Life cycle assessment of acetylene production from calcium carbide and methane in China

Sustainable synthesis of bio-based PTMEG and methane beyond the Reppe method

“…The Reppe method uses acetylene as one raw material, which is dependent on the fossil energy-derived calcium carbide industry that exhibits high energy consumption, as well as high CO 2 and waste-water emissions. 36 For example, an annual production of 30 million tons of calcium carbide consumed an estimated 96 billion kW h of electricity, and generated approximately 14 million tons of CO 2 and 25 900 tons of waste liquids containing butanediol, hydroxybutyraldehyde, and methylbutanediol. 36 In addition, these waste liquids were usually managed through incineration, causing additional pollution concerns.…”

“…36 For example, an annual production of 30 million tons of calcium carbide consumed an estimated 96 billion kW h of electricity, and generated approximately 14 million tons of CO 2 and 25 900 tons of waste liquids containing butanediol, hydroxybutyraldehyde, and methylbutanediol. 36 In addition, these waste liquids were usually managed through incineration, causing additional pollution concerns. 37 In comparison, the furfural method uses renewable hemicellulose-derived furfural as its raw material and co-produces bio-PTMEG and bio-methane as its main products via consecutive hydrogenation–hydrodeoxygenation–polymerization steps; processes known to be of low energy consumption and low carbon emissions.…”

Enantioselective Metal-Catalyzed Reductive Coupling of Alkynes with Carbonyl Compounds and Imines: Convergent Construction of Allylic Alcohols and Amines

“…Hydrogenation of acetylene, an abundant feedstock (>10 × 10 6 tons/yr), in the presence of carbonyl compounds (Scheme A) or imines (Scheme B) provides products of reductive C–C coupling in the form of (Z)-dienyl allylic alcohols and amines, respectively. , Here, a cationic rhodium complex with the BAr 4 F counterion, tetrakis­[3,5-bis­(trifluoromethyl)­phenyl]­borate, was employed as the catalyst. Using enantiomeric rhodium catalysts ligated by ( R )- and ( S )-MeO-BIPHEP, l -glyceraldehyde acetonide is converted to the indicated diastereomeric adducts with good levels of catalyst-directed asymmetric induction and, therefrom, all eight l -hexoses (Scheme A) .…”

Bio-based 1,4-butanediol and tetrahydrofuran synthesis: perspective

“…The Reppe process is currently the dominant process for the production of 1,4-BDO and THF worldwide, with a total capacity of about 1.16 million ton per year, accounting for 53% of the total global capacity. However, as the raw material, acetylene is dependent on fossil energy derived from the calcium carbide industry, 33 while production of calcium carbide generates a large amount of CO 2 . Annual production of 30 million tons of calcium carbide is accompanied by approximately 14 million tons of CO 2 .…”