A process for biomass conversion comprising: a) providing a riser reactor having a mixing zone, an intermediate zone located above said mixing zone, and an upper zone located above said intermediate zone; b) charging a biomass feed and a heat carrier material to said mixing zone above the location where a lift gas is charged to said mixing zone, thereby forming a mixture, wherein said biomass feed comprises a solid lignocellulosic material; c) converting said biomass feed in said mixture to thereby form a reaction mixture comprising said heat carrier material and a product stream comprising oxygenated hydrocarbons; d) charging at least one quench stream to said riser reactor through at least one quench stream conduit connected in fluid flow communication with said riser reactor at a location within said intermediate zone, thereby lowering the temperature of said reaction mixture, wherein said heat carrier material is at a sufficient temperature to ensure that said reaction mixture has temperature from 300 to 600 °C by the time said reaction mixture reaches the interface between said mixing zone and said intermediate zone; and wherein said at least one quench stream comprises a fluid selected from the group consisting of water, steam, caustic solutions, hydrotreated organics liquids, recycle bio-oil, carbon monoxide, carbon dioxide, ethane, ethylene, propane, propylene, methanol and other alcohols, naphthas, gas oil, and combinations thereof, and e) separating at least a portion of said product stream from said heat carrier material in a disengager which is connected in fluid flow communication with said upper zone of said riser reactor. a) providing a riser reactor having a mixing zone, an intermediate zone located above said mixing zone, and an upper zone located above said intermediate zone; b) charging a biomass feed and a heat carrier material to said mixing zone above the location where a lift gas is charged to said mixing zone, thereby forming a mixture, wherein said biomass feed comprises a solid lignocellulosic material; c) converting said biomass feed in said mixture to thereby form a reaction mixture comprising said heat carrier material and a product stream comprising oxygenated hydrocarbons; d) charging at least one quench stream to said riser reactor through at least one quench stream conduit connected in fluid flow communication with said riser reactor at a location within said intermediate zone, thereby lowering the temperature of said reaction mixture, wherein said heat carrier material is at a sufficient temperature to ensure that said reaction mixture has temperature from 300 to 600 °C by the time said reaction mixture reaches the interface between said mixing zone and said intermediate zone; and wherein said at least one quench stream comprises a fluid selected from the group consisting of water, steam, caustic solutions, hydrotreated organics liquids, recycle bio-oil, carbon monoxide, carbon dioxide, ethane, ethylene, propane, propylene, methanol and other alcohols, naphthas, gas oil, and combinations thereof, and e) separating at least a portion of said product stream from said heat carrier material in a disengager which is connected in fluid flow communication with said upper zone of said riser reactor.