New developments include microwave pyrolysis and hydropyrolysis. Microwave pyrolysis reportedly overcomes the disadvantages of slow heating and feedstock size, and even improved product quality. Major limitations include the absence of sufficient data to quantify the dielectric properties of the treated streams, and the uncertainty about the actual costs. Interestingly, microwave heating allows a different heating rate and residence time of volatiles compared with conventional heating. In hydropyrolysis, a single pyrolysis step is applied to in-situ crack and upgrade the bio-oil vapors using (hydro)cracking catalysts in the presence of (high pressure) hydrogen. The latter subject may be dealt with elsewhere in this handbook; the interested reader is referred to the IH2 process.