Kinetics of maize cob and bean straw pyrolysis and combustion.

Kinetic studies are important for the design and optimisation of thermochemical processes. This study involved analysis of the pyrolysis and combustion behaviour of the agricultural residues (bean straw and maize cob) by non-isothermal thermogravimetric analysis. Increasing the heating rate from 10 to 40 K min-1 during both combustion and pyrolysis increased the degradation rate of both feedstocks and the gaseous yields of H2O, CO and CO2. The activation energies determined by the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods varied which reveals that the pyrolysis and combustion of these agricultural residues are complex processes involving multiple reactions. The average activation energy of maize cob and bean straw were 214.15 and 252.09 kJ mol-1 for pyrolysis and 202.26 and 165.64 kJ mol-1 for combustion, respectively. The order of reaction ranged between 9.0-10.3 and 6.3-13.3 for both feedstocks in combustion and inert environments, respectively. Modelled data is important to enable the optimisation of reactor design for pyrolysis and combustion for energy generation from agricultural residues.

The impact of the EU neonicotinoid seed-dressing ban on oilseed rape production in England.

BACKGROUND: Neonicotinoid seed dressings on oilseed rape were banned in the European Union (EU) from December 2013. A survey of > 200 farms was conducted in England in the 2014/15 and 2015/16 seasons to assess the impact of the ban on changes in crop area, crop losses to cabbage stem flea beetle (CSFB), insecticide use and the economics of oilseed rape production. RESULTS: The area of oilseed rape grown fell in both seasons, with CSFB identified as the third most important reason for the decrease. Crop losses to CSFB were 3% and 5% in the respective seasons, with clear variation by county. There were clear differences in the crop area treated (1.14 vs 0.77 million ha) and the number of insecticide applications per crop (2.0 vs 1.4) to combat CSFB in 2014/15 and 2015/16, respectively. Within the derogation area counties there was a clear reduction in the number of applications per crop when neonicotinoid-treated vs non-treated seed was used (1.0 vs 1.9), respectively. CONCLUSION: Increasing resistance to pyrethroid insecticides in combination with the neonicotinoid seed dressing ban is likely to have significant impacts on the viability of growing oilseed rape in England particularly where CSFB activity/risk is high. © 2018 Society of Chemical Industry.