STUDY OF THE EFFECT OF PARAMETERS ON THE COGASIFICATION OF LIGNITE AND BIOMASS USING DOWNDRAFT GASIFIER: A CRITICAL REVIEW

• Main Author: Kholif Ma'ruf, Adnan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/56275
• Institution: Institut Teknologi Bandung

Gasification is a coal downstream technology that is being developed in an effort to fulfill energy in Indonesia. The majority of coal in Indonesia is low and medium quality coal with a relatively high content of ash, moisture and sulfur. Meanwhile, biomass as a renewable energy source has abundant potential, but its calorific value is lower and its tar content is higher than coal. In the utilization of national energy fulfillment, co-gasification between the two carbon sources is necessary to produce high quality syngas and extend the life of coal reserves. The downdraft gasifier reactor was chosen because it can produce gas with low tar content and can use raw materials with high ash content. In this study, the effect of biomass type and its mixing ratio with coal on gasification performance is studied and analyzed. The synergistic effect of gasification of three types of biomass with lignite was observed, besides that, the process parameters were also reviewed because they had an effect on the composition of the gas produced. In this literature study, the collection of literature sources was carried out with the keywords lignite, biomass, gasification, and downdraft gasifier. Each literature source is analyzed and conclusions are drawn. Three types of biomass analyzed for synergistic effects with lignite are corn cobs, rice straw, and oil palm shells. While the process parameters reviewed are particle size, mixing ratio, and temperature. The results of each experiment were in the form of gas product composition, carbon conversion, weight loss, and differences in experimental and calculated values to observe the synergy effect that occurred. The results of the review show that the synergistic effect in the gasification process of a mixture of lignite and biomass is largely determined by the main chemical components of the biomass used. The synergistic effect occurs in the gasification of the mixture of lignite-rice straw and lignite-palm shell, whereas in the mixture of lignite-corn cobs there is no synergy, this difference occurs because the volatile components in corncobs are more than in other biomass. The optimum particle size of the mixture of lignite and biomass is 1-3 mm. Mixing of biomass to lignite was found to be optimal at a ratio of 50%. The optimum temperature occurs in the temperature range of 800-900 oC. Temperature has the most significant influence on the gasification product. Meanwhile, particle size has a very small effect compared to other parameters.