Published April 2014 | Version v1
Journal article

Yield and nutrient composition of biochar produced from different feedstocks at varying pyrolytic temperatures

  • 1. University of Agriculture, Faisalabad (Pakistan). Dept. of Environmental Sciences
  • 2. University of Agriculture, Faisalabad (Pakistan). Dept. of Crop Physiology

Description

Variation in pyrolytic temperatures and feedstocks affects the yield and nutrient composition of biochar. Selection of suitable feedstock and optimum pyrolytic temperature is crucial before using it for agricultural purposes. We compared biochars produced from two feedstocks (wheat straw and rice) at three temperatures (300, 400 and 500 degree C). Biochar yield decreased significantly (p<0.05) with increasing pyrolysis temperature, while ash contents were increased. The cation exchange capacity was significantly higher (119 cmolc kg/sup -1/) at temperature 400 degree C. The pH, electrical conductivity (EC) and carbon content of biochars increased significantly with increasing temperature and maximum pH (10.4) and EC (3.35 dS m/sup -1/) were observed in rice straw biochar (WSB) at 500 degree C and carbon content (662 g kg/sup -1/) in wheat straw biochar (RSB) at 500 degree C. Concentration of phosphorus (P) and potassium (K) increased significantly with increasing temperature, while of nitrogen (N) decreased. Overall, the maximum N (13.8 g kg/sup -1/at 300 degree C) and P (3.4 g kg/sup -1/at 500 degree C) concentrations were observed in WSB while, maximum K (48 g kg/sup -1/ at 500 degree C)in RSB. High pyrolysis temperature reduced AB-DTPA extractable nutrients (expect Mn). The highest AB-DTPA extractable nutrients such as P (113 mg kg/sup -1/) and Ca (1.07 g kg/sup -1/) were observed in WSB at 300 degree C while, K (18 g kg/sup -1/) and magnesium (Mg) (1.55 g kg/sup -1/) in RSB at 300 degree C. Selected feedstock and use of low pyrolysis temperature may produce nutrient-rich biochar, with high CEC and low pH and these could have positive effects on calcareous soils. (author)

Additional details

Publishing Information

Journal Title
Pakistan Journal of Agricultural Sciences
Journal Volume
51
Journal Issue
1
Journal Page Range
p. 75-82
ISSN
0552-9034

INIS

Country of Publication
Pakistan
Country of Input or Organization
Pakistan
INIS RN
45082666
Subject category
S09: BIOMASS FUELS;
Quality check status
Yes
Descriptors DEI
BIOFUELS; CHEMICAL FEEDSTOCKS; NUTRIENTS; PH VALUE; PYROLYSIS; SOILS; THERMAL DEGRADATION; YIELDS;
Descriptors DEC
ALTERNATIVE FUELS; CHEMICAL REACTIONS; DECOMPOSITION; FUELS; MATERIALS; RAW MATERIALS; THERMOCHEMICAL PROCESSES;