NOVELTY - Solar-driven chemical reactor system comprises: a solar thermal receiver (302) aligned to absorb concentrated solar energy from at least one solar energy concentrating field; a solar driven chemical reactor (306) that has multiple reactor tubes located inside solar thermal receiver; and at least one aperture in the receiver, which is open to an atmosphere of the earth, or with a transparent window covering the aperture, to pass the concentrated solar energy into solar thermal receiver to impinge on multiple reactor tubes and cavity walls of the receiver.    USE - The solar-driven chemical reactor system is useful for refining biomass and other materials.    ADVANTAGE - The solar-driven chemical reactor system: compensates for missing data including missing weather reports; allows enough energy from the radiant energy to raise the heat to initiate and sustain a sufficiently high temperature so that the gasification occurs of greater than 90% of the biomass particles into reactant products including hydrogen and carbon monoxide gas in a very short residence time of 0.01-5 seconds; and allows for independent temperature control and balancing of amount of particles of biomass or other gases flowing in each of the reactor tubes.    DETAILED DESCRIPTION - Solar-driven chemical reactor system comprises: a solar thermal receiver (302) aligned to absorb concentrated solar energy from at least one solar energy concentrating field including either an array of heliostats (304) and/or a solar concentrating dish; a solar driven chemical reactor (306) that has multiple reactor tubes located inside the solar thermal receiver, where an endothermic chemical reaction driven principally by radiant heat occurs in the multiple reactor tubes, which increase the available reactor surface area for radiative exchange to the reactants and creates an inter-tube radiation exchange, and the endothermic chemical reaction includes at least one of: biomass gasification, steam methane reforming, methane cracking, steam ethane or naphtha cracking to produce ethylene and related olefins, metals refining, carbon dioxide splitting, or water splitting to be conducted in this chemical reactor using solar thermal energy coming from the concentrated solar energy; and at least one aperture in the receiver, which is open to an atmosphere of the earth, or with a transparent window covering the aperture, to pass the concentrated solar energy into the solar thermal receiver to impinge on the multiple reactor tubes and cavity walls of the receiver, and transfer energy by absorption, re-radiation, convection and conduction to the reactants in the chemical reaction to drive the endothermic chemical reaction flowing in the reactor tubes, where a design of the multiple reactor tubes and solar thermal receiver are adapted per solar flux profile to take advantage of variations in concentrations of solar flux in the solar flux profile including adapting at least two of: an amount of at least two reactor tubes present in the cavity of the solar thermal receiver; a size diameter of each of the reactor tubes in which a first reactor tube may have a different diameter than a second reactor tube; a geometric arrangement of the multiple reactor tubes relative to each other; a shape of each individual reactor tube may vary with respect to other tubes per flux profile to take advantage of variations in solar flux in the profile; or a size, shape, and orientation of the apertures relative to the concentrated solar energy coming from the solar energy concentrating field. An INDEPENDENT CLAIM is also included for a solar-driven chemical reactor system comprising: the solar thermal receiver; the solar driven chemical reactor that has multiple reactor tubes located inside the solar thermal receiver, where an endothermic chemical reaction driven by radiant heat occurs in the multiple reactor tubes using solar thermal energy coming from the concentrated solar energy; and the aperture open to an atmosphere of the earth to pass the concentrated solar energy into the solar thermal receiver to impinge on the multiple reactor tubes and cavity walls of the receiver and transfer energy to the reactants of the chemical reaction to drive the endothermic chemical reaction flowing in the reactor tubes, where a design of the multiple reactor tubes and solar thermal receiver are adapted per solar flux profile to take advantage of variations in concentrations of solar flux in the solar flux profile including adapting: an amount of reactor tubes present in the cavity; a size of the reactor tubes; a geometric arrangement of the multiple reactor tubes relative to each other; and a size, shape, and orientation of the aperture relative to the concentrated solar energy coming from the array of heliostats.    DESCRIPTION OF DRAWING(S) - The figure shows a diagram of a solar tower with receivers and heliostat field.    Solar tower (300)    Solar thermal receiver (302)    Heliostats (304)    Solar driven chemical reactor (306)