Acid plants temperature effects

Pollution Control. Zeolite adsorbents can effectively remove pollutants such as S02, H2S, and NO from industrial off-gas streams at near ambient temperature (54-57). Since water vapor usually exists along with these acidic compounds, an acid-stable or acid-resistant zeolite adsorbent is necessary for a long service life. Union Carbide announced three new processes for pollution control recently. They are the PuraSiv-Hg process for mercury vapor removal, the PuraSiv-N process for NO removal from nitric acid plant off-gas, and the PuraSiv-S process for S02 removal from... 

Figure 1. (A) Effect of the titration temperature during Fe-decomplexation exchanged on the N2O decomposition activity using citrate Fe-precursor at ( ) 333 ( ) 353 and (A) 373 K. For comparison, a reference catalyst based on ion-exchange using ferric nitrate (same Fe loading) is included (O). Reaction conditions 4.5 mbar N2O, He balance. (B) Stability test for ( ) in A spot under typical conditions for nitric acid plants in The Netherlands 4.5 mbar N2O + 0.6 mbar NO + 15 mbar H2O + 75 mbar O2. In both cases, total pressure was 3 bar-a and a space time W/F (N20) of 900 kgxsxmoT (W is the catalyst mass and F (N20) the molar flow of N2O in the reactor inlet) was applied.

J.A. Wilmer, J.P.F.G. Helsper L.H.W. van der Plas Effects of abscisic acid and temperature on erucic acid accumulation in oilseed rape (Brassica napus L.). J.Plant Physiol, (submitted). 

The fatty acid composition of soybean oil is influenced by growing conditions, especially temperature during oil deposition in the later stages of seed development. The linoleate and linolenate content of soybeans is increased by low temperature (Howell and Collins, 1957). The linolenate content of A5 particularly can be increased by low temperatures, and it is important to plant this variety early so that it matures under warm conditions (Hammond and Fehr, 1984 Rennie and Tanner, 1989). Although soybean mutants with elevated oleate levels are common, efforts to produce a line with consistently elevated oleate percentages have been frustrated by temperature effects. The line shown in Table 4.3 with an oleate concentration of 70% was produced under warm weather conditions. In a year where the growing season was cool it might drop to <50% oleate. 

Troughton,J.H., Card,K.A. Temperature effects on the carbon isotope ratio of C3, C4, and Crassulacean Acid Metabolism (CAM) plants. Planta 123,185-190 (1975)... 

Figure 20.4 shows the effect of gas input temperature on 3-1 acid plant SO2 oxidation ejficiency. 

CDU in pure form is a white powder. It is made slowly available to the soil solution by nature of its limited solubihty in water. Once in the soil solution, nitrogen from CDU is made available to the plant through a combination of hydrolysis and microbial decomposition. As with any CRE which is dependent on microbial action, the mineralization of CDU is temperature dependent. Product particle size has a significant effect on CDU nitrogen release rate. Smaller particles mineralize more rapidly because of the larger surface contact with the soil solution and the microbial environment. The rate of nitrogen release is also affected by pH because CDU degrades more rapidly in acidic soils. 

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