Margarita Stoytcheva

By Benjamin Valdez Salas, Michael Schorr Wiener, Gustavo Lopez Badilla, Monica Carrillo Beltran, Roumen Zlatev, Margarita Stoycheva, Juan de Dios Ocampo Diaz, Lidia Vargas Osuna and Juan Terrazas Gaynor

Part of the book: Air Quality

By Margarita Stoytcheva and Roumen Zlatev

Part of the book: Modern Electrochemical Methods in Nano, Surface and Corrosion Science

By Gisela Montero, Margarita Stoytcheva, Marcos Coronado, Conrado García, Jesús Cerezo, Lydia Toscano, Ana M. Vázquez and José A. León

Part of the book: Biofuels

By Gisela Montero, Conrado García, Marcos A. Coronado, Lydia Toscano, Margarita Stoytcheva, Ricardo Torres, Ana M. Vázquez and Daniela G. Montes

Wheat is one of the main crops worldwide with a production of 733 million of tons by 2015. By 2013, the wheat grain production in Mexico was 3,357,307 t. Wheat straw is generated as a biomass waste once the wheat is harvested. However, the agricultural biomass waste has acquired international relevance as a source of bioenergy. The utilization of bioenergy has significant environmental benefits, and also economic benefits because the biomass waste is valorized as biofuel. The use of wheat straw as raw material for any productive process presents diverse factors that must be considered. Among those factors are the low density of biomass, handling and high transportation cost, an attractive heating value, and the physicochemical characterization. Therefore, the aim of this work was to apply the SWOT analysis to wheat straw utilization as a biofuel in Mexico. The main findings highlighted an estimation of 4,612,950.23 t of wheat straw generated. The experimental results of proximate analysis were 64.42% volatile matter, 19.49% fixed carbon and 16.09% ash. The higher heating was 14.86 MJ/kg. An energy potential of 69 PJ per agricultural cycle was calculated, equivalent to 19% of the biomass energy share reported in Mexico’s National Energy Balance, by 2014.

Part of the book: Frontiers in Bioenergy and Biofuels

By Margarita Stoytcheva and Roumen Zlatev

Part of the book: Arsenic

By Michael Schorr, Benjamín Valdez, Margarita Stoytcheva and Roumen Zlatev

The dissolution of metals in acids is a heterogeneous electrochemical reaction, taking place at the interface between a solid and a liquid, described in terms of energy and configuration of the species involved. The energy of activation for two stainless steels (SSs) in phosphoric acid (PA) was determined from their corrosion rates in the temperature range of 20–120°C, applying the Arrhenius equation. Energy of activation values for the overall process of anodic metal dissolution and cathodic hydrogen release is in the 10–20 Kcal mol−1 range. Metal corrosion is a structure-sensitive process; its mechanism and rate are related to the density of surface defects, based on the Boltzmann expression. A model for the activated complex is proposed based on considerations of energy and configuration. This work is an integration of a theoretical analysis and an experimental investigation of metal corrosion in acids.

Part of the book: Corrosion

By Margarita Stoytcheva and Roumen Zlatev

Part of the book: Arsenic Monitoring, Removal and Remediation