Dynamic and equilibrium precipitation of struvite from the concentrated cellulosic ethanol stillage

The phosphate rock mineral is the main source of P-fertilizer production. It is estimated to become depleted in next century. Thus, the recovery of phosphorus from waste streams have attracted great interest. The cellulosic ethanol production is seen more and more important in future. During the production of cellulosic ethanol, the phosphorus element is released from lignocellulosic biomasses and end up dissolved as phosphate ions in the stillage stream. In this study, the struvite (MgNH4PO4 · 6 H2O) recovery from the concentrated cellulosic ethanol stillage (ES) was conducted under room conditions with an initial pH at 7–9. The effect of Mg2+, PO43−, NH4+ and Ca2+ during struvite precipitation testes are investigated. The optimized pH value for struvite recovery is estimated at 8.5, by which 85% of PO43− and 46% of Mg2+ are removed from the liquid stream. The mass fraction of struvite in recovered crystal sample reaches 82 wt.%. The economic evaluation of struvite recovery from ES was also investigated. This work proves that the struvite is potentially to be recovered with high purity from the concentrated cellulosic ethanol stillage.

Jet mixing unit for introducing a light bulk substance into a liquid stream

For the oil spill emergency response, a ship system for supplying an active substance to the contaminated zone has been proposed. Various chemical compounds and substances, microorganisms can be used as active substances. To collect most of the oil spill, it was proposed to use a thermally split graphite sorbent. Its supply to the contaminated zone should be carried out in the form of a pulp. One of the key elements of the system is a mixer for introducing the sorbent into the water flow. This article presents the results of three stages of the study of the influence of the geometric parameters of the jet mixer on the average volumetric content of the sorbent in the pulp, the shape of the nozzle and flow of the working fluid. The necessity of mandatory use of a arch destruction device in a bunker with a light sorbent is noted.

Regular Pertibution Solutions In Fluid Mechanics

Disregarding the fast advances in both scalar and equal computational devices, the huge number and expansiveness of factors associated with both plan and opposite issues utilize refined and even generally straightforward (parabolized or limit layer) liquid stream models unreasonable. With this limitation, it very well might be presumed that a significant group of strategies for numerical/computational advancement are decreased or surmised models. In this examination a joined perturbation/mathematical displaying approach is created which will give a thoroughly inferred chain of importance of arrangements. These arrangements are described by changing degrees of unpredictability versus logical devotion.

INVESTIGATION OF PARAMETERS OF HYDROMONITOR JET OF A BIT

The movement of drilling mud through hydromonitor nozzles is investigated in the work. On the basis of the theory of destruction of rocks by a liquid stream the necessary values of pressure on hydromonitor nozzles of a drilling head for concrete values of mechanical properties of the drilled breed are found. The results of the performed analytical researches were used for modeling of processes of movement of a stream of washing liquid through hydromonitor nozzles of a bit with use of the Flow Simulation CAD / CAM package of the Solid Works system. During the simulation following parameters were investigated: the location of the nozzles at different distances from the axis of the bit and from the bottom of the well, pressure distribution at the bottom of the well at the exit of the flushing fluid from each nozzle and the velocity of the jet and the wall of the well, the vorticity of the jets on the bottom and the walls of the well. According to the results of research design of the hydromonitor unit of the drilling head was improved and new tests were carried out in industrial conditions.

The Influence of Hydrodynamic Changes in a System with a Pitched Blade Turbine on Mixing Power

This paper presents an analysis of hydrodynamics in a tank with a 45° and 60° pitched blade turbine impeller operating while emptying the mixer and with an axial agitator working during axial pumping-down of water at different water levels above the impeller. Measurements made with the PIV method confirmed the change in direction of pumping liquid after the level dropped below the critical value, with an almost unchanged liquid stream flowing through the mixer. It was found that an increase in the value of the tangential velocity in the area of the impeller took place and the quantity of this increase depended on the angle of the blade pitch and the rotational frequency of the impeller. Change in this velocity component increased the mixing power.