bio-char is carbon-rich product generated from biomass through batch type slow pyrolysis. In this study, the effects of pyrolysis temperature and residence time on the yield and properties of bio-chars obtained from shredded cotton stalks were investigated. Safely said that the quality of bio-char of shredded cotton stalk obtained at 500°C temperature and 240 min is best out of the all experimental levels of variables of temperature and residence time. At this temperature and residence time, the quality of bio-char in terms higher heating value (8101.3cal /g or 33.89 MJ/kg), nitrogen (1.56%), Carbon (79.30%), and C/N ratio (50.83) respectively. The quality of bio-char for various applications is discussed along with different quality parameters. The bio-char could be used for the production of activated carbon, in fuel applications, and water purification processes. Average bulk density of whole cotton stalk and shredded cotton stalk was found as 29.90 kg/m3 and 147.02 kg/m3 respectively. Thus density was increased by 3.91 times. The value of pH, EC and CEC of shredded cotton stalk biomass was found as 5.59, 0.03 dS/m and 38.84 cmol/kg respectively. Minimum and maximum values pH, EC and CEC of its bio-char was found as 5.85 to9.86, 0.04 to 0.10 dS/m and 38.02 to 24.39 cmol/kg at 200°C and 60 min and; 500°C and 240 min temperature and residence time respectively. Moisture content, ash content, volatile matter and fixed carbon of shredded cotton stalk biomass were found as, 12.5, 5.27, 80.22, and 14.51 (%, d.b) respectively. The minimum and maximum value of bio-char in terms of ash content, volatile matter and fixed carbon of bio-char were found as 5.5 to 15.56, 48.02 to 79.48 and 15.02 to 36.40 (%, d.b) respectively. Calorific value of cotton stalk biomass was found as 3685.3 cal /g. The minimum and maximum higher heating value of its bio-char was found as 4622.0 cal/ g and 8101.3 cal/g at 200°C and 60 min and; 500˚C and 240 min temperature and residence time.

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The effects of pyrolysis temperature and storage time on the compositions and properties of the pyroligneous acids generated from cotton stalk based on a polygeneration process

Industrial Crops and Products ◽

10.1016/j.indcrop.2020.113226 ◽

2021 ◽

Vol 161 ◽

pp. 113226

Author(s):

Jie Cheng ◽

Sheng-Chun Hu ◽

Kang Kang ◽

Xiao-Ming Li ◽

Zeng-Chao Geng ◽

...

Keyword(s):

Storage Time ◽

Pyrolysis Temperature ◽

Cotton Stalk ◽

And Storage

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OPTIMIZING THE PYROLYSIS TEMPERATURE OF TMSH THERMOCHEMOLYSIS FOR USE IN GC-MS BIOSIGNATURE DETECTION

10.1130/abs/2020am-358946 ◽

2020 ◽

Author(s):

Lydia Kivrak ◽

◽

Amy Williams ◽

Arnaud Buch ◽

Yuanyuan He

Keyword(s):

Pyrolysis Temperature

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Bio-Oil Characterizations of Spirulina Platensis Residue (SPR) Pyrolysis Products for Renewable Energy Development

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.849.47 ◽

2020 ◽

Vol 849 ◽

pp. 47-52

Author(s):

Siti Jamilatun ◽

Aster Rahayu ◽

Yano Surya Pradana ◽

Budhijanto ◽

Rochmadi ◽

...

Keyword(s):

Renewable Energy ◽

Spirulina Platensis ◽

Pyrolysis Temperature ◽

Renewable Energy Sources ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Oil Yield ◽

Optimum Temperature ◽

Pyrolysis Products ◽

Bio Oil

Nowadays, energy consumption has increased as a population increases with socio-economic developments and improved living standards. Therefore, it is necessary to find a replacement for fossil energy with renewable energy sources, and the potential to develop is biofuels. Bio-oil, water phase, gas, and char products will be produced by utilizing Spirulina platensis (SPR) microalgae extraction residue as pyrolysis raw material. The purpose of this study is to characterize pyrolysis products and bio-oil analysis with GC-MS. Quality fuel is good if O/C is low, H/C is high, HHV is high, and oxygenate compounds are low, but aliphatic and aromatic are high. Pyrolysis was carried out at a temperature of 300-600°C with a feed of 50 grams in atmospheric conditions with a heating rate of 5-35°C/min, the equipment used was a fixed-bed reactor. The higher the pyrolysis temperature, the higher the bio-oil yield will be to an optimum temperature, then lower. The optimum temperature of pyrolysis is 550°C with a bio-oil yield of 23.99 wt%. The higher the pyrolysis temperature, the higher the H/C, the lower O/C. The optimum condition was reached at a temperature of 500°C with the values of H/C, and O/C is 1.17 and 0.47. With an increase in temperature of 300-600°C, HHV increased from 11.64 MJ/kg to 20.63 MJ/kg, the oxygenate compound decreased from 85.26 to 37.55 wt%. Aliphatics and aromatics increased, respectively, from 5.76 to 36.72 wt% and 1.67 to 6.67 wt%.

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Effect of pyrolysis temperature on Si release of alkali-enhanced Si-rich biochar and plant response

Biochar ◽

10.1007/s42773-021-00112-3 ◽

2021 ◽

Author(s):

Meng Wang ◽

Negar D. Tafti ◽

Jim J. Wang ◽

Xudong Wang

Keyword(s):

Rice Straw ◽

Rice Husk ◽

Pyrolysis Temperature ◽

Weak Acid ◽

Rice Grain ◽

Neutral Salt ◽

Salt Solutions ◽

Plant Disease Control ◽

Si Content ◽

Lower Temperature

AbstractRecent studies have shown that silicon (Si) dissolution from biochar may be influenced by the pyrolysis temperature. In addition, the enhancement of biochar by treatment with alkali has been proposed to produce a Si source that can be used for environmentally friendly plant disease control. In this study, biochars from rice straw and rice husk pretreated with KOH, CaO and K2CO3 and then pyrolyzed at 350, 450 and 550 °C were prepared to evaluate the effects of pyrolysis temperature on Si release and plant uptake from alkali-enhanced Si-rich biochar. Extractable Si and dissolution Si from the prepared biochars were assessed by different short-term chemical methods and long-term (30-day) release in dilute acid and neutral salt solutions, respectively, along with a rice potting experiment in greenhouse. For both rice straw- and husk-derived alkali-enhanced biochars (RS-10KB and HS-10K2B, respectively), increasing the pyrolysis temperature from 350 to 550 °C generally had the highest extractable Si and increased Si content extracted by 5-day sodium carbonate and ammonium nitrate (5dSCAN) designated for fertilizer Si by 61–142%, whereas non-enhanced biochars had more extractable Si at 350 °C. The alkali-enhanced biochars produced at 550 °C pyrolysis temperature also released 82–172% and 27–79% more Si than that of 350 °C produced biochar in unbuffered weak acid and neutral salt solutions, respectively, over 30 days. In addition, alkali-enhanced biochars, especially that derived from rice husk at 550 °C facilitated 6–21% greater Si uptake by rice and 44–101% higher rice grain yields than lower temperature biochars, non-enhanced biochars, or conventional Si fertilizers (wollastonite and silicate calcium slag). Overall, this study demonstrated that 550 °C is more efficient than lower pyrolysis temperature for preparing alkali-enhanced biochar to improve Si release for plant growth.

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