| Pinyon and juniper are invasive woody species in Western United States that occupy over 47 million acres of land. The US Bureau of Land Management (BLM) has embarked on harvesting these woody species to make room for range grasses for grazing. The major application of harvested pinyon-juniper (PJ) is low value firewood. Thus, there is a need to develop new high value products from this woody biomass to reduce the cost of harvesting. In this research PJ biomass was processed through pyrolysis technology to produce value added products. The first part of the thesis demonstrates the effect of PJ wood, bark and mixture biomass and temperature on the product yield and on the quality of the bio-oil produced. The second part focuses on the optimization of process parameters for maximum yield and the third part focuses on upgrading the bio-oil with an industrial catalyst (HZSM5) and an industrial waste product (red mud). The results obtained from the first part showed that PJ wood produced maximum bio-oil yield, followed by PJ mixture and bark. The bio-oil yield from PJ wood had low viscosity when compared to PJ mixture and PJ bark. The second part focused on studying the effect of process parameters (temperature, feed rate and the gas flow rate) on the total liquid, organic, water, char and gas yield. The results show that each response is affected by different factor level combinations, and maximum yield for each response was obtained at different factors level. The third part focused on catalytic pyrolysis of PJ biomass using both HZSM-5 catalyst and red mud. The mechanisms of catalysis by the two catalysts were quite different. Whereas the HZSM-5 rejected oxygen mostly as carbon monoxide and water and produced lower amounts of carbon dioxide, on the contrary the red mud produced more carbon dioxide and water and less carbon monoxide. The higher heating value of the red mud catalyzed oil (29.46 MJ/kg) was slightly higher than that catalyzed by HZSM-5 (28.55 MJ/kg). Thus, red mud can be used to achieve similar catalytic pyrolysis results as HZSM-5 catalysts. |
