Chemical reactions in the phosphorite-sulfuric acid-urea-water system in relation to process safety and product quality. Part 3. System CO(NH2)2-H3PO4-Ca(H2PO4)2-CaHPO4-H2O Reakcje chemiczne w układzie fosforyt-kwas siarkowy(VI)-mocznik-woda a bezpieczeństwo procesowe i jakość produktu. Cz. III**. Układ CO(NH2)2-H3PO4-Ca(H2PO4)2-CaHPO4-H2O

2016 ◽  
Vol 1 (9) ◽  
pp. 91-98
Author(s):  
Sebastian Schab
Keyword(s):  
Sulfuric Acid ◽  
Product Quality ◽  
Chemical Reactions ◽  
Water System ◽  
Process Safety

scholarly journals Ancient acid rains in Ediacaran – an alternative story for sulfate sedimentation

2021 ◽  
Author(s):  
Michail Shaldybin
Keyword(s):  
Sulfuric Acid ◽  
Chemical Reactions ◽  
Volcanic Activity ◽  
Siberian Craton ◽  
Point Of View ◽  
East Siberia ◽  
Earth’S Atmosphere ◽  
Early Stages ◽  
Terrigenous Rocks ◽  
Unstable Phase

Abstract Vast deposits of anhydrite and magnesite widely distributed in Ediacaran strata of East Siberia near the Riphean unconformity. Anhydrite-rich rocks are not look like of evaporitic origin find mostly nodules and the layers of chicken-wire structure otherwise disseminated as tiny sulfate forms amongst the terrigenous rocks. Here we propose an alternative point of view for anhydrite appearance – the enrichment of Sulphur because of the slashing increase the content of sulfur in the Ediacaran atmosphere due to high volcanic activity. It is suggested that the ancient Earth's atmosphere could have also been influenced by powerful sulfuric acid rains that eroded the Precambrian dolomites causing their aggressive degradation. Chemical reactions with dolomite and sulfuric acid showed that in the early stages an unstable phase of bassanite occur which later stabilized as anhydrite after its heating as an analogue of aging. Aggressive acids have caused global process of dolomite karstification of the Siberian craton with appearance in Ediacaran strata in addition to the sulfate phases, including magnesite and sulphurous phases of pyrite and barite.

scholarly journals New particle formation in the sulfuric acid–dimethylamine–water system: reevaluation of CLOUD chamber measurements and comparison to an aerosol nucleation and growth model

2018 ◽  
Vol 18 (2) ◽  
pp. 845-863 ◽  
Author(s):  
Andreas Kürten ◽  
Chenxi Li ◽  
Federico Bianchi ◽  
Joachim Curtius ◽  
António Dias ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Detection Threshold ◽  
Sulfuric Acid Concentration ◽  
Water System ◽  
Particle Formation ◽  
New Particle Formation ◽  
Flow Tube ◽  
Aerosol Model ◽  
Wide Range ◽  
Good Agreement

Abstract. A recent CLOUD (Cosmics Leaving OUtdoor Droplets) chamber study showed that sulfuric acid and dimethylamine produce new aerosols very efficiently and yield particle formation rates that are compatible with boundary layer observations. These previously published new particle formation (NPF) rates are reanalyzed in the present study with an advanced method. The results show that the NPF rates at 1.7 nm are more than a factor of 10 faster than previously published due to earlier approximations in correcting particle measurements made at a larger detection threshold. The revised NPF rates agree almost perfectly with calculated rates from a kinetic aerosol model at different sizes (1.7 and 4.3 nm mobility diameter). In addition, modeled and measured size distributions show good agreement over a wide range of sizes (up to ca. 30 nm). Furthermore, the aerosol model is modified such that evaporation rates for some clusters can be taken into account; these evaporation rates were previously published from a flow tube study. Using this model, the findings from the present study and the flow tube experiment can be brought into good agreement for the high base-to-acid ratios (∼ 100) relevant for this study. This confirms that nucleation proceeds at rates that are compatible with collision-controlled (a.k.a. kinetically controlled) NPF for the conditions during the CLOUD7 experiment (278 K, 38 % relative humidity, sulfuric acid concentration between 1 × 106 and 3 × 107 cm−3, and dimethylamine mixing ratio of ∼ 40 pptv, i.e., 1 × 109 cm−3).

Research advances on process systems integration and process safety in China

2019 ◽  
Vol 36 (1) ◽  
pp. 147-185
Author(s):  
Siyu Yang ◽  
Xiao Feng ◽  
Linlin Liu ◽  
Zhanpeng Zhang ◽  
Chun Deng ◽  
...  
Keyword(s):  
System Integration ◽  
Safety Management ◽  
Waste Heat ◽  
Water System ◽  
Energy Utilization ◽  
Oil Refining ◽  
Research Progress ◽  
Process Synthesis ◽  
Process Safety ◽  
Process Systems

Abstract Process systems engineering research focuses on the planning, design, operation, and safety of process systems rather than unit operations. In response to the rapid growth of the chemical process industry in the last 20 years in China, advanced system integration and process safety technologies are investigated and applied for better resource utilization, less environmental impact, and safer working places. In this regard, the review in this article consists of four main achievements: (1) process synthesis, (2) energy system integration, (3) water system integration, and (4) process safety management. The purpose of process synthesis and integration is to improve resource and energy utilization, at the same time lowering by-products and emissions. Optimization is conducted on process structure and operation, following the principles of resource coupling and energy cascade utilization. Typical examples are coupling of coal and hydrogen-rich resources and integration of coal-based polygeneration process of chemicals, electricity, and heat. Energy integration implements the coordinated optimization of total site energy systems. Reviews are made on specific methodologies based on the thermodynamics and applications of design and retrofit in ethylene, oil refining, and synthetic ammonia industries. There are energy savings by 10%–20% and yields increasing by 20%–30%. In addition, waste heat recovery and cold energy utilization are also important research areas. Reviews on the progress of water system integration and its industrial applications are also conducted. It includes the direct reuse, regeneration, and reuse/recycle in water systems and systems with internal water mains. Finally, safety management and technologies are also indispensable technological advancements of the process. The legislation system and the work safety-related standard system have been gradually established and enforced. Process safety research progress is reviewed, and questions are proposed for improving the accident prevention and safety management agenda.

Investigation the solubility difference of sodium 4-nitrotoluene-2-sulfonate and 4-nitrotoluene-2-sulfonic acid in (sulfuric acid+water) system

2013 ◽  
Vol 358 ◽  
pp. 151-155 ◽  
Author(s):  
Ying Yang ◽  
Qing Xia ◽  
Hui Zhang ◽  
Feng-Bao Zhang ◽  
Guo-Liang Zhang
Keyword(s):  
Sulfuric Acid ◽  
Sulfonic Acid ◽  
Water System ◽  
Acid Water
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