Abstract
Biomass pyrolysis processes for bio-oil production were commonly done using batch, semi-continuous or continuous process. However, past studies have shown many concerning issues in regard to the use of batch process such as high residence time, product inconsistencies across batches, high labor cost and difficulty in industrial scale up. With these, scientists are now placing a greater interest and focus in the study of semi-continuous and continuous pyrolysis processes with their commercialization and industrialization as the major outcomes. The production rates of semi-continuous and continuous pyrolysis process are certainly more superior to the former owing to their facile in-situ withdrawal of products during pyrolysis. Nevertheless, they are of higher design complexities, thus requiring a better controllability of the operating parameters. This article reviewed on semi-continuous and continuous pyrolysis process through several perspectives: feed treatment, feeding system, operating parameters, reactor technologies and additional product separation devices. The expressed contents of this review will provide an understanding of the technical aspect of pyrolysis process comprehensively, starting from the material treatment to the end of product collection.