Abstract

This paper presents an analysis of the potential for household-scale biogas production based on cattle and buffalo dung in three geographical regions of Nepal. A field survey was conducted in 240 livestock-holding households, and data of daily fresh dung yield were obtained from 210 livestock individuals classified into four categories: mature buffalo (>3 year), young buffalo ($\le$3 year), mature cattle (>3 year) and young cattle ($\le$3 year). The data were collected in three different seasons with varying temperature and humidity. The energy values of the dung were experimentally measured. The results showed that the average daily dung yield per livestock in the monsoon was higher than that of the other seasons, for all geographical regions, because of higher fodder availability. Despite the highest livestock number per household in the mountains as compared to the hills and lowlands, the net availability of dung in the mountains was only about 30% of that of other two regions due to lower availability of fodder. Fodder availability, livestock herding hours, quality of dung and seasonal variations were found to be important parameters in determining the net potential biogas production. Based on these findings, measures to increase biogas production from available dung are discussed and generalized.

摘要

本文分析了尼泊尔三个地理区域基于牛和水牛粪的家庭规模沼气生产潜力。对 240 户畜牧业户进行了实地调查，获得了 210 头牲畜个体的每日新鲜粪便产量数据，分为四类：成熟水牛（>3 年）、幼水牛（$\le$3 年）、成熟牛（>3 年）和幼牛（$\le$3 年）。这些数据是在温度和湿度不同的三个不同季节收集的。粪便的能量值是通过实验测量的。结果表明，在所有地理区域，季风期间每头牲畜的平均每日粪便产量高于其他季节，因为饲料供应量较高。尽管与丘陵和低地相比，山区的每户牲畜数量最多，但由于饲料供应量较低，山区的粪便净供应量仅为其他两个地区的 30% 左右。发现饲料供应、牲畜放牧时间、粪便质量和季节变化是确定潜在沼气产量的重要参数。基于这些发现，