Feasibility study for sustainable, affordable solar PV/T-biomethane energy solution for rural Pakistan

巴基斯坦是世界第六人口大国，人口2.165亿，年增长率为2%。它是一个农业国家，三分之二的人口生活在农村地区。尽管巴基斯坦拥有丰富的可再生能源，但它面临着严重的能源危机，该国三分之一的能源需求依赖进口，而且仍在使用传统的发电方法，这些方法会产生大量的二氧化碳排放。巴基斯坦大多数农村人口通过在传统的烹饪炉子上燃烧动物粪便、木材燃料和木炭等生物质来满足他们的烹饪和取暖需求，这些炉子效率低下，会造成家庭室内空气污染(HAP)。每年约有28,000人死于HAP，占每年4000万例急性呼吸系统疾病的病例，造成巨大的经济负担，每年约占GDP的1%。此外，巴基斯坦面临着严重的森林砍伐问题，目前森林仅占国土面积的2.5%，每年由于森林砍伐导致大气中二氧化碳积累增加而损失27000公顷。巴基斯坦有大量的废物，包括每年20公吨的固体废物，其中几乎一半是生物质，如食物垃圾、纸叶、草和饲料)，70公吨/年的农业废物，如小麦和稻壳，棉花棒和甘蔗残渣，以及365公吨/年的动物粪便，来自1.7亿多头牛、水牛、牛、绵羊、骆驼和山羊。利用这些农业和动物废物，该项目旨在研究一种新的废物转化能源系统生产沼气的可行性，沼气将进一步升级并分离为生物甲烷和二氧化碳。沼气(在升级之前)将通过管道输送到厌氧消化厂附近的家庭，并调查烹饪情况，并将与使用木材做饭相比，评估使用沼气对室内空气质量的影响。然后，升级后的沼气将用于烹饪和取暖，而二氧化碳将用于广泛的工业应用。此外，拟议的系统还将生产可用于土壤改良、提高土地肥力和粮食生产的富氮生物肥料。拟议技术的普及将对巴基斯坦人口产生重大影响，在那里，可以利用当地可获得的废物产生清洁、负担得起和安全的能源。仅以7000万头奶牛和水牛产生的粪便计算，每年就可以生产超过5748万立方米的沼气和3000万吨富氮生物肥料。这将大大减少巴基斯坦的燃料进口，提高农村社区，特别是妇女、女孩和弱势群体的生活水平，减少二氧化碳排放，改善环境。

Pakistan is the sixth most populous country in the world with a population of 216.5M and annual growth rate of 2%. It is an agrarian country with two thirds of its population living in rural areas. Despite its abundant renewable energy sources, Pakistan is facing severe energy crises where it imports a third of its energy requirements and is still using conventional methods of energy generation that produce significant CO2 emissions.Majority of the rural population in Pakistan meet their cooking and heating needs by burning biomass like animal dung, wood fuel and charcoal in traditional cook stoves which are inefficient and causes household indoor air pollution (HAP). About 28,000 people die each year due to HAP, and it accounts for 40 million cases of acute respiratory illnesses per annum causing significant economic burden which costs about 1% of GDP per annum. Also, Pakistan is facing severe deforestation problem and currently forests cover only 2.5% of the land area as every year 27000 hectare is lost due to deforestation leading to increased CO2 accumulation in the atmosphere.There are huge amounts of waste in Pakistan including 20MT/yr solid waste of which almost half is biomass like (food waste, paper leaves, grass and fodders), 70MT/year of agriwaste like wheat and rice husks, cotton sticks and sugar-cane residues, and 365MT/Yr of animal waste coming from more than 170M heads of cows, buffalos, cattle, sheep, camels and goats. Exploiting this agricultural and animal waste, this project aims to investigate the feasibility of a novel Waste to Energy system to produce biogas which will be further upgraded and separated into biomethane and carbon dioxide. The biogas (before upgrading) will be piped to households close to the anaerobic digestion plant and investigated for cooking and the effects of using it on the indoor air quality will be assessed compared to using wood for cooking. Then the upgraded biogas to biomethane will be used for cooking and heating while CO2 will be used for wide range of industrial applications. Also, the proposed system will produce nitrogen enriched bio-fertilisers that can be used for soil enhancement, increased land fertility and food production.The widespread of the proposed technology will have major impacts on Pakistan population where clean, affordable and secure source of energy can be generated using locally available waste. Based on the waste produced from the 70M heads of cows and Buffalos only, over 57488Mm³/yr of biogas and 30MT/yr of nitrogen enriched bio-fertilisers can be produced. This will significantly reduce Pakistan fuel imports, enhance the living standards of the rural communities particularly women, girls and disadvantaged groups, reduce CO2 emissions and improve the environment.