Ammonia and GHG emission from environmental techniques in livestock farms based on modelization

Abstract

In trying to respond to socíeta! demands for sustainable development, fanning systems have to deal with environmental, technical 1 ru1d economic challenges) in whích innovative solutions are required. At this regard, poultry and swine fanns over certain size i must have a pennit to operate based on !he ímplementation of Best Available Techniques (BAT) according to Industrial 1 Emissíons Directive IED 2010175/EU. In this thesis we bave developed a practica! model (BATF ARM model) for environmental ¡' techniques selection in swine, poultiy and daíry cattle farms. The model aims to identify the key stages gíving rise to farm gas emíssions (ammonia and greenhouse gases, GHG), which would most benefit from implementing environmental techniques and predicts fimn emíssion variation under dífferent scenarios. Designed with methodological rigour and as a user-friendly tool, the model calculates mass balances throughout fimn stages in order to estímate manure evolution, rclated emissions, feed consumptions and animal production. It was set up using a combination of methodologies includíng emission factors, empirical equations and process􀅨oriented mechanisms. Model testing seems to indicate that the model consíders relevant interactions between farm components and captures the effect of factors having an importan! impact on gas emíssion. However, results must : be interpreted as indícative of the relative ernission red.uction achieved due to implementatíon of mitigation practices rather than 1 absolute values. Besides, direct measurements on farm are required to establísh emission factors for up-scaling farm level , processes in modeling work. In this thesis, the evaluation of the performance of a wet scrubber in a commercial pig farm has been carried out and results have been incorporated ín the model. Wet scrubbers seem to be. also in our climatic conditions; very effective for ammonia reduction. However air cleaning may not be a generally applicable technique due to the high irnplementation cost and it can lose íts efficiency if applied V>'ithout any further measures in downstream farming activíties. Precisely, whole-farm models can help in these integrated scenario evaluations and can support in the selection of most effective mitigation option in each particular fann case.