Method and apparatus to extract products from heat treatment process

A method of treating a vent gas steam from heat treatment of plant biomass, the method comprising:

• heat treating plant biomass in a heat treatment chamber at a temperature between 160° C. and a temperature that is below a point where carbonization begins to occur, defined as before initiation of exothermal degradation of cellulose, using a shielding gas in the heat treatment, the shielding gas being steam, the steam being water vapor,
• directing the vent gas steam from the heat treatment to a series of condensers connected to each other to provide flow of the vent gas steam through each condenser in the series,
• collecting at least part of the components of the vent gas steam in each condenser,
• wherein each of the condensers is set at a temperature that is lower than the temperature in the previous condenser in the series,
• wherein a first condenser in the series is set at a temperature that is lower than the temperature in the heat treatment chamber, and
• wherein the series of condensers comprises at least two condensers set at a temperature of above 100° C. and at least one condenser set at a temperature of below 100° C., wherein the at least two condensers set at the temperature of above 100° C. are operated to produce a tar phase and a wood vinegar phase, and the at least one condenser set at the temperature of below 100° C. is operated to produce a wood vinegar phase and a terpene phase.