This work explores a two-step, complexity reducing methodology, to analyze heat integration opportunities of an existing Olefins Plant, identify and quantify reduction of energy consumption, and propose changes of the existing heat exchanger network to achieve these goals. Besides the analysis of plant design conditions, multiple operational scenarios were considered to propose modifications for handling real plant operation (flexibility). On the strength of plant complexity and large dimension, work methodology was split into two parts: initially, the whole plant was evaluated with traditional Pinch Analysis tools. Several opportunities were identified and modifications proposed. Modifications were segregated to represent small and independent portions of the original process. One of them was selected to be re-analyzed, considering two scenarios. Reduction of problem dimension allowed mathematical methodologies (formulation with decomposition, applying LP, MILP and NLP optimization methods) to synthesize flexible networks to be applied, generating a feasible modification capable of fulfilling the proposed operational scenarios.

Os amidos nativos são estruturalmente fracos e pouco resistentes para aplicações tecnológicas na indústria alimentícia. O processamento é necessário para conferir aos amidos maior aplicabilidade. Os amidos nativos podem ser modificados por vários processos como: físicos, químicos, enzimáticos ou até combinações dos mesmos, dependendo da finalidade industrial. Amostras de amido de milho nativo foram submetidas à hidrólise por solução de ácido clorídrico e investigadas através das técnicas termoanalíticas: termogravimetria (TG), análise térmica diferencial (DTA) e calorimetria exploratória diferencial (DSC), bem como microscopia óptica e difratometria de raios X pelo método do pó. Após tratamento com ácido clorídrico a 30 e a 50 ºC, foi verificado um decréscimo na entalpia de gelatinização (ΔHgel). A microscopia óptica e difratometria de raios X permitiram verificar os contornos de grão e rugosidade típica dos amidos de cereais.

Unprocessed native starches are structurally too weak and functionally too restricted for application in today's advanced food technologies. Processing is necessary to engender a range of functionality. Naturals or natives starches can be modified by using several methods physical, chemical, enzymatic or combined, according industrial purposes. In this work, native corn starch was hydrolyzed by hydrochloric acid solution and investigated by using thermoanalytical techniques (thermogravimetry - TG, differential thermal analysis - DTA and differential scanning calorimetry - DSC), as well as optical microscopy and X-ray diffractometry. After acid treatment at 30 and 50°C, a decrease of gelatinization enthalpy (ΔHgel) was verified. Optical microscopy and X-ray diffractometry allowed us to verify the granules contorn and rugosity typical of cereal starches.