Combined heat and power from the intermediate pyrolysis of biomass materials: performance, economics and environmental impact

- Performance of the Pyrolysis and CHP systems is studied and evaluated.
- Overall CHP efficiency of the 1000 kg/h Pyro-CHP system is 42.5%.
- Levelised Energy Cost is high, but the optimistic scenario is potentially profitable.
- Life-cycle GHG analysis shows strong positive environmental benefits.

Combined heat and power from the intermediate pyrolysis of biomass materials offers flexible, on-demand renewable energy with some significant advantages over other renewable routes. To maximise the deployment of this technology an understanding of the dynamics and sensitivities of such a system is required. In the present work the system performance, economics and life-cycle environmental impact is analysed with the aid of the process simulation software Aspen Plus. Under the base conditions for the UK, such schemes are not currently economically competitive with energy and char products produced from conventional means. However, under certain scenarios as modelled using a sensitivity analysis this technology can compete and can therefore potentially contribute to the energy and resource sustainability of the economy, particularly in on-site applications with low-value waste feedstocks. The major areas for potential performance improvement are in reactor cost reductions, the reliable use of waste feedstocks and a high value end use for the char by-product from pyrolysis.