生物甲烷抑制剂缓释扩散模型推导与优化

以石蜡和松香为缓释基质,以碳化钙为生物甲烷抑制材料,对有效抑制组分——乙炔的扩散规律进行了研究.以T.Higuchi方程为基础,针对复杂基质的气体缓释进行了修正,得到缓释抑制剂的扩散机制模型,该模型可以有效预测乙炔的扩散系数De.同时考察了基质优化对扩散系数的影响,如果缓释基质的硬度不够,碳化钙与水反应产生的热量可导致缓释抑制剂内部膨胀从而影响缓释效果.当基质中松香的质量分数为20%,基质与碳化钙的质量比为1/1时,缓释基质的硬度和致密度提高,乙炔的扩散系数达到2.2849×10-8cm2/min(R2=0.9901),该缓释抑制剂可以有效地解决生活垃圾填埋场等人为源生物甲烷的减排问题.

Optimization on Slow-Release Inhibition of Biomethane and the Kinetics Model of Diffusion

The diffusion mechanism of acetylene,which can inhibit the activity of methanogens,was studied.Paraffin wax and rosin were used as matrix of slow-release and calcium carbide was used as inhibition material.Based on the T.Higuchi equation and the characteristics of slow-release inhibitors,a mechanism model was derived.Moreover,the effective diffusion coefficients (D_e) can be acquired by this model.During the diffusion process,the reaction heat of calcium carbide and water could make acetylene gas expansion and caused the slow-release inhibitors expansion if the hardness of the slow-release inhibitors is inadequate.The hardness and compactness were enhanced and the effective diffusion coefficientsreached 2.2849×10^-8 cm²/min (R²= 0.9901) when the mass faction of rosin was 20% and the mass ratio of matrix to calcium carbide was 1/1.Hence,the mitigation the methane generation with municipal solid waste (MSW) can be achieved by the technology of slow-release inhibition.