CASE STUDY OF CONVERTER PERFORMANCE EVALUATION ON SULFURIC ACID PRODUCTION (DEPARTMENT III PT B)

Converter was one tool unit that consisting 4 beds in the production process of sulfuric acid. The performance of this converter was supported by the addition of a vanadium pentaoxide (V2O5) catalyst. The process that occurring in the converter was double contacts – double absorbers. The purpose of this case was converter performance evaluation that using by SO2 conversion parameter to SO3. Primary data was the dry air flow rate that entering the burner, the SO2 gas content that be into the converter, the catalyst temperature of each converter bed, and the catalyst pressure in each bed converter. Data on the field showed that activity on bed I was 72,96%, and theoretical was 60%. Then, bed II gave 91,22%; 87%; on bed III was 96,85%; 94%; and bed IV was 99,9%; 99,73% as respectively. From these experiments could be concluded that result data was greater than the theoretical. The difference of this conversion indicated that the performance of the converter did not increase

A Modified Sine-Cosine Algorithm Based on Neighborhood Search and Greedy Levy Mutation

For the deficiency of the basic sine-cosine algorithm in dealing with global optimization problems such as the low solution precision and the slow convergence speed, a new improved sine-cosine algorithm is proposed in this paper. The improvement involves three optimization strategies. Firstly, the method of exponential decreasing conversion parameter and linear decreasing inertia weight is adopted to balance the global exploration and local development ability of the algorithm. Secondly, it uses the random individuals near the optimal individuals to replace the optimal individuals in the primary algorithm, which allows the algorithm to easily jump out of the local optimum and increases the search range effectively. Finally, the greedy Levy mutation strategy is used for the optimal individuals to enhance the local development ability of the algorithm. The experimental results show that the proposed algorithm can effectively avoid falling into the local optimum, and it has faster convergence speed and higher optimization accuracy.

Preparation of Molecular Sieve Al-SBA-15 with Two Ratios Si/Al Catalyst for Use in the Transesterification Reaction of Soybean Oil

Molecular sieves have been applied to the triacylglycerides processing in the production of biodiesel through transesterification reaction. The purpose of obtain a material that has characteristics favorable to higher biodiesel conversion, this paper aims to synthesize molecular sieves SBA-15 and Al-SBA-15 on two reasons Si/Al (Si/Al= 10 and 100) evaluated in the transesterification reaction of soybean oil and investigate the potential of Si/Al ratios in the reaction over the acid each material. The catalysts were prepared by conventional hydrothermal method by varying the composition of the aluminum consequently altering the acidity of the material, since this reaction takes place in acid medium. The samples were characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM), Spectroscopy in the infrared region by Fourier transform (FTIR). The results of the characterization of the catalysts have shown that the materials were successfully obtained, from the characterization observed. The biodiesel syntheses were conducted with soybean oil using ethyl alcohol 12: 1 relative to the oil and 5% of catalyst in the reactor with autogenous pressure. Were realized viscosity analyzes as conversion parameter of the vegetable oil into biodiesel. From the results of biodiesel viscosity was obtained a yield of 13% on average by using the Al-SBA-15. However, even not have remained within the specifications the standards of the National Petroleum, Natural Gas and Biofuels, catalysts showed efficiency compared with the SBA-15 in biodiesel synthesis.

Sensitivity of a Cumulus Parameterization Scheme to Precipitation Production Representation and Its Impact on a Heavy Rain Event over Korea

The sensitivity of a cumulus parameterization scheme (CPS) to a representation of precipitation production is examined. To do this, the parameter that determines the fraction of cloud condensate converted to precipitation in the simplified Arakawa–Schubert (SAS) convection scheme is modified following the results from a cloud-resolving simulation. While the original conversion parameter is assumed to be constant, the revised parameter includes a temperature dependency above the freezing level, which leads to less production of frozen precipitating condensate with height. The revised CPS has been evaluated for a heavy rainfall event over Korea as well as medium-range forecasts using the Global/Regional Integrated Model system (GRIMs). The inefficient conversion of cloud condensate to convective precipitation at colder temperatures generally leads to a decrease in precipitation, especially in the category of heavy rainfall. The resultant increase of detrained moisture induces moistening and cooling at the top of clouds. A statistical evaluation of the medium-range forecasts with the revised precipitation conversion parameter shows an overall improvement of the forecast skill in precipitation and large-scale fields, indicating importance of more realistic representation of microphysical processes in CPSs.