本研究以孟宗竹與桂竹為材料,利用土窯燒製竹炭並於煙囪溫度150℃以下時,以不銹鋼製之裝置採用氣冷方式收集竹醋液,土窯之底部如扇子形狀,其寬度為2.8m、深度為2.8m,窯頂成拱形,其高度為1.4m。燒製竹炭時在窯內中央與後方離地面高10與90cm處,分別以熱電偶測定炭化溫度,於煙囪溫度150℃以下時收集竹醋液並以磅秤累計收集量。為了探討炭化溫度對竹醋液性質之影響,於不同煙囪溫度下收集竹醋液試樣,進行比重、焦油率、pH與酸度等測試。 由試驗結果得知竹醋液之收率為進窯時氣乾竹材重量之5.5~8.0%,其收集量與收集速度受煙囪溫度上升速度與收集時間之影響。兩種竹醋液之比重與焦油率於煙囪溫度80~120℃時,受煙囪溫度上升之影響較不明顯,而煙囪溫度150℃時則明顯增大。竹醋液之pH均隨煙囪溫度上升而增大,但酸度受煙囪溫度上升之影響不明顯。
In this study, Moso bamboo (Phyllostachys pubescens) and Makino bamboo (Phyllostachys makino) were used for charcoal making. Bamboo vinegars were collected by an air-cooled device made of stainless steel. The temperature of the chimney for collecting bamboo vinegar was below 150℃ during charcoal making in an earthen kiln. The kiln, the same as a fan in the bottom, is 2.8m in width, 2.8m in depth, and 1.4m in height with an arched ceiling. The carbonization temperatures on lines of heights of 10 and 90cm above the kiln floor in the central and rear parts, respectively, were measured by K-type thermocouples. The collected quantity of bamboo vinegar was measured by a weighing-scale. In order to investigate if the properties of the bamboo vinegar were affected by the carbonization temperature in the earthen kiln, the specific gravity, tar content, pH, and acidity were measured for samples collected at different chimney temperatures. The yields of bamboo vinegar were 5.5~8.0% for the air-dried raw material placed into the earthen kiln. The collection quantity and speed of bamboo vinegar were affected by the rate of temperature rise of the chimney and the collecting time. The specific gravity and tar content of the bamboo vinegar collected at a chimney temperature of 150℃ were larger than those collected below 150℃ for both Moso bamboo and Makino bamboo. The pH of the bamboo vinegar increased with an increase in the chimney temperature, but the acidity of the bamboo vinegar was not obviously affected by the temperature of the chimney.