牛粪复混生物质颗粒燃料成型及特性分析

为了提高以牛粪为主料的多原料混合生物质燃料的发热量,降低成型颗粒燃料含硫量,提升燃料的适用性和综合品质,选取锯末、谷糠、果树残枝3种常见的木质类和非木质类有机废弃物为辅料,通过调节原料配比及含水率,采用挤压成型和特性测定等方法,分析了原料含水率和原料配比对颗粒成型燃料成型率、全水分、灰分、挥发分、固定碳、含硫量和发热量的影响。结果表明：颗粒成型率和全水分受原料组成和含水率共同作用,低灰、低硫和高热量的生物质燃料更有利于市场应用,在满足颗粒成型的条件下,颗粒的热值与灰分、全水分呈负相关,与固定碳含量呈正相关。在牛粪中添加锯末和果树残枝更有利于降低灰分含量,增加果树残枝更有利于提高颗粒的固定碳含量,混合物料中牛粪+果树残枝2∶1混合处理的固定碳含量最高,达到17.6%。牛粪含硫量偏高,3种辅料都有利于降低成型燃料的含硫量,牛粪+果树残枝2∶1混合与牛粪+锯末+果树残枝1∶1∶1混合等多个组合可以将牛粪含硫量从0.30%降到0.10%~0.12%,与单独牛粪相比,发热量提高2.88%~4.63%。综合各处理组的原料成型率和燃料燃烧特性,牛粪与果树残枝2∶1混合是牛粪制备颗粒燃料的最优组合配方。

Fuel molding of cattle manure mixed with biomass pellet and its characteristic analysis

In order to improve the calorific value of the multi-materials mixed biomass fuel with cow dung as the main material, reduce the sulfur content of the pellet fuel, and improve the applicability and comprehensive quality of the fuel. In this study, three kinds of common woody and non-woody organic wastes, sawdust, rice chaff and fruit tree residues, were selected as auxiliary materials. The experiment was carried out by adjusting the ratio of raw materials and moisture content, extrusion molding and characteristic measurement. The influence of water content and ratio of raw materials on several parameters of pellet forming fuel was analyzed, which mainly included molding rate, total moisture, ash, volatile, fixed carbon, sulfur content and calorific value. The results showed that the pellet forming rate and total water content were affected by the feedstock composition and water content. The biomass fuel with low ash and sulfur content at high heat was more favorable for market applications. Under pellet forming conditions, the calorific value of the pellet negatively correlated with the ash and total water content and positively correlated with the fixed carbon content. Sawdust and fruit tree residue supplementation to the cow dung was beneficial to reduce ash content, and the fruit tree residue supplementation allowed the increase of the fixed carbon content in the granules. The 2:1 mixture of cow dung and fruit tree residue exhibited the highest fixed carbon content, reaching 17.6%. The sulfur content in the cow dung on the high side; three kinds of complementary preparations were beneficial to reduce the sulfur content in the molding fuel:2:1 mixture of cow dung+fruit tree residue, 1:1:1 mixture of cow dung+sawdust+fruit tree residue, and other combinations containing 0.30% of the sulfur content in the cow dung to 0.10%~0.12%, compared with cow dung, at the same time, an improved calorific value of 2.88%~4.63% could be reached, and the raw material forming rate and fuel combustion characteristics of each treatment group showed that the 2:1 mixture of cow dung and fruit tree residue was the optimal combination for the preparation of pellet fuel formulation.