Proposta de processos químicos para melhor recuperação de hidrocarboneto de alto valor agregado de uma indústria de biotecnologia

Abstract

The biotechnology industry studied produces a long-chain branched hydrocarbon as one of its main products with high added value and precursor to various chemicals of commercial interest. This hydrocarbon is produced by aerobic respiration of a genetically modified microorganism, and part of the target product during the purification step. The fraction of the bioproduct lost in the downstream step, if recovered, could have a positive impact on the overall bioprocess performance and, therefore, on the company’s profitability. This work proposes to evaluate the characteristics of the effluent streams of the hydrocarbon (oil) recovery and purification steps, based on the quantification of their concentration in these streams and their association form with the other by-products, to propose alternatives for its recovery. The industrial production data from 2020 were used for this study, and the statistical analysis of the quantitative data of the effluent stream identified two important point of oil losses. The first one occurs in the fermentation broth cell separation step (separation step 1), which 4.21% of the hydrocarbon is lost either by emulsification with vinasse or by microbial cells internal association. The second one occurs in the oil/water separation phase (separation step 2), which approximately 12% of the hydrocarbon fed is lost either by emulsification with the aqueous phase or by emulsification with dead cells still present in the feed stream (<1%). From this study, it is proposed that cells be separated (step 1) by cross-flow filtration or centrifugation, followed by cell disruption by high pressure homogenization for oil extraction aided by an apolar organic solvent. For the separation step 2, it is proposed to separate the cells remaining from step 1 by crossflow filtration or by series membrane filtration with appropriate sized pores. then the filtrate, mostly containing an aqueous phase would be sent to a liquid-liquid extraction column for the separation of the oil phase. As an alternative, if the separation step 2 feed stream contains less emulsified oil, it could be recovered by evaporations in steps at low pressures for water evaporation (first step) and oil evaporation (second step), remaining the solids in the evaporator. It is concluded the downstream steps of the studied industry could be modified to increasing the overall yield of the process by recovering the lost fraction of the interested product. However, the modification proposed requires future studies of economic viability and process capability to achieve the final product required purity (>97%) to decision making.