Performance investigation of a non-combustion heat carrier biomass gasifier for various reforming methods of pyrolysis products

ABSTRACT

Conventional biomass gasifiers such as fixed bed gasifiers, fluidized bed gasifiers, and entrained flow gasifiers have been widely studied in the literature covering biomass gasification systems. However, there are few published studies on non-combustion heat carrier biomass gasifier technology in the literature. Therefore, further studies are needed to reveal potential advantages, disadvantages, and possible improvement opportunities for this gasifier type. In this work, we investigate the effects of various operating parameters: reformation temperature, steam-to-biomass ratio, and steam-to-oxygen ratio on important performance indicators of non-combustion biomass gasifiers. To estimate the pyrolysis products, we use stoichiometric methods based on published data in the literature. The reforming of pyrolysis products is estimated using the Gibbs free energy minimization method using Aspen Plus. In addition, calculator blocks, sensitivity blocks, and design specifications are used to obtain the results. The results reveal that the desired hydrogen to carbon monoxide ratio can be obtained for steam reforming and autothermal reforming of pyrolysis products while a low hydrogen-to-carbon ratio (less than 1.5) is obtained for partial oxidation of pyrolysis products. However, partial oxidation can be beneficial in increasing the heating value of the syn-gas. The results presented in this study will be useful in improving the current configuration of non-combustion heat carrier biomass gasifiers. In future studies, the effects of gasifying agents on the tar content of the syn-gas, impurities in the syn-gas, start-up time of the gasifier, and size of the gasifier should be investigated.

KEYWORDS:

• Biomass gasification
• Syn-gas
• non-combustion heat carrier ball biomass gasifier