Current status and future development of solvent-based carbon capture

Solvent-based carbon capture is the most commercially-ready technology for economically and sustainably reaching carbon emission reduction targets in the power sector. Globally, the technology has been deployed to deal with flue gases from large scale power plants and different carbon-intensive industries. The success of the technology is due to significant R&D activities on the process development and decades of industrial experience on acid gas removal processes from gaseous mixtures. In this paper, current status of PCC based on chemical absorption—commercial deployment and demonstration projects, analysis of different solvents and process configurations—is reviewed. Although some successes have been recorded in developing this technology, its commercialization has been generally slow as evidenced in the cancellation of high profile projects across the world. This is partly due to the huge cost burden of the technology and unpredictable government policies. Different research directions, namely new process development involving process intensification, new solvent development and a combination of both, are discussed in this paper as possible pathways for reducing the huge cost of the technology

Thermodynamics of Mixtures Containing Amines. XV. Liquid–Liquid Equilibria for Benzylamine + CH3(CH2)nCH3 (n = 8, 9, 10, 12, 14)

Coexistence curves for the liquid−liquid equilibria (LLE) of 1-phenylmethanamine (benzylamine) + CH3(CH2)nCH3 (n = 8, 9, 10, 12, 14) have been determined using the critical opalescence method by means of a laser scattering technique. All of the LLE curves show an upper critical solution temperature (UCST), which increases with increasing n. For systems including a given n-alkane, the UCST decreases in the sequence aniline > 2-methylaniline (o-toluidine) > benzylamine > N-methylaniline > pyridine. This means that amine−amine interactions become weaker in the same order. Most of the DISQUAC interaction parameters for the aliphatic/amine (a,n) and aromatic/ amine (b,n) contacts previously determined for solutions with aniline, o-toluidine, or N-methylaniline have been used for the representation of the LLE data. Only the first dispersive interaction parameter of the (a,n) contact has been modified. The coordinates of the critical points are correctly represented by the model

Environmentally Benign Bifunctional Solid Acid and Base Catalysts

Solid bifunctional acid–base catalysts were prepared in two ways on an amorphous silica support: (1) by grafting mercaptopropyl units (followed by oxidation to propylsulfonic acid) and aminopropyl groups to the silica surface (NH2–SiO2–SO3H), and (2) by grafting only aminopropyl groups and then partially neutralizing with phosphotungstic acid, relying on the H2PW12O40– ion for surface acidity (NH2–SiO2–NH3+[H2PW12O40–], denoted as NH2–SiO2–PTA). Surface acidity and basicity were characterized by adsorption calorimetry, using SO2 as a probe for surface basicity and NH3 for surface acidity. Catalytic activities were compared in a two-stage cascade: an acid-catalyzed deacetalization followed directly by a base-catalyzed Henry reaction. Overall, the NH2–SiO2–SO3H catalysts showed higher concentrations and strengths of both acid and base sites, and higher activities than NH2–SiO2–PTA. Both catalysts showed evidence of cooperative acid–base catalysis. Importantly, the bifunctional catalysts exhibited catalytic advantage over physical mixtures of singly functionalized catalyst

Effects of fulvic acids on gut barrier, microbial composition, fecal ammonia emission, and growth performance in broiler chickens

SUMMARY: This study investigated the effects of fulvic acid (FA) on the growth performance, intestinal function, and fecal ammonia excretion of broilers. A total of 480 1-day-old male broilers were randomly divided into 4 treatments: control (CON) treatment, and the treatment on a basal diet supplemented with 0.15, 0.3, or 0.5% FA. The addition of 0.5% FA increased the feed-to-gain ratio and average daily feed intake during the first 7 d of the experiment, whereas, 0.3% FA addition increased the feed-to-gain ratio at 15 to 21 d, but FA addition had no effect on growth performance at other times. Compared to the CON treatment, 0.5% FA addition increased the serum IgA content, amylase, and lipase activities in the jejunum, as well as the lipase activity and mucin 2 content in the ileum. Feeding broilers with 0.15% FA increased the occludin and zonula occluden-1 content in the ileum, elevated intestinal permeability markers such as diamine oxidase, lipopolysaccharide, and D-lactate dehydrogenase, and further enriched functional pathways including nitrogen metabolism and riboflavin metabolism. Also, FA addition (0.15, 0.3, or 0.5%) increased the jejunum mucin 2 content and maintained the relative stability of the cecal microbiota without detrimental changes to the microbiota composition. Importantly, FA addition decreased the fecal ammonia yield on 2, 4, and 5 d of the fecal ammonia determination in a dose-dependent manner and also lowered the urease activity on 1 and 3 d. Therefore, the addition of 0.15% FA was considered the most effective in maintaining the intestinal health and microbial composition of broilers

Tree integration in homestead farms in southeast Nigeria: propositions and evidence.

This paper contributes to wider debates on the dominant factors determining the emergence and sustainability of intermediate systems of forest management in developing countries. The theoretical framework and propositions for analysing tree integration in homestead farms are presented, with reference to southeast Nigeria. The paper argues that, first, at the household level, livelihood strategies constitute the main determinant of the decision to integrate trees in homestead farms. Secondly, induced innovation has a wider and more significant role at the community level than at the household level in encouraging the integration of trees in farms. Thirdly, the sustainability of observed patterns of tree integration is influenced by the interaction of environmental, ecological, political, economic and social factors. Based on these propositions, the paper analyses the internal (household) and external (wider community) factors influencing tree integration in homestead farms in southeast Nigeria

Vitamin D supplements and prevention of tuberculosis infection and disease

BACKGROUND: Vitamin D metabolites support innate immune responses to Mycobacterium tuberculosis. METHODS: We randomly assigned children who had negative results for Mycobacterium tuberculosis infection, using the QuantiFERON-TB Gold In-tube assay (QFT), to receive a weekly oral dose of 14,000 IU vitamin D3 or placebo over 3 years. The primary outcome was the proportion of children having a positive QFT result at 3 years. Secondary outcomes included end-study vitamin D status and incidence of tuberculosis disease, acute respiratory infections and adverse events. RESULTS: 8851 participants underwent randomization (4418 to vitamin D, 4433 to placebo), of whom 95.6% had baseline serum 25-hydroxyvitamin D concentrations <20 ng/mL. Mean end-study 25-hydroxyvitamin D concentration in participants randomized to vitamin D vs. placebo was 31.0 vs. 10.7 ng/mL (95% CI for difference, 19.9 to 20.6 ng/mL), and 147 participants in the vitamin D group vs. 134 participants in the placebo group tested positive by QFT (adjusted risk ratio [aRR] 1.10, 95% CI 0.87 to 1.38, P=0.42). Tuberculosis disease was diagnosed in 21 children in the vitamin D group and 25 children in the placebo group (aRR 0.87, 95% CI 0.49 to 1.55). 29 participants randomized to vitamin D and 34 randomized to placebo were hospitalized for treatment of acute respiratory infections (aRR 0.86, 95% CI 0.52 to 1.40). Incidence of adverse events did not differ significantly between study arms. CONCLUSIONS: Vitamin D supplementation did not reduce risk of tuberculosis infection, tuberculosis disease or acute respiratory infections among vitamin D-deficient schoolchildren in Mongolia