The invention provides an improved alkylation process and reactor apparatus. The invention utilizes a vessel containing a riser-reactor conduit, an acid settler and an acid cooler. Hydrocarbons are introduced beneath said riser-reactor conduit, mixed with acid catalyst, and passed generally upwards through the riser-reactor conduit to enter the acid settler. Within the acid settler, alkylate is separate from the acid catalyst and is removed from the vessel. Acid catalyst from the acid settler is cooled in the internal acid coolers and returned to the region beneath the riser-reactor conduit.

A high-yield process for converting lignin into reformulated, partially oxygenated gasoline compositions of high quality is provided. The process is a two-stage catalytic reaction process that produces a reformulated, partially oxygenated gasoline product with a controlled amount of aromatics. In the first stage of the process, a lignin feed material is subjected to a base-catalyzed depolymerization reaction, followed by a selective hydrocracking reaction which utilizes a superacid catalyst to produce a high oxygen-content depolymerized lignin product mainly composed of alkylated phenols, alkylated alkoxyphenols, and alkylbenzenes. In the second stage of the process, the depolymerized lignin product is subjected to an exhaustive etherification reaction, optionally followed by a partial ring hydrogenation reaction, to produce a reformulated, partially oxygenated/etherified gasoline product, which includes a mixture of substituted phenyl/methyl ethers, cycloalkyl methyl ethers, C.sub.7 -C.sub.10 alkylbenzenes, C.sub.6 -C.sub.10 branched and multibranched paraffins, and alkylated and polyalkylated cycloalkanes.