Life cycle assessment of ammonia production from biomass gasification compared to natural gas

Use life cycle assessment (LCA) tools to determine the environmental benefits and feasibility of producing ammonia fertiliser from biomass gasification, compared to using natural gas. Ammonia is used for the production of nitrogen based fertilisers and whilst the fertiliser improves crop yield, the production process is energy intensive and produces 0.93 % of global greenhouse gas (GHG) emissions.

The biomass system analysed includes energy crop cultivation under typical UK agronomic practice, gasification in a fast internally circulating fluidised bed gasifier to produce syngas, steam reforming to convert the syngas into a H2 rich feedstock and combination with N2 separated from air, to produce ammonia using the Haber-Bosch process. The GWP is quantified using LCA software, along with other notable impacts on biodiversity.

Results are also presented for the net energy balance of the system, which is a significant consideration in determining the most appropriate use of biomass amongst the sometimes competing pathways of heat, electricity or transport fuel production. 

Duration: - April 2011

Funder: SuperGen Bioenergy (EPSRC)

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