Gasification-based methanol production from biomass in industrial clusters: Characterisation of energy balances and greenhouse gas emissions

This study evaluates the potential for reducing life cycle greenhouse gas (GHG) emissions of biomass gasification-based methanol production systems based on energy balances. Configurations which are process integrated with a chemical cluster have been compared to stand-alone units, i.e. units with no connection to any other industry but with the possibility to district heating connection. Two different uses of methanol are considered: the use as a vehicle fuel and the use for production of olefins via the methanol-to-olefins process. An added value of the integration can be the availability of excess hydrogen. For the studied case, the methanol production could be increased by 10% by using excess hydrogen from the cluster. The results show that the integrated systems have greater potential to reduce GHG emissions than the stand-alone systems. The sensitivity analysis demonstrated that the references for electricity production and district heating production technology have important impacts on the outcomes. Using excess heat for district heating was found to have positive or negative impacts on GHG emissions depending on what heat production technologies it replaces. The investigated olefins production systems resulted in GHG emissions reductions that were similar in magnitude to those of the investigated biofuel production systems. © 2014 Elsevier Ltd.