Effects of Heating Temperature and Moisture on Indirect Gasification of Rubber Wood in Closed Gasifier Chamber

Hiroki Homma,Akio Furuta,Naoya Nishida

doi:10.4236/jsbs.2016.61001

Abstract

Rural area in Indonesia of which electrification ratio is still low has a strong demand for off-grid electric power supply. On the other hand, Indonesia is a leading natural rubber production country and these rubber wood trees are cultivated in vast plantation farms. A rubber wood tree is woody biomass resource which can be stably supplied because a lot of trees aged more than 25 years are logged and nursery trees are planted constantly. Woody biomass is burned directly as solid fuel and the generated thermal energy can be applied only for room heating or cooking. Otherwise, direct conversion of biomass to electric energy requires a large scale equipment such as a boiler and a steam turbine, whereas gasified woody biomass can be easily handled and can have wide application. A closed gasifier chamber which was kept vacuum and fulfilled with gas yield during gasification was recently developed by the authors for indirect gasification. It was confirmed that generated gas by the gasifier is clean and can be directly used to drive an engine generator to supply electricity. In this study, planer dust of rubber wood is used as gasification feedstock for indirect gasifying in the closed gasifier chamber, and effects of heating temperature and moisture content on gasification performance are discussed to examine characteristics of the closed gasifier chamber in details.

Highlights

Economic growth in ASEAN (Association of Southeast Asian Nations) countries is significant in recent years
This system has the following advantages: 1) gas produced in an indirect heating gasifier does not contain inert gas because of pre-vacuuming process before gasification and high calorie gas is obtained; 2) reduction of tar content in gas yield is a tradeoff between increase in reaction time and deterioration of energy efficiency; 3) if a biomass stove is used for heat source, it is no need to supply electricity for the gasifier operation except for pre-vacuuming; 4) the gasifier can be used for a temporary gas storage tank after gasification is terminated
Experimental procedures are as follows: The feedstock sample is put into the stainless steel cup and distilled water is poured over it; The stainless steel cup is placed at the bottom of the chamber, the chamber is closed with the flange; Air inside the chamber is suctioned by a vacuum pump until the vacuum reaches a certain level; The chamber is positioned in the electric furnace controlled at the preset temperature, and gasification starts; When pressure inside the chamber increases and reaches plateau, small volume of generated gas is collected into the gas sampling bag to analyze gas components by a gas chromatography; Volume of remaining gas in the chamber is measured by downward displacement of water

Summary

Introduction

Economic growth in ASEAN (Association of Southeast Asian Nations) countries is significant in recent years. The closed gasifier chamber is a stainless steel vessel closed by flanges and used for a vacuum and pressurized vessel that is initially vacuumed and pressurized during gasification process This system has the following advantages: 1) gas produced in an indirect heating gasifier does not contain inert gas because of pre-vacuuming process before gasification and high calorie gas is obtained; 2) reduction of tar content in gas yield is a tradeoff between increase in reaction time and deterioration of energy efficiency; 3) if a biomass stove is used for heat source, it is no need to supply electricity for the gasifier operation except for pre-vacuuming; 4) the gasifier can be used for a temporary gas storage tank after gasification is terminated. It can be expected that generated gas is used without any treatment to drive a small gasoline engine generator for electric power This system is supposed to use rubber wood for gasification feedstock and to supply off-grid electricity at rural areas in Indonesia. To examine effects of heating temperature and moisture content on gasification characteristics, experiments are carried out in the closed gasification chamber using planer dust of rubber wood for gasification feedstock

Experimental Apparatus

Experimental Condition and Procedure

Total Gas Yield

Findings

Conclusions