Small-scale biomass gasification systems for power generation (<200 kW class): A review

Biomass gasification to provide gas fuels for power generation is considered as one of the best ways for substituting fossil fuels. Large scale unit of biomass gasification with capacity over 2 MW is preferably chosen due to its efficiency to investment ratio even though collecting large amount of biomass takes high cost. To effectively utilize the biomass resources in local and regional areas, it is expected to apply more small-scale biomass gasifiers with a capacity less than 200 kW for a small community or even a family. This will make bioenergy more popular in our daily life. In this review, developed gasification techniques and the effects of biomass composition, gasifying agents, biomass particle size, operating condition of gasification (temperature and pressure) on the gasification efficiency, and type of gasifier are introduced at first and then, the research and development (R&D) and application progresses of the small-scale biomass gasification systems with capacities of 10–200 kW over the world are summarized, and the challenges and prospects in the future renewable energy markets are analyzed and discussed. European, North American and Asia areas are developing and begin to apply various small-scale biomass gasification systems, and African, Latin America, and Oceania countries should be the growing and promising potential regions for the application of this technique in the future, especially in the developing countries. In addition, lowering investment cost and making supporting policies are significantly required to utilize such small-scale renewable energy system.