Theoretic and experimental research on the possibilities for moderning and reabilitating the extraction installation of the Slănic Prahova salt mine

The paper deals with the subject of rehabilitation and mechanical modernization of the extraction plant within the mining operation of the salt mine from Slanic Prahova region. The extraction plant serves the 23 August mine shaft of the Unirea mine, and also this mine has been converted into a tourist mine. The rehabilitation of the extraction installation consists in the change of the cutting wheels from the extraction tower due to excessive degradation, requiring the redesign under strict conditions, and also the rehabilitation and extension of the saline water extraction system from the tourist mine. The modernization of the extraction plant consists in the change of the DC hoist engine with an asynchronous engine of the same energy power and research on the possibilities of increasing the cable transport capacity with technical changes made to the extraction tower, mine shaft and the sump. Modernization and rehabilitation carried out on the extraction installation at the Slanic Prahova salt mine, will provide a safety in operation and efficiency to using the necessary electricity for hoist engine operations.

Identification of the microbiota in sugar extraction juices by sequencing-based techniques

The importance of microorganisms in the beet sugar industry came up in 1930. Since then, several approaches have been made to describe these bacteria. For this purpose, mainly cultivation-based methods were applied. However, the majority of the microorganisms cannot be cultivated or are in the viable-but-non-culturable state. In addition, these methods are time-consuming and costly. Progress in molecular biology allows a cheaper, faster and more precise identification of the microbiota. This study evaluates the application of an 16S rDNA-based metagenomic sequencing approach based on Illumina MiSeq technology to identify the microbiota in raw juice and juice of mid-tower in a beet sugar production plant and compares the results with those obtained by cultivation-based techniques. All bacteria orders detected with cultivation-based methods could be also found with the applied metagenomic approach. In raw juice, mainly mesophilic bacteria such as Lactobacillus spp. and Leuconostoc spp. species were identified. Additionally, a partly large proportion of gram-negative bacteria belonging to the order Enterobacterales were detected by the metagenomic approach. The diversity in juice of mid-tower was much lower and predominated by mainly thermophilic genera such as Geobacillus, Caldanaerobius and Thermoanaerobacter. The last two mentioned genera belong to the class of Clostridia. Surprisingly, in the juice of mid-tower Lactobacillus species could be verified by cultivation-based methods as well as by the metagenomic approach. As a consequence, it can be presumed that lactobacilli can survive in this very specific environment at 70 °C occurring in the central part of the extraction tower.

Simulation of Citronellal Extraction Tower Based on Aspen Plus Software

Aspen Plus is a simulation system of large-scale generalized flowsheet. It is to describe the chemical process by using a digital model, and to obtain the desired results on the computer by changing various effective conditions. The main component with higher value in citronella oil is high purity citronellal. Due to its boiling point, temperature-sensitive and other issues, the difficulty of distillation process increases. This paper conducts process design and simulation on citronella oil high vacuum distillation process by using Aspen Plus software, obtains the process parameters of citronellal extraction tower, explores the relationship between reflux ratio and the number of theoretical plates, and provides data support for the continuous production of citronellal in citronella oil system.