A vast amount of work has been carried out regarding the preparation of fine chemicals, with oxidation being one of the main paths followed. Based on those literature data, renewable value added chemicals were prepared in this work using solid and liquid agro-industrial wastes from rice and citrus production, as renewable raw materials, avoiding the use of substances toxic to the environment and achieving a reduction in energy expenditure. The whole process is consistent with a sustainable development. A combination of catalysts based on rice husk derived silica (RHS), iron oxide as source of active basic sites that act as antennae for dielectric heating, allows an environmentally sound transformation of limonene, a byproduct of the citrus industry, into value-added chemicals, which are also renewable, given their origin. Thus, the present investigation has demonstrated how the transformation of a low value subproduct into high value materials can be achieved with similar conversions and selectivities to those found in the literature for catalysts that have higher toxicities and are less environmentally friendly. Through the use of dielectric heating the process is rapid and thus avoids the formation of unwanted secondary byproducts and furthermore the energy requirements are greatly reduced. (C) 2011 Elsevier B.V. All rights reserved.