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Abstract: CO2 recycling in refineries is of primary importance nowadays, particularly the fluid cracking process which is responsible for about 30% of CO2 emissions in the refinery, as spent catalyst undergoes coke regeneration in air. The possibility of performing this step in the presence of CO2/O2, instead of air can remarkably mitigate greenhouse gas emissions and simultaneously produce a huge amount of CO for sequential uses. Herein, we report that alumina (usually present in 20–40wt.% in the catalyst composition) modified by both potassium (5wt.%) and vanadium (1wt.%) was able to perform this goal under regular regeneration conditions, i.e. at 700°C. The apparent activation energy values for CO2 and coke reaction on alumina, alumina with potassium and with both potassium and vanadium were 349, 249 and 192kJ/mol respectively. In the presence of 13CO2 and O2 the primary observed product was 13CO, followed by 12CO and then by 12CO2. These results unambiguously demonstrate that the stage of catalyst regeneration can be kept under heat balance and simultaneously produce a huge amount of CO and, therefore mitigate CO2 emissions. [Copyright &y& Elsevier]

Nitrous oxide (N2O) is one of the main gases emitted from soils, and the changes in land use in the Amazon may alter gas emission patterns. The objective of this study was to evaluate the effects of land use, temperature, and nitrogen on N2O emissions in soils in the Amazon. For this, three treatments randomized, with five repetitions, were incubated to quantify N2O emissions: (i) three different land uses (wet rainforest, pasture, and agriculture); (ii) different temperatures (25, 30, 35, and 40 °C); and (iii) different nitrogen additions to the soil (0, 90, 180, and 270 kg of N ha−1). Our results show that land use alters the flux of N2O, with the highest emissions observed in agricultural soils compared to that in forest and pasture areas. The change in soil temperature to 30 °C increased N2O emissions with land use, at which the emission of N2O was higher in the pasture and agriculture soils. Our results showed that the emission of N2O in the soil of the Amazon rainforest was low regardless of the temperature and nitrogen treatment. Therefore, the change in land use alters the resilience of the ecosystem, providing emissions of N2O. [ABSTRACT FROM AUTHOR]

The present study explored the effects of sodium benzoate (SB), relocation, and storage time on the quality of sugarcane silage. The experiments followed a completely randomized design with a 2 × 4 × 2 factorial arrangement and four replicates. The treatments were as follows: (i) with (SB+) or without (SB−) SB (2 g∙kg−1 on a fresh matter basis); (ii) with (R) or without (R0) relocation for 12, 48, and 72 h (R12, R48, and R72, respectively); and (iii) storage for 10 or 60 days after relocation. SB− silage showed a lower (p < 0.05) dry matter loss (DML = 155 g·kg−1) without relocation (R0). SB+ silage showed the highest (p < 0.05) DML (257 g·kg−1) with R72. SB use reduced (p < 0.05) the yeast count in silage that was stored for 10 days (SB+: 4.63 CFU·g−1; SB−: 5.58 CFU·g−1). The yeast count was higher (p < 0.05) in silage that was stored for 10 days after relocation, regardless of the relocation time. SB use increased the aerobic stability of silage after 10 days of storage. Thus, SB application is effective for the inhibition of yeast in relocated sugarcane silage. We recommend the use of SB when silage is relocated for 12 h and stored for 60 days after relocation. [ABSTRACT FROM AUTHOR]

Coffee hulls obtained from dry processing, have the potential to be used in ruminant diets. Objective: To evaluate the chemical composition and in situ degradability of dry matter (DM) and neutral detergent fiber (NDF) of coffee hulls treated with calcium oxide (CaO) in different environmental conditions (EC). Methods: Coffee hulls were subjected to treatments distributed in a 2 × 2 factorial arrangement, consisting of two levels of CaO (0 and 5%, on a DM basis) and two environmental conditions (aerobiosis and anaerobiosis) in a completely randomized design with four replicates, totaling sixteen experimental units. Five-gram samples were incubated in the rumen of two male cattle for 0, 3, 6, 9, 12, 24, 48, 72, 96, and 120 h. Results: Regarding dry matter degradation kinetic parameters, except for fraction b, the potential and effective degradability was affected (p<0.05) by a CaO × EC interaction. As for estimated fiber degradation parameters, the potentially degradable fraction b was affected (p<0.05) by CaO and EC. Treatment with CaO increased fraction b in 4.08 percentage points. Conclusions: The use of CaO in the treatment of coffee hulls increases the effective and potential degradability of DM and reduces the undegradable fiber fraction. Anaerobic condition is the best environment for the treatment of coffee hulls with CaO. [ABSTRACT FROM AUTHOR]

We evaluated the effectiveness of an additive comprising sodium benzoate, potassium sorbate, and sodium nitrite (SSL) as active ingredients for its ability to improve the aerobic stability of corn silages made in North America. In experiment 1, treatment with SSL (1.5 and 2.0 L/t) on whole-plant corn (WPC) was compared with treatment with an additive containing buffered propionic acid and citric acid (BPA; 2 L/t) on corn harvested at 32 and 38% DM and ensiled for 120 d. Silage treated with BPA was higher in ammonia-N and propionic acid relative to other treatments. Treatments with all of the additives had numerically, but not statistically, fewer yeasts compared with untreated silage. Both application rates of SSL resulted in lower concentrations of ethanol compared with untreated and BPA silages. Treatment with BPA improved the aerobic stability of silages compared with untreated silage, but the effect from SSL was markedly greater. In experiment 2, WPC was untreated or treated with 2 or 3 L of SSL/t or a microbial inoculant containing Enterococcus faecium M74, Lactobacillus plantarum CH6072, and Lactobacillus buchneri LN1819 (final total lactic acid bacteria application rate of 150,000 cfu/g of fresh forage). Silages were air stressed for 24 h at 28 and 42 d of storage and ensiled for 49 d before opening. Inoculation had no effect on acid end products, ethanol, number of yeasts, or aerobic stability compared with other treatments. Treatment with SSL decreased the amount of ethanol, had no effect on number of yeasts, and improved aerobic stability in a dose-dependent manner compared with other treatments. In experiment 3, WPC was untreated or treated with 2 L of SSL/t and ensiled for 5, 15, and 30 d. Treatment with SSL resulted in silage with fewer yeasts and lower concentrations of ethanol after all times of ensiling compared with untreated silage. In addition, SSL improved aerobic stability after each period of ensiling, but the effect was more at 15 and 30 d compared with 5 d of storage. Treating WPC with SSL can improve the aerobic stability of corn silage made in North America, and the effect can be observed as soon as 5 d after ensiling. [ABSTRACT FROM AUTHOR]